Mauro Carvalho Chehab | e53dd08 | 2007-09-15 07:38:47 -0300 | [diff] [blame] | 1 | Kernel Parameters |
| 2 | ~~~~~~~~~~~~~~~~~ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | |
| 4 | The following is a consolidated list of the kernel parameters as implemented |
| 5 | (mostly) by the __setup() macro and sorted into English Dictionary order |
| 6 | (defined as ignoring all punctuation and sorting digits before letters in a |
| 7 | case insensitive manner), and with descriptions where known. |
| 8 | |
| 9 | Module parameters for loadable modules are specified only as the |
| 10 | parameter name with optional '=' and value as appropriate, such as: |
| 11 | |
| 12 | modprobe usbcore blinkenlights=1 |
| 13 | |
| 14 | Module parameters for modules that are built into the kernel image |
| 15 | are specified on the kernel command line with the module name plus |
| 16 | '.' plus parameter name, with '=' and value if appropriate, such as: |
| 17 | |
| 18 | usbcore.blinkenlights=1 |
| 19 | |
Randy Dunlap | ca1eda2 | 2009-05-06 16:02:58 -0700 | [diff] [blame] | 20 | Hyphens (dashes) and underscores are equivalent in parameter names, so |
| 21 | log_buf_len=1M print-fatal-signals=1 |
| 22 | can also be entered as |
| 23 | log-buf-len=1M print_fatal_signals=1 |
| 24 | |
| 25 | |
Stefan Richter | a901ebb | 2006-04-01 01:43:18 +0200 | [diff] [blame] | 26 | This document may not be entirely up to date and comprehensive. The command |
| 27 | "modinfo -p ${modulename}" shows a current list of all parameters of a loadable |
| 28 | module. Loadable modules, after being loaded into the running kernel, also |
| 29 | reveal their parameters in /sys/module/${modulename}/parameters/. Some of these |
| 30 | parameters may be changed at runtime by the command |
| 31 | "echo -n ${value} > /sys/module/${modulename}/parameters/${parm}". |
| 32 | |
Stefan Richter | 6585fa8 | 2006-04-01 01:44:30 +0200 | [diff] [blame] | 33 | The parameters listed below are only valid if certain kernel build options were |
| 34 | enabled and if respective hardware is present. The text in square brackets at |
| 35 | the beginning of each description states the restrictions within which a |
| 36 | parameter is applicable: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | |
| 38 | ACPI ACPI support is enabled. |
Chuck Ebbert | c99c108 | 2007-07-27 10:46:20 +1000 | [diff] [blame] | 39 | AGP AGP (Accelerated Graphics Port) is enabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | ALSA ALSA sound support is enabled. |
| 41 | APIC APIC support is enabled. |
| 42 | APM Advanced Power Management support is enabled. |
Randy Dunlap | 1629024 | 2011-08-13 12:34:52 -0700 | [diff] [blame] | 43 | ARM ARM architecture is enabled. |
Haavard Skinnemoen | e7ba176 | 2007-10-10 14:58:29 +0200 | [diff] [blame] | 44 | AVR32 AVR32 architecture is enabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | AX25 Appropriate AX.25 support is enabled. |
Robin Getz | 0ae5364 | 2007-10-09 17:24:49 +0800 | [diff] [blame] | 46 | BLACKFIN Blackfin architecture is enabled. |
Olof Johansson | 1e43525 | 2013-04-27 14:10:18 -0700 | [diff] [blame] | 47 | CLK Common clock infrastructure is enabled. |
Robert Tivy | 5c71d61 | 2013-03-28 18:41:46 -0700 | [diff] [blame] | 48 | CMA Contiguous Memory Area support is enabled. |
Alan Cox | 9cfe268 | 2011-01-25 14:18:38 +0000 | [diff] [blame] | 49 | DRM Direct Rendering Management support is enabled. |
| 50 | DYNAMIC_DEBUG Build in debug messages and enable them at runtime |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | EDD BIOS Enhanced Disk Drive Services (EDD) is enabled |
| 52 | EFI EFI Partitioning (GPT) is enabled |
| 53 | EIDE EIDE/ATAPI support is enabled. |
Mimi Zohar | 7102ebc | 2011-05-12 18:33:20 -0400 | [diff] [blame] | 54 | EVM Extended Verification Module |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | FB The frame buffer device is enabled. |
Randy Dunlap | 1629024 | 2011-08-13 12:34:52 -0700 | [diff] [blame] | 56 | FTRACE Function tracing enabled. |
Peter Oberparleiter | 2521f2c | 2009-06-17 16:28:08 -0700 | [diff] [blame] | 57 | GCOV GCOV profiling is enabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | HW Appropriate hardware is enabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | IA-64 IA-64 architecture is enabled. |
Mimi Zohar | 6146f0d | 2009-02-04 09:06:57 -0500 | [diff] [blame] | 60 | IMA Integrity measurement architecture is enabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | IOSCHED More than one I/O scheduler is enabled. |
Adrian Bunk | 41e2e8b | 2005-07-12 13:58:33 -0700 | [diff] [blame] | 62 | IP_PNP IP DHCP, BOOTP, or RARP is enabled. |
Brian Haley | b0f83b2 | 2010-02-04 13:36:50 -0800 | [diff] [blame] | 63 | IPV6 IPv6 support is enabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | ISAPNP ISA PnP code is enabled. |
| 65 | ISDN Appropriate ISDN support is enabled. |
| 66 | JOY Appropriate joystick support is enabled. |
Jason Wessel | 84c08fd | 2010-05-20 21:04:24 -0500 | [diff] [blame] | 67 | KGDB Kernel debugger support is enabled. |
Andre Przywara | fef07aa | 2009-07-10 14:20:35 +0200 | [diff] [blame] | 68 | KVM Kernel Virtual Machine support is enabled. |
Kristen Carlson Accardi | 11ef697 | 2006-09-28 11:29:01 -0700 | [diff] [blame] | 69 | LIBATA Libata driver is enabled |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | LP Printer support is enabled. |
| 71 | LOOP Loopback device support is enabled. |
| 72 | M68k M68k architecture is enabled. |
| 73 | These options have more detailed description inside of |
| 74 | Documentation/m68k/kernel-options.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | MDA MDA console support is enabled. |
Randy Dunlap | 1629024 | 2011-08-13 12:34:52 -0700 | [diff] [blame] | 76 | MIPS MIPS architecture is enabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | MOUSE Appropriate mouse support is enabled. |
Matthew Wilcox | 309e57d | 2006-03-05 22:33:34 -0700 | [diff] [blame] | 78 | MSI Message Signaled Interrupts (PCI). |
Randy Dunlap | c8facbb | 2007-07-31 00:37:40 -0700 | [diff] [blame] | 79 | MTD MTD (Memory Technology Device) support is enabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | NET Appropriate network support is enabled. |
| 81 | NUMA NUMA support is enabled. |
| 82 | NFS Appropriate NFS support is enabled. |
| 83 | OSS OSS sound support is enabled. |
Randy Dunlap | c8facbb | 2007-07-31 00:37:40 -0700 | [diff] [blame] | 84 | PV_OPS A paravirtualized kernel is enabled. |
| 85 | PARIDE The ParIDE (parallel port IDE) subsystem is enabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 86 | PARISC The PA-RISC architecture is enabled. |
| 87 | PCI PCI bus support is enabled. |
Randy Dunlap | 7f78576 | 2007-10-05 13:17:58 -0700 | [diff] [blame] | 88 | PCIE PCI Express support is enabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | PCMCIA The PCMCIA subsystem is enabled. |
| 90 | PNP Plug & Play support is enabled. |
| 91 | PPC PowerPC architecture is enabled. |
| 92 | PPT Parallel port support is enabled. |
| 93 | PS2 Appropriate PS/2 support is enabled. |
| 94 | RAM RAM disk support is enabled. |
| 95 | S390 S390 architecture is enabled. |
| 96 | SCSI Appropriate SCSI support is enabled. |
Randy Dunlap | 163475f | 2010-08-14 12:36:14 -0700 | [diff] [blame] | 97 | A lot of drivers have their options described inside |
| 98 | the Documentation/scsi/ sub-directory. |
James Morris | 20510f2 | 2007-10-16 23:31:32 -0700 | [diff] [blame] | 99 | SECURITY Different security models are enabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | SELINUX SELinux support is enabled. |
John Johansen | c1c124e | 2010-07-29 14:48:09 -0700 | [diff] [blame] | 101 | APPARMOR AppArmor support is enabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | SERIAL Serial support is enabled. |
Paul Mundt | e523d93 | 2007-02-28 18:30:01 +0900 | [diff] [blame] | 103 | SH SuperH architecture is enabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | SMP The kernel is an SMP kernel. |
| 105 | SPARC Sparc architecture is enabled. |
David Brownell | 77437fd | 2008-07-23 21:28:33 -0700 | [diff] [blame] | 106 | SWSUSP Software suspend (hibernation) is enabled. |
| 107 | SUSPEND System suspend states are enabled. |
Rajiv Andrade | 225a9be | 2010-03-25 00:55:32 -0300 | [diff] [blame] | 108 | TPM TPM drivers are enabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | TS Appropriate touchscreen support is enabled. |
Alan Stern | d4f373e | 2008-11-10 14:07:45 -0500 | [diff] [blame] | 110 | UMS USB Mass Storage support is enabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | USB USB support is enabled. |
| 112 | USBHID USB Human Interface Device support is enabled. |
| 113 | V4L Video For Linux support is enabled. |
Pawel Moll | 81a054c | 2012-05-09 18:30:16 +0100 | [diff] [blame] | 114 | VMMIO Driver for memory mapped virtio devices is enabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | VGA The VGA console has been enabled. |
| 116 | VT Virtual terminal support is enabled. |
| 117 | WDT Watchdog support is enabled. |
| 118 | XT IBM PC/XT MFM hard disk support is enabled. |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 119 | X86-32 X86-32, aka i386 architecture is enabled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | X86-64 X86-64 architecture is enabled. |
| 121 | More X86-64 boot options can be found in |
Uwe Hermann | 71cced6 | 2008-10-20 09:32:21 -0700 | [diff] [blame] | 122 | Documentation/x86/x86_64/boot-options.txt . |
Randy Dunlap | 1629024 | 2011-08-13 12:34:52 -0700 | [diff] [blame] | 123 | X86 Either 32-bit or 64-bit x86 (same as X86-32+X86-64) |
Stefano Stabellini | c1c5413 | 2010-05-14 12:44:30 +0100 | [diff] [blame] | 124 | XEN Xen support is enabled |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | |
| 126 | In addition, the following text indicates that the option: |
| 127 | |
| 128 | BUGS= Relates to possible processor bugs on the said processor. |
| 129 | KNL Is a kernel start-up parameter. |
| 130 | BOOT Is a boot loader parameter. |
| 131 | |
| 132 | Parameters denoted with BOOT are actually interpreted by the boot |
| 133 | loader, and have no meaning to the kernel directly. |
| 134 | Do not modify the syntax of boot loader parameters without extreme |
Kyle McMartin | 954a8b8 | 2009-02-19 16:48:14 -0500 | [diff] [blame] | 135 | need or coordination with <Documentation/x86/boot.txt>. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | |
Karsten Weiss | 5558870 | 2007-02-13 13:26:21 +0100 | [diff] [blame] | 137 | There are also arch-specific kernel-parameters not documented here. |
Uwe Hermann | 71cced6 | 2008-10-20 09:32:21 -0700 | [diff] [blame] | 138 | See for example <Documentation/x86/x86_64/boot-options.txt>. |
Karsten Weiss | 5558870 | 2007-02-13 13:26:21 +0100 | [diff] [blame] | 139 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | Note that ALL kernel parameters listed below are CASE SENSITIVE, and that |
| 141 | a trailing = on the name of any parameter states that that parameter will |
| 142 | be entered as an environment variable, whereas its absence indicates that |
| 143 | it will appear as a kernel argument readable via /proc/cmdline by programs |
| 144 | running once the system is up. |
| 145 | |
jens m. noedler | 9c4751f | 2006-09-29 02:00:27 -0700 | [diff] [blame] | 146 | The number of kernel parameters is not limited, but the length of the |
| 147 | complete command line (parameters including spaces etc.) is limited to |
| 148 | a fixed number of characters. This limit depends on the architecture |
| 149 | and is between 256 and 4096 characters. It is defined in the file |
| 150 | ./include/asm/setup.h as COMMAND_LINE_SIZE. |
| 151 | |
Ahmed S. Darwish | 7a19a23 | 2011-02-20 20:08:35 -0800 | [diff] [blame] | 152 | Finally, the [KMG] suffix is commonly described after a number of kernel |
| 153 | parameter values. These 'K', 'M', and 'G' letters represent the _binary_ |
| 154 | multipliers 'Kilo', 'Mega', and 'Giga', equalling 2^10, 2^20, and 2^30 |
| 155 | bytes respectively. Such letter suffixes can also be entirely omitted. |
| 156 | |
jens m. noedler | 9c4751f | 2006-09-29 02:00:27 -0700 | [diff] [blame] | 157 | |
Jaswinder Singh Rajput | 6cececf | 2009-04-14 14:03:43 +0530 | [diff] [blame] | 158 | acpi= [HW,ACPI,X86] |
Bernhard Walle | 03d926f | 2007-03-06 02:29:44 -0800 | [diff] [blame] | 159 | Advanced Configuration and Power Interface |
Len Brown | 68ca406 | 2010-02-19 00:09:22 -0500 | [diff] [blame] | 160 | Format: { force | off | strict | noirq | rsdt } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | force -- enable ACPI if default was off |
| 162 | off -- disable ACPI if default was on |
| 163 | noirq -- do not use ACPI for IRQ routing |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 164 | strict -- Be less tolerant of platforms that are not |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | strictly ACPI specification compliant. |
Zhao Yakui | 237889b | 2008-12-17 16:55:18 +0800 | [diff] [blame] | 166 | rsdt -- prefer RSDT over (default) XSDT |
Lin Ming | aa2110c | 2010-04-08 14:34:27 +0800 | [diff] [blame] | 167 | copy_dsdt -- copy DSDT to memory |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | |
Paul Bolle | 395cf96 | 2011-08-15 02:02:26 +0200 | [diff] [blame] | 169 | See also Documentation/power/runtime_pm.txt, pci=noacpi |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | |
Takao Indoh | 4996c02 | 2011-07-14 18:05:21 -0400 | [diff] [blame] | 171 | acpi_rsdp= [ACPI,EFI,KEXEC] |
| 172 | Pass the RSDP address to the kernel, mostly used |
| 173 | on machines running EFI runtime service to boot the |
| 174 | second kernel for kdump. |
| 175 | |
Len Brown | a1fdcc0 | 2007-03-11 03:26:14 -0400 | [diff] [blame] | 176 | acpi_apic_instance= [ACPI, IOAPIC] |
| 177 | Format: <int> |
| 178 | 2: use 2nd APIC table, if available |
| 179 | 1,0: use 1st APIC table |
Len Brown | 4e381a4 | 2007-03-30 14:16:10 -0400 | [diff] [blame] | 180 | default: 0 |
Len Brown | a1fdcc0 | 2007-03-11 03:26:14 -0400 | [diff] [blame] | 181 | |
Thomas Renninger | c3d6de6 | 2008-08-01 17:37:55 +0200 | [diff] [blame] | 182 | acpi_backlight= [HW,ACPI] |
| 183 | acpi_backlight=vendor |
| 184 | acpi_backlight=video |
| 185 | If set to vendor, prefer vendor specific driver |
| 186 | (e.g. thinkpad_acpi, sony_acpi, etc.) instead |
| 187 | of the ACPI video.ko driver. |
| 188 | |
Bjorn Helgaas | a0d84a9 | 2008-11-07 16:58:05 -0700 | [diff] [blame] | 189 | acpi.debug_layer= [HW,ACPI,ACPI_DEBUG] |
| 190 | acpi.debug_level= [HW,ACPI,ACPI_DEBUG] |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | Format: <int> |
Bjorn Helgaas | a0d84a9 | 2008-11-07 16:58:05 -0700 | [diff] [blame] | 192 | CONFIG_ACPI_DEBUG must be enabled to produce any ACPI |
| 193 | debug output. Bits in debug_layer correspond to a |
| 194 | _COMPONENT in an ACPI source file, e.g., |
| 195 | #define _COMPONENT ACPI_PCI_COMPONENT |
| 196 | Bits in debug_level correspond to a level in |
| 197 | ACPI_DEBUG_PRINT statements, e.g., |
| 198 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, ... |
Bjorn Helgaas | e76f427 | 2008-11-13 17:30:13 -0600 | [diff] [blame] | 199 | The debug_level mask defaults to "info". See |
| 200 | Documentation/acpi/debug.txt for more information about |
| 201 | debug layers and levels. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | |
Bjorn Helgaas | e76f427 | 2008-11-13 17:30:13 -0600 | [diff] [blame] | 203 | Enable processor driver info messages: |
| 204 | acpi.debug_layer=0x20000000 |
| 205 | Enable PCI/PCI interrupt routing info messages: |
| 206 | acpi.debug_layer=0x400000 |
Bjorn Helgaas | a0d84a9 | 2008-11-07 16:58:05 -0700 | [diff] [blame] | 207 | Enable AML "Debug" output, i.e., stores to the Debug |
| 208 | object while interpreting AML: |
| 209 | acpi.debug_layer=0xffffffff acpi.debug_level=0x2 |
Bjorn Helgaas | a0d84a9 | 2008-11-07 16:58:05 -0700 | [diff] [blame] | 210 | Enable all messages related to ACPI hardware: |
| 211 | acpi.debug_layer=0x2 acpi.debug_level=0xffffffff |
Thomas Renninger | 36eec5e | 2008-08-11 15:03:20 +0200 | [diff] [blame] | 212 | |
Bjorn Helgaas | a0d84a9 | 2008-11-07 16:58:05 -0700 | [diff] [blame] | 213 | Some values produce so much output that the system is |
| 214 | unusable. The "log_buf_len" parameter may be useful |
| 215 | if you need to capture more output. |
Zhang Rui | f989106 | 2007-04-24 13:53:22 +0800 | [diff] [blame] | 216 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 217 | acpi_irq_balance [HW,ACPI] |
| 218 | ACPI will balance active IRQs |
| 219 | default in APIC mode |
| 220 | |
| 221 | acpi_irq_nobalance [HW,ACPI] |
| 222 | ACPI will not move active IRQs (default) |
| 223 | default in PIC mode |
| 224 | |
| 225 | acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA |
| 226 | Format: <irq>,<irq>... |
| 227 | |
| 228 | acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for |
| 229 | use by PCI |
| 230 | Format: <irq>,<irq>... |
| 231 | |
Lv Zheng | 08e1d7c | 2014-03-24 14:49:22 +0800 | [diff] [blame] | 232 | acpi_no_auto_serialize [HW,ACPI] |
| 233 | Disable auto-serialization of AML methods |
Bob Moore | 22b5afc | 2014-03-24 14:49:00 +0800 | [diff] [blame] | 234 | AML control methods that contain the opcodes to create |
| 235 | named objects will be marked as "Serialized" by the |
| 236 | auto-serialization feature. |
Lv Zheng | 08e1d7c | 2014-03-24 14:49:22 +0800 | [diff] [blame] | 237 | This feature is enabled by default. |
| 238 | This option allows to turn off the feature. |
Bob Moore | 22b5afc | 2014-03-24 14:49:00 +0800 | [diff] [blame] | 239 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 240 | acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT |
| 241 | |
Lv Zheng | 4dde507 | 2014-02-11 11:01:52 +0800 | [diff] [blame] | 242 | acpica_no_return_repair [HW, ACPI] |
| 243 | Disable AML predefined validation mechanism |
| 244 | This mechanism can repair the evaluation result to make |
| 245 | the return objects more ACPI specification compliant. |
| 246 | This option is useful for developers to identify the |
| 247 | root cause of an AML interpreter issue when the issue |
| 248 | has something to do with the repair mechanism. |
| 249 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 250 | acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS |
| 251 | Format: To spoof as Windows 98: ="Microsoft Windows" |
| 252 | |
| 253 | acpi_osi= [HW,ACPI] Modify list of supported OS interface strings |
Lv Zheng | 5dc1798 | 2013-07-22 16:08:25 +0800 | [diff] [blame] | 254 | acpi_osi="string1" # add string1 |
| 255 | acpi_osi="!string2" # remove string2 |
Lv Zheng | 741d812 | 2013-07-22 16:08:36 +0800 | [diff] [blame] | 256 | acpi_osi=!* # remove all strings |
Lv Zheng | 5dc1798 | 2013-07-22 16:08:25 +0800 | [diff] [blame] | 257 | acpi_osi=! # disable all built-in OS vendor |
| 258 | strings |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 259 | acpi_osi= # disable all strings |
| 260 | |
Lv Zheng | 5dc1798 | 2013-07-22 16:08:25 +0800 | [diff] [blame] | 261 | 'acpi_osi=!' can be used in combination with single or |
| 262 | multiple 'acpi_osi="string1"' to support specific OS |
| 263 | vendor string(s). Note that such command can only |
| 264 | affect the default state of the OS vendor strings, thus |
| 265 | it cannot affect the default state of the feature group |
| 266 | strings and the current state of the OS vendor strings, |
| 267 | specifying it multiple times through kernel command line |
Lv Zheng | 741d812 | 2013-07-22 16:08:36 +0800 | [diff] [blame] | 268 | is meaningless. This command is useful when one do not |
| 269 | care about the state of the feature group strings which |
| 270 | should be controlled by the OSPM. |
Lv Zheng | 5dc1798 | 2013-07-22 16:08:25 +0800 | [diff] [blame] | 271 | Examples: |
| 272 | 1. 'acpi_osi=! acpi_osi="Windows 2000"' is equivalent |
| 273 | to 'acpi_osi="Windows 2000" acpi_osi=!', they all |
| 274 | can make '_OSI("Windows 2000")' TRUE. |
| 275 | |
| 276 | 'acpi_osi=' cannot be used in combination with other |
| 277 | 'acpi_osi=' command lines, the _OSI method will not |
| 278 | exist in the ACPI namespace. NOTE that such command can |
| 279 | only affect the _OSI support state, thus specifying it |
| 280 | multiple times through kernel command line is also |
| 281 | meaningless. |
| 282 | Examples: |
| 283 | 1. 'acpi_osi=' can make 'CondRefOf(_OSI, Local1)' |
| 284 | FALSE. |
| 285 | |
Lv Zheng | 741d812 | 2013-07-22 16:08:36 +0800 | [diff] [blame] | 286 | 'acpi_osi=!*' can be used in combination with single or |
| 287 | multiple 'acpi_osi="string1"' to support specific |
| 288 | string(s). Note that such command can affect the |
| 289 | current state of both the OS vendor strings and the |
| 290 | feature group strings, thus specifying it multiple times |
| 291 | through kernel command line is meaningful. But it may |
| 292 | still not able to affect the final state of a string if |
| 293 | there are quirks related to this string. This command |
| 294 | is useful when one want to control the state of the |
| 295 | feature group strings to debug BIOS issues related to |
| 296 | the OSPM features. |
| 297 | Examples: |
| 298 | 1. 'acpi_osi="Module Device" acpi_osi=!*' can make |
| 299 | '_OSI("Module Device")' FALSE. |
| 300 | 2. 'acpi_osi=!* acpi_osi="Module Device"' can make |
| 301 | '_OSI("Module Device")' TRUE. |
| 302 | 3. 'acpi_osi=! acpi_osi=!* acpi_osi="Windows 2000"' is |
| 303 | equivalent to |
| 304 | 'acpi_osi=!* acpi_osi=! acpi_osi="Windows 2000"' |
| 305 | and |
| 306 | 'acpi_osi=!* acpi_osi="Windows 2000" acpi_osi=!', |
| 307 | they all will make '_OSI("Windows 2000")' TRUE. |
| 308 | |
Jaswinder Singh Rajput | 6cececf | 2009-04-14 14:03:43 +0530 | [diff] [blame] | 309 | acpi_pm_good [X86] |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 310 | Override the pmtimer bug detection: force the kernel |
| 311 | to assume that this machine's pmtimer latches its value |
| 312 | and always returns good values. |
| 313 | |
Randy Dunlap | 4af94f3 | 2009-04-17 18:30:28 -0700 | [diff] [blame] | 314 | acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode |
| 315 | Format: { level | edge | high | low } |
| 316 | |
Randy Dunlap | 4af94f3 | 2009-04-17 18:30:28 -0700 | [diff] [blame] | 317 | acpi_skip_timer_override [HW,ACPI] |
| 318 | Recognize and ignore IRQ0/pin2 Interrupt Override. |
| 319 | For broken nForce2 BIOS resulting in XT-PIC timer. |
| 320 | |
| 321 | acpi_sleep= [HW,ACPI] Sleep options |
| 322 | Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig, |
Amerigo Wang | c3b0795 | 2011-05-10 21:09:38 +0200 | [diff] [blame] | 323 | old_ordering, nonvs, sci_force_enable } |
Randy Dunlap | 4af94f3 | 2009-04-17 18:30:28 -0700 | [diff] [blame] | 324 | See Documentation/power/video.txt for information on |
| 325 | s3_bios and s3_mode. |
| 326 | s3_beep is for debugging; it makes the PC's speaker beep |
| 327 | as soon as the kernel's real-mode entry point is called. |
| 328 | s4_nohwsig prevents ACPI hardware signature from being |
| 329 | used during resume from hibernation. |
| 330 | old_ordering causes the ACPI 1.0 ordering of the _PTS |
| 331 | control method, with respect to putting devices into |
| 332 | low power states, to be enforced (the ACPI 2.0 ordering |
| 333 | of _PTS is used by default). |
Rafael J. Wysocki | 72ad5d7 | 2010-07-23 22:59:09 +0200 | [diff] [blame] | 334 | nonvs prevents the kernel from saving/restoring the |
| 335 | ACPI NVS memory during suspend/hibernation and resume. |
Zhang Rui | d7f0eea | 2009-12-30 15:36:42 +0800 | [diff] [blame] | 336 | sci_force_enable causes the kernel to set SCI_EN directly |
| 337 | on resume from S1/S3 (which is against the ACPI spec, |
| 338 | but some broken systems don't work without it). |
Randy Dunlap | 4af94f3 | 2009-04-17 18:30:28 -0700 | [diff] [blame] | 339 | |
| 340 | acpi_use_timer_override [HW,ACPI] |
| 341 | Use timer override. For some broken Nvidia NF5 boards |
| 342 | that require a timer override, but don't have HPET |
| 343 | |
Luca Tettamanti | 7e90560 | 2009-03-30 00:01:27 +0200 | [diff] [blame] | 344 | acpi_enforce_resources= [ACPI] |
| 345 | { strict | lax | no } |
| 346 | Check for resource conflicts between native drivers |
| 347 | and ACPI OperationRegions (SystemIO and SystemMemory |
| 348 | only). IO ports and memory declared in ACPI might be |
| 349 | used by the ACPI subsystem in arbitrary AML code and |
| 350 | can interfere with legacy drivers. |
| 351 | strict (default): access to resources claimed by ACPI |
| 352 | is denied; legacy drivers trying to access reserved |
| 353 | resources will fail to bind to device using them. |
| 354 | lax: access to resources claimed by ACPI is allowed; |
| 355 | legacy drivers trying to access reserved resources |
| 356 | will bind successfully but a warning message is logged. |
| 357 | no: ACPI OperationRegions are not marked as reserved, |
| 358 | no further checks are performed. |
| 359 | |
Prarit Bhargava | 00159a2 | 2014-01-14 14:21:13 -0500 | [diff] [blame] | 360 | acpi_no_memhotplug [ACPI] Disable memory hotplug. Useful for kdump |
| 361 | kernels. |
| 362 | |
Randy Dunlap | 4af94f3 | 2009-04-17 18:30:28 -0700 | [diff] [blame] | 363 | add_efi_memmap [EFI; X86] Include EFI memory map in |
| 364 | kernel's map of available physical RAM. |
| 365 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 366 | agp= [AGP] |
| 367 | { off | try_unsupported } |
| 368 | off: disable AGP support |
| 369 | try_unsupported: try to drive unsupported chipsets |
| 370 | (may crash computer or cause data corruption) |
| 371 | |
Randy Dunlap | bcfde33 | 2010-06-07 17:10:38 -0700 | [diff] [blame] | 372 | ALSA [HW,ALSA] |
| 373 | See Documentation/sound/alsa/alsa-parameters.txt |
| 374 | |
Russell King | d944d54 | 2010-02-20 16:13:29 +0000 | [diff] [blame] | 375 | alignment= [KNL,ARM] |
| 376 | Allow the default userspace alignment fault handler |
| 377 | behaviour to be specified. Bit 0 enables warnings, |
| 378 | bit 1 enables fixups, and bit 2 sends a segfault. |
| 379 | |
Borislav Petkov | dfb09f9 | 2011-08-05 15:15:08 +0200 | [diff] [blame] | 380 | align_va_addr= [X86-64] |
| 381 | Align virtual addresses by clearing slice [14:12] when |
| 382 | allocating a VMA at process creation time. This option |
| 383 | gives you up to 3% performance improvement on AMD F15h |
| 384 | machines (where it is enabled by default) for a |
| 385 | CPU-intensive style benchmark, and it can vary highly in |
| 386 | a microbenchmark depending on workload and compiler. |
| 387 | |
Borislav Petkov | 8360ee2 | 2011-11-21 12:10:19 +0100 | [diff] [blame] | 388 | 32: only for 32-bit processes |
| 389 | 64: only for 64-bit processes |
Borislav Petkov | dfb09f9 | 2011-08-05 15:15:08 +0200 | [diff] [blame] | 390 | on: enable for both 32- and 64-bit processes |
| 391 | off: disable for both 32- and 64-bit processes |
| 392 | |
Steven Rostedt (Red Hat) | 55034cd | 2013-03-07 22:48:09 -0500 | [diff] [blame] | 393 | alloc_snapshot [FTRACE] |
| 394 | Allocate the ftrace snapshot buffer on boot up when the |
| 395 | main buffer is allocated. This is handy if debugging |
| 396 | and you need to use tracing_snapshot() on boot up, and |
| 397 | do not want to use tracing_snapshot_alloc() as it needs |
| 398 | to be done where GFP_KERNEL allocations are allowed. |
| 399 | |
Sedat Dilek | 89e0b9a | 2011-12-05 23:08:32 +0100 | [diff] [blame] | 400 | amd_iommu= [HW,X86-64] |
Joerg Roedel | 54b4cbd | 2008-06-26 21:28:10 +0200 | [diff] [blame] | 401 | Pass parameters to the AMD IOMMU driver in the system. |
| 402 | Possible values are: |
FUJITA Tomonori | afa9fdc | 2008-09-20 01:23:30 +0900 | [diff] [blame] | 403 | fullflush - enable flushing of IO/TLB entries when |
| 404 | they are unmapped. Otherwise they are |
| 405 | flushed before they will be reused, which |
| 406 | is a lot of faster |
Joerg Roedel | a523572 | 2010-05-11 17:12:33 +0200 | [diff] [blame] | 407 | off - do not initialize any AMD IOMMU found in |
| 408 | the system |
Joerg Roedel | 5abcdba | 2011-12-01 15:49:45 +0100 | [diff] [blame] | 409 | force_isolation - Force device isolation for all |
| 410 | devices. The IOMMU driver is not |
| 411 | allowed anymore to lift isolation |
| 412 | requirements as needed. This option |
| 413 | does not override iommu=pt |
FUJITA Tomonori | afa9fdc | 2008-09-20 01:23:30 +0900 | [diff] [blame] | 414 | |
Shuah Khan | c099cf1 | 2012-05-24 15:58:25 -0600 | [diff] [blame] | 415 | amd_iommu_dump= [HW,X86-64] |
| 416 | Enable AMD IOMMU driver option to dump the ACPI table |
| 417 | for AMD IOMMU. With this option enabled, AMD IOMMU |
| 418 | driver will print ACPI tables for AMD IOMMU during |
| 419 | IOMMU initialization. |
| 420 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 421 | amijoy.map= [HW,JOY] Amiga joystick support |
| 422 | Map of devices attached to JOY0DAT and JOY1DAT |
| 423 | Format: <a>,<b> |
Paul Bolle | 395cf96 | 2011-08-15 02:02:26 +0200 | [diff] [blame] | 424 | See also Documentation/input/joystick.txt |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 425 | |
| 426 | analog.map= [HW,JOY] Analog joystick and gamepad support |
| 427 | Specifies type or capabilities of an analog joystick |
| 428 | connected to one of 16 gameports |
| 429 | Format: <type1>,<type2>,..<type16> |
| 430 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 431 | apc= [HW,SPARC] |
| 432 | Power management functions (SPARCstation-4/5 + deriv.) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | Format: noidle |
| 434 | Disable APC CPU standby support. SPARCstation-Fox does |
| 435 | not play well with APC CPU idle - disable it if you have |
| 436 | APC and your system crashes randomly. |
| 437 | |
Randy Dunlap | ca1eda2 | 2009-05-06 16:02:58 -0700 | [diff] [blame] | 438 | apic= [APIC,X86-32] Advanced Programmable Interrupt Controller |
Randy Dunlap | c8facbb | 2007-07-31 00:37:40 -0700 | [diff] [blame] | 439 | Change the output verbosity whilst booting |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | Format: { quiet (default) | verbose | debug } |
| 441 | Change the amount of debugging information output |
| 442 | when initialising the APIC and IO-APIC components. |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 443 | |
Brian Haley | b0f83b2 | 2010-02-04 13:36:50 -0800 | [diff] [blame] | 444 | autoconf= [IPV6] |
| 445 | See Documentation/networking/ipv6.txt. |
| 446 | |
Cyrill Gorcunov | 9636bc0 | 2009-10-14 19:09:04 +0400 | [diff] [blame] | 447 | show_lapic= [APIC,X86] Advanced Programmable Interrupt Controller |
| 448 | Limit apic dumping. The parameter defines the maximal |
| 449 | number of local apics being dumped. Also it is possible |
| 450 | to set it to "all" by meaning -- no limit here. |
| 451 | Format: { 1 (default) | 2 | ... | all }. |
| 452 | The parameter valid if only apic=debug or |
| 453 | apic=verbose is specified. |
| 454 | Example: apic=debug show_lapic=all |
| 455 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | apm= [APM] Advanced Power Management |
Pavel Machek | 71f7705 | 2008-07-04 09:59:43 -0700 | [diff] [blame] | 457 | See header of arch/x86/kernel/apm_32.c. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards |
| 460 | Format: <io>,<irq>,<nodeID> |
| 461 | |
| 462 | ataflop= [HW,M68k] |
| 463 | |
| 464 | atarimouse= [HW,MOUSE] Atari Mouse |
| 465 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess, |
| 467 | EzKey and similar keyboards |
| 468 | |
| 469 | atkbd.reset= [HW] Reset keyboard during initialization |
| 470 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 471 | atkbd.set= [HW] Select keyboard code set |
| 472 | Format: <int> (2 = AT (default), 3 = PS/2) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | |
| 474 | atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar |
| 475 | keyboards |
| 476 | |
| 477 | atkbd.softraw= [HW] Choose between synthetic and real raw mode |
| 478 | Format: <bool> (0 = real, 1 = synthetic (default)) |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 479 | |
| 480 | atkbd.softrepeat= [HW] |
| 481 | Use software keyboard repeat |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | |
Richard Guy Briggs | a106fb0 | 2013-09-23 21:53:35 -0400 | [diff] [blame] | 483 | audit= [KNL] Enable the audit sub-system |
| 484 | Format: { "0" | "1" } (0 = disabled, 1 = enabled) |
Eric Paris | d796114 | 2014-01-13 16:01:06 -0500 | [diff] [blame] | 485 | 0 - kernel audit is disabled and can not be enabled |
| 486 | until the next reboot |
| 487 | unset - kernel audit is initialized but disabled and |
| 488 | will be fully enabled by the userspace auditd. |
| 489 | 1 - kernel audit is initialized and partially enabled, |
| 490 | storing at most audit_backlog_limit messages in |
| 491 | RAM until it is fully enabled by the userspace |
| 492 | auditd. |
Richard Guy Briggs | a106fb0 | 2013-09-23 21:53:35 -0400 | [diff] [blame] | 493 | Default: unset |
Richard Guy Briggs | f3411cb | 2013-09-17 12:34:52 -0400 | [diff] [blame] | 494 | |
Richard Guy Briggs | f910fde | 2013-09-17 12:34:52 -0400 | [diff] [blame] | 495 | audit_backlog_limit= [KNL] Set the audit queue size limit. |
| 496 | Format: <int> (must be >=0) |
| 497 | Default: 64 |
| 498 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | baycom_epp= [HW,AX25] |
| 500 | Format: <io>,<mode> |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 501 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem |
| 503 | Format: <io>,<mode> |
| 504 | See header of drivers/net/hamradio/baycom_par.c. |
| 505 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 506 | baycom_ser_fdx= [HW,AX25] |
| 507 | BayCom Serial Port AX.25 Modem (Full Duplex Mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | Format: <io>,<irq>,<mode>[,<baud>] |
| 509 | See header of drivers/net/hamradio/baycom_ser_fdx.c. |
| 510 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 511 | baycom_ser_hdx= [HW,AX25] |
| 512 | BayCom Serial Port AX.25 Modem (Half Duplex Mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 513 | Format: <io>,<irq>,<mode> |
| 514 | See header of drivers/net/hamradio/baycom_ser_hdx.c. |
| 515 | |
Paul Gortmaker | 080506a | 2013-09-30 13:45:19 -0700 | [diff] [blame] | 516 | blkdevparts= Manual partition parsing of block device(s) for |
| 517 | embedded devices based on command line input. |
| 518 | See Documentation/block/cmdline-partition.txt |
| 519 | |
Randy Dunlap | bfe8df3 | 2007-10-16 01:23:46 -0700 | [diff] [blame] | 520 | boot_delay= Milliseconds to delay each printk during boot. |
| 521 | Values larger than 10 seconds (10000) are changed to |
| 522 | no delay (0). |
| 523 | Format: integer |
| 524 | |
Andreas Herrmann | 35fc908 | 2008-08-20 14:08:58 -0700 | [diff] [blame] | 525 | bootmem_debug [KNL] Enable bootmem allocator debug messages. |
| 526 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 527 | bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards) |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 528 | bttv.radio= Most important insmod options are available as |
| 529 | kernel args too. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | bttv.pll= See Documentation/video4linux/bttv/Insmod-options |
Paul Bolle | 395cf96 | 2011-08-15 02:02:26 +0200 | [diff] [blame] | 531 | bttv.tuner= |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | |
Will Schmidt | 4e89a2d | 2010-09-28 15:33:12 +0000 | [diff] [blame] | 533 | bulk_remove=off [PPC] This parameter disables the use of the pSeries |
| 534 | firmware feature for flushing multiple hpte entries |
| 535 | at a time. |
| 536 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | c101= [NET] Moxa C101 synchronous serial card |
| 538 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 539 | cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 540 | Sometimes CPU hardware bugs make them report the cache |
| 541 | size incorrectly. The kernel will attempt work arounds |
| 542 | to fix known problems, but for some CPUs it is not |
| 543 | possible to determine what the correct size should be. |
| 544 | This option provides an override for these situations. |
| 545 | |
Sebastian Ott | 14ff56b | 2008-01-26 14:10:37 +0100 | [diff] [blame] | 546 | ccw_timeout_log [S390] |
| 547 | See Documentation/s390/CommonIO for details. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | |
Paul Menage | 8bab8dd | 2008-04-04 14:29:57 -0700 | [diff] [blame] | 549 | cgroup_disable= [KNL] Disable a particular controller |
| 550 | Format: {name of the controller(s) to disable} |
Qiang Huang | ca0bdbb | 2013-11-06 13:18:09 -0800 | [diff] [blame] | 551 | The effects of cgroup_disable=foo are: |
| 552 | - foo isn't auto-mounted if you mount all cgroups in |
| 553 | a single hierarchy |
| 554 | - foo isn't visible as an individually mountable |
| 555 | subsystem |
| 556 | {Currently only "memory" controller deal with this and |
| 557 | cut the overhead, others just disable the usage. So |
| 558 | only cgroup_disable=memory is actually worthy} |
Paul Menage | 8bab8dd | 2008-04-04 14:29:57 -0700 | [diff] [blame] | 559 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 560 | checkreqprot [SELINUX] Set initial checkreqprot flag value. |
| 561 | Format: { "0" | "1" } |
| 562 | See security/selinux/Kconfig help text. |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 563 | 0 -- check protection applied by kernel (includes |
| 564 | any implied execute protection). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | 1 -- check protection requested by application. |
| 566 | Default value is set via a kernel config option. |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 567 | Value can be changed at runtime via |
| 568 | /selinux/checkreqprot. |
| 569 | |
Sebastian Ott | 661ca0d | 2008-01-26 14:10:36 +0100 | [diff] [blame] | 570 | cio_ignore= [S390] |
| 571 | See Documentation/s390/CommonIO for details. |
Olof Johansson | 1e43525 | 2013-04-27 14:10:18 -0700 | [diff] [blame] | 572 | clk_ignore_unused |
| 573 | [CLK] |
| 574 | Keep all clocks already enabled by bootloader on, |
| 575 | even if no driver has claimed them. This is useful |
| 576 | for debug and development, but should not be |
| 577 | needed on a platform with proper driver support. |
| 578 | For more information, see Documentation/clk.txt. |
Sebastian Ott | 661ca0d | 2008-01-26 14:10:36 +0100 | [diff] [blame] | 579 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 580 | clock= [BUGS=X86-32, HW] gettimeofday clocksource override. |
john stultz | 734efb4 | 2006-06-26 00:25:05 -0700 | [diff] [blame] | 581 | [Deprecated] |
Matt LaPlante | 3f6dee9 | 2006-10-03 22:45:33 +0200 | [diff] [blame] | 582 | Forces specified clocksource (if available) to be used |
john stultz | 734efb4 | 2006-06-26 00:25:05 -0700 | [diff] [blame] | 583 | when calculating gettimeofday(). If specified |
Matt LaPlante | 3f6dee9 | 2006-10-03 22:45:33 +0200 | [diff] [blame] | 584 | clocksource is not available, it defaults to PIT. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 585 | Format: { pit | tsc | cyclone | pmtmr } |
| 586 | |
John Stultz | 592913e | 2010-07-13 17:56:20 -0700 | [diff] [blame] | 587 | clocksource= Override the default clocksource |
Randy Dunlap | 3d6ac98 | 2007-05-23 13:58:16 -0700 | [diff] [blame] | 588 | Format: <string> |
| 589 | Override the default clocksource and use the clocksource |
| 590 | with the name specified. |
| 591 | Some clocksource names to choose from, depending on |
| 592 | the platform: |
| 593 | [all] jiffies (this is the base, fallback clocksource) |
| 594 | [ACPI] acpi_pm |
| 595 | [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2, |
| 596 | pxa_timer,timer3,32k_counter,timer0_1 |
| 597 | [AVR32] avr32 |
Alok Kataria | 9863c90 | 2010-08-23 14:49:11 -0700 | [diff] [blame] | 598 | [X86-32] pit,hpet,tsc; |
Randy Dunlap | 3d6ac98 | 2007-05-23 13:58:16 -0700 | [diff] [blame] | 599 | scx200_hrt on Geode; cyclone on IBM x440 |
| 600 | [MIPS] MIPS |
| 601 | [PARISC] cr16 |
| 602 | [S390] tod |
| 603 | [SH] SuperH |
| 604 | [SPARC64] tick |
| 605 | [X86-64] hpet,tsc |
| 606 | |
Andi Kleen | ac72e78 | 2008-01-30 13:33:21 +0100 | [diff] [blame] | 607 | clearcpuid=BITNUM [X86] |
| 608 | Disable CPUID feature X for the kernel. See |
Randy Dunlap | 07983f0 | 2009-01-06 14:42:41 -0800 | [diff] [blame] | 609 | arch/x86/include/asm/cpufeature.h for the valid bit |
| 610 | numbers. Note the Linux specific bits are not necessarily |
Andi Kleen | ac72e78 | 2008-01-30 13:33:21 +0100 | [diff] [blame] | 611 | stable over kernel options, but the vendor specific |
| 612 | ones should be. |
| 613 | Also note that user programs calling CPUID directly |
| 614 | or using the feature without checking anything |
| 615 | will still see it. This just prevents it from |
| 616 | being used by the kernel or shown in /proc/cpuinfo. |
| 617 | Also note the kernel might malfunction if you disable |
| 618 | some critical bits. |
| 619 | |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 620 | cma=nn[MG] [ARM,KNL] |
| 621 | Sets the size of kernel global memory area for contiguous |
| 622 | memory allocations. For more information, see |
| 623 | include/linux/dma-contiguous.h |
| 624 | |
Robert Jennings | 14f966e | 2009-04-15 05:55:32 +0000 | [diff] [blame] | 625 | cmo_free_hint= [PPC] Format: { yes | no } |
| 626 | Specify whether pages are marked as being inactive |
| 627 | when they are freed. This is used in CMO environments |
| 628 | to determine OS memory pressure for page stealing by |
| 629 | a hypervisor. |
| 630 | Default: yes |
| 631 | |
Marek Szyprowski | c790950 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 632 | coherent_pool=nn[KMG] [ARM,KNL] |
| 633 | Sets the size of memory pool for coherent, atomic dma |
Marek Szyprowski | e9da6e9 | 2012-07-30 09:11:33 +0200 | [diff] [blame] | 634 | allocations, by default set to 256K. |
Marek Szyprowski | c790950 | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 635 | |
Jaswinder Singh Rajput | 6cececf | 2009-04-14 14:03:43 +0530 | [diff] [blame] | 636 | code_bytes [X86] How many bytes of object code to print |
Arjan van de Ven | a25bd94 | 2008-01-30 13:33:08 +0100 | [diff] [blame] | 637 | in an oops report. |
Chuck Ebbert | 86c4183 | 2007-02-13 13:26:25 +0100 | [diff] [blame] | 638 | Range: 0 - 8192 |
| 639 | Default: 64 |
| 640 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 641 | com20020= [HW,NET] ARCnet - COM20020 chipset |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 642 | Format: |
| 643 | <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]] |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 644 | |
| 645 | com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers) |
| 646 | Format: <io>[,<irq>] |
| 647 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 648 | com90xx= [HW,NET] |
| 649 | ARCnet - COM90xx chipset (memory-mapped buffers) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 650 | Format: <io>[,<irq>[,<memstart>]] |
| 651 | |
| 652 | condev= [HW,S390] console device |
| 653 | conmode= |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 654 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 655 | console= [KNL] Output console device and options. |
| 656 | |
| 657 | tty<n> Use the virtual console device <n>. |
| 658 | |
| 659 | ttyS<n>[,options] |
Randy Dunlap | f1a1c2d | 2006-03-25 03:08:17 -0800 | [diff] [blame] | 660 | ttyUSB0[,options] |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 661 | Use the specified serial port. The options are of |
Randy Dunlap | f1a1c2d | 2006-03-25 03:08:17 -0800 | [diff] [blame] | 662 | the form "bbbbpnf", where "bbbb" is the baud rate, |
| 663 | "p" is parity ("n", "o", or "e"), "n" is number of |
| 664 | bits, and "f" is flow control ("r" for RTS or |
| 665 | omit it). Default is "9600n8". |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 666 | |
Randy Dunlap | f1a1c2d | 2006-03-25 03:08:17 -0800 | [diff] [blame] | 667 | See Documentation/serial-console.txt for more |
| 668 | information. See |
| 669 | Documentation/networking/netconsole.txt for an |
| 670 | alternative. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 671 | |
Yinghai Lu | 18a8bd9 | 2007-07-15 23:37:59 -0700 | [diff] [blame] | 672 | uart[8250],io,<addr>[,options] |
| 673 | uart[8250],mmio,<addr>[,options] |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 674 | Start an early, polled-mode console on the 8250/16550 |
| 675 | UART at the specified I/O port or MMIO address, |
| 676 | switching to the matching ttyS device later. The |
| 677 | options are the same as for ttyS, above. |
Konrad Rzeszutek Wilk | a2fd641 | 2013-02-25 15:54:09 -0500 | [diff] [blame] | 678 | hvc<n> Use the hypervisor console device <n>. This is for |
| 679 | both Xen and PowerPC hypervisors. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 680 | |
Samuel Thibault | f7511d5 | 2008-04-30 00:54:51 -0700 | [diff] [blame] | 681 | If the device connected to the port is not a TTY but a braille |
| 682 | device, prepend "brl," before the device type, for instance |
| 683 | console=brl,ttyS0 |
| 684 | For now, only VisioBraille is supported. |
| 685 | |
Daniel Mack | f324edc | 2009-06-16 15:33:52 -0700 | [diff] [blame] | 686 | consoleblank= [KNL] The console blank (screen saver) timeout in |
| 687 | seconds. Defaults to 10*60 = 10mins. A value of 0 |
| 688 | disables the blank timer. |
| 689 | |
Hidehiro Kawai | 4cb0e11 | 2009-01-06 14:42:47 -0800 | [diff] [blame] | 690 | coredump_filter= |
| 691 | [KNL] Change the default value for |
| 692 | /proc/<pid>/coredump_filter. |
| 693 | See also Documentation/filesystems/proc.txt. |
| 694 | |
Len Brown | 62027ae | 2011-04-01 18:13:10 -0400 | [diff] [blame] | 695 | cpuidle.off=1 [CPU_IDLE] |
| 696 | disable the cpuidle sub-system |
| 697 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 699 | Format: |
| 700 | <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>] |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 701 | |
Ahmed S. Darwish | 6f21e64 | 2011-02-20 20:08:35 -0800 | [diff] [blame] | 702 | crashkernel=size[KMG][@offset[KMG]] |
| 703 | [KNL] Using kexec, Linux can switch to a 'crash kernel' |
| 704 | upon panic. This parameter reserves the physical |
| 705 | memory region [offset, offset + size] for that kernel |
| 706 | image. If '@offset' is omitted, then a suitable offset |
| 707 | is selected automatically. Check |
| 708 | Documentation/kdump/kdump.txt for further details. |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 709 | |
Bernhard Walle | fb39159 | 2007-10-18 23:41:02 -0700 | [diff] [blame] | 710 | crashkernel=range1:size1[,range2:size2,...][@offset] |
| 711 | [KNL] Same as above, but depends on the memory |
| 712 | in the running system. The syntax of range is |
| 713 | start-[end] where start and end are both |
| 714 | a memory unit (amount[KMG]). See also |
Ahmed S. Darwish | 6f21e64 | 2011-02-20 20:08:35 -0800 | [diff] [blame] | 715 | Documentation/kdump/kdump.txt for an example. |
Bernhard Walle | fb39159 | 2007-10-18 23:41:02 -0700 | [diff] [blame] | 716 | |
Yinghai Lu | adbc742 | 2013-04-15 22:23:48 -0700 | [diff] [blame] | 717 | crashkernel=size[KMG],high |
Yinghai Lu | 55a20ee | 2013-04-15 22:23:47 -0700 | [diff] [blame] | 718 | [KNL, x86_64] range could be above 4G. Allow kernel |
| 719 | to allocate physical memory region from top, so could |
| 720 | be above 4G if system have more than 4G ram installed. |
| 721 | Otherwise memory region will be allocated below 4G, if |
| 722 | available. |
| 723 | It will be ignored if crashkernel=X is specified. |
Yinghai Lu | adbc742 | 2013-04-15 22:23:48 -0700 | [diff] [blame] | 724 | crashkernel=size[KMG],low |
| 725 | [KNL, x86_64] range under 4G. When crashkernel=X,high |
| 726 | is passed, kernel could allocate physical memory region |
Yinghai Lu | c729de8 | 2013-04-15 22:23:45 -0700 | [diff] [blame] | 727 | above 4G, that cause second kernel crash on system |
| 728 | that require some amount of low memory, e.g. swiotlb |
| 729 | requires at least 64M+32K low memory. Kernel would |
| 730 | try to allocate 72M below 4G automatically. |
| 731 | This one let user to specify own low range under 4G |
| 732 | for second kernel instead. |
| 733 | 0: to disable low allocation. |
Yinghai Lu | adbc742 | 2013-04-15 22:23:48 -0700 | [diff] [blame] | 734 | It will be ignored when crashkernel=X,high is not used |
Yinghai Lu | 55a20ee | 2013-04-15 22:23:47 -0700 | [diff] [blame] | 735 | or memory reserved is below 4G. |
Yinghai Lu | c729de8 | 2013-04-15 22:23:45 -0700 | [diff] [blame] | 736 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 737 | cs89x0_dma= [HW,NET] |
| 738 | Format: <dma> |
| 739 | |
| 740 | cs89x0_media= [HW,NET] |
| 741 | Format: { rj45 | aui | bnc } |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 742 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 743 | dasd= [HW,NET] |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 744 | See header of drivers/s390/block/dasd_devmap.c. |
| 745 | |
| 746 | db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port |
| 747 | (one device per port) |
| 748 | Format: <port#>,<type> |
| 749 | See also Documentation/input/joystick-parport.txt |
| 750 | |
Thomas Renninger | a648ec0 | 2010-08-06 16:11:02 +0200 | [diff] [blame] | 751 | ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot |
| 752 | time. See Documentation/dynamic-debug-howto.txt for |
Jim Cromie | 29e36c9 | 2012-04-27 14:30:41 -0600 | [diff] [blame] | 753 | details. Deprecated, see dyndbg. |
Thomas Renninger | a648ec0 | 2010-08-06 16:11:02 +0200 | [diff] [blame] | 754 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 755 | debug [KNL] Enable kernel debugging (events log level). |
| 756 | |
Ingo Molnar | cae2ed9 | 2006-07-03 00:24:48 -0700 | [diff] [blame] | 757 | debug_locks_verbose= |
| 758 | [KNL] verbose self-tests |
| 759 | Format=<0|1> |
| 760 | Print debugging info while doing the locking API |
| 761 | self-tests. |
| 762 | We default to 0 (no extra messages), setting it to |
| 763 | 1 will print _a lot_ more information - normally |
| 764 | only useful to kernel developers. |
| 765 | |
Thomas Gleixner | 3ac7fe5 | 2008-04-30 00:55:01 -0700 | [diff] [blame] | 766 | debug_objects [KNL] Enable object debugging |
| 767 | |
Kyle McMartin | 3e8ebb5 | 2009-03-01 20:41:41 -0500 | [diff] [blame] | 768 | no_debug_objects |
| 769 | [KNL] Disable object debugging |
| 770 | |
Stanislaw Gruszka | c0a32fc5 | 2012-01-10 15:07:28 -0800 | [diff] [blame] | 771 | debug_guardpage_minorder= |
| 772 | [KNL] When CONFIG_DEBUG_PAGEALLOC is set, this |
| 773 | parameter allows control of the order of pages that will |
| 774 | be intentionally kept free (and hence protected) by the |
| 775 | buddy allocator. Bigger value increase the probability |
| 776 | of catching random memory corruption, but reduce the |
| 777 | amount of memory for normal system use. The maximum |
| 778 | possible value is MAX_ORDER/2. Setting this parameter |
| 779 | to 1 or 2 should be enough to identify most random |
| 780 | memory corruption problems caused by bugs in kernel or |
| 781 | driver code when a CPU writes to (or reads from) a |
| 782 | random memory location. Note that there exists a class |
| 783 | of memory corruptions problems caused by buggy H/W or |
| 784 | F/W or by drivers badly programing DMA (basically when |
| 785 | memory is written at bus level and the CPU MMU is |
| 786 | bypassed) which are not detectable by |
| 787 | CONFIG_DEBUG_PAGEALLOC, hence this option will not help |
| 788 | tracking down these problems. |
| 789 | |
Thomas Gleixner | d3af01f | 2008-07-15 15:04:56 +0200 | [diff] [blame] | 790 | debugpat [X86] Enable PAT debugging |
| 791 | |
Robert P. J. Day | 2d27a96 | 2008-02-03 15:18:45 +0200 | [diff] [blame] | 792 | decnet.addr= [HW,NET] |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 793 | Format: <area>[,<node>] |
| 794 | See also Documentation/networking/decnet.txt. |
| 795 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 796 | default_hugepagesz= |
| 797 | [same as hugepagesz=] The size of the default |
| 798 | HugeTLB page size. This is the size represented by |
| 799 | the legacy /proc/ hugepages APIs, used for SHM, and |
| 800 | default size when mounting hugetlbfs filesystems. |
| 801 | Defaults to the default architecture's huge page size |
| 802 | if not specified. |
Antonino A. Daplas | 55ff978 | 2007-05-08 00:38:53 -0700 | [diff] [blame] | 803 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 804 | dhash_entries= [KNL] |
| 805 | Set number of hash buckets for dentry cache. |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 806 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 807 | digi= [HW,SERIAL] |
| 808 | IO parameters + enable/disable command. |
| 809 | |
| 810 | digiepca= [HW,SERIAL] |
| 811 | See drivers/char/README.epca and |
Randy Dunlap | 31c00fc | 2008-11-13 21:33:24 +0000 | [diff] [blame] | 812 | Documentation/serial/digiepca.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 813 | |
Brian Haley | b0f83b2 | 2010-02-04 13:36:50 -0800 | [diff] [blame] | 814 | disable= [IPV6] |
| 815 | See Documentation/networking/ipv6.txt. |
| 816 | |
HATAYAMA Daisuke | 151e0c7 | 2014-01-15 15:44:58 +0900 | [diff] [blame] | 817 | disable_cpu_apicid= [X86,APIC,SMP] |
| 818 | Format: <int> |
| 819 | The number of initial APIC ID for the |
| 820 | corresponding CPU to be disabled at boot, |
| 821 | mostly used for the kdump 2nd kernel to |
| 822 | disable BSP to wake up multiple CPUs without |
| 823 | causing system reset or hang due to sending |
| 824 | INIT from AP to BSP. |
| 825 | |
Nishanth Aravamudan | 4e8b0cf | 2011-02-10 09:10:47 +0000 | [diff] [blame] | 826 | disable_ddw [PPC/PSERIES] |
| 827 | Disable Dynamic DMA Window support. Use this if |
| 828 | to workaround buggy firmware. |
| 829 | |
Brian Haley | b0f83b2 | 2010-02-04 13:36:50 -0800 | [diff] [blame] | 830 | disable_ipv6= [IPV6] |
| 831 | See Documentation/networking/ipv6.txt. |
| 832 | |
Yinghai Lu | 95ffa24 | 2008-04-29 03:52:33 -0700 | [diff] [blame] | 833 | disable_mtrr_cleanup [X86] |
Yinghai Lu | 95ffa24 | 2008-04-29 03:52:33 -0700 | [diff] [blame] | 834 | The kernel tries to adjust MTRR layout from continuous |
| 835 | to discrete, to make X server driver able to add WB |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 836 | entry later. This parameter disables that. |
Yinghai Lu | 95ffa24 | 2008-04-29 03:52:33 -0700 | [diff] [blame] | 837 | |
Yinghai Lu | 093af8d | 2008-01-30 13:33:32 +0100 | [diff] [blame] | 838 | disable_mtrr_trim [X86, Intel and AMD only] |
Jesse Barnes | 99fc8d4 | 2008-01-30 13:33:18 +0100 | [diff] [blame] | 839 | By default the kernel will trim any uncacheable |
| 840 | memory out of your available memory pool based on |
| 841 | MTRR settings. This parameter disables that behavior, |
| 842 | possibly causing your machine to run very slowly. |
| 843 | |
Jaswinder Singh Rajput | 6cececf | 2009-04-14 14:03:43 +0530 | [diff] [blame] | 844 | disable_timer_pin_1 [X86] |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 845 | Disable PIN 1 of APIC timer |
| 846 | Can be useful to work around chipset bugs. |
| 847 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 848 | dma_debug=off If the kernel is compiled with DMA_API_DEBUG support, |
| 849 | this option disables the debugging code at boot. |
| 850 | |
| 851 | dma_debug_entries=<number> |
| 852 | This option allows to tune the number of preallocated |
| 853 | entries for DMA-API debugging code. One entry is |
| 854 | required per DMA-API allocation. Use this if the |
| 855 | DMA-API debugging code disables itself because the |
| 856 | architectural default is too low. |
| 857 | |
Joerg Roedel | 1745de5 | 2009-05-22 21:49:51 +0200 | [diff] [blame] | 858 | dma_debug_driver=<driver_name> |
| 859 | With this option the DMA-API debugging driver |
| 860 | filter feature can be enabled at boot time. Just |
| 861 | pass the driver to filter for as the parameter. |
| 862 | The filter can be disabled or changed to another |
| 863 | driver later using sysfs. |
| 864 | |
Carsten Emde | da0df92 | 2012-03-18 22:37:33 +0100 | [diff] [blame] | 865 | drm_kms_helper.edid_firmware=[<connector>:]<file> |
| 866 | Broken monitors, graphic adapters and KVMs may |
| 867 | send no or incorrect EDID data sets. This parameter |
| 868 | allows to specify an EDID data set in the |
| 869 | /lib/firmware directory that is used instead. |
| 870 | Generic built-in EDID data sets are used, if one of |
| 871 | edid/1024x768.bin, edid/1280x1024.bin, |
| 872 | edid/1680x1050.bin, or edid/1920x1080.bin is given |
| 873 | and no file with the same name exists. Details and |
| 874 | instructions how to build your own EDID data are |
| 875 | available in Documentation/EDID/HOWTO.txt. An EDID |
| 876 | data set will only be used for a particular connector, |
| 877 | if its name and a colon are prepended to the EDID |
| 878 | name. |
| 879 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 880 | dscc4.setup= [NET] |
| 881 | |
Jim Cromie | 29e36c9 | 2012-04-27 14:30:41 -0600 | [diff] [blame] | 882 | dyndbg[="val"] [KNL,DYNAMIC_DEBUG] |
| 883 | module.dyndbg[="val"] |
| 884 | Enable debug messages at boot time. See |
| 885 | Documentation/dynamic-debug-howto.txt for details. |
| 886 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 887 | earlycon= [KNL] Output early console device and options. |
| 888 | uart[8250],io,<addr>[,options] |
| 889 | uart[8250],mmio,<addr>[,options] |
Samium Gromoff | 1917ac7 | 2010-07-20 15:26:51 -0700 | [diff] [blame] | 890 | uart[8250],mmio32,<addr>[,options] |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 891 | Start an early, polled-mode console on the 8250/16550 |
| 892 | UART at the specified I/O port or MMIO address. |
Randy Dunlap | 1629024 | 2011-08-13 12:34:52 -0700 | [diff] [blame] | 893 | MMIO inter-register address stride is either 8-bit |
| 894 | (mmio) or 32-bit (mmio32). |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 895 | The options are the same as for ttyS, above. |
| 896 | |
Dave Hansen | 147ea09 | 2013-04-10 14:03:38 -0700 | [diff] [blame] | 897 | earlyprintk= [X86,SH,BLACKFIN,ARM] |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 898 | earlyprintk=vga |
Matt Fleming | 72548e8 | 2013-10-04 09:36:56 +0100 | [diff] [blame] | 899 | earlyprintk=efi |
Konrad Rzeszutek Wilk | 2482a92 | 2013-02-25 15:54:08 -0500 | [diff] [blame] | 900 | earlyprintk=xen |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 901 | earlyprintk=serial[,ttySn[,baudrate]] |
Dave Hansen | 147ea09 | 2013-04-10 14:03:38 -0700 | [diff] [blame] | 902 | earlyprintk=serial[,0x...[,baudrate]] |
Jason Wessel | ea3acb1 | 2009-09-24 09:08:30 -0500 | [diff] [blame] | 903 | earlyprintk=ttySn[,baudrate] |
Jason Wessel | 9780bc4 | 2009-08-20 15:39:57 -0500 | [diff] [blame] | 904 | earlyprintk=dbgp[debugController#] |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 905 | |
Dave Hansen | 147ea09 | 2013-04-10 14:03:38 -0700 | [diff] [blame] | 906 | earlyprintk is useful when the kernel crashes before |
| 907 | the normal console is initialized. It is not enabled by |
| 908 | default because it has some cosmetic problems. |
| 909 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 910 | Append ",keep" to not disable it when the real console |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 911 | takes over. |
| 912 | |
Matt Fleming | 72548e8 | 2013-10-04 09:36:56 +0100 | [diff] [blame] | 913 | Only one of vga, efi, serial, or usb debug port can |
| 914 | be used at a time. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 915 | |
Dave Hansen | 147ea09 | 2013-04-10 14:03:38 -0700 | [diff] [blame] | 916 | Currently only ttyS0 and ttyS1 may be specified by |
| 917 | name. Other I/O ports may be explicitly specified |
| 918 | on some architectures (x86 and arm at least) by |
| 919 | replacing ttySn with an I/O port address, like this: |
| 920 | earlyprintk=serial,0x1008,115200 |
| 921 | You can find the port for a given device in |
| 922 | /proc/tty/driver/serial: |
| 923 | 2: uart:ST16650V2 port:00001008 irq:18 ... |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 924 | |
| 925 | Interaction with the standard serial driver is not |
| 926 | very good. |
| 927 | |
Matt Fleming | 72548e8 | 2013-10-04 09:36:56 +0100 | [diff] [blame] | 928 | The VGA and EFI output is eventually overwritten by |
| 929 | the real console. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 930 | |
Konrad Rzeszutek Wilk | 2482a92 | 2013-02-25 15:54:08 -0500 | [diff] [blame] | 931 | The xen output can only be used by Xen PV guests. |
| 932 | |
Chen, Gong | c700f01 | 2013-12-06 01:17:08 -0500 | [diff] [blame] | 933 | edac_report= [HW,EDAC] Control how to report EDAC event |
| 934 | Format: {"on" | "off" | "force"} |
| 935 | on: enable EDAC to report H/W event. May be overridden |
| 936 | by other higher priority error reporting module. |
| 937 | off: disable H/W event reporting through EDAC. |
| 938 | force: enforce the use of EDAC to report H/W event. |
| 939 | default: on. |
| 940 | |
Jason Wessel | 9731191 | 2010-05-20 21:04:30 -0500 | [diff] [blame] | 941 | ekgdboc= [X86,KGDB] Allow early kernel console debugging |
| 942 | ekgdboc=kbd |
| 943 | |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 944 | This is designed to be used in conjunction with |
Jason Wessel | 9731191 | 2010-05-20 21:04:30 -0500 | [diff] [blame] | 945 | the boot argument: earlyprintk=vga |
| 946 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 947 | edd= [EDD] |
Tim Gardner | 8c4dd60 | 2008-04-29 01:02:45 -0700 | [diff] [blame] | 948 | Format: {"off" | "on" | "skip[mbr]"} |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 949 | |
Borislav Petkov | d2f7cbe | 2013-10-31 17:25:08 +0100 | [diff] [blame] | 950 | efi= [EFI] |
| 951 | Format: { "old_map" } |
| 952 | old_map [X86-64]: switch to the old ioremap-based EFI |
| 953 | runtime services mapping. 32-bit still uses this one by |
| 954 | default. |
| 955 | |
Richard Weinberger | 8c58bf3 | 2013-04-17 01:00:53 +0200 | [diff] [blame] | 956 | efi_no_storage_paranoia [EFI; X86] |
| 957 | Using this parameter you can use more than 50% of |
| 958 | your efi variable storage. Use this parameter only if |
| 959 | you are really sure that your UEFI does sane gc and |
| 960 | fulfills the spec otherwise your board may brick. |
| 961 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 962 | eisa_irq_edge= [PARISC,HW] |
| 963 | See header of drivers/parisc/eisa.c. |
| 964 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 965 | elanfreq= [X86-32] |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 966 | See comment before function elanfreq_setup() in |
Pavel Machek | 71f7705 | 2008-07-04 09:59:43 -0700 | [diff] [blame] | 967 | arch/x86/kernel/cpu/cpufreq/elanfreq.c. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 968 | |
| 969 | elevator= [IOSCHED] |
Randy Dunlap | 17a9e7b | 2010-11-11 12:09:59 +0100 | [diff] [blame] | 970 | Format: {"cfq" | "deadline" | "noop"} |
Paul Bolle | 395cf96 | 2011-08-15 02:02:26 +0200 | [diff] [blame] | 971 | See Documentation/block/cfq-iosched.txt and |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 972 | Documentation/block/deadline-iosched.txt for details. |
| 973 | |
Michael Holzheu | d3bf3795 | 2011-10-30 15:16:37 +0100 | [diff] [blame] | 974 | elfcorehdr=[size[KMG]@]offset[KMG] [IA64,PPC,SH,X86,S390] |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 975 | Specifies physical address of start of kernel core |
Michael Holzheu | d3bf3795 | 2011-10-30 15:16:37 +0100 | [diff] [blame] | 976 | image elf header and optionally the size. Generally |
| 977 | kexec loader will pass this option to capture kernel. |
Vivek Goyal | aac04b3 | 2006-01-09 20:51:47 -0800 | [diff] [blame] | 978 | See Documentation/kdump/kdump.txt for details. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 979 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 980 | enable_mtrr_cleanup [X86] |
| 981 | The kernel tries to adjust MTRR layout from continuous |
| 982 | to discrete, to make X server driver able to add WB |
| 983 | entry later. This parameter enables that. |
| 984 | |
Randy Dunlap | ca1eda2 | 2009-05-06 16:02:58 -0700 | [diff] [blame] | 985 | enable_timer_pin_1 [X86] |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 986 | Enable PIN 1 of APIC timer |
| 987 | Can be useful to work around chipset bugs |
| 988 | (in particular on some ATI chipsets). |
| 989 | The kernel tries to set a reasonable default. |
| 990 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 991 | enforcing [SELINUX] Set initial enforcing status. |
| 992 | Format: {"0" | "1"} |
| 993 | See security/selinux/Kconfig help text. |
| 994 | 0 -- permissive (log only, no denials). |
| 995 | 1 -- enforcing (deny and log). |
| 996 | Default value is 0. |
| 997 | Value can be changed at runtime via /selinux/enforce. |
| 998 | |
Huang Ying | a08f82d | 2010-05-18 14:35:21 +0800 | [diff] [blame] | 999 | erst_disable [ACPI] |
| 1000 | Disable Error Record Serialization Table (ERST) |
| 1001 | support. |
| 1002 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1003 | ether= [HW,NET] Ethernet cards parameters |
| 1004 | This option is obsoleted by the "netdev=" option, which |
| 1005 | has equivalent usage. See its documentation for details. |
| 1006 | |
Mimi Zohar | 7102ebc | 2011-05-12 18:33:20 -0400 | [diff] [blame] | 1007 | evm= [EVM] |
| 1008 | Format: { "fix" } |
| 1009 | Permit 'security.evm' to be updated regardless of |
| 1010 | current integrity status. |
| 1011 | |
Akinobu Mita | de1ba09 | 2006-12-08 02:39:42 -0800 | [diff] [blame] | 1012 | failslab= |
| 1013 | fail_page_alloc= |
| 1014 | fail_make_request=[KNL] |
| 1015 | General fault injection mechanism. |
| 1016 | Format: <interval>,<probability>,<space>,<times> |
Paul Bolle | 395cf96 | 2011-08-15 02:02:26 +0200 | [diff] [blame] | 1017 | See also Documentation/fault-injection/. |
Akinobu Mita | de1ba09 | 2006-12-08 02:39:42 -0800 | [diff] [blame] | 1018 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1019 | floppy= [HW] |
Randy Dunlap | 31c00fc | 2008-11-13 21:33:24 +0000 | [diff] [blame] | 1020 | See Documentation/blockdev/floppy.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1021 | |
Alex Chiang | f13ae30 | 2008-05-08 14:03:23 -0600 | [diff] [blame] | 1022 | force_pal_cache_flush |
| 1023 | [IA-64] Avoid check_sal_cache_flush which may hang on |
| 1024 | buggy SAL_CACHE_FLUSH implementations. Using this |
| 1025 | parameter will force ia64_sal_cache_flush to call |
| 1026 | ia64_pal_cache_flush instead of SAL_CACHE_FLUSH. |
| 1027 | |
Chris Bainbridge | 69f2366 | 2014-03-07 18:40:42 +0700 | [diff] [blame] | 1028 | forcepae [X86-32] |
| 1029 | Forcefully enable Physical Address Extension (PAE). |
| 1030 | Many Pentium M systems disable PAE but may have a |
| 1031 | functionally usable PAE implementation. |
| 1032 | Warning: use of this parameter will taint the kernel |
| 1033 | and may cause unknown problems. |
| 1034 | |
Peter Zijlstra | d9e5407 | 2008-11-01 19:57:37 +0100 | [diff] [blame] | 1035 | ftrace=[tracer] |
Steven Rostedt | 2af15d6 | 2009-05-28 13:37:24 -0400 | [diff] [blame] | 1036 | [FTRACE] will set and start the specified tracer |
Peter Zijlstra | d9e5407 | 2008-11-01 19:57:37 +0100 | [diff] [blame] | 1037 | as early as possible in order to facilitate early |
| 1038 | boot debugging. |
| 1039 | |
Frederic Weisbecker | cecbca9 | 2010-04-18 19:08:41 +0200 | [diff] [blame] | 1040 | ftrace_dump_on_oops[=orig_cpu] |
Steven Rostedt | 2af15d6 | 2009-05-28 13:37:24 -0400 | [diff] [blame] | 1041 | [FTRACE] will dump the trace buffers on oops. |
Frederic Weisbecker | cecbca9 | 2010-04-18 19:08:41 +0200 | [diff] [blame] | 1042 | If no parameter is passed, ftrace will dump |
| 1043 | buffers of all CPUs, but if you pass orig_cpu, it will |
| 1044 | dump only the buffer of the CPU that triggered the |
| 1045 | oops. |
Steven Rostedt | 2af15d6 | 2009-05-28 13:37:24 -0400 | [diff] [blame] | 1046 | |
| 1047 | ftrace_filter=[function-list] |
| 1048 | [FTRACE] Limit the functions traced by the function |
| 1049 | tracer at boot up. function-list is a comma separated |
| 1050 | list of functions. This list can be changed at run |
| 1051 | time by the set_ftrace_filter file in the debugfs |
Randy Dunlap | 1629024 | 2011-08-13 12:34:52 -0700 | [diff] [blame] | 1052 | tracing directory. |
Steven Rostedt | 2af15d6 | 2009-05-28 13:37:24 -0400 | [diff] [blame] | 1053 | |
| 1054 | ftrace_notrace=[function-list] |
| 1055 | [FTRACE] Do not trace the functions specified in |
| 1056 | function-list. This list can be changed at run time |
| 1057 | by the set_ftrace_notrace file in the debugfs |
| 1058 | tracing directory. |
Peter Zijlstra | d9e5407 | 2008-11-01 19:57:37 +0100 | [diff] [blame] | 1059 | |
Stefan Assmann | 369bc18 | 2009-10-12 22:17:21 +0200 | [diff] [blame] | 1060 | ftrace_graph_filter=[function-list] |
| 1061 | [FTRACE] Limit the top level callers functions traced |
| 1062 | by the function graph tracer at boot up. |
| 1063 | function-list is a comma separated list of functions |
| 1064 | that can be changed at run time by the |
| 1065 | set_graph_function file in the debugfs tracing directory. |
| 1066 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1067 | gamecon.map[2|3]= |
| 1068 | [HW,JOY] Multisystem joystick and NES/SNES/PSX pad |
| 1069 | support via parallel port (up to 5 devices per port) |
| 1070 | Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5> |
| 1071 | See also Documentation/input/joystick-parport.txt |
| 1072 | |
| 1073 | gamma= [HW,DRM] |
| 1074 | |
Yinghai Lu | aaf2304 | 2008-01-30 13:33:09 +0100 | [diff] [blame] | 1075 | gart_fix_e820= [X86_64] disable the fix e820 for K8 GART |
| 1076 | Format: off | on |
| 1077 | default: on |
| 1078 | |
Peter Oberparleiter | 2521f2c | 2009-06-17 16:28:08 -0700 | [diff] [blame] | 1079 | gcov_persist= [GCOV] When non-zero (default), profiling data for |
| 1080 | kernel modules is saved and remains accessible via |
| 1081 | debugfs, even when the module is unloaded/reloaded. |
| 1082 | When zero, profiling data is discarded and associated |
| 1083 | debugfs files are removed at module unload time. |
| 1084 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1085 | gpt [EFI] Forces disk with valid GPT signature but |
Davidlohr Bueso | 6c5de79 | 2014-01-23 15:56:03 -0800 | [diff] [blame] | 1086 | invalid Protective MBR to be treated as GPT. If the |
| 1087 | primary GPT is corrupted, it enables the backup/alternate |
| 1088 | GPT to be used instead. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1089 | |
Andreas Larsson | 6cec9b0 | 2012-11-15 08:47:14 +0100 | [diff] [blame] | 1090 | grcan.enable0= [HW] Configuration of physical interface 0. Determines |
| 1091 | the "Enable 0" bit of the configuration register. |
| 1092 | Format: 0 | 1 |
| 1093 | Default: 0 |
| 1094 | grcan.enable1= [HW] Configuration of physical interface 1. Determines |
| 1095 | the "Enable 0" bit of the configuration register. |
| 1096 | Format: 0 | 1 |
| 1097 | Default: 0 |
| 1098 | grcan.select= [HW] Select which physical interface to use. |
| 1099 | Format: 0 | 1 |
| 1100 | Default: 0 |
| 1101 | grcan.txsize= [HW] Sets the size of the tx buffer. |
| 1102 | Format: <unsigned int> such that (txsize & ~0x1fffc0) == 0. |
| 1103 | Default: 1024 |
| 1104 | grcan.rxsize= [HW] Sets the size of the rx buffer. |
| 1105 | Format: <unsigned int> such that (rxsize & ~0x1fffc0) == 0. |
| 1106 | Default: 1024 |
| 1107 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1108 | hashdist= [KNL,NUMA] Large hashes allocated during boot |
| 1109 | are distributed across NUMA nodes. Defaults on |
Randy Dunlap | 1629024 | 2011-08-13 12:34:52 -0700 | [diff] [blame] | 1110 | for 64-bit NUMA, off otherwise. |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 1111 | Format: 0 | 1 (for off | on) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1112 | |
| 1113 | hcl= [IA-64] SGI's Hardware Graph compatibility layer |
| 1114 | |
| 1115 | hd= [EIDE] (E)IDE hard drive subsystem geometry |
| 1116 | Format: <cyl>,<head>,<sect> |
| 1117 | |
Huang Ying | ea8c071 | 2010-05-18 14:35:15 +0800 | [diff] [blame] | 1118 | hest_disable [ACPI] |
| 1119 | Disable Hardware Error Source Table (HEST) support; |
| 1120 | corresponding firmware-first mode error processing |
| 1121 | logic will be disabled. |
| 1122 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1123 | highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact |
| 1124 | size of <nn>. This works even on boxes that have no |
| 1125 | highmem otherwise. This also works to reduce highmem |
| 1126 | size on bigger boxes. |
| 1127 | |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 1128 | highres= [KNL] Enable/disable high resolution timer mode. |
| 1129 | Valid parameters: "on", "off" |
| 1130 | Default: "on" |
| 1131 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1132 | hisax= [HW,ISDN] |
| 1133 | See Documentation/isdn/README.HiSax. |
| 1134 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 1135 | hlt [BUGS=ARM,SH] |
| 1136 | |
| 1137 | hpet= [X86-32,HPET] option to control HPET usage |
| 1138 | Format: { enable (default) | disable | force | |
| 1139 | verbose } |
| 1140 | disable: disable HPET and use PIT instead |
| 1141 | force: allow force enabled of undocumented chips (ICH4, |
| 1142 | VIA, nVidia) |
| 1143 | verbose: show contents of HPET registers during setup |
| 1144 | |
Prarit Bhargava | 3d035f5 | 2013-11-12 15:08:33 -0800 | [diff] [blame] | 1145 | hpet_mmap= [X86, HPET_MMAP] Allow userspace to mmap HPET |
| 1146 | registers. Default set by CONFIG_HPET_MMAP_DEFAULT. |
| 1147 | |
Andi Kleen | b4718e6 | 2008-07-23 21:27:51 -0700 | [diff] [blame] | 1148 | hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot. |
| 1149 | hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages. |
Jon Tollefson | 0d9ea75 | 2008-07-23 21:27:56 -0700 | [diff] [blame] | 1150 | On x86-64 and powerpc, this option can be specified |
| 1151 | multiple times interleaved with hugepages= to reserve |
| 1152 | huge pages of different sizes. Valid pages sizes on |
| 1153 | x86-64 are 2M (when the CPU supports "pse") and 1G |
| 1154 | (when the CPU supports the "pdpe1gb" cpuinfo flag) |
Andi Kleen | b4718e6 | 2008-07-23 21:27:51 -0700 | [diff] [blame] | 1155 | Note that 1GB pages can only be allocated at boot time |
| 1156 | using hugepages= and not freed afterwards. |
Paul Mundt | 6902aa8 | 2008-09-21 17:14:42 +0900 | [diff] [blame] | 1157 | |
Hendrik Brueckner | 555d61d | 2009-01-09 12:15:02 +0100 | [diff] [blame] | 1158 | hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC) |
| 1159 | terminal devices. Valid values: 0..8 |
Hendrik Brueckner | 431429f | 2009-03-26 15:23:55 +0100 | [diff] [blame] | 1160 | hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs. |
| 1161 | If specified, z/VM IUCV HVC accepts connections |
| 1162 | from listed z/VM user IDs only. |
Hendrik Brueckner | cef7125 | 2008-12-25 13:39:55 +0100 | [diff] [blame] | 1163 | |
James Hogan | fdabf52 | 2012-10-09 11:00:27 +0100 | [diff] [blame] | 1164 | hwthread_map= [METAG] Comma-separated list of Linux cpu id to |
| 1165 | hardware thread id mappings. |
| 1166 | Format: <cpu>:<hwthread> |
| 1167 | |
Fabio M. Di Nitto | 7bf6939 | 2011-03-22 16:34:20 -0700 | [diff] [blame] | 1168 | keep_bootcon [KNL] |
| 1169 | Do not unregister boot console at start. This is only |
| 1170 | useful for debugging when something happens in the window |
| 1171 | between unregistering the boot console and initializing |
| 1172 | the real console. |
| 1173 | |
Jarkko Nikula | 3a853fb | 2009-03-23 18:07:47 -0700 | [diff] [blame] | 1174 | i2c_bus= [HW] Override the default board specific I2C bus speed |
Jarkko Nikula | 7954763 | 2009-03-23 18:07:48 -0700 | [diff] [blame] | 1175 | or register an additional I2C bus that is not |
| 1176 | registered from board initialization code. |
Jarkko Nikula | 3a853fb | 2009-03-23 18:07:47 -0700 | [diff] [blame] | 1177 | Format: |
| 1178 | <bus_id>,<clkrate> |
| 1179 | |
Jiri Kosina | 36d9573 | 2008-10-06 02:51:09 -0400 | [diff] [blame] | 1180 | i8042.debug [HW] Toggle i8042 debug mode |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1181 | i8042.direct [HW] Put keyboard port into non-translated mode |
Matt LaPlante | 84eb8d0 | 2006-10-03 22:53:09 +0200 | [diff] [blame] | 1182 | i8042.dumbkbd [HW] Pretend that controller can only read data from |
| 1183 | keyboard and cannot control its state |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1184 | (Don't attempt to blink the leds) |
| 1185 | i8042.noaux [HW] Don't check for auxiliary (== mouse) port |
Dmitry Torokhov | 945ef0d | 2005-09-04 01:42:00 -0500 | [diff] [blame] | 1186 | i8042.nokbd [HW] Don't check/create keyboard port |
Jiri Kosina | 75d08c7 | 2008-03-13 16:13:59 -0400 | [diff] [blame] | 1187 | i8042.noloop [HW] Disable the AUX Loopback command while probing |
| 1188 | for the AUX port |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1189 | i8042.nomux [HW] Don't check presence of an active multiplexing |
| 1190 | controller |
| 1191 | i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX |
| 1192 | controllers |
Masanari Iida | 24775d6 | 2012-02-15 00:26:42 +0900 | [diff] [blame] | 1193 | i8042.notimeout [HW] Ignore timeout condition signalled by controller |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1194 | i8042.reset [HW] Reset the controller during init and cleanup |
| 1195 | i8042.unlock [HW] Unlock (ignore) the keylock |
| 1196 | |
| 1197 | i810= [HW,DRM] |
| 1198 | |
Dmitry Torokhov | e70c9d5 | 2005-06-25 14:54:25 -0700 | [diff] [blame] | 1199 | i8k.ignore_dmi [HW] Continue probing hardware even if DMI data |
| 1200 | indicates that the driver is running on unsupported |
| 1201 | hardware. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1202 | i8k.force [HW] Activate i8k driver even if SMM BIOS signature |
| 1203 | does not match list of supported models. |
| 1204 | i8k.power_status |
| 1205 | [HW] Report power status in /proc/i8k |
| 1206 | (disabled by default) |
| 1207 | i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN |
| 1208 | capability is set. |
| 1209 | |
Carsten Emde | 4dca20e | 2012-03-15 15:56:26 +0100 | [diff] [blame] | 1210 | i915.invert_brightness= |
Carsten Emde | 7bd9090 | 2012-03-15 15:56:25 +0100 | [diff] [blame] | 1211 | [DRM] Invert the sense of the variable that is used to |
| 1212 | set the brightness of the panel backlight. Normally a |
Carsten Emde | 4dca20e | 2012-03-15 15:56:26 +0100 | [diff] [blame] | 1213 | brightness value of 0 indicates backlight switched off, |
| 1214 | and the maximum of the brightness value sets the backlight |
| 1215 | to maximum brightness. If this parameter is set to 0 |
| 1216 | (default) and the machine requires it, or this parameter |
| 1217 | is set to 1, a brightness value of 0 sets the backlight |
| 1218 | to maximum brightness, and the maximum of the brightness |
| 1219 | value switches the backlight off. |
| 1220 | -1 -- never invert brightness |
| 1221 | 0 -- machine default |
| 1222 | 1 -- force brightness inversion |
Carsten Emde | 7bd9090 | 2012-03-15 15:56:25 +0100 | [diff] [blame] | 1223 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1224 | icn= [HW,ISDN] |
| 1225 | Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]] |
| 1226 | |
David Fries | 0af80c0 | 2009-02-25 20:28:21 +0100 | [diff] [blame] | 1227 | ide-core.nodma= [HW] (E)IDE subsystem |
| 1228 | Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc |
Bartlomiej Zolnierkiewicz | 075affc | 2009-06-07 13:52:52 +0200 | [diff] [blame] | 1229 | .vlb_clock .pci_clock .noflush .nohpa .noprobe .nowerr |
| 1230 | .cdrom .chs .ignore_cable are additional options |
Randy Dunlap | 1c10e93 | 2008-03-07 21:53:50 +0100 | [diff] [blame] | 1231 | See Documentation/ide/ide.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1232 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 1233 | ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem |
| 1234 | Claim all unknown PCI IDE storage controllers. |
| 1235 | |
Andi Kleen | f039b75 | 2007-05-02 19:27:12 +0200 | [diff] [blame] | 1236 | idle= [X86] |
Len Brown | 69fb367 | 2013-02-10 01:38:39 -0500 | [diff] [blame] | 1237 | Format: idle=poll, idle=halt, idle=nomwait |
Randy Dunlap | ada9cfd | 2008-12-19 10:57:32 -0800 | [diff] [blame] | 1238 | Poll forces a polling idle loop that can slightly |
| 1239 | improve the performance of waking up a idle CPU, but |
| 1240 | will use a lot of power and make the system run hot. |
| 1241 | Not recommended. |
Randy Dunlap | ada9cfd | 2008-12-19 10:57:32 -0800 | [diff] [blame] | 1242 | idle=halt: Halt is forced to be used for CPU idle. |
Zhao Yakui | c1e3b37 | 2008-06-24 17:58:53 +0800 | [diff] [blame] | 1243 | In such case C2/C3 won't be used again. |
Randy Dunlap | ada9cfd | 2008-12-19 10:57:32 -0800 | [diff] [blame] | 1244 | idle=nomwait: Disable mwait for CPU C-states |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 1245 | |
Ingo Molnar | 79290822 | 2006-12-06 20:40:51 -0800 | [diff] [blame] | 1246 | ignore_loglevel [KNL] |
| 1247 | Ignore loglevel setting - this will print /all/ |
| 1248 | kernel messages to the console. Useful for debugging. |
Yanmin Zhang | 0eca6b7 | 2011-10-31 17:11:25 -0700 | [diff] [blame] | 1249 | We also add it as printk module parameter, so users |
| 1250 | could change it dynamically, usually by |
| 1251 | /sys/module/printk/parameters/ignore_loglevel. |
Ingo Molnar | 79290822 | 2006-12-06 20:40:51 -0800 | [diff] [blame] | 1252 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1253 | ihash_entries= [KNL] |
| 1254 | Set number of hash buckets for inode cache. |
| 1255 | |
Mimi Zohar | 2fe5d6d | 2012-02-13 10:15:05 -0500 | [diff] [blame] | 1256 | ima_appraise= [IMA] appraise integrity measurements |
| 1257 | Format: { "off" | "enforce" | "fix" } |
| 1258 | default: "enforce" |
| 1259 | |
Mimi Zohar | 07f6a79 | 2011-03-09 22:25:48 -0500 | [diff] [blame] | 1260 | ima_appraise_tcb [IMA] |
| 1261 | The builtin appraise policy appraises all files |
| 1262 | owned by uid=0. |
| 1263 | |
Mimi Zohar | 3323eec9 | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 1264 | ima_hash= [IMA] |
Mimi Zohar | e7a2ad7 | 2013-06-07 12:16:37 +0200 | [diff] [blame] | 1265 | Format: { md5 | sha1 | rmd160 | sha256 | sha384 |
| 1266 | | sha512 | ... } |
Mimi Zohar | 3323eec9 | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 1267 | default: "sha1" |
| 1268 | |
Mimi Zohar | e7a2ad7 | 2013-06-07 12:16:37 +0200 | [diff] [blame] | 1269 | The list of supported hash algorithms is defined |
| 1270 | in crypto/hash_info.h. |
| 1271 | |
Eric Paris | 5789ba3 | 2009-05-21 15:47:06 -0400 | [diff] [blame] | 1272 | ima_tcb [IMA] |
| 1273 | Load a policy which meets the needs of the Trusted |
| 1274 | Computing Base. This means IMA will measure all |
| 1275 | programs exec'd, files mmap'd for exec, and all files |
| 1276 | opened for read by uid=0. |
| 1277 | |
Roberto Sassu | 9b9d4ce | 2013-06-07 12:16:35 +0200 | [diff] [blame] | 1278 | ima_template= [IMA] |
| 1279 | Select one of defined IMA measurements template formats. |
| 1280 | Formats: { "ima" | "ima-ng" } |
| 1281 | Default: "ima-ng" |
| 1282 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1283 | init= [KNL] |
| 1284 | Format: <full_path> |
| 1285 | Run specified binary instead of /sbin/init as init |
| 1286 | process. |
| 1287 | |
| 1288 | initcall_debug [KNL] Trace initcalls as they are executed. Useful |
| 1289 | for working out where the kernel is dying during |
| 1290 | startup. |
| 1291 | |
| 1292 | initrd= [BOOT] Specify the location of the initial ramdisk |
| 1293 | |
| 1294 | inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver |
| 1295 | Format: <irq> |
| 1296 | |
Fenghua Yu | 6bb2ff8 | 2013-05-21 15:35:17 -0400 | [diff] [blame] | 1297 | int_pln_enable [x86] Enable power limit notification interrupt |
| 1298 | |
Mimi Zohar | d726d8d | 2013-03-18 14:48:02 -0400 | [diff] [blame] | 1299 | integrity_audit=[IMA] |
| 1300 | Format: { "0" | "1" } |
| 1301 | 0 -- basic integrity auditing messages. (Default) |
| 1302 | 1 -- additional integrity auditing messages. |
| 1303 | |
Keshavamurthy, Anil S | ba39592 | 2007-10-21 16:41:49 -0700 | [diff] [blame] | 1304 | intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option |
Kyle McMartin | 0cd5c3c | 2009-02-04 14:29:19 -0800 | [diff] [blame] | 1305 | on |
| 1306 | Enable intel iommu driver. |
Keshavamurthy, Anil S | ba39592 | 2007-10-21 16:41:49 -0700 | [diff] [blame] | 1307 | off |
| 1308 | Disable intel iommu driver. |
| 1309 | igfx_off [Default Off] |
| 1310 | By default, gfx is mapped as normal device. If a gfx |
| 1311 | device has a dedicated DMAR unit, the DMAR unit is |
| 1312 | bypassed by not enabling DMAR with this option. In |
| 1313 | this case, gfx device will use physical address for |
| 1314 | DMA. |
Keshavamurthy, Anil S | 7d3b03c | 2007-10-21 16:41:53 -0700 | [diff] [blame] | 1315 | forcedac [x86_64] |
| 1316 | With this option iommu will not optimize to look |
Randy Dunlap | 1629024 | 2011-08-13 12:34:52 -0700 | [diff] [blame] | 1317 | for io virtual address below 32-bit forcing dual |
Keshavamurthy, Anil S | 7d3b03c | 2007-10-21 16:41:53 -0700 | [diff] [blame] | 1318 | address cycle on pci bus for cards supporting greater |
Randy Dunlap | 1629024 | 2011-08-13 12:34:52 -0700 | [diff] [blame] | 1319 | than 32-bit addressing. The default is to look |
| 1320 | for translation below 32-bit and if not available |
Keshavamurthy, Anil S | 7d3b03c | 2007-10-21 16:41:53 -0700 | [diff] [blame] | 1321 | then look in the higher range. |
mark gross | 5e0d2a6 | 2008-03-04 15:22:08 -0800 | [diff] [blame] | 1322 | strict [Default Off] |
| 1323 | With this option on every unmap_single operation will |
| 1324 | result in a hardware IOTLB flush operation as opposed |
| 1325 | to batching them for performance. |
Youquan Song | 6dd9a7c | 2011-05-25 19:13:49 +0100 | [diff] [blame] | 1326 | sp_off [Default Off] |
| 1327 | By default, super page will be supported if Intel IOMMU |
| 1328 | has the capability. With this option, super page will |
| 1329 | not be supported. |
Masanari Iida | 2e92c7a | 2011-12-15 01:18:52 +0900 | [diff] [blame] | 1330 | |
| 1331 | intel_idle.max_cstate= [KNL,HW,ACPI,X86] |
| 1332 | 0 disables intel_idle and fall back on acpi_idle. |
| 1333 | 1 to 6 specify maximum depth of C-state. |
| 1334 | |
Dirk Brandewie | 6be2649 | 2013-02-15 22:55:10 +0100 | [diff] [blame] | 1335 | intel_pstate= [X86] |
| 1336 | disable |
| 1337 | Do not enable intel_pstate as the default |
| 1338 | scaling driver for the supported processors |
| 1339 | |
Chris Wright | d1423d5 | 2010-07-20 11:06:49 -0700 | [diff] [blame] | 1340 | intremap= [X86-64, Intel-IOMMU] |
Chris Wright | d1423d5 | 2010-07-20 11:06:49 -0700 | [diff] [blame] | 1341 | on enable Interrupt Remapping (default) |
| 1342 | off disable Interrupt Remapping |
| 1343 | nosid disable Source ID checking |
Suresh Siddha | 41750d3 | 2011-08-23 17:05:18 -0700 | [diff] [blame] | 1344 | no_x2apic_optout |
| 1345 | BIOS x2APIC opt-out request will be ignored |
Chris Wright | d1423d5 | 2010-07-20 11:06:49 -0700 | [diff] [blame] | 1346 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 1347 | iomem= Disable strict checking of access to MMIO memory |
| 1348 | strict regions from userspace. |
| 1349 | relaxed |
| 1350 | |
| 1351 | iommu= [x86] |
| 1352 | off |
| 1353 | force |
| 1354 | noforce |
| 1355 | biomerge |
| 1356 | panic |
| 1357 | nopanic |
| 1358 | merge |
| 1359 | nomerge |
| 1360 | forcesac |
| 1361 | soft |
Alex Williamson | bcb71ab | 2011-10-21 15:56:24 -0400 | [diff] [blame] | 1362 | pt [x86, IA-64] |
Alex Williamson | bcb71ab | 2011-10-21 15:56:24 -0400 | [diff] [blame] | 1363 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 1364 | |
| 1365 | io7= [HW] IO7 for Marvel based alpha systems |
| 1366 | See comment before marvel_specify_io7 in |
| 1367 | arch/alpha/kernel/core_marvel.c. |
| 1368 | |
Jaswinder Singh Rajput | 6cececf | 2009-04-14 14:03:43 +0530 | [diff] [blame] | 1369 | io_delay= [X86] I/O delay method |
Ingo Molnar | 6e7c402 | 2008-01-30 13:30:05 +0100 | [diff] [blame] | 1370 | 0x80 |
| 1371 | Standard port 0x80 based delay |
| 1372 | 0xed |
| 1373 | Alternate port 0xed based delay (needed on some systems) |
Rene Herman | b02aae9 | 2008-01-30 13:30:05 +0100 | [diff] [blame] | 1374 | udelay |
Ingo Molnar | 6e7c402 | 2008-01-30 13:30:05 +0100 | [diff] [blame] | 1375 | Simple two microseconds delay |
| 1376 | none |
| 1377 | No delay |
Rene Herman | b02aae9 | 2008-01-30 13:30:05 +0100 | [diff] [blame] | 1378 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1379 | ip= [IP_PNP] |
J. Bruce Fields | dc7a081 | 2009-10-27 14:41:35 -0400 | [diff] [blame] | 1380 | See Documentation/filesystems/nfs/nfsroot.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1381 | |
| 1382 | ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards |
Randy Dunlap | c8facbb | 2007-07-31 00:37:40 -0700 | [diff] [blame] | 1383 | See comment before ip2_setup() in |
| 1384 | drivers/char/ip2/ip2base.c. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1385 | |
Alan Cox | 200803d | 2005-06-28 20:45:18 -0700 | [diff] [blame] | 1386 | irqfixup [HW] |
| 1387 | When an interrupt is not handled search all handlers |
| 1388 | for it. Intended to get systems with badly broken |
| 1389 | firmware running. |
| 1390 | |
| 1391 | irqpoll [HW] |
| 1392 | When an interrupt is not handled search all handlers |
| 1393 | for it. Also check all handlers each timer |
| 1394 | interrupt. Intended to get systems with badly broken |
| 1395 | firmware running. |
| 1396 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1397 | isapnp= [ISAPNP] |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 1398 | Format: <RDP>,<reset>,<pci_scan>,<verbosity> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1399 | |
| 1400 | isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler. |
Derek Fults | 22f2e28 | 2006-12-06 20:37:11 -0800 | [diff] [blame] | 1401 | Format: |
| 1402 | <cpu number>,...,<cpu number> |
| 1403 | or |
Li Zefan | b225d44 | 2008-11-06 12:53:39 -0800 | [diff] [blame] | 1404 | <cpu number>-<cpu number> |
| 1405 | (must be a positive range in ascending order) |
Derek Fults | 22f2e28 | 2006-12-06 20:37:11 -0800 | [diff] [blame] | 1406 | or a mixture |
| 1407 | <cpu number>,...,<cpu number>-<cpu number> |
Li Zefan | b225d44 | 2008-11-06 12:53:39 -0800 | [diff] [blame] | 1408 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1409 | This option can be used to specify one or more CPUs |
| 1410 | to isolate from the general SMP balancing and scheduling |
Li Zefan | b225d44 | 2008-11-06 12:53:39 -0800 | [diff] [blame] | 1411 | algorithms. You can move a process onto or off an |
| 1412 | "isolated" CPU via the CPU affinity syscalls or cpuset. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1413 | <cpu number> begins at 0 and the maximum value is |
| 1414 | "number of CPUs in system - 1". |
| 1415 | |
| 1416 | This option is the preferred way to isolate CPUs. The |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 1417 | alternative -- manually setting the CPU mask of all |
| 1418 | tasks in the system -- can cause problems and |
| 1419 | suboptimal load balancer performance. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1420 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 1421 | iucv= [HW,NET] |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1422 | |
Joerg Roedel | 7d8bfa2 | 2013-04-09 21:27:19 +0200 | [diff] [blame] | 1423 | ivrs_ioapic [HW,X86_64] |
| 1424 | Provide an override to the IOAPIC-ID<->DEVICE-ID |
| 1425 | mapping provided in the IVRS ACPI table. For |
| 1426 | example, to map IOAPIC-ID decimal 10 to |
| 1427 | PCI device 00:14.0 write the parameter as: |
| 1428 | ivrs_ioapic[10]=00:14.0 |
| 1429 | |
| 1430 | ivrs_hpet [HW,X86_64] |
| 1431 | Provide an override to the HPET-ID<->DEVICE-ID |
| 1432 | mapping provided in the IVRS ACPI table. For |
| 1433 | example, to map HPET-ID decimal 0 to |
| 1434 | PCI device 00:14.0 write the parameter as: |
| 1435 | ivrs_hpet[0]=00:14.0 |
| 1436 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1437 | js= [HW,JOY] Analog joystick |
| 1438 | See Documentation/input/joystick.txt. |
| 1439 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 1440 | keepinitrd [HW,ARM] |
| 1441 | |
Jaswinder Singh Rajput | 6cececf | 2009-04-14 14:03:43 +0530 | [diff] [blame] | 1442 | kernelcore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter |
Mel Gorman | ed7ed36 | 2007-07-17 04:03:14 -0700 | [diff] [blame] | 1443 | specifies the amount of memory usable by the kernel |
| 1444 | for non-movable allocations. The requested amount is |
| 1445 | spread evenly throughout all nodes in the system. The |
| 1446 | remaining memory in each node is used for Movable |
| 1447 | pages. In the event, a node is too small to have both |
| 1448 | kernelcore and Movable pages, kernelcore pages will |
| 1449 | take priority and other nodes will have a larger number |
Weiping Pan | 675217f | 2013-09-30 13:45:10 -0700 | [diff] [blame] | 1450 | of Movable pages. The Movable zone is used for the |
Mel Gorman | ed7ed36 | 2007-07-17 04:03:14 -0700 | [diff] [blame] | 1451 | allocation of pages that may be reclaimed or moved |
| 1452 | by the page migration subsystem. This means that |
| 1453 | HugeTLB pages may not be allocated from this zone. |
| 1454 | Note that allocations like PTEs-from-HighMem still |
| 1455 | use the HighMem zone if it exists, and the Normal |
| 1456 | zone if it does not. |
| 1457 | |
Jason Wessel | 4fe1da4 | 2010-05-20 21:04:31 -0500 | [diff] [blame] | 1458 | kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port. |
| 1459 | Format: <Controller#>[,poll interval] |
| 1460 | The controller # is the number of the ehci usb debug |
| 1461 | port as it is probed via PCI. The poll interval is |
| 1462 | optional and is the number seconds in between |
| 1463 | each poll cycle to the debug port in case you need |
| 1464 | the functionality for interrupting the kernel with |
| 1465 | gdb or control-c on the dbgp connection. When |
| 1466 | not using this parameter you use sysrq-g to break into |
| 1467 | the kernel debugger. |
| 1468 | |
Jason Wessel | 84c08fd | 2010-05-20 21:04:24 -0500 | [diff] [blame] | 1469 | kgdboc= [KGDB,HW] kgdb over consoles. |
Jason Wessel | ada64e4 | 2010-05-20 21:04:24 -0500 | [diff] [blame] | 1470 | Requires a tty driver that supports console polling, |
| 1471 | or a supported polling keyboard driver (non-usb). |
Jason Wessel | 65b5ac1 | 2010-08-05 09:22:33 -0500 | [diff] [blame] | 1472 | Serial only format: <serial_device>[,baud] |
| 1473 | keyboard only format: kbd |
| 1474 | keyboard and serial format: kbd,<serial_device>[,baud] |
| 1475 | Optional Kernel mode setting: |
| 1476 | kms, kbd format: kms,kbd |
| 1477 | kms, kbd and serial format: kms,kbd,<ser_dev>[,baud] |
Jason Wessel | 6cdf6e0 | 2008-04-17 20:05:38 +0200 | [diff] [blame] | 1478 | |
Jason Wessel | 84c08fd | 2010-05-20 21:04:24 -0500 | [diff] [blame] | 1479 | kgdbwait [KGDB] Stop kernel execution and enter the |
| 1480 | kernel debugger at the earliest opportunity. |
| 1481 | |
Florian Fainelli | 9bed90c6 | 2008-08-23 18:54:37 +0200 | [diff] [blame] | 1482 | kmac= [MIPS] korina ethernet MAC address. |
| 1483 | Configure the RouterBoard 532 series on-chip |
| 1484 | Ethernet adapter MAC address. |
| 1485 | |
Catalin Marinas | 04f7033 | 2009-06-11 13:22:39 +0100 | [diff] [blame] | 1486 | kmemleak= [KNL] Boot-time kmemleak enable/disable |
| 1487 | Valid arguments: on, off |
| 1488 | Default: on |
| 1489 | |
Xishi Qiu | c3ac14b | 2014-01-23 15:53:33 -0800 | [diff] [blame] | 1490 | kmemcheck= [X86] Boot-time kmemcheck enable/disable/one-shot mode |
| 1491 | Valid arguments: 0, 1, 2 |
| 1492 | kmemcheck=0 (disabled) |
| 1493 | kmemcheck=1 (enabled) |
| 1494 | kmemcheck=2 (one-shot mode) |
| 1495 | Default: 2 (one-shot mode) |
| 1496 | |
Jaswinder Singh Rajput | 6cececf | 2009-04-14 14:03:43 +0530 | [diff] [blame] | 1497 | kstack=N [X86] Print N words from the kernel stack |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 1498 | in oops dumps. |
| 1499 | |
Andre Przywara | fef07aa | 2009-07-10 14:20:35 +0200 | [diff] [blame] | 1500 | kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs. |
| 1501 | Default is 0 (don't ignore, but inject #GP) |
| 1502 | |
Xiao Guangrong | a182d87 | 2010-09-20 22:17:48 +0800 | [diff] [blame] | 1503 | kvm.mmu_audit= [KVM] This is a R/W parameter which allows audit |
| 1504 | KVM MMU at runtime. |
Andre Przywara | fef07aa | 2009-07-10 14:20:35 +0200 | [diff] [blame] | 1505 | Default is 0 (off) |
| 1506 | |
Andre Przywara | fef07aa | 2009-07-10 14:20:35 +0200 | [diff] [blame] | 1507 | kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM. |
Xiao Guangrong | 8475f94 | 2010-09-20 22:16:45 +0800 | [diff] [blame] | 1508 | Default is 1 (enabled) |
Andre Przywara | fef07aa | 2009-07-10 14:20:35 +0200 | [diff] [blame] | 1509 | |
| 1510 | kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU) |
| 1511 | for all guests. |
Randy Dunlap | 1629024 | 2011-08-13 12:34:52 -0700 | [diff] [blame] | 1512 | Default is 1 (enabled) if in 64-bit or 32-bit PAE mode. |
Andre Przywara | fef07aa | 2009-07-10 14:20:35 +0200 | [diff] [blame] | 1513 | |
Andre Przywara | fef07aa | 2009-07-10 14:20:35 +0200 | [diff] [blame] | 1514 | kvm-intel.ept= [KVM,Intel] Disable extended page tables |
| 1515 | (virtualized MMU) support on capable Intel chips. |
| 1516 | Default is 1 (enabled) |
| 1517 | |
| 1518 | kvm-intel.emulate_invalid_guest_state= |
| 1519 | [KVM,Intel] Enable emulation of invalid guest states |
| 1520 | Default is 0 (disabled) |
| 1521 | |
| 1522 | kvm-intel.flexpriority= |
| 1523 | [KVM,Intel] Disable FlexPriority feature (TPR shadow). |
| 1524 | Default is 1 (enabled) |
| 1525 | |
Sasha Levin | e1a72ae | 2011-08-09 14:28:35 +0300 | [diff] [blame] | 1526 | kvm-intel.nested= |
| 1527 | [KVM,Intel] Enable VMX nesting (nVMX). |
| 1528 | Default is 0 (disabled) |
| 1529 | |
Andre Przywara | fef07aa | 2009-07-10 14:20:35 +0200 | [diff] [blame] | 1530 | kvm-intel.unrestricted_guest= |
| 1531 | [KVM,Intel] Disable unrestricted guest feature |
| 1532 | (virtualized real and unpaged mode) on capable |
| 1533 | Intel chips. Default is 1 (enabled) |
| 1534 | |
| 1535 | kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification |
| 1536 | feature (tagged TLBs) on capable Intel chips. |
| 1537 | Default is 1 (enabled) |
| 1538 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1539 | l2cr= [PPC] |
| 1540 | |
Robert Brose | a78bfbf | 2008-03-29 07:20:23 +1100 | [diff] [blame] | 1541 | l3cr= [PPC] |
| 1542 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 1543 | lapic [X86-32,APIC] Enable the local APIC even if BIOS |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 1544 | disabled it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1545 | |
Suresh Siddha | 279f146 | 2012-10-22 14:37:58 -0700 | [diff] [blame] | 1546 | lapic= [x86,APIC] "notscdeadline" Do not use TSC deadline |
| 1547 | value for LAPIC timer one-shot implementation. Default |
| 1548 | back to the programmable timer unit in the LAPIC. |
| 1549 | |
Jaswinder Singh Rajput | 6cececf | 2009-04-14 14:03:43 +0530 | [diff] [blame] | 1550 | lapic_timer_c2_ok [X86,APIC] trust the local apic timer |
Randy Dunlap | ada9cfd | 2008-12-19 10:57:32 -0800 | [diff] [blame] | 1551 | in C2 power state. |
Thomas Gleixner | e585bef | 2007-03-23 16:08:01 +0100 | [diff] [blame] | 1552 | |
FD Cami | fcb71f6 | 2008-01-06 19:08:56 +0100 | [diff] [blame] | 1553 | libata.dma= [LIBATA] DMA control |
| 1554 | libata.dma=0 Disable all PATA and SATA DMA |
| 1555 | libata.dma=1 PATA and SATA Disk DMA only |
| 1556 | libata.dma=2 ATAPI (CDROM) DMA only |
Randy Dunlap | 1629024 | 2011-08-13 12:34:52 -0700 | [diff] [blame] | 1557 | libata.dma=4 Compact Flash DMA only |
FD Cami | fcb71f6 | 2008-01-06 19:08:56 +0100 | [diff] [blame] | 1558 | Combinations also work, so libata.dma=3 enables DMA |
| 1559 | for disks and CDROMs, but not CFs. |
Randy Dunlap | 1629024 | 2011-08-13 12:34:52 -0700 | [diff] [blame] | 1560 | |
Michael Prokop | 2030887 | 2009-08-06 00:14:10 +0200 | [diff] [blame] | 1561 | libata.ignore_hpa= [LIBATA] Ignore HPA limit |
| 1562 | libata.ignore_hpa=0 keep BIOS limits (default) |
| 1563 | libata.ignore_hpa=1 ignore limits, using full disk |
FD Cami | fcb71f6 | 2008-01-06 19:08:56 +0100 | [diff] [blame] | 1564 | |
Dave Jones | 78e70c2 | 2007-09-27 11:50:13 -0400 | [diff] [blame] | 1565 | libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume |
| 1566 | when set. |
| 1567 | Format: <int> |
| 1568 | |
Tejun Heo | 3326732 | 2008-02-13 09:15:09 +0900 | [diff] [blame] | 1569 | libata.force= [LIBATA] Force configurations. The format is comma |
| 1570 | separated list of "[ID:]VAL" where ID is |
Roman Fietze | 4c44f30 | 2010-04-21 12:17:12 +0200 | [diff] [blame] | 1571 | PORT[.DEVICE]. PORT and DEVICE are decimal numbers |
Tejun Heo | 3326732 | 2008-02-13 09:15:09 +0900 | [diff] [blame] | 1572 | matching port, link or device. Basically, it matches |
| 1573 | the ATA ID string printed on console by libata. If |
| 1574 | the whole ID part is omitted, the last PORT and DEVICE |
| 1575 | values are used. If ID hasn't been specified yet, the |
| 1576 | configuration applies to all ports, links and devices. |
| 1577 | |
| 1578 | If only DEVICE is omitted, the parameter applies to |
| 1579 | the port and all links and devices behind it. DEVICE |
| 1580 | number of 0 either selects the first device or the |
| 1581 | first fan-out link behind PMP device. It does not |
| 1582 | select the host link. DEVICE number of 15 selects the |
| 1583 | host link and device attached to it. |
| 1584 | |
| 1585 | The VAL specifies the configuration to force. As long |
| 1586 | as there's no ambiguity shortcut notation is allowed. |
| 1587 | For example, both 1.5 and 1.5G would work for 1.5Gbps. |
| 1588 | The following configurations can be forced. |
| 1589 | |
| 1590 | * Cable type: 40c, 80c, short40c, unk, ign or sata. |
| 1591 | Any ID with matching PORT is used. |
| 1592 | |
| 1593 | * SATA link speed limit: 1.5Gbps or 3.0Gbps. |
| 1594 | |
| 1595 | * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7]. |
| 1596 | udma[/][16,25,33,44,66,100,133] notation is also |
| 1597 | allowed. |
| 1598 | |
| 1599 | * [no]ncq: Turn on or off NCQ. |
| 1600 | |
Tejun Heo | 05944bd | 2008-08-13 20:19:09 +0900 | [diff] [blame] | 1601 | * nohrst, nosrst, norst: suppress hard, soft |
| 1602 | and both resets. |
| 1603 | |
Dan Williams | ca6d43b | 2012-06-21 23:41:41 -0700 | [diff] [blame] | 1604 | * rstonce: only attempt one reset during |
| 1605 | hot-unplug link recovery |
| 1606 | |
Tejun Heo | 43c9c59 | 2010-05-23 12:59:11 +0200 | [diff] [blame] | 1607 | * dump_id: dump IDENTIFY data. |
| 1608 | |
Vincent Pelletier | 966fbe1 | 2013-05-21 22:30:58 +0200 | [diff] [blame] | 1609 | * atapi_dmadir: Enable ATAPI DMADIR bridge support |
| 1610 | |
Robin H. Johnson | b8bd6dc | 2013-12-16 09:31:19 -0800 | [diff] [blame] | 1611 | * disable: Disable this device. |
| 1612 | |
Tejun Heo | 3326732 | 2008-02-13 09:15:09 +0900 | [diff] [blame] | 1613 | If there are multiple matching configurations changing |
| 1614 | the same attribute, the last one is used. |
| 1615 | |
Yinghai Lu | 95f72d1 | 2010-07-12 14:36:09 +1000 | [diff] [blame] | 1616 | memblock=debug [KNL] Enable memblock debug messages. |
Randy Dunlap | 7c4be253 | 2009-01-06 14:42:44 -0800 | [diff] [blame] | 1617 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1618 | load_ramdisk= [RAM] List of ramdisks to load from floppy |
Randy Dunlap | 31c00fc | 2008-11-13 21:33:24 +0000 | [diff] [blame] | 1619 | See Documentation/blockdev/ramdisk.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1620 | |
Randy Dunlap | a6b25b6 | 2006-01-14 13:21:19 -0800 | [diff] [blame] | 1621 | lockd.nlm_grace_period=P [NFS] Assign grace period. |
| 1622 | Format: <integer> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1623 | |
Randy Dunlap | a6b25b6 | 2006-01-14 13:21:19 -0800 | [diff] [blame] | 1624 | lockd.nlm_tcpport=N [NFS] Assign TCP port. |
| 1625 | Format: <integer> |
| 1626 | |
| 1627 | lockd.nlm_timeout=T [NFS] Assign timeout value. |
| 1628 | Format: <integer> |
| 1629 | |
| 1630 | lockd.nlm_udpport=M [NFS] Assign UDP port. |
| 1631 | Format: <integer> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1632 | |
| 1633 | logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver |
| 1634 | Format: <irq> |
| 1635 | |
| 1636 | loglevel= All Kernel Messages with a loglevel smaller than the |
| 1637 | console loglevel will be printed to the console. It can |
| 1638 | also be changed with klogd or other programs. The |
| 1639 | loglevels are defined as follows: |
| 1640 | |
| 1641 | 0 (KERN_EMERG) system is unusable |
| 1642 | 1 (KERN_ALERT) action must be taken immediately |
| 1643 | 2 (KERN_CRIT) critical conditions |
| 1644 | 3 (KERN_ERR) error conditions |
| 1645 | 4 (KERN_WARNING) warning conditions |
| 1646 | 5 (KERN_NOTICE) normal but significant condition |
| 1647 | 6 (KERN_INFO) informational |
| 1648 | 7 (KERN_DEBUG) debug-level messages |
| 1649 | |
Randy Dunlap | c756d08 | 2011-02-20 20:08:35 -0800 | [diff] [blame] | 1650 | log_buf_len=n[KMG] Sets the size of the printk ring buffer, |
| 1651 | in bytes. n must be a power of two. The default |
| 1652 | size is set in the kernel config file. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1653 | |
Randy Dunlap | accaa24 | 2007-10-16 01:29:37 -0700 | [diff] [blame] | 1654 | logo.nologo [FB] Disables display of the built-in Linux logo. |
| 1655 | This may be used to provide more screen space for |
| 1656 | kernel log messages and is useful when debugging |
| 1657 | kernel boot problems. |
| 1658 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1659 | lp=0 [LP] Specify parallel ports to use, e.g, |
| 1660 | lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses |
| 1661 | lp=reset first parallel port). 'lp=0' disables the |
| 1662 | lp=auto printer driver. 'lp=reset' (which can be |
| 1663 | specified in addition to the ports) causes |
| 1664 | attached printers to be reset. Using |
| 1665 | lp=port1,port2,... specifies the parallel ports |
| 1666 | to associate lp devices with, starting with |
| 1667 | lp0. A port specification may be 'none' to skip |
| 1668 | that lp device, or a parport name such as |
| 1669 | 'parport0'. Specifying 'lp=auto' instead of a |
| 1670 | port specification list means that device IDs |
| 1671 | from each port should be examined, to see if |
| 1672 | an IEEE 1284-compliant printer is attached; if |
| 1673 | so, the driver will manage that printer. |
| 1674 | See also header of drivers/char/lp.c. |
| 1675 | |
| 1676 | lpj=n [KNL] |
| 1677 | Sets loops_per_jiffy to given constant, thus avoiding |
| 1678 | time-consuming boot-time autodetection (up to 250 ms per |
| 1679 | CPU). 0 enables autodetection (default). To determine |
| 1680 | the correct value for your kernel, boot with normal |
| 1681 | autodetection and see what value is printed. Note that |
| 1682 | on SMP systems the preset will be applied to all CPUs, |
| 1683 | which is likely to cause problems if your CPUs need |
| 1684 | significantly divergent settings. An incorrect value |
| 1685 | will cause delays in the kernel to be wrong, leading to |
| 1686 | unpredictable I/O errors and other breakage. Although |
| 1687 | unlikely, in the extreme case this might damage your |
| 1688 | hardware. |
| 1689 | |
| 1690 | ltpc= [NET] |
| 1691 | Format: <io>,<irq>,<dma> |
| 1692 | |
Randy Dunlap | 1629024 | 2011-08-13 12:34:52 -0700 | [diff] [blame] | 1693 | machvec= [IA-64] Force the use of a particular machine-vector |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 1694 | (machvec) in a generic kernel. |
| 1695 | Example: machvec=hpzx1_swiotlb |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1696 | |
Wu Zhangjin | 3209e70 | 2009-07-02 23:27:12 +0800 | [diff] [blame] | 1697 | machtype= [Loongson] Share the same kernel image file between different |
| 1698 | yeeloong laptop. |
| 1699 | Example: machtype=lemote-yeeloong-2f-7inch |
| 1700 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 1701 | max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater |
| 1702 | than or equal to this physical address is ignored. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1703 | |
| 1704 | maxcpus= [SMP] Maximum number of processors that an SMP kernel |
Len Brown | 61ec756 | 2007-08-16 03:34:22 -0400 | [diff] [blame] | 1705 | should make use of. maxcpus=n : n >= 0 limits the |
| 1706 | kernel to using 'n' processors. n=0 is a special case, |
| 1707 | it is equivalent to "nosmp", which also disables |
| 1708 | the IO APIC. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1709 | |
Kay Sievers | d134b00 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1710 | max_loop= [LOOP] The number of loop block devices that get |
| 1711 | (loop.max_loop) unconditionally pre-created at init time. The default |
| 1712 | number is configured by BLK_DEV_LOOP_MIN_COUNT. Instead |
| 1713 | of statically allocating a predefined number, loop |
| 1714 | devices can be requested on-demand with the |
| 1715 | /dev/loop-control interface. |
Bob Picco | 2b2c375 | 2005-06-29 18:00:00 -0700 | [diff] [blame] | 1716 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 1717 | mce [X86-32] Machine Check Exception |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1718 | |
Uwe Hermann | 71cced6 | 2008-10-20 09:32:21 -0700 | [diff] [blame] | 1719 | mce=option [X86-64] See Documentation/x86/x86_64/boot-options.txt |
Andi Kleen | 909dd32 | 2007-10-17 18:04:38 +0200 | [diff] [blame] | 1720 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1721 | md= [HW] RAID subsystems devices and level |
| 1722 | See Documentation/md.txt. |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 1723 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1724 | mdacon= [MDA] |
| 1725 | Format: <first>,<last> |
| 1726 | Specifies range of consoles to be captured by the MDA. |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 1727 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1728 | mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory |
| 1729 | Amount of memory to be used when the kernel is not able |
| 1730 | to see the whole system memory or for test. |
Wen Congyang | fbb97d8 | 2012-12-17 15:59:29 -0800 | [diff] [blame] | 1731 | [X86] Work as limiting max address. Use together |
| 1732 | with memmap= to avoid physical address space collisions. |
| 1733 | Without memmap= PCI devices could be placed at addresses |
| 1734 | belonging to unused RAM. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1735 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 1736 | mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1737 | memory. |
| 1738 | |
Paul Mundt | 6902aa8 | 2008-09-21 17:14:42 +0900 | [diff] [blame] | 1739 | memchunk=nn[KMG] |
| 1740 | [KNL,SH] Allow user to override the default size for |
| 1741 | per-device physically contiguous DMA buffers. |
| 1742 | |
Jaswinder Singh Rajput | 6cececf | 2009-04-14 14:03:43 +0530 | [diff] [blame] | 1743 | memmap=exactmap [KNL,X86] Enable setting of an exact |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1744 | E820 memory map, as specified by the user. |
| 1745 | Such memmap=exactmap lines can be constructed based on |
| 1746 | BIOS output or other requirements. See the memmap=nn@ss |
| 1747 | option description. |
| 1748 | |
| 1749 | memmap=nn[KMG]@ss[KMG] |
Randy Dunlap | 277cba1 | 2014-02-06 12:04:19 -0800 | [diff] [blame] | 1750 | [KNL] Force usage of a specific region of memory. |
| 1751 | Region of memory to be used is from ss to ss+nn. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1752 | |
| 1753 | memmap=nn[KMG]#ss[KMG] |
| 1754 | [KNL,ACPI] Mark specific memory as ACPI data. |
Randy Dunlap | 277cba1 | 2014-02-06 12:04:19 -0800 | [diff] [blame] | 1755 | Region of memory to be marked is from ss to ss+nn. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1756 | |
| 1757 | memmap=nn[KMG]$ss[KMG] |
| 1758 | [KNL,ACPI] Mark specific memory as reserved. |
Randy Dunlap | 277cba1 | 2014-02-06 12:04:19 -0800 | [diff] [blame] | 1759 | Region of memory to be reserved is from ss to ss+nn. |
Pavel Machek | 1312848 | 2008-03-24 12:29:43 -0700 | [diff] [blame] | 1760 | Example: Exclude memory from 0x18690000-0x1869ffff |
| 1761 | memmap=64K$0x18690000 |
| 1762 | or |
| 1763 | memmap=0x10000$0x18690000 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1764 | |
Jeremy Fitzhardinge | 9f07787 | 2008-09-07 01:51:34 -0700 | [diff] [blame] | 1765 | memory_corruption_check=0/1 [X86] |
| 1766 | Some BIOSes seem to corrupt the first 64k of |
| 1767 | memory when doing things like suspend/resume. |
| 1768 | Setting this option will scan the memory |
| 1769 | looking for corruption. Enabling this will |
| 1770 | both detect corruption and prevent the kernel |
| 1771 | from using the memory being corrupted. |
| 1772 | However, its intended as a diagnostic tool; if |
| 1773 | repeatable BIOS-originated corruption always |
| 1774 | affects the same memory, you can use memmap= |
| 1775 | to prevent the kernel from using that memory. |
| 1776 | |
| 1777 | memory_corruption_check_size=size [X86] |
| 1778 | By default it checks for corruption in the low |
| 1779 | 64k, making this memory unavailable for normal |
| 1780 | use. Use this parameter to scan for |
| 1781 | corruption in more or less memory. |
| 1782 | |
| 1783 | memory_corruption_check_period=seconds [X86] |
| 1784 | By default it checks for corruption every 60 |
| 1785 | seconds. Use this parameter to check at some |
| 1786 | other rate. 0 disables periodic checking. |
| 1787 | |
Yinghai Lu | caadbdc | 2008-07-15 00:03:44 -0700 | [diff] [blame] | 1788 | memtest= [KNL,X86] Enable memtest |
Yinghai Lu | c64df70 | 2008-03-21 18:56:19 -0700 | [diff] [blame] | 1789 | Format: <integer> |
Yinghai Lu | c64df70 | 2008-03-21 18:56:19 -0700 | [diff] [blame] | 1790 | default : 0 <disable> |
Andreas Herrmann | 9e5f6cf | 2009-02-25 11:30:45 +0100 | [diff] [blame] | 1791 | Specifies the number of memtest passes to be |
| 1792 | performed. Each pass selects another test |
| 1793 | pattern from a given set of patterns. Memtest |
| 1794 | fills the memory with this pattern, validates |
| 1795 | memory contents and reserves bad memory |
| 1796 | regions that are detected. |
Yinghai Lu | c64df70 | 2008-03-21 18:56:19 -0700 | [diff] [blame] | 1797 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1798 | meye.*= [HW] Set MotionEye Camera parameters |
| 1799 | See Documentation/video4linux/meye.txt. |
| 1800 | |
Andres Salomon | 8f36881 | 2007-10-12 23:04:06 +0200 | [diff] [blame] | 1801 | mfgpt_irq= [IA-32] Specify the IRQ to use for the |
| 1802 | Multi-Function General Purpose Timers on AMD Geode |
| 1803 | platforms. |
| 1804 | |
Willy Tarreau | e6c4dc6 | 2008-01-30 13:33:33 +0100 | [diff] [blame] | 1805 | mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when |
| 1806 | the BIOS has incorrectly applied a workaround. TinyBIOS |
| 1807 | version 0.98 is known to be affected, 0.99 fixes the |
| 1808 | problem by letting the user disable the workaround. |
| 1809 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1810 | mga= [HW,DRM] |
| 1811 | |
Randy Dunlap | 1c207f9 | 2008-11-19 15:36:16 -0800 | [diff] [blame] | 1812 | min_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory below this |
| 1813 | physical address is ignored. |
| 1814 | |
Michel Pollet | 39f45d7 | 2009-05-20 11:10:31 +0100 | [diff] [blame] | 1815 | mini2440= [ARM,HW,KNL] |
| 1816 | Format:[0..2][b][c][t] |
| 1817 | Default: "0tb" |
| 1818 | MINI2440 configuration specification: |
| 1819 | 0 - The attached screen is the 3.5" TFT |
| 1820 | 1 - The attached screen is the 7" TFT |
| 1821 | 2 - The VGA Shield is attached (1024x768) |
| 1822 | Leaving out the screen size parameter will not load |
| 1823 | the TFT driver, and the framebuffer will be left |
| 1824 | unconfigured. |
| 1825 | b - Enable backlight. The TFT backlight pin will be |
| 1826 | linked to the kernel VESA blanking code and a GPIO |
| 1827 | LED. This parameter is not necessary when using the |
| 1828 | VGA shield. |
| 1829 | c - Enable the s3c camera interface. |
| 1830 | t - Reserved for enabling touchscreen support. The |
| 1831 | touchscreen support is not enabled in the mainstream |
| 1832 | kernel as of 2.6.30, a preliminary port can be found |
| 1833 | in the "bleeding edge" mini2440 support kernel at |
| 1834 | http://repo.or.cz/w/linux-2.6/mini2440.git |
| 1835 | |
Mel Gorman | 6b74ab9 | 2008-07-23 21:26:49 -0700 | [diff] [blame] | 1836 | mminit_loglevel= |
| 1837 | [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this |
| 1838 | parameter allows control of the logging verbosity for |
| 1839 | the additional memory initialisation checks. A value |
| 1840 | of 0 disables mminit logging and a level of 4 will |
| 1841 | log everything. Information is printed at KERN_DEBUG |
| 1842 | so loglevel=8 may also need to be specified. |
| 1843 | |
Rusty Russell | 106a4ee | 2012-09-26 10:09:40 +0100 | [diff] [blame] | 1844 | module.sig_enforce |
| 1845 | [KNL] When CONFIG_MODULE_SIG is set, this means that |
| 1846 | modules without (valid) signatures will fail to load. |
Paul Bolle | 2a039be | 2013-03-25 20:42:06 +0100 | [diff] [blame] | 1847 | Note that if CONFIG_MODULE_SIG_FORCE is set, that |
Rusty Russell | 106a4ee | 2012-09-26 10:09:40 +0100 | [diff] [blame] | 1848 | is always true, so this option does nothing. |
| 1849 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1850 | mousedev.tap_time= |
| 1851 | [MOUSE] Maximum time between finger touching and |
| 1852 | leaving touchpad surface for touch to be considered |
| 1853 | a tap and be reported as a left button click (for |
| 1854 | touchpads working in absolute mode only). |
| 1855 | Format: <msecs> |
| 1856 | mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices |
| 1857 | reporting absolute coordinates, such as tablets |
| 1858 | mousedev.yres= [MOUSE] Vertical screen resolution, used for devices |
| 1859 | reporting absolute coordinates, such as tablets |
| 1860 | |
Jaswinder Singh Rajput | 6cececf | 2009-04-14 14:03:43 +0530 | [diff] [blame] | 1861 | movablecore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 1862 | is similar to kernelcore except it specifies the |
| 1863 | amount of memory used for migratable allocations. |
| 1864 | If both kernelcore and movablecore is specified, |
| 1865 | then kernelcore will be at *least* the specified |
| 1866 | value but may be more. If movablecore on its own |
| 1867 | is specified, the administrator must be careful |
| 1868 | that the amount of memory usable for all allocations |
| 1869 | is not too small. |
| 1870 | |
Tang Chen | c532092 | 2013-11-12 15:08:10 -0800 | [diff] [blame] | 1871 | movable_node [KNL,X86] Boot-time switch to enable the effects |
| 1872 | of CONFIG_MOVABLE_NODE=y. See mm/Kconfig for details. |
| 1873 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1874 | MTD_Partition= [MTD] |
| 1875 | Format: <name>,<region-number>,<size>,<offset> |
| 1876 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 1877 | MTD_Region= [MTD] Format: |
| 1878 | <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>] |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1879 | |
| 1880 | mtdparts= [MTD] |
Randy Dunlap | c8facbb | 2007-07-31 00:37:40 -0700 | [diff] [blame] | 1881 | See drivers/mtd/cmdlinepart.c. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1882 | |
Will Schmidt | 4e89a2d | 2010-09-28 15:33:12 +0000 | [diff] [blame] | 1883 | multitce=off [PPC] This parameter disables the use of the pSeries |
| 1884 | firmware feature for updating multiple TCE entries |
| 1885 | at a time. |
| 1886 | |
Rohit Hagargundgi | 5988af2 | 2009-05-12 13:46:57 -0700 | [diff] [blame] | 1887 | onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration |
| 1888 | |
| 1889 | Format: [die0_boundary][,die0_lock][,die1_boundary][,die1_lock] |
| 1890 | |
| 1891 | boundary - index of last SLC block on Flex-OneNAND. |
| 1892 | The remaining blocks are configured as MLC blocks. |
| 1893 | lock - Configure if Flex-OneNAND boundary should be locked. |
| 1894 | Once locked, the boundary cannot be changed. |
| 1895 | 1 indicates lock status, 0 indicates unlock status. |
| 1896 | |
Ben Dooks | 9db829f | 2008-07-03 11:24:29 +0100 | [diff] [blame] | 1897 | mtdset= [ARM] |
| 1898 | ARM/S3C2412 JIVE boot control |
| 1899 | |
| 1900 | See arch/arm/mach-s3c2412/mach-jive.c |
| 1901 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1902 | mtouchusb.raw_coordinates= |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 1903 | [HW] Make the MicroTouch USB driver use raw coordinates |
| 1904 | ('y', default) or cooked coordinates ('n') |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1905 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 1906 | mtrr_chunk_size=nn[KMG] [X86] |
Matt LaPlante | 19f5946 | 2009-04-27 15:06:31 +0200 | [diff] [blame] | 1907 | used for mtrr cleanup. It is largest continuous chunk |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 1908 | that could hold holes aka. UC entries. |
| 1909 | |
| 1910 | mtrr_gran_size=nn[KMG] [X86] |
| 1911 | Used for mtrr cleanup. It is granularity of mtrr block. |
| 1912 | Default is 1. |
| 1913 | Large value could prevent small alignment from |
| 1914 | using up MTRRs. |
| 1915 | |
| 1916 | mtrr_spare_reg_nr=n [X86] |
| 1917 | Format: <integer> |
| 1918 | Range: 0,7 : spare reg number |
| 1919 | Default : 1 |
| 1920 | Used for mtrr cleanup. It is spare mtrr entries number. |
| 1921 | Set to 2 or more if your graphical card needs more. |
| 1922 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1923 | n2= [NET] SDL Inc. RISCom/N2 synchronous serial card |
| 1924 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1925 | netdev= [NET] Network devices parameters |
| 1926 | Format: <irq>,<io>,<mem_start>,<mem_end>,<name> |
| 1927 | Note that mem_start is often overloaded to mean |
| 1928 | something different and driver-specific. |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 1929 | This usage is only documented in each driver source |
| 1930 | file if at all. |
| 1931 | |
Krzysztof Piotr Oledzki | 5840157 | 2008-07-21 10:01:34 -0700 | [diff] [blame] | 1932 | nf_conntrack.acct= |
| 1933 | [NETFILTER] Enable connection tracking flow accounting |
| 1934 | 0 to disable accounting |
| 1935 | 1 to enable accounting |
Tim Gardner | d70a011 | 2010-06-25 14:46:56 +0200 | [diff] [blame] | 1936 | Default value is 0. |
Krzysztof Piotr Oledzki | 5840157 | 2008-07-21 10:01:34 -0700 | [diff] [blame] | 1937 | |
Chuck Lever | 306a075 | 2010-09-17 10:54:37 -0400 | [diff] [blame] | 1938 | nfsaddrs= [NFS] Deprecated. Use ip= instead. |
J. Bruce Fields | dc7a081 | 2009-10-27 14:41:35 -0400 | [diff] [blame] | 1939 | See Documentation/filesystems/nfs/nfsroot.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1940 | |
| 1941 | nfsroot= [NFS] nfs root filesystem for disk-less boxes. |
J. Bruce Fields | dc7a081 | 2009-10-27 14:41:35 -0400 | [diff] [blame] | 1942 | See Documentation/filesystems/nfs/nfsroot.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1943 | |
Chuck Lever | 306a075 | 2010-09-17 10:54:37 -0400 | [diff] [blame] | 1944 | nfsrootdebug [NFS] enable nfsroot debugging messages. |
| 1945 | See Documentation/filesystems/nfs/nfsroot.txt. |
| 1946 | |
Trond Myklebust | a72b442 | 2006-01-03 09:55:41 +0100 | [diff] [blame] | 1947 | nfs.callback_tcpport= |
| 1948 | [NFS] set the TCP port on which the NFSv4 callback |
| 1949 | channel should listen. |
| 1950 | |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 1951 | nfs.cache_getent= |
| 1952 | [NFS] sets the pathname to the program which is used |
| 1953 | to update the NFS client cache entries. |
| 1954 | |
| 1955 | nfs.cache_getent_timeout= |
| 1956 | [NFS] sets the timeout after which an attempt to |
| 1957 | update a cache entry is deemed to have failed. |
| 1958 | |
Trond Myklebust | 58df095 | 2006-01-03 09:55:57 +0100 | [diff] [blame] | 1959 | nfs.idmap_cache_timeout= |
| 1960 | [NFS] set the maximum lifetime for idmapper cache |
| 1961 | entries. |
| 1962 | |
Trond Myklebust | f43bf0b | 2007-10-09 12:01:04 -0400 | [diff] [blame] | 1963 | nfs.enable_ino64= |
| 1964 | [NFS] enable 64-bit inode numbers. |
| 1965 | If zero, the NFS client will fake up a 32-bit inode |
| 1966 | number for the readdir() and stat() syscalls instead |
| 1967 | of returning the full 64-bit number. |
| 1968 | The default is to return 64-bit inode numbers. |
| 1969 | |
Trond Myklebust | ef159e9 | 2012-02-06 19:50:40 -0500 | [diff] [blame] | 1970 | nfs.max_session_slots= |
| 1971 | [NFSv4.1] Sets the maximum number of session slots |
| 1972 | the client will attempt to negotiate with the server. |
| 1973 | This limits the number of simultaneous RPC requests |
| 1974 | that the client can send to the NFSv4.1 server. |
| 1975 | Note that there is little point in setting this |
| 1976 | value higher than the max_tcp_slot_table_limit. |
| 1977 | |
Trond Myklebust | b064eca2 | 2011-02-22 15:44:32 -0800 | [diff] [blame] | 1978 | nfs.nfs4_disable_idmapping= |
Trond Myklebust | 074b1d1 | 2012-01-09 13:46:26 -0500 | [diff] [blame] | 1979 | [NFSv4] When set to the default of '1', this option |
| 1980 | ensures that both the RPC level authentication |
| 1981 | scheme and the NFS level operations agree to use |
| 1982 | numeric uids/gids if the mount is using the |
| 1983 | 'sec=sys' security flavour. In effect it is |
| 1984 | disabling idmapping, which can make migration from |
| 1985 | legacy NFSv2/v3 systems to NFSv4 easier. |
| 1986 | Servers that do not support this mode of operation |
| 1987 | will be autodetected by the client, and it will fall |
| 1988 | back to using the idmapper. |
| 1989 | To turn off this behaviour, set the value to '0'. |
Chuck Lever | 6f2ea7f | 2012-09-14 17:24:41 -0400 | [diff] [blame] | 1990 | nfs.nfs4_unique_id= |
| 1991 | [NFS4] Specify an additional fixed unique ident- |
| 1992 | ification string that NFSv4 clients can insert into |
| 1993 | their nfs_client_id4 string. This is typically a |
| 1994 | UUID that is generated at system install time. |
Trond Myklebust | b064eca2 | 2011-02-22 15:44:32 -0800 | [diff] [blame] | 1995 | |
Weston Andros Adamson | db8ac8b | 2012-02-17 15:20:24 -0500 | [diff] [blame] | 1996 | nfs.send_implementation_id = |
| 1997 | [NFSv4.1] Send client implementation identification |
| 1998 | information in exchange_id requests. |
| 1999 | If zero, no implementation identification information |
| 2000 | will be sent. |
| 2001 | The default is to send the implementation identification |
| 2002 | information. |
Trond Myklebust | f6de7a3 | 2013-09-04 10:08:54 -0400 | [diff] [blame] | 2003 | |
| 2004 | nfs.recover_lost_locks = |
| 2005 | [NFSv4] Attempt to recover locks that were lost due |
| 2006 | to a lease timeout on the server. Please note that |
| 2007 | doing this risks data corruption, since there are |
| 2008 | no guarantees that the file will remain unchanged |
| 2009 | after the locks are lost. |
| 2010 | If you want to enable the kernel legacy behaviour of |
| 2011 | attempting to recover these locks, then set this |
| 2012 | parameter to '1'. |
| 2013 | The default parameter value of '0' causes the kernel |
| 2014 | not to attempt recovery of lost locks. |
Weston Andros Adamson | db8ac8b | 2012-02-17 15:20:24 -0500 | [diff] [blame] | 2015 | |
J. Bruce Fields | e9541ce | 2012-03-22 16:07:18 -0400 | [diff] [blame] | 2016 | nfsd.nfs4_disable_idmapping= |
| 2017 | [NFSv4] When set to the default of '1', the NFSv4 |
| 2018 | server will return only numeric uids and gids to |
| 2019 | clients using auth_sys, and will accept numeric uids |
| 2020 | and gids from such clients. This is intended to ease |
| 2021 | migration from NFSv2/v3. |
Weston Andros Adamson | db8ac8b | 2012-02-17 15:20:24 -0500 | [diff] [blame] | 2022 | |
Sachin Bhamare | 18d98f6 | 2012-03-19 20:47:58 -0700 | [diff] [blame] | 2023 | objlayoutdriver.osd_login_prog= |
| 2024 | [NFS] [OBJLAYOUT] sets the pathname to the program which |
| 2025 | is used to automatically discover and login into new |
| 2026 | osd-targets. Please see: |
| 2027 | Documentation/filesystems/pnfs.txt for more explanations |
| 2028 | |
Paul Mundt | 1e1030d | 2009-09-01 17:38:32 +0900 | [diff] [blame] | 2029 | nmi_debug= [KNL,AVR32,SH] Specify one or more actions to take |
Haavard Skinnemoen | e7ba176 | 2007-10-10 14:58:29 +0200 | [diff] [blame] | 2030 | when a NMI is triggered. |
| 2031 | Format: [state][,regs][,debounce][,die] |
| 2032 | |
Jaswinder Singh Rajput | 6cececf | 2009-04-14 14:03:43 +0530 | [diff] [blame] | 2033 | nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels |
Don Zickus | fef2c9b | 2011-03-22 16:34:16 -0700 | [diff] [blame] | 2034 | Format: [panic,][nopanic,][num] |
Don Zickus | 5dc3055 | 2010-11-29 17:07:17 -0500 | [diff] [blame] | 2035 | Valid num: 0 |
Cyrill Gorcunov | 5b9a0e1 | 2008-11-01 18:06:51 +0300 | [diff] [blame] | 2036 | 0 - turn nmi_watchdog off |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 2037 | When panic is specified, panic when an NMI watchdog |
Don Zickus | fef2c9b | 2011-03-22 16:34:16 -0700 | [diff] [blame] | 2038 | timeout occurs (or 'nopanic' to override the opposite |
| 2039 | default). |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 2040 | This is useful when you use a panic=... timeout and |
| 2041 | need the box quickly up again. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2042 | |
Anton Vorontsov | bff3877 | 2009-07-08 11:10:56 -0700 | [diff] [blame] | 2043 | netpoll.carrier_timeout= |
| 2044 | [NET] Specifies amount of time (in seconds) that |
| 2045 | netpoll should wait for a carrier. By default netpoll |
| 2046 | waits 4 seconds. |
| 2047 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 2048 | no387 [BUGS=X86-32] Tells the kernel to use the 387 maths |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2049 | emulation library even if a 387 maths coprocessor |
| 2050 | is present. |
| 2051 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 2052 | no_console_suspend |
| 2053 | [HW] Never suspend the console |
| 2054 | Disable suspending of consoles during suspend and |
| 2055 | hibernate operations. Once disabled, debugging |
| 2056 | messages can reach various consoles while the rest |
| 2057 | of the system is being put to sleep (ie, while |
| 2058 | debugging driver suspend/resume hooks). This may |
| 2059 | not work reliably with all consoles, but is known |
| 2060 | to work with serial and VGA consoles. |
Yanmin Zhang | 134620f | 2011-10-31 17:11:27 -0700 | [diff] [blame] | 2061 | To facilitate more flexible debugging, we also add |
| 2062 | console_suspend, a printk module parameter to control |
| 2063 | it. Users could use console_suspend (usually |
| 2064 | /sys/module/printk/parameters/console_suspend) to |
| 2065 | turn on/off it dynamically. |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 2066 | |
Christoph Lameter | c1aee21 | 2007-05-31 00:40:47 -0700 | [diff] [blame] | 2067 | noaliencache [MM, NUMA, SLAB] Disables the allocation of alien |
| 2068 | caches in the slab allocator. Saves per-node memory, |
| 2069 | but will impact performance. |
Paul Menage | 3395ee0 | 2006-12-06 20:32:16 -0800 | [diff] [blame] | 2070 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2071 | noalign [KNL,ARM] |
| 2072 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2073 | noapic [SMP,APIC] Tells the kernel to not make use of any |
| 2074 | IOAPICs that may be present in the system. |
| 2075 | |
Kees Cook | 8ab3820 | 2013-10-10 17:18:14 -0700 | [diff] [blame] | 2076 | nokaslr [X86] |
Kees Cook | e2b32e6 | 2014-02-25 16:59:17 -0800 | [diff] [blame] | 2077 | Disable kernel and module base offset ASLR (Address |
| 2078 | Space Layout Randomization) if built into the kernel. |
Kees Cook | 8ab3820 | 2013-10-10 17:18:14 -0700 | [diff] [blame] | 2079 | |
Mike Galbraith | 5091faa | 2010-11-30 14:18:03 +0100 | [diff] [blame] | 2080 | noautogroup Disable scheduler automatic task group creation. |
| 2081 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2082 | nobats [PPC] Do not use BATs for mapping kernel lowmem |
| 2083 | on "Classic" PPC cores. |
| 2084 | |
| 2085 | nocache [ARM] |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2086 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 2087 | noclflush [BUGS=X86] Don't use the CLFLUSH instruction |
| 2088 | |
Shailabh Nagar | 163ecdf | 2006-07-30 03:03:11 -0700 | [diff] [blame] | 2089 | nodelayacct [KNL] Disable per-task delay accounting |
| 2090 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2091 | nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects. |
| 2092 | |
Paul Mundt | 6902aa8 | 2008-09-21 17:14:42 +0900 | [diff] [blame] | 2093 | nodsp [SH] Disable hardware DSP at boot time. |
| 2094 | |
Jaswinder Singh Rajput | 6cececf | 2009-04-14 14:03:43 +0530 | [diff] [blame] | 2095 | noefi [X86] Disable EFI runtime services support. |
Huang, Ying | 8b2cb7a | 2008-01-30 13:32:11 +0100 | [diff] [blame] | 2096 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2097 | noexec [IA-64] |
| 2098 | |
Jaswinder Singh Rajput | 6cececf | 2009-04-14 14:03:43 +0530 | [diff] [blame] | 2099 | noexec [X86] |
Jiri Slaby | f5a1b19 | 2008-04-12 10:28:25 +0200 | [diff] [blame] | 2100 | On X86-32 available only on PAE configured kernels. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2101 | noexec=on: enable non-executable mappings (default) |
Jiri Slaby | f5a1b19 | 2008-04-12 10:28:25 +0200 | [diff] [blame] | 2102 | noexec=off: disable non-executable mappings |
| 2103 | |
H. Peter Anvin | 52b6179 | 2012-09-21 12:43:13 -0700 | [diff] [blame] | 2104 | nosmap [X86] |
| 2105 | Disable SMAP (Supervisor Mode Access Prevention) |
| 2106 | even if it is supported by processor. |
| 2107 | |
Fenghua Yu | de5397a | 2011-05-11 16:51:05 -0700 | [diff] [blame] | 2108 | nosmep [X86] |
H. Peter Anvin | 52b6179 | 2012-09-21 12:43:13 -0700 | [diff] [blame] | 2109 | Disable SMEP (Supervisor Mode Execution Prevention) |
Fenghua Yu | de5397a | 2011-05-11 16:51:05 -0700 | [diff] [blame] | 2110 | even if it is supported by processor. |
| 2111 | |
Jiri Slaby | f5a1b19 | 2008-04-12 10:28:25 +0200 | [diff] [blame] | 2112 | noexec32 [X86-64] |
| 2113 | This affects only 32-bit executables. |
| 2114 | noexec32=on: enable non-executable mappings (default) |
| 2115 | read doesn't imply executable mappings |
| 2116 | noexec32=off: disable non-executable mappings |
| 2117 | read implies executable mappings |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2118 | |
Paul Mundt | 6902aa8 | 2008-09-21 17:14:42 +0900 | [diff] [blame] | 2119 | nofpu [SH] Disable hardware FPU at boot time. |
| 2120 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 2121 | nofxsr [BUGS=X86-32] Disables x86 floating point extended |
Chuck Ebbert | 4f88651 | 2006-03-23 02:59:34 -0800 | [diff] [blame] | 2122 | register save and restore. The kernel will only save |
| 2123 | legacy floating-point registers on task switch. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2124 | |
Suresh Siddha | 0c752a9 | 2009-05-22 12:17:45 -0700 | [diff] [blame] | 2125 | noxsave [BUGS=X86] Disables x86 extended register state save |
| 2126 | and restore using xsave. The kernel will fallback to |
| 2127 | enabling legacy floating-point and sse state. |
| 2128 | |
Suresh Siddha | 5d2bd70 | 2012-09-06 14:58:52 -0700 | [diff] [blame] | 2129 | eagerfpu= [X86] |
Suresh Siddha | e002298 | 2012-09-10 10:32:32 -0700 | [diff] [blame] | 2130 | on enable eager fpu restore |
Suresh Siddha | 5d2bd70 | 2012-09-06 14:58:52 -0700 | [diff] [blame] | 2131 | off disable eager fpu restore |
Suresh Siddha | e002298 | 2012-09-10 10:32:32 -0700 | [diff] [blame] | 2132 | auto selects the default scheme, which automatically |
| 2133 | enables eagerfpu restore for xsaveopt. |
Suresh Siddha | 5d2bd70 | 2012-09-06 14:58:52 -0700 | [diff] [blame] | 2134 | |
Paulius Zaleckas | 01a24d2 | 2009-03-31 13:55:44 +0100 | [diff] [blame] | 2135 | nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or |
| 2136 | wfi(ARM) instruction doesn't work correctly and not to |
| 2137 | use it. This is also useful when using JTAG debugger. |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2138 | |
Serge E. Hallyn | 1f29fae | 2008-11-05 16:08:52 -0600 | [diff] [blame] | 2139 | no_file_caps Tells the kernel not to honor file capabilities. The |
| 2140 | only way then for a file to be executed with privilege |
| 2141 | is to be setuid root or executed by root. |
| 2142 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2143 | nohalt [IA-64] Tells the kernel not to use the power saving |
| 2144 | function PAL_HALT_LIGHT when idle. This increases |
| 2145 | power-consumption. On the positive side, it reduces |
| 2146 | interrupt wake-up latency, which may improve performance |
| 2147 | in certain environments such as networked servers or |
| 2148 | real-time systems. |
| 2149 | |
Thomas Gleixner | 79bf2bb | 2007-02-16 01:28:03 -0800 | [diff] [blame] | 2150 | nohz= [KNL] Boottime enable/disable dynamic ticks |
| 2151 | Valid arguments: on, off |
| 2152 | Default: on |
| 2153 | |
Frederic Weisbecker | c5bfece | 2013-04-12 16:45:34 +0200 | [diff] [blame] | 2154 | nohz_full= [KNL,BOOT] |
| 2155 | In kernels built with CONFIG_NO_HZ_FULL=y, set |
Frederic Weisbecker | a831881 | 2012-12-18 17:32:19 +0100 | [diff] [blame] | 2156 | the specified list of CPUs whose tick will be stopped |
Frederic Weisbecker | 0453b43 | 2013-03-27 02:18:34 +0100 | [diff] [blame] | 2157 | whenever possible. The boot CPU will be forced outside |
| 2158 | the range to maintain the timekeeping. |
Frederic Weisbecker | d1e43fa | 2013-03-26 23:47:24 +0100 | [diff] [blame] | 2159 | The CPUs in this range must also be included in the |
| 2160 | rcu_nocbs= set. |
Frederic Weisbecker | a831881 | 2012-12-18 17:32:19 +0100 | [diff] [blame] | 2161 | |
Paul Mundt | eeee785 | 2009-04-02 12:31:16 +0900 | [diff] [blame] | 2162 | noiotrap [SH] Disables trapped I/O port accesses. |
| 2163 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 2164 | noirqdebug [X86-32] Disables the code which attempts to detect and |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2165 | disable unhandled interrupt sources. |
| 2166 | |
Jaswinder Singh Rajput | 6cececf | 2009-04-14 14:03:43 +0530 | [diff] [blame] | 2167 | no_timer_check [X86,APIC] Disables the code which tests for |
Zachary Amsden | 8542b20 | 2006-12-07 02:14:09 +0100 | [diff] [blame] | 2168 | broken timer IRQ sources. |
| 2169 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2170 | noisapnp [ISAPNP] Disables ISA PnP code. |
| 2171 | |
| 2172 | noinitrd [RAM] Tells the kernel not to load any configured |
| 2173 | initial RAM disk. |
| 2174 | |
Weidong Han | 03ea815 | 2009-04-17 16:42:15 +0800 | [diff] [blame] | 2175 | nointremap [X86-64, Intel-IOMMU] Do not enable interrupt |
| 2176 | remapping. |
Chris Wright | d1423d5 | 2010-07-20 11:06:49 -0700 | [diff] [blame] | 2177 | [Deprecated - use intremap=off] |
Weidong Han | 03ea815 | 2009-04-17 16:42:15 +0800 | [diff] [blame] | 2178 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2179 | nointroute [IA-64] |
| 2180 | |
Randy Dunlap | 1629024 | 2011-08-13 12:34:52 -0700 | [diff] [blame] | 2181 | nojitter [IA-64] Disables jitter checking for ITC timers. |
Tony Luck | 0aa366f | 2007-07-20 11:22:30 -0700 | [diff] [blame] | 2182 | |
Jiri Kosina | 9cf4c4f | 2010-08-16 17:51:20 +0200 | [diff] [blame] | 2183 | no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver |
| 2184 | |
Gleb Natapov | fd10cde | 2010-10-14 11:22:51 +0200 | [diff] [blame] | 2185 | no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page |
| 2186 | fault handling. |
| 2187 | |
Glauber Costa | d910f5c | 2011-07-11 15:28:19 -0400 | [diff] [blame] | 2188 | no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting. |
| 2189 | steal time is computed, but won't influence scheduler |
| 2190 | behaviour |
| 2191 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 2192 | nolapic [X86-32,APIC] Do not enable or use the local APIC. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2193 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 2194 | nolapic_timer [X86-32,APIC] Do not use the local APIC timer. |
Thomas Gleixner | ad62ca2 | 2007-03-22 00:11:21 -0800 | [diff] [blame] | 2195 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2196 | noltlbs [PPC] Do not use large page/tlb entries for kernel |
| 2197 | lowmem mapping on PPC40x. |
| 2198 | |
Horms | 312f1f0 | 2006-02-22 09:57:55 +0900 | [diff] [blame] | 2199 | nomca [IA-64] Disable machine check abort handling |
| 2200 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 2201 | nomce [X86-32] Machine Check Exception |
Horms | abe37e5 | 2006-04-01 01:36:09 +0200 | [diff] [blame] | 2202 | |
Andres Salomon | 83d7384 | 2007-10-12 23:04:06 +0200 | [diff] [blame] | 2203 | nomfgpt [X86-32] Disable Multi-Function General Purpose |
| 2204 | Timer usage (for AMD Geode machines). |
| 2205 | |
Don Zickus | bda6263 | 2011-10-13 15:14:27 -0400 | [diff] [blame] | 2206 | nonmi_ipi [X86] Disable using NMI IPIs during panic/reboot to |
| 2207 | shutdown the other cpus. Instead use the REBOOT_VECTOR |
| 2208 | irq. |
| 2209 | |
Dave Young | 02608be | 2012-02-01 10:33:14 +0800 | [diff] [blame] | 2210 | nomodule Disable module load |
| 2211 | |
Jiri Kosina | 016ddd9 | 2010-01-18 17:05:40 +0100 | [diff] [blame] | 2212 | nopat [X86] Disable PAT (page attribute table extension of |
| 2213 | pagetables) support. |
| 2214 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 2215 | norandmaps Don't use address space randomization. Equivalent to |
| 2216 | echo 0 > /proc/sys/kernel/randomize_va_space |
| 2217 | |
Jiri Kosina | bbff216 | 2010-08-11 18:34:09 +0200 | [diff] [blame] | 2218 | noreplace-paravirt [X86,IA-64,PV_OPS] Don't patch paravirt_ops |
Jeremy Fitzhardinge | 959b4fd | 2007-05-02 19:27:16 +0200 | [diff] [blame] | 2219 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 2220 | noreplace-smp [X86-32,SMP] Don't replace SMP instructions |
Jeremy Fitzhardinge | b7fb4af | 2007-05-02 19:27:13 +0200 | [diff] [blame] | 2221 | with UP alternatives |
| 2222 | |
H. Peter Anvin | 49d859d | 2011-07-31 14:02:19 -0700 | [diff] [blame] | 2223 | nordrand [X86] Disable the direct use of the RDRAND |
| 2224 | instruction even if it is supported by the |
| 2225 | processor. RDRAND is still available to user |
| 2226 | space applications. |
| 2227 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2228 | noresume [SWSUSP] Disables resume and restores original swap |
| 2229 | space. |
| 2230 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2231 | no-scroll [VGA] Disables scrollback. |
| 2232 | This is required for the Braillex ib80-piezo Braille |
| 2233 | reader made by F.H. Papenmeier (Germany). |
| 2234 | |
| 2235 | nosbagart [IA-64] |
| 2236 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 2237 | nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support. |
Chuck Ebbert | 4f88651 | 2006-03-23 02:59:34 -0800 | [diff] [blame] | 2238 | |
Len Brown | 61ec756 | 2007-08-16 03:34:22 -0400 | [diff] [blame] | 2239 | nosmp [SMP] Tells an SMP kernel to act as a UP kernel, |
| 2240 | and disable the IO APIC. legacy for "maxcpus=0". |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2241 | |
Dave Jones | 9784221 | 2007-07-15 23:41:05 -0700 | [diff] [blame] | 2242 | nosoftlockup [KNL] Disable the soft-lockup detector. |
| 2243 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2244 | nosync [HW,M68K] Disables sync negotiation for all devices. |
| 2245 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 2246 | notsc [BUGS=X86-32] Disable Time Stamp Counter |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2247 | |
| 2248 | nousb [USB] Disable the USB subsystem |
| 2249 | |
Ben Hutchings | 5514237 | 2011-01-02 23:02:42 +0000 | [diff] [blame] | 2250 | nowatchdog [KNL] Disable the lockup detector (NMI watchdog). |
Don Zickus | 58687ac | 2010-05-07 17:11:44 -0400 | [diff] [blame] | 2251 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2252 | nowb [ARM] |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2253 | |
Weidong Han | 2b2fd87 | 2009-04-17 16:42:12 +0800 | [diff] [blame] | 2254 | nox2apic [X86-64,APIC] Do not enable x2APIC mode. |
| 2255 | |
Fenghua Yu | f78cff4 | 2012-11-13 11:32:38 -0800 | [diff] [blame] | 2256 | cpu0_hotplug [X86] Turn on CPU0 hotplug feature when |
| 2257 | CONFIG_BOOTPARAM_HOTPLUG_CPU0 is off. |
| 2258 | Some features depend on CPU0. Known dependencies are: |
| 2259 | 1. Resume from suspend/hibernate depends on CPU0. |
| 2260 | Suspend/hibernate will fail if CPU0 is offline and you |
| 2261 | need to online CPU0 before suspend/hibernate. |
| 2262 | 2. PIC interrupts also depend on CPU0. CPU0 can't be |
| 2263 | removed if a PIC interrupt is detected. |
| 2264 | It's said poweroff/reboot may depend on CPU0 on some |
| 2265 | machines although I haven't seen such issues so far |
| 2266 | after CPU0 is offline on a few tested machines. |
| 2267 | If the dependencies are under your control, you can |
| 2268 | turn on cpu0_hotplug. |
| 2269 | |
Randy Dunlap | 1629024 | 2011-08-13 12:34:52 -0700 | [diff] [blame] | 2270 | nptcg= [IA-64] Override max number of concurrent global TLB |
Fenghua Yu | a6c75b86 | 2008-03-14 13:57:08 -0700 | [diff] [blame] | 2271 | purges which is reported from either PAL_VM_SUMMARY or |
| 2272 | SAL PALO. |
| 2273 | |
Yinghai Lu | 2b633e3 | 2010-02-10 01:20:37 -0800 | [diff] [blame] | 2274 | nr_cpus= [SMP] Maximum number of processors that an SMP kernel |
| 2275 | could support. nr_cpus=n : n >= 1 limits the kernel to |
| 2276 | supporting 'n' processors. Later in runtime you can not |
| 2277 | use hotplug cpu feature to put more cpu back to online. |
| 2278 | just like you compile the kernel NR_CPUS=n |
| 2279 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 2280 | nr_uarts= [SERIAL] maximum number of UARTs to be registered. |
| 2281 | |
Mel Gorman | 1a687c2 | 2012-11-22 11:16:36 +0000 | [diff] [blame] | 2282 | numa_balancing= [KNL,X86] Enable or disable automatic NUMA balancing. |
| 2283 | Allowed values are enable and disable |
| 2284 | |
KAMEZAWA Hiroyuki | f0c0b2b | 2007-07-15 23:38:01 -0700 | [diff] [blame] | 2285 | numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA. |
| 2286 | one of ['zone', 'node', 'default'] can be specified |
| 2287 | This can be set from sysctl after boot. |
| 2288 | See Documentation/sysctl/vm.txt for details. |
| 2289 | |
Randy Dunlap | 7c4be253 | 2009-01-06 14:42:44 -0800 | [diff] [blame] | 2290 | ohci1394_dma=early [HW] enable debugging via the ohci1394 driver. |
| 2291 | See Documentation/debugging-via-ohci1394.txt for more |
| 2292 | info. |
| 2293 | |
Andres Salomon | 3ef0e1f | 2008-04-29 00:59:53 -0700 | [diff] [blame] | 2294 | olpc_ec_timeout= [OLPC] ms delay when issuing EC commands |
| 2295 | Rather than timing out after 20 ms if an EC |
| 2296 | command is not properly ACKed, override the length |
| 2297 | of the timeout. We have interrupts disabled while |
| 2298 | waiting for the ACK, so if this is set too high |
| 2299 | interrupts *may* be lost! |
| 2300 | |
Tony Lindgren | 15ac7af | 2009-12-11 16:16:32 -0800 | [diff] [blame] | 2301 | omap_mux= [OMAP] Override bootloader pin multiplexing. |
| 2302 | Format: <mux_mode0.mode_name=value>... |
| 2303 | For example, to override I2C bus2: |
| 2304 | omap_mux=i2c2_scl.i2c2_scl=0x100,i2c2_sda.i2c2_sda=0x100 |
| 2305 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2306 | oprofile.timer= [HW] |
| 2307 | Use timer interrupt instead of performance counters |
| 2308 | |
Robert Richter | 7e4e0bd | 2009-05-06 12:10:23 +0200 | [diff] [blame] | 2309 | oprofile.cpu_type= Force an oprofile cpu type |
| 2310 | This might be useful if you have an older oprofile |
| 2311 | userland or if you want common events. |
Robert Richter | 8d7ff4f | 2009-06-23 11:48:14 +0200 | [diff] [blame] | 2312 | Format: { arch_perfmon } |
| 2313 | arch_perfmon: [X86] Force use of architectural |
Robert Richter | 7e4e0bd | 2009-05-06 12:10:23 +0200 | [diff] [blame] | 2314 | perfmon on Intel CPUs instead of the |
| 2315 | CPU specific event set. |
Robert Richter | 159a80b | 2011-10-11 19:39:16 +0200 | [diff] [blame] | 2316 | timer: [X86] Force use of architectural NMI |
| 2317 | timer mode (see also oprofile.timer |
| 2318 | for generic hr timer mode) |
Andreas Krebbel | dd3c467 | 2011-11-25 20:03:05 +0100 | [diff] [blame] | 2319 | [s390] Force legacy basic mode sampling |
| 2320 | (report cpu_type "timer") |
Andi Kleen | 1dcdb5a | 2009-04-27 17:44:11 +0200 | [diff] [blame] | 2321 | |
Randy Dunlap | 44a4dcf | 2011-04-04 15:02:24 -0700 | [diff] [blame] | 2322 | oops=panic Always panic on oopses. Default is to just kill the |
| 2323 | process, but there is a small probability of |
| 2324 | deadlocking the machine. |
Olaf Hering | d404ab0 | 2011-03-22 16:34:04 -0700 | [diff] [blame] | 2325 | This will also cause panics on machine check exceptions. |
| 2326 | Useful together with panic=30 to trigger a reboot. |
| 2327 | |
Randy Dunlap | bcfde33 | 2010-06-07 17:10:38 -0700 | [diff] [blame] | 2328 | OSS [HW,OSS] |
| 2329 | See Documentation/sound/oss/oss-parameters.txt |
| 2330 | |
Randy Dunlap | 44a4dcf | 2011-04-04 15:02:24 -0700 | [diff] [blame] | 2331 | panic= [KNL] Kernel behaviour on panic: delay <timeout> |
Hugh Dickins | 4302fbc | 2011-07-26 16:08:52 -0700 | [diff] [blame] | 2332 | timeout > 0: seconds before rebooting |
| 2333 | timeout = 0: wait forever |
| 2334 | timeout < 0: reboot immediately |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2335 | Format: <timeout> |
| 2336 | |
| 2337 | parkbd.port= [HW] Parallel port number the keyboard adapter is |
| 2338 | connected to, default is 0. |
| 2339 | Format: <parport#> |
| 2340 | parkbd.mode= [HW] Parallel port keyboard adapter mode of operation, |
| 2341 | 0 for XT, 1 for AT (default is AT). |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2342 | Format: <mode> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2343 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2344 | parport= [HW,PPT] Specify parallel ports. 0 disables. |
| 2345 | Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] } |
| 2346 | Use 'auto' to force the driver to use any |
| 2347 | IRQ/DMA settings detected (the default is to |
| 2348 | ignore detected IRQ/DMA settings because of |
| 2349 | possible conflicts). You can specify the base |
| 2350 | address, IRQ, and DMA settings; IRQ and DMA |
| 2351 | should be numbers, or 'auto' (for using detected |
| 2352 | settings on that particular port), or 'nofifo' |
| 2353 | (to avoid using a FIFO even if it is detected). |
| 2354 | Parallel ports are assigned in the order they |
| 2355 | are specified on the command line, starting |
| 2356 | with parport0. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2357 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2358 | parport_init_mode= [HW,PPT] |
| 2359 | Configure VIA parallel port to operate in |
| 2360 | a specific mode. This is necessary on Pegasos |
| 2361 | computer where firmware has no options for setting |
| 2362 | up parallel port mode and sets it to spp. |
| 2363 | Currently this function knows 686a and 8231 chips. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2364 | Format: [spp|ps2|epp|ecp|ecpepp] |
| 2365 | |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 2366 | pause_on_oops= |
| 2367 | Halt all CPUs after the first oops has been printed for |
| 2368 | the specified number of seconds. This is to be used if |
| 2369 | your oopses keep scrolling off the screen. |
| 2370 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2371 | pcbit= [HW,ISDN] |
| 2372 | |
| 2373 | pcd. [PARIDE] |
| 2374 | See header of drivers/block/paride/pcd.c. |
Randy Dunlap | 31c00fc | 2008-11-13 21:33:24 +0000 | [diff] [blame] | 2375 | See also Documentation/blockdev/paride.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2376 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2377 | pci=option[,option...] [PCI] various PCI subsystem options: |
Bjorn Helgaas | 1cc0ca2 | 2009-01-14 10:04:36 -0700 | [diff] [blame] | 2378 | earlydump [X86] dump PCI config space before the kernel |
| 2379 | changes anything |
Andi Kleen | c011560 | 2008-08-22 09:53:39 +0200 | [diff] [blame] | 2380 | off [X86] don't probe for the PCI bus |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 2381 | bios [X86-32] force use of PCI BIOS, don't access |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2382 | the hardware directly. Use this if your machine |
| 2383 | has a non-standard PCI host bridge. |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 2384 | nobios [X86-32] disallow use of PCI BIOS, only direct |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2385 | hardware access methods are allowed. Use this |
| 2386 | if you experience crashes upon bootup and you |
| 2387 | suspect they are caused by the BIOS. |
Andi Kleen | c011560 | 2008-08-22 09:53:39 +0200 | [diff] [blame] | 2388 | conf1 [X86] Force use of PCI Configuration |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2389 | Mechanism 1. |
Andi Kleen | c011560 | 2008-08-22 09:53:39 +0200 | [diff] [blame] | 2390 | conf2 [X86] Force use of PCI Configuration |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2391 | Mechanism 2. |
Randy Dunlap | 7f78576 | 2007-10-05 13:17:58 -0700 | [diff] [blame] | 2392 | noaer [PCIE] If the PCIEAER kernel config parameter is |
| 2393 | enabled, this kernel boot option can be used to |
| 2394 | disable the use of PCIE advanced error reporting. |
Jeff Garzik | 32a2eea | 2007-10-11 16:57:27 -0400 | [diff] [blame] | 2395 | nodomains [PCI] Disable support for multiple PCI |
| 2396 | root domains (aka PCI segments, in ACPI-speak). |
Jaswinder Singh Rajput | 6cececf | 2009-04-14 14:03:43 +0530 | [diff] [blame] | 2397 | nommconf [X86] Disable use of MMCONFIG for PCI |
Bjorn Helgaas | 61be6d6 | 2006-02-15 15:17:43 -0800 | [diff] [blame] | 2398 | Configuration |
Andreas Herrmann | 1298307 | 2009-06-07 16:15:16 +0200 | [diff] [blame] | 2399 | check_enable_amd_mmconf [X86] check for and enable |
| 2400 | properly configured MMIO access to PCI |
| 2401 | config space on AMD family 10h CPU |
Matthew Wilcox | 309e57d | 2006-03-05 22:33:34 -0700 | [diff] [blame] | 2402 | nomsi [MSI] If the PCI_MSI kernel config parameter is |
| 2403 | enabled, this kernel boot option can be used to |
| 2404 | disable the use of MSI interrupts system-wide. |
Stefan Assmann | a9322f6 | 2008-06-11 16:35:14 +0200 | [diff] [blame] | 2405 | noioapicquirk [APIC] Disable all boot interrupt quirks. |
| 2406 | Safety option to keep boot IRQs enabled. This |
| 2407 | should never be necessary. |
Stefan Assmann | 9197979 | 2008-06-11 16:35:15 +0200 | [diff] [blame] | 2408 | ioapicreroute [APIC] Enable rerouting of boot IRQs to the |
| 2409 | primary IO-APIC for bridges that cannot disable |
| 2410 | boot IRQs. This fixes a source of spurious IRQs |
| 2411 | when the system masks IRQs. |
Stefan Assmann | 41b9eb2 | 2008-07-15 13:48:55 +0200 | [diff] [blame] | 2412 | noioapicreroute [APIC] Disable workaround that uses the |
| 2413 | boot IRQ equivalent of an IRQ that connects to |
| 2414 | a chipset where boot IRQs cannot be disabled. |
| 2415 | The opposite of ioapicreroute. |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 2416 | biosirq [X86-32] Use PCI BIOS calls to get the interrupt |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2417 | routing table. These calls are known to be buggy |
| 2418 | on several machines and they hang the machine |
| 2419 | when used, but on other computers it's the only |
| 2420 | way to get the interrupt routing table. Try |
| 2421 | this option if the kernel is unable to allocate |
| 2422 | IRQs or discover secondary PCI buses on your |
| 2423 | motherboard. |
Andi Kleen | c011560 | 2008-08-22 09:53:39 +0200 | [diff] [blame] | 2424 | rom [X86] Assign address space to expansion ROMs. |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2425 | Use with caution as certain devices share |
| 2426 | address decoders between ROMs and other |
| 2427 | resources. |
Andi Kleen | c011560 | 2008-08-22 09:53:39 +0200 | [diff] [blame] | 2428 | norom [X86] Do not assign address space to |
Gary Hade | bb71ad8 | 2008-05-12 13:57:46 -0700 | [diff] [blame] | 2429 | expansion ROMs that do not already have |
| 2430 | BIOS assigned address ranges. |
Mike Habeck | 7bd1c36 | 2010-05-12 11:14:32 -0700 | [diff] [blame] | 2431 | nobar [X86] Do not assign address space to the |
| 2432 | BARs that weren't assigned by the BIOS. |
Andi Kleen | c011560 | 2008-08-22 09:53:39 +0200 | [diff] [blame] | 2433 | irqmask=0xMMMM [X86] Set a bit mask of IRQs allowed to be |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2434 | assigned automatically to PCI devices. You can |
| 2435 | make the kernel exclude IRQs of your ISA cards |
| 2436 | this way. |
Andi Kleen | c011560 | 2008-08-22 09:53:39 +0200 | [diff] [blame] | 2437 | pirqaddr=0xAAAAA [X86] Specify the physical address |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2438 | of the PIRQ table (normally generated |
| 2439 | by the BIOS) if it is outside the |
| 2440 | F0000h-100000h range. |
Andi Kleen | c011560 | 2008-08-22 09:53:39 +0200 | [diff] [blame] | 2441 | lastbus=N [X86] Scan all buses thru bus #N. Can be |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2442 | useful if the kernel is unable to find your |
| 2443 | secondary buses and you want to tell it |
| 2444 | explicitly which ones they are. |
Andi Kleen | c011560 | 2008-08-22 09:53:39 +0200 | [diff] [blame] | 2445 | assign-busses [X86] Always assign all PCI bus |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2446 | numbers ourselves, overriding |
| 2447 | whatever the firmware may have done. |
Andi Kleen | c011560 | 2008-08-22 09:53:39 +0200 | [diff] [blame] | 2448 | usepirqmask [X86] Honor the possible IRQ mask stored |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2449 | in the BIOS $PIR table. This is needed on |
| 2450 | some systems with broken BIOSes, notably |
| 2451 | some HP Pavilion N5400 and Omnibook XE3 |
| 2452 | notebooks. This will have no effect if ACPI |
| 2453 | IRQ routing is enabled. |
Andi Kleen | c011560 | 2008-08-22 09:53:39 +0200 | [diff] [blame] | 2454 | noacpi [X86] Do not use ACPI for IRQ routing |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2455 | or for PCI scanning. |
Bjorn Helgaas | 7bc5e3f | 2010-02-23 10:24:41 -0700 | [diff] [blame] | 2456 | use_crs [X86] Use PCI host bridge window information |
| 2457 | from ACPI. On BIOSes from 2008 or later, this |
| 2458 | is enabled by default. If you need to use this, |
| 2459 | please report a bug. |
| 2460 | nocrs [X86] Ignore PCI host bridge windows from ACPI. |
| 2461 | If you need to use this, please report a bug. |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2462 | routeirq Do IRQ routing for all PCI devices. |
| 2463 | This is normally done in pci_enable_device(), |
| 2464 | so this option is a temporary workaround |
| 2465 | for broken drivers that don't call it. |
Yinghai Lu | 13a6ddb | 2008-03-27 01:31:18 -0700 | [diff] [blame] | 2466 | skip_isa_align [X86] do not align io start addr, so can |
| 2467 | handle more pci cards |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2468 | firmware [ARM] Do not re-enumerate the bus but instead |
| 2469 | just use the configuration from the |
| 2470 | bootloader. This is currently used on |
| 2471 | IXP2000 systems where the bus has to be |
| 2472 | configured a certain way for adjunct CPUs. |
Andi Kleen | 0637a70 | 2006-09-26 10:52:41 +0200 | [diff] [blame] | 2473 | noearly [X86] Don't do any early type 1 scanning. |
| 2474 | This might help on some broken boards which |
| 2475 | machine check when some devices' config space |
| 2476 | is read. But various workarounds are disabled |
| 2477 | and some IOMMU drivers will not work. |
Matt Domsch | 6b4b78f | 2006-09-29 15:23:23 -0500 | [diff] [blame] | 2478 | bfsort Sort PCI devices into breadth-first order. |
| 2479 | This sorting is done to get a device |
| 2480 | order compatible with older (<= 2.4) kernels. |
| 2481 | nobfsort Don't sort PCI devices into breadth-first order. |
Yijing Wang | fa23871 | 2013-01-30 09:40:52 +0800 | [diff] [blame] | 2482 | pcie_bus_tune_off Disable PCIe MPS (Max Payload Size) |
| 2483 | tuning and use the BIOS-configured MPS defaults. |
| 2484 | pcie_bus_safe Set every device's MPS to the largest value |
| 2485 | supported by all devices below the root complex. |
| 2486 | pcie_bus_perf Set device MPS to the largest allowable MPS |
| 2487 | based on its parent bus. Also set MRRS (Max |
| 2488 | Read Request Size) to the largest supported |
| 2489 | value (no larger than the MPS that the device |
| 2490 | or bus can support) for best performance. |
| 2491 | pcie_bus_peer2peer Set every device's MPS to 128B, which |
| 2492 | every device is guaranteed to support. This |
| 2493 | configuration allows peer-to-peer DMA between |
| 2494 | any pair of devices, possibly at the cost of |
| 2495 | reduced performance. This also guarantees |
| 2496 | that hot-added devices will work. |
Atsushi Nemoto | 4516a61 | 2007-02-05 16:36:06 -0800 | [diff] [blame] | 2497 | cbiosize=nn[KMG] The fixed amount of bus space which is |
| 2498 | reserved for the CardBus bridge's IO window. |
| 2499 | The default value is 256 bytes. |
| 2500 | cbmemsize=nn[KMG] The fixed amount of bus space which is |
| 2501 | reserved for the CardBus bridge's memory |
| 2502 | window. The default value is 64 megabytes. |
Yuji Shimada | 32a9a682 | 2009-03-16 17:13:39 +0900 | [diff] [blame] | 2503 | resource_alignment= |
| 2504 | Format: |
| 2505 | [<order of align>@][<domain>:]<bus>:<slot>.<func>[; ...] |
| 2506 | Specifies alignment and device to reassign |
| 2507 | aligned memory resources. |
| 2508 | If <order of align> is not specified, |
| 2509 | PAGE_SIZE is used as alignment. |
| 2510 | PCI-PCI bridge can be specified, if resource |
| 2511 | windows need to be expanded. |
Andrew Patterson | 43c1640 | 2009-04-22 16:52:09 -0600 | [diff] [blame] | 2512 | ecrc= Enable/disable PCIe ECRC (transaction layer |
| 2513 | end-to-end CRC checking). |
| 2514 | bios: Use BIOS/firmware settings. This is the |
| 2515 | the default. |
| 2516 | off: Turn ECRC off |
| 2517 | on: Turn ECRC on. |
Yijing Wang | 8c8803c | 2013-01-23 20:29:06 +0800 | [diff] [blame] | 2518 | hpiosize=nn[KMG] The fixed amount of bus space which is |
| 2519 | reserved for hotplug bridge's IO window. |
| 2520 | Default size is 256 bytes. |
| 2521 | hpmemsize=nn[KMG] The fixed amount of bus space which is |
| 2522 | reserved for hotplug bridge's memory window. |
| 2523 | Default size is 2 megabytes. |
Yinghai Lu | b55438f | 2012-02-23 19:23:30 -0800 | [diff] [blame] | 2524 | realloc= Enable/disable reallocating PCI bridge resources |
| 2525 | if allocations done by BIOS are too small to |
| 2526 | accommodate resources required by all child |
| 2527 | devices. |
| 2528 | off: Turn realloc off |
| 2529 | on: Turn realloc on |
| 2530 | realloc same as realloc=on |
Rafael J. Wysocki | 6748dcc | 2012-03-01 00:06:33 +0100 | [diff] [blame] | 2531 | noari do not use PCIe ARI. |
Bjorn Helgaas | 284f5f9 | 2012-04-30 15:21:02 -0600 | [diff] [blame] | 2532 | pcie_scan_all Scan all possible PCIe devices. Otherwise we |
| 2533 | only look for one device below a PCIe downstream |
| 2534 | port. |
Matt Domsch | 6b4b78f | 2006-09-29 15:23:23 -0500 | [diff] [blame] | 2535 | |
Chuck Ebbert | e5665a4 | 2008-09-24 20:40:34 -0400 | [diff] [blame] | 2536 | pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power |
| 2537 | Management. |
| 2538 | off Disable ASPM. |
| 2539 | force Enable ASPM even on devices that claim not to support it. |
| 2540 | WARNING: Forcing ASPM on may cause system lockups. |
| 2541 | |
MUNEDA Takahiro | 7570a33 | 2012-02-02 11:09:22 -0500 | [diff] [blame] | 2542 | pcie_hp= [PCIE] PCI Express Hotplug driver options: |
| 2543 | nomsi Do not use MSI for PCI Express Native Hotplug (this |
| 2544 | makes all PCIe ports use INTx for hotplug services). |
| 2545 | |
Rafael J. Wysocki | 79dd918 | 2010-08-21 01:51:44 +0200 | [diff] [blame] | 2546 | pcie_ports= [PCIE] PCIe ports handling: |
Rafael J. Wysocki | 28eb5f2 | 2010-08-21 22:02:38 +0200 | [diff] [blame] | 2547 | auto Ask the BIOS whether or not to use native PCIe services |
| 2548 | associated with PCIe ports (PME, hot-plug, AER). Use |
| 2549 | them only if that is allowed by the BIOS. |
| 2550 | native Use native PCIe services associated with PCIe ports |
| 2551 | unconditionally. |
Rafael J. Wysocki | 79dd918 | 2010-08-21 01:51:44 +0200 | [diff] [blame] | 2552 | compat Treat PCIe ports as PCI-to-PCI bridges, disable the PCIe |
| 2553 | ports driver. |
| 2554 | |
Rafael J. Wysocki | c7f4865 | 2010-02-17 23:39:08 +0100 | [diff] [blame] | 2555 | pcie_pme= [PCIE,PM] Native PCIe PME signaling options: |
Rafael J. Wysocki | c39fae1 | 2010-02-17 23:40:07 +0100 | [diff] [blame] | 2556 | nomsi Do not use MSI for native PCIe PME signaling (this makes |
Rafael J. Wysocki | 28eb5f2 | 2010-08-21 22:02:38 +0200 | [diff] [blame] | 2557 | all PCIe root ports use INTx for all services). |
Rafael J. Wysocki | c7f4865 | 2010-02-17 23:39:08 +0100 | [diff] [blame] | 2558 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2559 | pcmv= [HW,PCMCIA] BadgePAD 4 |
| 2560 | |
| 2561 | pd. [PARIDE] |
Randy Dunlap | 31c00fc | 2008-11-13 21:33:24 +0000 | [diff] [blame] | 2562 | See Documentation/blockdev/paride.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2563 | |
| 2564 | pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at |
| 2565 | boot time. |
| 2566 | Format: { 0 | 1 } |
| 2567 | See arch/parisc/kernel/pdc_chassis.c |
| 2568 | |
Tejun Heo | f58dc01 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 2569 | percpu_alloc= Select which percpu first chunk allocator to use. |
Tejun Heo | e933a73 | 2009-08-14 15:00:53 +0900 | [diff] [blame] | 2570 | Currently supported values are "embed" and "page". |
| 2571 | Archs may support subset or none of the selections. |
| 2572 | See comments in mm/percpu.c for details on each |
| 2573 | allocator. This parameter is primarily for debugging |
| 2574 | and performance comparison. |
Tejun Heo | fa8a709 | 2009-06-22 11:56:24 +0900 | [diff] [blame] | 2575 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2576 | pf. [PARIDE] |
Randy Dunlap | 31c00fc | 2008-11-13 21:33:24 +0000 | [diff] [blame] | 2577 | See Documentation/blockdev/paride.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2578 | |
| 2579 | pg. [PARIDE] |
Randy Dunlap | 31c00fc | 2008-11-13 21:33:24 +0000 | [diff] [blame] | 2580 | See Documentation/blockdev/paride.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2581 | |
| 2582 | pirq= [SMP,APIC] Manual mp-table setup |
Uwe Hermann | 71cced6 | 2008-10-20 09:32:21 -0700 | [diff] [blame] | 2583 | See Documentation/x86/i386/IO-APIC.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2584 | |
| 2585 | plip= [PPT,NET] Parallel port network link |
| 2586 | Format: { parport<nr> | timid | 0 } |
| 2587 | See also Documentation/parport.txt. |
| 2588 | |
Randy Dunlap | 1629024 | 2011-08-13 12:34:52 -0700 | [diff] [blame] | 2589 | pmtmr= [X86] Manual setup of pmtmr I/O Port. |
Thomas Gleixner | de32a24 | 2008-07-12 05:33:30 +0200 | [diff] [blame] | 2590 | Override pmtimer IOPort with a hex value. |
| 2591 | e.g. pmtmr=0x508 |
| 2592 | |
Bjorn Helgaas | 9624211 | 2011-08-11 12:14:05 -0600 | [diff] [blame] | 2593 | pnp.debug=1 [PNP] |
| 2594 | Enable PNP debug messages (depends on the |
| 2595 | CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time |
| 2596 | via /sys/module/pnp/parameters/debug. We always show |
| 2597 | current resource usage; turning this on also shows |
| 2598 | possible settings and some assignment information. |
Bjorn Helgaas | 97ef062 | 2008-08-19 16:53:41 -0600 | [diff] [blame] | 2599 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2600 | pnpacpi= [ACPI] |
| 2601 | { off } |
| 2602 | |
| 2603 | pnpbios= [ISAPNP] |
| 2604 | { on | off | curr | res | no-curr | no-res } |
| 2605 | |
| 2606 | pnp_reserve_irq= |
| 2607 | [ISAPNP] Exclude IRQs for the autoconfiguration |
| 2608 | |
| 2609 | pnp_reserve_dma= |
| 2610 | [ISAPNP] Exclude DMAs for the autoconfiguration |
| 2611 | |
| 2612 | pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2613 | Ranges are in pairs (I/O port base and size). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2614 | |
| 2615 | pnp_reserve_mem= |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2616 | [ISAPNP] Exclude memory regions for the |
| 2617 | autoconfiguration. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2618 | Ranges are in pairs (memory base and size). |
| 2619 | |
Randy Dunlap | 4af94f3 | 2009-04-17 18:30:28 -0700 | [diff] [blame] | 2620 | ports= [IP_VS_FTP] IPVS ftp helper module |
| 2621 | Default is 21. |
| 2622 | Up to 8 (IP_VS_APP_MAX_PORTS) ports |
| 2623 | may be specified. |
| 2624 | Format: <port>,<port>.... |
| 2625 | |
Ingo Molnar | 45807a1 | 2007-07-15 23:40:10 -0700 | [diff] [blame] | 2626 | print-fatal-signals= |
| 2627 | [KNL] debug: print fatal signals |
Naohiro Ooiwa | f84d49b | 2009-11-09 00:46:42 +0900 | [diff] [blame] | 2628 | |
| 2629 | If enabled, warn about various signal handling |
| 2630 | related application anomalies: too many signals, |
| 2631 | too many POSIX.1 timers, fatal signals causing a |
| 2632 | coredump - etc. |
| 2633 | |
| 2634 | If you hit the warning due to signal overflow, |
| 2635 | you might want to try "ulimit -i unlimited". |
| 2636 | |
Ingo Molnar | 45807a1 | 2007-07-15 23:40:10 -0700 | [diff] [blame] | 2637 | default: off. |
| 2638 | |
Matthew Garrett | c22ab33 | 2012-03-05 14:59:10 -0800 | [diff] [blame] | 2639 | printk.always_kmsg_dump= |
| 2640 | Trigger kmsg_dump for cases other than kernel oops or |
| 2641 | panics |
| 2642 | Format: <bool> (1/Y/y=enable, 0/N/n=disable) |
| 2643 | default: disabled |
| 2644 | |
Randy Dunlap | e84845c | 2007-07-15 23:40:25 -0700 | [diff] [blame] | 2645 | printk.time= Show timing data prefixed to each printk message line |
| 2646 | Format: <bool> (1/Y/y=enable, 0/N/n=disable) |
| 2647 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 2648 | processor.max_cstate= [HW,ACPI] |
| 2649 | Limit processor to maximum C-state |
| 2650 | max_cstate=9 overrides any DMI blacklist limit. |
| 2651 | |
| 2652 | processor.nocst [HW,ACPI] |
| 2653 | Ignore the _CST method to determine C-states, |
| 2654 | instead using the legacy FADT method |
| 2655 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2656 | profile= [KNL] Enable kernel profiling via /proc/profile |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2657 | Format: [schedule,]<number> |
| 2658 | Param: "schedule" - profile schedule points. |
| 2659 | Param: <number> - step/bucket size as a power of 2 for |
| 2660 | statistical time based profiling. |
Mel Gorman | b3da2a7 | 2007-10-24 18:23:50 +0200 | [diff] [blame] | 2661 | Param: "sleep" - profile D-state sleeping (millisecs). |
| 2662 | Requires CONFIG_SCHEDSTATS |
Dave Jones | c0fe2e6 | 2007-10-20 03:08:22 +0200 | [diff] [blame] | 2663 | Param: "kvm" - profile VM exits. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2664 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2665 | prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk |
| 2666 | before loading. |
Randy Dunlap | 31c00fc | 2008-11-13 21:33:24 +0000 | [diff] [blame] | 2667 | See Documentation/blockdev/ramdisk.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2668 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2669 | psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to |
| 2670 | probe for; one of (bare|imps|exps|lifebook|any). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2671 | psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports |
| 2672 | per second. |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2673 | psmouse.resetafter= [HW,MOUSE] |
| 2674 | Try to reset the device after so many bad packets |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2675 | (0 = never). |
| 2676 | psmouse.resolution= |
| 2677 | [HW,MOUSE] Set desired mouse resolution, in dpi. |
| 2678 | psmouse.smartscroll= |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2679 | [HW,MOUSE] Controls Logitech smartscroll autorepeat. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2680 | 0 = disabled, 1 = enabled (default). |
| 2681 | |
Matthew Garrett | dee28e7 | 2011-07-21 16:57:55 -0400 | [diff] [blame] | 2682 | pstore.backend= Specify the name of the pstore backend to use |
| 2683 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2684 | pt. [PARIDE] |
Randy Dunlap | 31c00fc | 2008-11-13 21:33:24 +0000 | [diff] [blame] | 2685 | See Documentation/blockdev/paride.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2686 | |
Kay Sievers | dc8c858 | 2007-08-15 12:25:38 +0200 | [diff] [blame] | 2687 | pty.legacy_count= |
| 2688 | [KNL] Number of legacy pty's. Overwrites compiled-in |
| 2689 | default number. |
| 2690 | |
Randy Dunlap | 7d2c502 | 2006-09-29 02:01:02 -0700 | [diff] [blame] | 2691 | quiet [KNL] Disable most log messages |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2692 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2693 | r128= [HW,DRM] |
| 2694 | |
| 2695 | raid= [HW,RAID] |
| 2696 | See Documentation/md.txt. |
| 2697 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2698 | ramdisk_blocksize= [RAM] |
Randy Dunlap | 31c00fc | 2008-11-13 21:33:24 +0000 | [diff] [blame] | 2699 | See Documentation/blockdev/ramdisk.txt. |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2700 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2701 | ramdisk_size= [RAM] Sizes of RAM disks in kilobytes |
Randy Dunlap | 31c00fc | 2008-11-13 21:33:24 +0000 | [diff] [blame] | 2702 | See Documentation/blockdev/ramdisk.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2703 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2704 | rcu_nocbs= [KNL] |
Paul E. McKenney | 3fbfbf7 | 2012-08-19 21:35:53 -0700 | [diff] [blame] | 2705 | In kernels built with CONFIG_RCU_NOCB_CPU=y, set |
| 2706 | the specified list of CPUs to be no-callback CPUs. |
| 2707 | Invocation of these CPUs' RCU callbacks will |
Paul E. McKenney | a488985 | 2012-12-03 08:16:28 -0800 | [diff] [blame] | 2708 | be offloaded to "rcuox/N" kthreads created for |
| 2709 | that purpose, where "x" is "b" for RCU-bh, "p" |
| 2710 | for RCU-preempt, and "s" for RCU-sched, and "N" |
| 2711 | is the CPU number. This reduces OS jitter on the |
Paul E. McKenney | 3fbfbf7 | 2012-08-19 21:35:53 -0700 | [diff] [blame] | 2712 | offloaded CPUs, which can be useful for HPC and |
| 2713 | real-time workloads. It can also improve energy |
| 2714 | efficiency for asymmetric multiprocessors. |
| 2715 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2716 | rcu_nocb_poll [KNL] |
Paul E. McKenney | 3fbfbf7 | 2012-08-19 21:35:53 -0700 | [diff] [blame] | 2717 | Rather than requiring that offloaded CPUs |
| 2718 | (specified by rcu_nocbs= above) explicitly |
| 2719 | awaken the corresponding "rcuoN" kthreads, |
| 2720 | make these kthreads poll for callbacks. |
| 2721 | This improves the real-time response for the |
| 2722 | offloaded CPUs by relieving them of the need to |
| 2723 | wake up the corresponding kthread, but degrades |
| 2724 | energy efficiency by requiring that the kthreads |
| 2725 | periodically wake up to do the polling. |
| 2726 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2727 | rcutree.blimit= [KNL] |
Paul E. McKenney | 97e63f0 | 2013-10-27 09:44:03 -0700 | [diff] [blame] | 2728 | Set maximum number of finished RCU callbacks to |
| 2729 | process in one batch. |
Dipankar Sarma | 21a1ea9 | 2006-03-07 21:55:33 -0800 | [diff] [blame] | 2730 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2731 | rcutree.rcu_fanout_leaf= [KNL] |
Paul E. McKenney | f885b7f | 2012-04-23 15:52:53 -0700 | [diff] [blame] | 2732 | Increase the number of CPUs assigned to each |
| 2733 | leaf rcu_node structure. Useful for very large |
| 2734 | systems. |
| 2735 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2736 | rcutree.jiffies_till_first_fqs= [KNL] |
Paul E. McKenney | c0f4dfd | 2012-12-28 11:30:36 -0800 | [diff] [blame] | 2737 | Set delay from grace-period initialization to |
| 2738 | first attempt to force quiescent states. |
| 2739 | Units are jiffies, minimum value is zero, |
| 2740 | and maximum value is HZ. |
| 2741 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2742 | rcutree.jiffies_till_next_fqs= [KNL] |
Paul E. McKenney | c0f4dfd | 2012-12-28 11:30:36 -0800 | [diff] [blame] | 2743 | Set delay between subsequent attempts to force |
| 2744 | quiescent states. Units are jiffies, minimum |
| 2745 | value is one, and maximum value is HZ. |
| 2746 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2747 | rcutree.qhimark= [KNL] |
Paul E. McKenney | 97e63f0 | 2013-10-27 09:44:03 -0700 | [diff] [blame] | 2748 | Set threshold of queued RCU callbacks beyond which |
| 2749 | batch limiting is disabled. |
Dipankar Sarma | 21a1ea9 | 2006-03-07 21:55:33 -0800 | [diff] [blame] | 2750 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2751 | rcutree.qlowmark= [KNL] |
Robert P. J. Day | 24aaef8 | 2008-02-03 15:20:26 +0200 | [diff] [blame] | 2752 | Set threshold of queued RCU callbacks below which |
| 2753 | batch limiting is re-enabled. |
Dipankar Sarma | 21a1ea9 | 2006-03-07 21:55:33 -0800 | [diff] [blame] | 2754 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2755 | rcutree.rcu_idle_gp_delay= [KNL] |
Paul E. McKenney | c0f4dfd | 2012-12-28 11:30:36 -0800 | [diff] [blame] | 2756 | Set wakeup interval for idle CPUs that have |
| 2757 | RCU callbacks (RCU_FAST_NO_HZ=y). |
Paul E. McKenney | d40011f | 2012-06-26 20:45:57 -0700 | [diff] [blame] | 2758 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2759 | rcutree.rcu_idle_lazy_gp_delay= [KNL] |
Paul E. McKenney | c0f4dfd | 2012-12-28 11:30:36 -0800 | [diff] [blame] | 2760 | Set wakeup interval for idle CPUs that have |
| 2761 | only "lazy" RCU callbacks (RCU_FAST_NO_HZ=y). |
| 2762 | Lazy RCU callbacks are those which RCU can |
| 2763 | prove do nothing more than free memory. |
Paul E. McKenney | d40011f | 2012-06-26 20:45:57 -0700 | [diff] [blame] | 2764 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2765 | rcutorture.fqs_duration= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2766 | Set duration of force_quiescent_state bursts. |
| 2767 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2768 | rcutorture.fqs_holdoff= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2769 | Set holdoff time within force_quiescent_state bursts. |
| 2770 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2771 | rcutorture.fqs_stutter= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2772 | Set wait time between force_quiescent_state bursts. |
| 2773 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2774 | rcutorture.gp_exp= [KNL] |
| 2775 | Use expedited update-side primitives. |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2776 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2777 | rcutorture.gp_normal= [KNL] |
| 2778 | Use normal (non-expedited) update-side primitives. |
| 2779 | If both gp_exp and gp_normal are set, do both. |
| 2780 | If neither gp_exp nor gp_normal are set, still |
| 2781 | do both. |
| 2782 | |
| 2783 | rcutorture.n_barrier_cbs= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2784 | Set callbacks/threads for rcu_barrier() testing. |
| 2785 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2786 | rcutorture.nfakewriters= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2787 | Set number of concurrent RCU writers. These just |
| 2788 | stress RCU, they don't participate in the actual |
| 2789 | test, hence the "fake". |
| 2790 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2791 | rcutorture.nreaders= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2792 | Set number of RCU readers. |
| 2793 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2794 | rcutorture.object_debug= [KNL] |
| 2795 | Enable debug-object double-call_rcu() testing. |
| 2796 | |
| 2797 | rcutorture.onoff_holdoff= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2798 | Set time (s) after boot for CPU-hotplug testing. |
| 2799 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2800 | rcutorture.onoff_interval= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2801 | Set time (s) between CPU-hotplug operations, or |
| 2802 | zero to disable CPU-hotplug testing. |
| 2803 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2804 | rcutorture.rcutorture_runnable= [BOOT] |
| 2805 | Start rcutorture running at boot time. |
| 2806 | |
| 2807 | rcutorture.shuffle_interval= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2808 | Set task-shuffle interval (s). Shuffling tasks |
| 2809 | allows some CPUs to go into dyntick-idle mode |
| 2810 | during the rcutorture test. |
| 2811 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2812 | rcutorture.shutdown_secs= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2813 | Set time (s) after boot system shutdown. This |
| 2814 | is useful for hands-off automated testing. |
| 2815 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2816 | rcutorture.stall_cpu= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2817 | Duration of CPU stall (s) to test RCU CPU stall |
| 2818 | warnings, zero to disable. |
| 2819 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2820 | rcutorture.stall_cpu_holdoff= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2821 | Time to wait (s) after boot before inducing stall. |
| 2822 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2823 | rcutorture.stat_interval= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2824 | Time (s) between statistics printk()s. |
| 2825 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2826 | rcutorture.stutter= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2827 | Time (s) to stutter testing, for example, specifying |
| 2828 | five seconds causes the test to run for five seconds, |
| 2829 | wait for five seconds, and so on. This tests RCU's |
| 2830 | ability to transition abruptly to and from idle. |
| 2831 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2832 | rcutorture.test_boost= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2833 | Test RCU priority boosting? 0=no, 1=maybe, 2=yes. |
| 2834 | "Maybe" means test if the RCU implementation |
| 2835 | under test support RCU priority boosting. |
| 2836 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2837 | rcutorture.test_boost_duration= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2838 | Duration (s) of each individual boost test. |
| 2839 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2840 | rcutorture.test_boost_interval= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2841 | Interval (s) between each boost test. |
| 2842 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2843 | rcutorture.test_no_idle_hz= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2844 | Test RCU's dyntick-idle handling. See also the |
| 2845 | rcutorture.shuffle_interval parameter. |
| 2846 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2847 | rcutorture.torture_type= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2848 | Specify the RCU implementation to test. |
| 2849 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2850 | rcutorture.verbose= [KNL] |
Paul E. McKenney | dabb8aa | 2012-04-23 10:54:45 -0700 | [diff] [blame] | 2851 | Enable additional printk() statements. |
| 2852 | |
Paul E. McKenney | 4102ada | 2013-10-08 20:23:47 -0700 | [diff] [blame] | 2853 | rcupdate.rcu_expedited= [KNL] |
| 2854 | Use expedited grace-period primitives, for |
| 2855 | example, synchronize_rcu_expedited() instead |
| 2856 | of synchronize_rcu(). This reduces latency, |
| 2857 | but can increase CPU utilization, degrade |
| 2858 | real-time latency, and degrade energy efficiency. |
| 2859 | |
| 2860 | rcupdate.rcu_cpu_stall_suppress= [KNL] |
| 2861 | Suppress RCU CPU stall warning messages. |
| 2862 | |
| 2863 | rcupdate.rcu_cpu_stall_timeout= [KNL] |
| 2864 | Set timeout for RCU CPU stall warning messages. |
| 2865 | |
Olof Johansson | ffdfc40 | 2005-09-06 15:17:19 -0700 | [diff] [blame] | 2866 | rdinit= [KNL] |
| 2867 | Format: <full_path> |
| 2868 | Run specified binary instead of /init from the ramdisk, |
| 2869 | used for early userspace startup. See initrd. |
| 2870 | |
Robin Holt | 1b3a5d0 | 2013-07-08 16:01:42 -0700 | [diff] [blame] | 2871 | reboot= [KNL] |
| 2872 | Format (x86 or x86_64): |
| 2873 | [w[arm] | c[old] | h[ard] | s[oft] | g[pio]] \ |
| 2874 | [[,]s[mp]#### \ |
| 2875 | [[,]b[ios] | a[cpi] | k[bd] | t[riple] | e[fi] | p[ci]] \ |
| 2876 | [[,]f[orce] |
| 2877 | Where reboot_mode is one of warm (soft) or cold (hard) or gpio, |
| 2878 | reboot_type is one of bios, acpi, kbd, triple, efi, or pci, |
| 2879 | reboot_force is either force or not specified, |
| 2880 | reboot_cpu is s[mp]#### with #### being the processor |
| 2881 | to be used for rebooting. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2882 | |
Paul Jackson | 46b6d94 | 2008-07-04 10:00:09 -0700 | [diff] [blame] | 2883 | relax_domain_level= |
| 2884 | [KNL, SMP] Set scheduler's default relax_domain_level. |
Thadeu Lima de Souza Cascardo | 21acb9c | 2009-02-04 10:12:08 +0100 | [diff] [blame] | 2885 | See Documentation/cgroups/cpusets.txt. |
Paul Jackson | 46b6d94 | 2008-07-04 10:00:09 -0700 | [diff] [blame] | 2886 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2887 | reserve= [KNL,BUGS] Force the kernel to ignore some iomem area |
| 2888 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 2889 | reservetop= [X86-32] |
Zachary Amsden | 461a9af | 2006-09-25 23:32:25 -0700 | [diff] [blame] | 2890 | Format: nn[KMG] |
| 2891 | Reserves a hole at the top of the kernel virtual |
| 2892 | address space. |
| 2893 | |
H. Peter Anvin | 9ea77bd | 2010-08-25 16:38:20 -0700 | [diff] [blame] | 2894 | reservelow= [X86] |
| 2895 | Format: nn[K] |
| 2896 | Set the amount of memory to reserve for BIOS at |
| 2897 | the bottom of the address space. |
| 2898 | |
Vivek Goyal | 7e96287 | 2006-09-27 01:50:44 -0700 | [diff] [blame] | 2899 | reset_devices [KNL] Force drivers to reset the underlying device |
| 2900 | during initialization. |
| 2901 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2902 | resume= [SWSUSP] |
| 2903 | Specify the partition device for software suspend |
Minho Ban | 2df83fa | 2012-05-14 21:45:31 +0200 | [diff] [blame] | 2904 | Format: |
| 2905 | {/dev/<dev> | PARTUUID=<uuid> | <int>:<int> | <hex>} |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2906 | |
Rafael J. Wysocki | ecbd0da | 2006-12-06 20:34:13 -0800 | [diff] [blame] | 2907 | resume_offset= [SWSUSP] |
| 2908 | Specify the offset from the beginning of the partition |
| 2909 | given by "resume=" at which the swap header is located, |
| 2910 | in <PAGE_SIZE> units (needed only for swap files). |
| 2911 | See Documentation/power/swsusp-and-swap-files.txt |
| 2912 | |
Barry Song | f126f73 | 2011-10-10 23:38:41 +0200 | [diff] [blame] | 2913 | resumedelay= [HIBERNATION] Delay (in seconds) to pause before attempting to |
| 2914 | read the resume files |
| 2915 | |
Barry Song | 6f8d702 | 2011-10-06 20:34:46 +0200 | [diff] [blame] | 2916 | resumewait [HIBERNATION] Wait (indefinitely) for resume device to show up. |
| 2917 | Useful for devices that are detected asynchronously |
| 2918 | (e.g. USB and MMC devices). |
| 2919 | |
Bojan Smojver | f996fc9 | 2010-09-09 23:06:23 +0200 | [diff] [blame] | 2920 | hibernate= [HIBERNATION] |
| 2921 | noresume Don't check if there's a hibernation image |
| 2922 | present during boot. |
| 2923 | nocompress Don't compress/decompress hibernation images. |
| 2924 | |
Michael Neuling | 0a7b35cb | 2007-02-10 01:44:33 -0800 | [diff] [blame] | 2925 | retain_initrd [RAM] Keep initrd memory after extraction |
| 2926 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2927 | rhash_entries= [KNL,NET] |
| 2928 | Set number of hash buckets for route cache |
| 2929 | |
| 2930 | riscom8= [HW,SERIAL] |
| 2931 | Format: <io_board1>[,<io_board2>[,...<io_boardN>]] |
| 2932 | |
| 2933 | ro [KNL] Mount root device read-only on boot |
| 2934 | |
| 2935 | root= [KNL] Root filesystem |
Will Drewry | f2d34fd | 2011-08-03 16:21:08 -0700 | [diff] [blame] | 2936 | See name_to_dev_t comment in init/do_mounts.c. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2937 | |
| 2938 | rootdelay= [KNL] Delay (in seconds) to pause before attempting to |
| 2939 | mount the root filesystem |
| 2940 | |
| 2941 | rootflags= [KNL] Set root filesystem mount option string |
| 2942 | |
| 2943 | rootfstype= [KNL] Set root filesystem type |
| 2944 | |
Pierre Ossman | cc1ed75 | 2007-07-15 23:40:35 -0700 | [diff] [blame] | 2945 | rootwait [KNL] Wait (indefinitely) for root device to show up. |
| 2946 | Useful for devices that are detected asynchronously |
| 2947 | (e.g. USB and MMC devices). |
| 2948 | |
Robert Tivy | 5c71d61 | 2013-03-28 18:41:46 -0700 | [diff] [blame] | 2949 | rproc_mem=nn[KMG][@address] |
| 2950 | [KNL,ARM,CMA] Remoteproc physical memory block. |
| 2951 | Memory area to be used by remote processor image, |
| 2952 | managed by CMA. |
| 2953 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2954 | rw [KNL] Mount root device read-write on boot |
| 2955 | |
| 2956 | S [KNL] Run init in single mode |
| 2957 | |
| 2958 | sa1100ir [NET] |
| 2959 | See drivers/net/irda/sa1100_ir.c. |
| 2960 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2961 | sbni= [NET] Granch SBNI12 leased line adapter |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 2962 | |
Mike Travis | f663011 | 2009-11-17 18:22:15 -0600 | [diff] [blame] | 2963 | sched_debug [KNL] Enables verbose scheduler debug messages. |
| 2964 | |
Mike Galbraith | 5307c95 | 2012-05-08 12:20:58 +0200 | [diff] [blame] | 2965 | skew_tick= [KNL] Offset the periodic timer tick per cpu to mitigate |
| 2966 | xtime_lock contention on larger systems, and/or RCU lock |
| 2967 | contention on all systems with CONFIG_MAXSMP set. |
| 2968 | Format: { "0" | "1" } |
| 2969 | 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1" |
| 2970 | 1 -- enable. |
| 2971 | Note: increases power consumption, thus should only be |
| 2972 | enabled if running jitter sensitive (HPC/RT) workloads. |
| 2973 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 2974 | security= [SECURITY] Choose a security module to enable at boot. |
| 2975 | If this boot parameter is not specified, only the first |
| 2976 | security module asking for security registration will be |
| 2977 | loaded. An invalid security module name will be treated |
| 2978 | as if no module has been chosen. |
| 2979 | |
| 2980 | selinux= [SELINUX] Disable or enable SELinux at boot time. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2981 | Format: { "0" | "1" } |
| 2982 | See security/selinux/Kconfig help text. |
| 2983 | 0 -- disable. |
| 2984 | 1 -- enable. |
| 2985 | Default value is set via kernel config option. |
| 2986 | If enabled at boot time, /selinux/disable can be used |
| 2987 | later to disable prior to initial policy load. |
| 2988 | |
John Johansen | c1c124e | 2010-07-29 14:48:09 -0700 | [diff] [blame] | 2989 | apparmor= [APPARMOR] Disable or enable AppArmor at boot time |
| 2990 | Format: { "0" | "1" } |
| 2991 | See security/apparmor/Kconfig help text |
| 2992 | 0 -- disable. |
| 2993 | 1 -- enable. |
| 2994 | Default value is set via kernel config option. |
| 2995 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 2996 | serialnumber [BUGS=X86-32] |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2997 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2998 | shapers= [NET] |
| 2999 | Maximal number of shapers. |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 3000 | |
Yinghai Lu | b05f78f | 2008-08-22 01:32:50 -0700 | [diff] [blame] | 3001 | show_msr= [x86] show boot-time MSR settings |
| 3002 | Format: { <integer> } |
| 3003 | Show boot-time (BIOS-initialized) MSR settings. |
| 3004 | The parameter means the number of CPUs to show, |
| 3005 | for example 1 means boot CPU only. |
| 3006 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3007 | simeth= [IA-64] |
| 3008 | simscsi= |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 3009 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3010 | slram= [HW,MTD] |
| 3011 | |
David Rientjes | 3df1ccc | 2011-10-18 22:09:28 -0700 | [diff] [blame] | 3012 | slab_max_order= [MM, SLAB] |
| 3013 | Determines the maximum allowed order for slabs. |
| 3014 | A high setting may cause OOMs due to memory |
| 3015 | fragmentation. Defaults to 1 for systems with |
| 3016 | more than 32MB of RAM, 0 otherwise. |
| 3017 | |
Christoph Lameter | f0630ff | 2007-07-15 23:38:14 -0700 | [diff] [blame] | 3018 | slub_debug[=options[,slabs]] [MM, SLUB] |
| 3019 | Enabling slub_debug allows one to determine the |
| 3020 | culprit if slab objects become corrupted. Enabling |
| 3021 | slub_debug can create guard zones around objects and |
| 3022 | may poison objects when not in use. Also tracks the |
| 3023 | last alloc / free. For more information see |
| 3024 | Documentation/vm/slub.txt. |
Christoph Lameter | c1aee21 | 2007-05-31 00:40:47 -0700 | [diff] [blame] | 3025 | |
| 3026 | slub_max_order= [MM, SLUB] |
Christoph Lameter | f0630ff | 2007-07-15 23:38:14 -0700 | [diff] [blame] | 3027 | Determines the maximum allowed order for slabs. |
| 3028 | A high setting may cause OOMs due to memory |
| 3029 | fragmentation. For more information see |
| 3030 | Documentation/vm/slub.txt. |
Christoph Lameter | c1aee21 | 2007-05-31 00:40:47 -0700 | [diff] [blame] | 3031 | |
| 3032 | slub_min_objects= [MM, SLUB] |
Christoph Lameter | f0630ff | 2007-07-15 23:38:14 -0700 | [diff] [blame] | 3033 | The minimum number of objects per slab. SLUB will |
| 3034 | increase the slab order up to slub_max_order to |
| 3035 | generate a sufficiently large slab able to contain |
| 3036 | the number of objects indicated. The higher the number |
| 3037 | of objects the smaller the overhead of tracking slabs |
| 3038 | and the less frequently locks need to be acquired. |
Christoph Lameter | c1aee21 | 2007-05-31 00:40:47 -0700 | [diff] [blame] | 3039 | For more information see Documentation/vm/slub.txt. |
| 3040 | |
| 3041 | slub_min_order= [MM, SLUB] |
Masanari Iida | 24775d6 | 2012-02-15 00:26:42 +0900 | [diff] [blame] | 3042 | Determines the minimum page order for slabs. Must be |
Christoph Lameter | f0630ff | 2007-07-15 23:38:14 -0700 | [diff] [blame] | 3043 | lower than slub_max_order. |
Christoph Lameter | c1aee21 | 2007-05-31 00:40:47 -0700 | [diff] [blame] | 3044 | For more information see Documentation/vm/slub.txt. |
| 3045 | |
| 3046 | slub_nomerge [MM, SLUB] |
Christoph Lameter | f0630ff | 2007-07-15 23:38:14 -0700 | [diff] [blame] | 3047 | Disable merging of slabs with similar size. May be |
Christoph Lameter | c1aee21 | 2007-05-31 00:40:47 -0700 | [diff] [blame] | 3048 | necessary if there is some reason to distinguish |
Christoph Lameter | f0630ff | 2007-07-15 23:38:14 -0700 | [diff] [blame] | 3049 | allocs to different slabs. Debug options disable |
| 3050 | merging on their own. |
Christoph Lameter | c1aee21 | 2007-05-31 00:40:47 -0700 | [diff] [blame] | 3051 | For more information see Documentation/vm/slub.txt. |
| 3052 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3053 | smart2= [HW] |
| 3054 | Format: <io1>[,<io2>[,...,<io8>]] |
| 3055 | |
Bjorn Helgaas | d0d4f69 | 2007-05-08 00:36:05 -0700 | [diff] [blame] | 3056 | smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices |
| 3057 | smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port |
| 3058 | smsc-ircc2.ircc_sir= [HW] SIR base I/O port |
| 3059 | smsc-ircc2.ircc_fir= [HW] FIR base I/O port |
| 3060 | smsc-ircc2.ircc_irq= [HW] IRQ line |
| 3061 | smsc-ircc2.ircc_dma= [HW] DMA channel |
| 3062 | smsc-ircc2.ircc_transceiver= [HW] Transceiver type: |
| 3063 | 0: Toshiba Satellite 1800 (GP data pin select) |
| 3064 | 1: Fast pin select (default) |
| 3065 | 2: ATC IRMode |
| 3066 | |
Ingo Molnar | 9c44bc0 | 2008-05-12 21:21:04 +0200 | [diff] [blame] | 3067 | softlockup_panic= |
| 3068 | [KNL] Should the soft-lockup detector generate panics. |
Randy Dunlap | 44a4dcf | 2011-04-04 15:02:24 -0700 | [diff] [blame] | 3069 | Format: <integer> |
Ingo Molnar | 9c44bc0 | 2008-05-12 21:21:04 +0200 | [diff] [blame] | 3070 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3071 | sonypi.*= [HW] Sony Programmable I/O Control Device driver |
Paul Bolle | 395cf96 | 2011-08-15 02:02:26 +0200 | [diff] [blame] | 3072 | See Documentation/laptops/sonypi.txt |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3073 | |
| 3074 | specialix= [HW,SERIAL] Specialix multi-serial port adapter |
Randy Dunlap | 31c00fc | 2008-11-13 21:33:24 +0000 | [diff] [blame] | 3075 | See Documentation/serial/specialix.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3076 | |
| 3077 | spia_io_base= [HW,MTD] |
| 3078 | spia_fio_base= |
| 3079 | spia_pedr= |
| 3080 | spia_peddr= |
| 3081 | |
Steven Rostedt | f38f1d2 | 2008-12-16 23:06:40 -0500 | [diff] [blame] | 3082 | stacktrace [FTRACE] |
| 3083 | Enabled the stack tracer on boot up. |
| 3084 | |
Steven Rostedt | 762e120 | 2011-12-19 22:01:00 -0500 | [diff] [blame] | 3085 | stacktrace_filter=[function-list] |
| 3086 | [FTRACE] Limit the functions that the stack tracer |
| 3087 | will trace at boot up. function-list is a comma separated |
| 3088 | list of functions. This list can be changed at run |
| 3089 | time by the stack_trace_filter file in the debugfs |
| 3090 | tracing directory. Note, this enables stack tracing |
| 3091 | and the stacktrace above is not needed. |
| 3092 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3093 | sti= [PARISC,HW] |
| 3094 | Format: <num> |
| 3095 | Set the STI (builtin display/keyboard on the HP-PARISC |
| 3096 | machines) console (graphic card) which should be used |
| 3097 | as the initial boot-console. |
| 3098 | See also comment in drivers/video/console/sticore.c. |
| 3099 | |
| 3100 | sti_font= [HW] |
| 3101 | See comment in drivers/video/console/sticore.c. |
| 3102 | |
| 3103 | stifb= [HW] |
| 3104 | Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]] |
| 3105 | |
Trond Myklebust | cbf1107 | 2009-08-09 15:06:19 -0400 | [diff] [blame] | 3106 | sunrpc.min_resvport= |
| 3107 | sunrpc.max_resvport= |
| 3108 | [NFS,SUNRPC] |
| 3109 | SunRPC servers often require that client requests |
| 3110 | originate from a privileged port (i.e. a port in the |
| 3111 | range 0 < portnr < 1024). |
| 3112 | An administrator who wishes to reserve some of these |
| 3113 | ports for other uses may adjust the range that the |
| 3114 | kernel's sunrpc client considers to be privileged |
| 3115 | using these two parameters to set the minimum and |
| 3116 | maximum port values. |
| 3117 | |
Greg Banks | 42a7fc4 | 2007-03-06 01:42:23 -0800 | [diff] [blame] | 3118 | sunrpc.pool_mode= |
| 3119 | [NFS] |
| 3120 | Control how the NFS server code allocates CPUs to |
| 3121 | service thread pools. Depending on how many NICs |
| 3122 | you have and where their interrupts are bound, this |
| 3123 | option will affect which CPUs will do NFS serving. |
| 3124 | Note: this parameter cannot be changed while the |
| 3125 | NFS server is running. |
| 3126 | |
| 3127 | auto the server chooses an appropriate mode |
| 3128 | automatically using heuristics |
| 3129 | global a single global pool contains all CPUs |
| 3130 | percpu one pool for each CPU |
| 3131 | pernode one pool for each NUMA node (equivalent |
| 3132 | to global on non-NUMA machines) |
| 3133 | |
Trond Myklebust | cbf1107 | 2009-08-09 15:06:19 -0400 | [diff] [blame] | 3134 | sunrpc.tcp_slot_table_entries= |
| 3135 | sunrpc.udp_slot_table_entries= |
| 3136 | [NFS,SUNRPC] |
| 3137 | Sets the upper limit on the number of simultaneous |
| 3138 | RPC calls that can be sent from the client to a |
| 3139 | server. Increasing these values may allow you to |
| 3140 | improve throughput, but will also increase the |
| 3141 | amount of memory reserved for use by the client. |
| 3142 | |
Michal Hocko | 07555ac | 2013-08-22 16:35:46 -0700 | [diff] [blame] | 3143 | swapaccount=[0|1] |
Michal Hocko | a42c390 | 2010-11-24 12:57:08 -0800 | [diff] [blame] | 3144 | [KNL] Enable accounting of swap in memory resource |
| 3145 | controller if no parameter or 1 is given or disable |
| 3146 | it if 0 is given (See Documentation/cgroups/memory.txt) |
| 3147 | |
Jiri Kosina | 91fec0f | 2013-11-27 13:48:09 +0100 | [diff] [blame] | 3148 | swiotlb= [ARM,IA-64,PPC,MIPS,X86] |
| 3149 | Format: { <int> | force } |
| 3150 | <int> -- Number of I/O TLB slabs |
| 3151 | force -- force using of bounce buffers even if they |
| 3152 | wouldn't be automatically used by the kernel |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 3153 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3154 | switches= [HW,M68k] |
| 3155 | |
Andi Kleen | e52eec1 | 2010-09-08 16:54:17 +0200 | [diff] [blame] | 3156 | sysfs.deprecated=0|1 [KNL] |
| 3157 | Enable/disable old style sysfs layout for old udev |
| 3158 | on older distributions. When this option is enabled |
| 3159 | very new udev will not work anymore. When this option |
| 3160 | is disabled (or CONFIG_SYSFS_DEPRECATED not compiled) |
| 3161 | in older udev will not work anymore. |
| 3162 | Default depends on CONFIG_SYSFS_DEPRECATED_V2 set in |
| 3163 | the kernel configuration. |
| 3164 | |
Ingo Molnar | 5d6f647 | 2006-12-13 00:34:36 -0800 | [diff] [blame] | 3165 | sysrq_always_enabled |
| 3166 | [KNL] |
| 3167 | Ignore sysrq setting - this boot parameter will |
| 3168 | neutralize any effect of /proc/sys/kernel/sysrq. |
| 3169 | Useful for debugging. |
| 3170 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3171 | tdfx= [HW,DRM] |
| 3172 | |
David Brownell | 77437fd | 2008-07-23 21:28:33 -0700 | [diff] [blame] | 3173 | test_suspend= [SUSPEND] |
| 3174 | Specify "mem" (for Suspend-to-RAM) or "standby" (for |
| 3175 | standby suspend) as the system sleep state to briefly |
| 3176 | enter during system startup. The system is woken from |
| 3177 | this state using a wakeup-capable RTC alarm. |
| 3178 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3179 | thash_entries= [KNL,NET] |
| 3180 | Set number of hash buckets for TCP connection |
| 3181 | |
Len Brown | f8707ec | 2007-08-12 00:12:54 -0400 | [diff] [blame] | 3182 | thermal.act= [HW,ACPI] |
| 3183 | -1: disable all active trip points in all thermal zones |
| 3184 | <degrees C>: override all lowest active trip points |
| 3185 | |
Len Brown | c52a741 | 2007-08-14 15:49:32 -0400 | [diff] [blame] | 3186 | thermal.crt= [HW,ACPI] |
| 3187 | -1: disable all critical trip points in all thermal zones |
Zhang Rui | 22a94d7 | 2008-10-17 02:41:20 -0400 | [diff] [blame] | 3188 | <degrees C>: override all critical trip points |
Len Brown | c52a741 | 2007-08-14 15:49:32 -0400 | [diff] [blame] | 3189 | |
Len Brown | f548714 | 2007-08-12 00:12:44 -0400 | [diff] [blame] | 3190 | thermal.nocrt= [HW,ACPI] |
| 3191 | Set to disable actions on ACPI thermal zone |
| 3192 | critical and hot trip points. |
| 3193 | |
Len Brown | 72b33ef | 2007-08-12 00:12:17 -0400 | [diff] [blame] | 3194 | thermal.off= [HW,ACPI] |
| 3195 | 1: disable ACPI thermal control |
| 3196 | |
Len Brown | a70cdc5 | 2007-08-12 00:12:35 -0400 | [diff] [blame] | 3197 | thermal.psv= [HW,ACPI] |
| 3198 | -1: disable all passive trip points |
Randy Dunlap | ada9cfd | 2008-12-19 10:57:32 -0800 | [diff] [blame] | 3199 | <degrees C>: override all passive trip points to this |
| 3200 | value |
Len Brown | a70cdc5 | 2007-08-12 00:12:35 -0400 | [diff] [blame] | 3201 | |
Len Brown | 730ff34 | 2007-08-12 00:12:26 -0400 | [diff] [blame] | 3202 | thermal.tzp= [HW,ACPI] |
| 3203 | Specify global default ACPI thermal zone polling rate |
| 3204 | <deci-seconds>: poll all this frequency |
| 3205 | 0: no polling (default) |
| 3206 | |
Thomas Gleixner | 8d32a30 | 2011-02-23 23:52:23 +0000 | [diff] [blame] | 3207 | threadirqs [KNL] |
| 3208 | Force threading of all interrupt handlers except those |
Masanari Iida | 24775d6 | 2012-02-15 00:26:42 +0900 | [diff] [blame] | 3209 | marked explicitly IRQF_NO_THREAD. |
Thomas Gleixner | 8d32a30 | 2011-02-23 23:52:23 +0000 | [diff] [blame] | 3210 | |
Konrad Rzeszutek Wilk | 2ca62b0 | 2013-05-08 17:12:44 -0400 | [diff] [blame] | 3211 | tmem [KNL,XEN] |
| 3212 | Enable the Transcendent memory driver if built-in. |
| 3213 | |
| 3214 | tmem.cleancache=0|1 [KNL, XEN] |
| 3215 | Default is on (1). Disable the usage of the cleancache |
| 3216 | API to send anonymous pages to the hypervisor. |
| 3217 | |
| 3218 | tmem.frontswap=0|1 [KNL, XEN] |
| 3219 | Default is on (1). Disable the usage of the frontswap |
Konrad Rzeszutek Wilk | 37d46e1 | 2013-05-14 13:56:42 -0400 | [diff] [blame] | 3220 | API to send swap pages to the hypervisor. If disabled |
| 3221 | the selfballooning and selfshrinking are force disabled. |
Konrad Rzeszutek Wilk | 2ca62b0 | 2013-05-08 17:12:44 -0400 | [diff] [blame] | 3222 | |
| 3223 | tmem.selfballooning=0|1 [KNL, XEN] |
| 3224 | Default is on (1). Disable the driving of swap pages |
| 3225 | to the hypervisor. |
| 3226 | |
| 3227 | tmem.selfshrinking=0|1 [KNL, XEN] |
| 3228 | Default is on (1). Partial swapoff that immediately |
| 3229 | transfers pages from Xen hypervisor back to the |
| 3230 | kernel based on different criteria. |
| 3231 | |
Heiko Carstens | 2b1a61f | 2008-12-25 13:39:23 +0100 | [diff] [blame] | 3232 | topology= [S390] |
| 3233 | Format: {off | on} |
| 3234 | Specify if the kernel should make use of the cpu |
Sylvestre Ledru | f65e51d | 2011-04-04 15:04:46 -0700 | [diff] [blame] | 3235 | topology information if the hardware supports this. |
| 3236 | The scheduler will make use of this information and |
Heiko Carstens | 2b1a61f | 2008-12-25 13:39:23 +0100 | [diff] [blame] | 3237 | e.g. base its process migration decisions on it. |
Heiko Carstens | c9af3fa | 2010-10-25 16:10:43 +0200 | [diff] [blame] | 3238 | Default is on. |
Heiko Carstens | 2b1a61f | 2008-12-25 13:39:23 +0100 | [diff] [blame] | 3239 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3240 | tp720= [HW,PS2] |
| 3241 | |
Rajiv Andrade | 225a9be | 2010-03-25 00:55:32 -0300 | [diff] [blame] | 3242 | tpm_suspend_pcr=[HW,TPM] |
| 3243 | Format: integer pcr id |
| 3244 | Specify that at suspend time, the tpm driver |
| 3245 | should extend the specified pcr with zeros, |
| 3246 | as a workaround for some chips which fail to |
| 3247 | flush the last written pcr on TPM_SaveState. |
| 3248 | This will guarantee that all the other pcrs |
| 3249 | are saved. |
| 3250 | |
Li Zefan | 9d612be | 2009-06-24 17:33:15 +0800 | [diff] [blame] | 3251 | trace_buf_size=nn[KMG] |
| 3252 | [FTRACE] will set tracing buffer size. |
KOSAKI Motohiro | 631595f | 2009-03-10 13:57:10 +0900 | [diff] [blame] | 3253 | |
Li Zefan | 020e5f8 | 2009-07-01 10:47:05 +0800 | [diff] [blame] | 3254 | trace_event=[event-list] |
| 3255 | [FTRACE] Set and start specified trace events in order |
| 3256 | to facilitate early boot debugging. |
| 3257 | See also Documentation/trace/events.txt |
| 3258 | |
Steven Rostedt | 7bcfaf5 | 2012-11-01 22:56:07 -0400 | [diff] [blame] | 3259 | trace_options=[option-list] |
| 3260 | [FTRACE] Enable or disable tracer options at boot. |
| 3261 | The option-list is a comma delimited list of options |
| 3262 | that can be enabled or disabled just as if you were |
| 3263 | to echo the option name into |
| 3264 | |
| 3265 | /sys/kernel/debug/tracing/trace_options |
| 3266 | |
| 3267 | For example, to enable stacktrace option (to dump the |
| 3268 | stack trace of each event), add to the command line: |
| 3269 | |
| 3270 | trace_options=stacktrace |
| 3271 | |
| 3272 | See also Documentation/trace/ftrace.txt "trace options" |
| 3273 | section. |
| 3274 | |
Steven Rostedt (Red Hat) | de7edd3 | 2013-06-14 16:21:43 -0400 | [diff] [blame] | 3275 | traceoff_on_warning |
| 3276 | [FTRACE] enable this option to disable tracing when a |
| 3277 | warning is hit. This turns off "tracing_on". Tracing can |
| 3278 | be enabled again by echoing '1' into the "tracing_on" |
| 3279 | file located in /sys/kernel/debug/tracing/ |
| 3280 | |
| 3281 | This option is useful, as it disables the trace before |
| 3282 | the WARNING dump is called, which prevents the trace to |
| 3283 | be filled with content caused by the warning output. |
| 3284 | |
| 3285 | This option can also be set at run time via the sysctl |
| 3286 | option: kernel/traceoff_on_warning |
| 3287 | |
Jiri Kosina | fcf4d82 | 2012-03-21 16:34:02 -0700 | [diff] [blame] | 3288 | transparent_hugepage= |
| 3289 | [KNL] |
| 3290 | Format: [always|madvise|never] |
| 3291 | Can be used to control the default behavior of the system |
| 3292 | with respect to transparent hugepages. |
| 3293 | See Documentation/vm/transhuge.txt for more details. |
| 3294 | |
john stultz | d3b8f88 | 2009-08-17 16:40:47 -0700 | [diff] [blame] | 3295 | tsc= Disable clocksource stability checks for TSC. |
Alok Kataria | 395628e | 2008-10-24 17:22:01 -0700 | [diff] [blame] | 3296 | Format: <string> |
| 3297 | [x86] reliable: mark tsc clocksource as reliable, this |
john stultz | d3b8f88 | 2009-08-17 16:40:47 -0700 | [diff] [blame] | 3298 | disables clocksource verification at runtime, as well |
| 3299 | as the stability checks done at bootup. Used to enable |
| 3300 | high-resolution timer mode on older hardware, and in |
| 3301 | virtualized environment. |
Venkatesh Pallipadi | e82b8e4 | 2010-10-04 17:03:20 -0700 | [diff] [blame] | 3302 | [x86] noirqtime: Do not use TSC to do irq accounting. |
| 3303 | Used to run time disable IRQ_TIME_ACCOUNTING on any |
| 3304 | platforms where RDTSC is slow and this accounting |
| 3305 | can add overhead. |
Alok Kataria | 395628e | 2008-10-24 17:22:01 -0700 | [diff] [blame] | 3306 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 3307 | turbografx.map[2|3]= [HW,JOY] |
| 3308 | TurboGraFX parallel port interface |
| 3309 | Format: |
| 3310 | <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3311 | See also Documentation/input/joystick-parport.txt |
| 3312 | |
Christian Kujau | b6935f8 | 2011-05-31 15:22:05 +0000 | [diff] [blame] | 3313 | udbg-immortal [PPC] When debugging early kernel crashes that |
| 3314 | happen after console_init() and before a proper |
| 3315 | console driver takes over, this boot options might |
| 3316 | help "seeing" what's going on. |
| 3317 | |
Eric Dumazet | f86dcc5 | 2009-10-07 00:37:59 +0000 | [diff] [blame] | 3318 | uhash_entries= [KNL,NET] |
| 3319 | Set number of hash buckets for UDP/UDP-Lite connections |
| 3320 | |
Alan Stern | 5f8364b | 2006-12-05 16:29:55 -0500 | [diff] [blame] | 3321 | uhci-hcd.ignore_oc= |
| 3322 | [USB] Ignore overcurrent events (default N). |
| 3323 | Some badly-designed motherboards generate lots of |
| 3324 | bogus events, for ports that aren't wired to |
| 3325 | anything. Set this parameter to avoid log spamming. |
| 3326 | Note that genuine overcurrent events won't be |
| 3327 | reported either. |
| 3328 | |
Simon Arlott | e3a61b0 | 2008-07-19 23:32:54 +0100 | [diff] [blame] | 3329 | unknown_nmi_panic |
Randy Dunlap | 44a4dcf | 2011-04-04 15:02:24 -0700 | [diff] [blame] | 3330 | [X86] Cause panic on unknown NMI. |
Simon Arlott | e3a61b0 | 2008-07-19 23:32:54 +0100 | [diff] [blame] | 3331 | |
Carl-Daniel Hailfinger | c4fc234 | 2011-05-31 21:31:08 +0200 | [diff] [blame] | 3332 | usbcore.authorized_default= |
| 3333 | [USB] Default USB device authorization: |
| 3334 | (default -1 = authorized except for wireless USB, |
| 3335 | 0 = not authorized, 1 = authorized) |
| 3336 | |
Alan Stern | b5e795f | 2007-02-20 15:00:53 -0500 | [diff] [blame] | 3337 | usbcore.autosuspend= |
| 3338 | [USB] The autosuspend time delay (in seconds) used |
| 3339 | for newly-detected USB devices (default 2). This |
| 3340 | is the time required before an idle device will be |
| 3341 | autosuspended. Devices for which the delay is set |
Alan Stern | eaafbc3 | 2007-03-13 16:39:15 -0400 | [diff] [blame] | 3342 | to a negative value won't be autosuspended at all. |
Alan Stern | b5e795f | 2007-02-20 15:00:53 -0500 | [diff] [blame] | 3343 | |
Jaroslav Kysela | fd7c519 | 2008-10-10 16:24:45 +0200 | [diff] [blame] | 3344 | usbcore.usbfs_snoop= |
| 3345 | [USB] Set to log all usbfs traffic (default 0 = off). |
| 3346 | |
| 3347 | usbcore.blinkenlights= |
| 3348 | [USB] Set to cycle leds on hubs (default 0 = off). |
| 3349 | |
| 3350 | usbcore.old_scheme_first= |
| 3351 | [USB] Start with the old device initialization |
| 3352 | scheme (default 0 = off). |
| 3353 | |
Alan Stern | 3f5eb8d | 2011-11-17 16:41:35 -0500 | [diff] [blame] | 3354 | usbcore.usbfs_memory_mb= |
| 3355 | [USB] Memory limit (in MB) for buffers allocated by |
| 3356 | usbfs (default = 16, 0 = max = 2047). |
| 3357 | |
Jaroslav Kysela | fd7c519 | 2008-10-10 16:24:45 +0200 | [diff] [blame] | 3358 | usbcore.use_both_schemes= |
| 3359 | [USB] Try the other device initialization scheme |
| 3360 | if the first one fails (default 1 = enabled). |
| 3361 | |
| 3362 | usbcore.initial_descriptor_timeout= |
| 3363 | [USB] Specifies timeout for the initial 64-byte |
| 3364 | USB_REQ_GET_DESCRIPTOR request in milliseconds |
| 3365 | (default 5000 = 5.0 seconds). |
| 3366 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3367 | usbhid.mousepoll= |
| 3368 | [USBHID] The interval which mice are to be polled at. |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 3369 | |
Alan Stern | d4f373e | 2008-11-10 14:07:45 -0500 | [diff] [blame] | 3370 | usb-storage.delay_use= |
| 3371 | [UMS] The delay in seconds before a new device is |
| 3372 | scanned for Logical Units (default 5). |
| 3373 | |
| 3374 | usb-storage.quirks= |
| 3375 | [UMS] A list of quirks entries to supplement or |
| 3376 | override the built-in unusual_devs list. List |
| 3377 | entries are separated by commas. Each entry has |
| 3378 | the form VID:PID:Flags where VID and PID are Vendor |
| 3379 | and Product ID values (4-digit hex numbers) and |
| 3380 | Flags is a set of characters, each corresponding |
| 3381 | to a common usb-storage quirk flag as follows: |
Alan Stern | c838ea4 | 2008-12-15 10:40:06 -0500 | [diff] [blame] | 3382 | a = SANE_SENSE (collect more than 18 bytes |
| 3383 | of sense data); |
Alan Stern | a0bb108 | 2009-12-07 16:39:16 -0500 | [diff] [blame] | 3384 | b = BAD_SENSE (don't collect more than 18 |
| 3385 | bytes of sense data); |
Alan Stern | d4f373e | 2008-11-10 14:07:45 -0500 | [diff] [blame] | 3386 | c = FIX_CAPACITY (decrease the reported |
| 3387 | device capacity by one sector); |
Karl Relton | 5116901 | 2011-05-18 21:42:34 +0100 | [diff] [blame] | 3388 | d = NO_READ_DISC_INFO (don't use |
| 3389 | READ_DISC_INFO command); |
| 3390 | e = NO_READ_CAPACITY_16 (don't use |
| 3391 | READ_CAPACITY_16 command); |
Alan Stern | c838ea4 | 2008-12-15 10:40:06 -0500 | [diff] [blame] | 3392 | h = CAPACITY_HEURISTICS (decrease the |
| 3393 | reported device capacity by one |
| 3394 | sector if the number is odd); |
Alan Stern | d4f373e | 2008-11-10 14:07:45 -0500 | [diff] [blame] | 3395 | i = IGNORE_DEVICE (don't bind to this |
| 3396 | device); |
| 3397 | l = NOT_LOCKABLE (don't try to lock and |
| 3398 | unlock ejectable media); |
| 3399 | m = MAX_SECTORS_64 (don't transfer more |
| 3400 | than 64 sectors = 32 KB at a time); |
Alan Stern | 21c13a4 | 2011-06-07 11:35:52 -0400 | [diff] [blame] | 3401 | n = INITIAL_READ10 (force a retry of the |
| 3402 | initial READ(10) command); |
Alan Stern | c838ea4 | 2008-12-15 10:40:06 -0500 | [diff] [blame] | 3403 | o = CAPACITY_OK (accept the capacity |
| 3404 | reported by the device); |
Namjae Jeon | eaa05df | 2012-07-07 23:05:28 -0400 | [diff] [blame] | 3405 | p = WRITE_CACHE (the device cache is ON |
| 3406 | by default); |
Alan Stern | d4f373e | 2008-11-10 14:07:45 -0500 | [diff] [blame] | 3407 | r = IGNORE_RESIDUE (the device reports |
| 3408 | bogus residue values); |
| 3409 | s = SINGLE_LUN (the device has only one |
| 3410 | Logical Unit); |
| 3411 | w = NO_WP_DETECT (don't test whether the |
| 3412 | medium is write-protected). |
| 3413 | Example: quirks=0419:aaf5:rl,0421:0433:rc |
| 3414 | |
Stephen Boyd | ac1667d | 2011-08-13 12:34:50 -0700 | [diff] [blame] | 3415 | user_debug= [KNL,ARM] |
| 3416 | Format: <int> |
| 3417 | See arch/arm/Kconfig.debug help text. |
| 3418 | 1 - undefined instruction events |
| 3419 | 2 - system calls |
| 3420 | 4 - invalid data aborts |
| 3421 | 8 - SIGSEGV faults |
| 3422 | 16 - SIGBUS faults |
| 3423 | Example: user_debug=31 |
| 3424 | |
Ian Campbell | 1431559 | 2010-02-17 10:38:10 +0000 | [diff] [blame] | 3425 | userpte= |
| 3426 | [X86] Flags controlling user PTE allocations. |
| 3427 | |
| 3428 | nohigh = do not allocate PTE pages in |
| 3429 | HIGHMEM regardless of setting |
| 3430 | of CONFIG_HIGHPTE. |
| 3431 | |
Jaswinder Singh Rajput | 6cececf | 2009-04-14 14:03:43 +0530 | [diff] [blame] | 3432 | vdso= [X86,SH] |
Andy Lutomirski | b0b49f2 | 2014-03-13 16:01:26 -0700 | [diff] [blame] | 3433 | On X86_32, this is an alias for vdso32=. Otherwise: |
| 3434 | |
| 3435 | vdso=1: enable VDSO (the default) |
Ingo Molnar | e6e5494 | 2006-06-27 02:53:50 -0700 | [diff] [blame] | 3436 | vdso=0: disable VDSO mapping |
| 3437 | |
Andy Lutomirski | b0b49f2 | 2014-03-13 16:01:26 -0700 | [diff] [blame] | 3438 | vdso32= [X86] Control the 32-bit vDSO |
| 3439 | vdso32=1: enable 32-bit VDSO |
| 3440 | vdso32=0 or vdso32=2: disable 32-bit VDSO |
| 3441 | |
| 3442 | See the help text for CONFIG_COMPAT_VDSO for more |
| 3443 | details. If CONFIG_COMPAT_VDSO is set, the default is |
| 3444 | vdso32=0; otherwise, the default is vdso32=1. |
| 3445 | |
| 3446 | For compatibility with older kernels, vdso32=2 is an |
| 3447 | alias for vdso32=0. |
| 3448 | |
| 3449 | Try vdso32=0 if you encounter an error that says: |
| 3450 | dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! |
Roland McGrath | af65d64 | 2008-01-30 13:30:43 +0100 | [diff] [blame] | 3451 | |
Yasuaki Ishimatsu | d080d39 | 2007-07-17 21:22:55 +0900 | [diff] [blame] | 3452 | vector= [IA-64,SMP] |
| 3453 | vector=percpu: enable percpu vector domain |
| 3454 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3455 | video= [FB] Frame buffer configuration |
| 3456 | See Documentation/fb/modedb.txt. |
| 3457 | |
Aaron Lu | 3afe6da | 2013-06-20 15:08:55 +0800 | [diff] [blame] | 3458 | video.brightness_switch_enabled= [0,1] |
| 3459 | If set to 1, on receiving an ACPI notify event |
| 3460 | generated by hotkey, video driver will adjust brightness |
| 3461 | level and then send out the event to user space through |
| 3462 | the allocated input device; If set to 0, video driver |
| 3463 | will only send out the event without touching backlight |
| 3464 | brightness level. |
| 3465 | default: 1 |
| 3466 | |
Pawel Moll | 81a054c | 2012-05-09 18:30:16 +0100 | [diff] [blame] | 3467 | virtio_mmio.device= |
| 3468 | [VMMIO] Memory mapped virtio (platform) device. |
| 3469 | |
| 3470 | <size>@<baseaddr>:<irq>[:<id>] |
| 3471 | where: |
| 3472 | <size> := size (can use standard suffixes |
| 3473 | like K, M and G) |
| 3474 | <baseaddr> := physical base address |
| 3475 | <irq> := interrupt number (as passed to |
| 3476 | request_irq()) |
| 3477 | <id> := (optional) platform device id |
| 3478 | example: |
| 3479 | virtio_mmio.device=1K@0x100b0000:48:7 |
| 3480 | |
| 3481 | Can be used multiple times for multiple devices. |
| 3482 | |
Alan Cox | cd4f0ef | 2007-07-31 00:37:59 -0700 | [diff] [blame] | 3483 | vga= [BOOT,X86-32] Select a particular video mode |
Kyle McMartin | 954a8b8 | 2009-02-19 16:48:14 -0500 | [diff] [blame] | 3484 | See Documentation/x86/boot.txt and |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 3485 | Documentation/svga.txt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3486 | Use vga=ask for menu. |
| 3487 | This is actually a boot loader parameter; the value is |
| 3488 | passed to the kernel using a special protocol. |
| 3489 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 3490 | vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3491 | size of <nn>. This can be used to increase the |
| 3492 | minimum size (128MB on x86). It can also be used to |
| 3493 | decrease the size and leave more room for directly |
| 3494 | mapped kernel RAM. |
| 3495 | |
Peter Oberparleiter | 585c304 | 2006-06-29 15:08:25 +0200 | [diff] [blame] | 3496 | vmhalt= [KNL,S390] Perform z/VM CP command after system halt. |
| 3497 | Format: <command> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3498 | |
Peter Oberparleiter | 585c304 | 2006-06-29 15:08:25 +0200 | [diff] [blame] | 3499 | vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic. |
| 3500 | Format: <command> |
| 3501 | |
| 3502 | vmpoff= [KNL,S390] Perform z/VM CP command after power off. |
| 3503 | Format: <command> |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 3504 | |
Andy Lutomirski | 3ae3665 | 2011-08-10 11:15:32 -0400 | [diff] [blame] | 3505 | vsyscall= [X86-64] |
| 3506 | Controls the behavior of vsyscalls (i.e. calls to |
| 3507 | fixed addresses of 0xffffffffff600x00 from legacy |
| 3508 | code). Most statically-linked binaries and older |
| 3509 | versions of glibc use these calls. Because these |
| 3510 | functions are at fixed addresses, they make nice |
| 3511 | targets for exploits that can control RIP. |
| 3512 | |
Andy Lutomirski | 2e57ae0 | 2011-11-07 16:33:41 -0800 | [diff] [blame] | 3513 | emulate [default] Vsyscalls turn into traps and are |
| 3514 | emulated reasonably safely. |
Andy Lutomirski | 3ae3665 | 2011-08-10 11:15:32 -0400 | [diff] [blame] | 3515 | |
Andy Lutomirski | 2e57ae0 | 2011-11-07 16:33:41 -0800 | [diff] [blame] | 3516 | native Vsyscalls are native syscall instructions. |
Andy Lutomirski | 3ae3665 | 2011-08-10 11:15:32 -0400 | [diff] [blame] | 3517 | This is a little bit faster than trapping |
| 3518 | and makes a few dynamic recompilers work |
| 3519 | better than they would in emulation mode. |
| 3520 | It also makes exploits much easier to write. |
| 3521 | |
| 3522 | none Vsyscalls don't work at all. This makes |
| 3523 | them quite hard to use for exploits but |
| 3524 | might break your system. |
| 3525 | |
Clemens Ladisch | 3855ae1 | 2013-08-04 13:09:50 +0200 | [diff] [blame] | 3526 | vt.color= [VT] Default text color. |
| 3527 | Format: 0xYX, X = foreground, Y = background. |
| 3528 | Default: 0x07 = light gray on black. |
| 3529 | |
Clemens Ladisch | 9ea9a88 | 2009-12-15 16:45:39 -0800 | [diff] [blame] | 3530 | vt.cur_default= [VT] Default cursor shape. |
| 3531 | Format: 0xCCBBAA, where AA, BB, and CC are the same as |
| 3532 | the parameters of the <Esc>[?A;B;Cc escape sequence; |
| 3533 | see VGA-softcursor.txt. Default: 2 = underline. |
| 3534 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 3535 | vt.default_blu= [VT] |
| 3536 | Format: <blue0>,<blue1>,<blue2>,...,<blue15> |
| 3537 | Change the default blue palette of the console. |
| 3538 | This is a 16-member array composed of values |
| 3539 | ranging from 0-255. |
| 3540 | |
| 3541 | vt.default_grn= [VT] |
| 3542 | Format: <green0>,<green1>,<green2>,...,<green15> |
| 3543 | Change the default green palette of the console. |
| 3544 | This is a 16-member array composed of values |
| 3545 | ranging from 0-255. |
| 3546 | |
| 3547 | vt.default_red= [VT] |
| 3548 | Format: <red0>,<red1>,<red2>,...,<red15> |
| 3549 | Change the default red palette of the console. |
| 3550 | This is a 16-member array composed of values |
| 3551 | ranging from 0-255. |
| 3552 | |
| 3553 | vt.default_utf8= |
| 3554 | [VT] |
| 3555 | Format=<0|1> |
| 3556 | Set system-wide default UTF-8 mode for all tty's. |
| 3557 | Default is 1, i.e. UTF-8 mode is enabled for all |
| 3558 | newly opened terminals. |
| 3559 | |
Matthew Garrett | f6c06b6 | 2009-11-13 15:14:11 -0500 | [diff] [blame] | 3560 | vt.global_cursor_default= |
| 3561 | [VT] |
| 3562 | Format=<-1|0|1> |
| 3563 | Set system-wide default for whether a cursor |
| 3564 | is shown on new VTs. Default is -1, |
| 3565 | i.e. cursors will be created by default unless |
| 3566 | overridden by individual drivers. 0 will hide |
| 3567 | cursors, 1 will display them. |
| 3568 | |
Clemens Ladisch | 3855ae1 | 2013-08-04 13:09:50 +0200 | [diff] [blame] | 3569 | vt.italic= [VT] Default color for italic text; 0-15. |
| 3570 | Default: 2 = green. |
| 3571 | |
| 3572 | vt.underline= [VT] Default color for underlined text; 0-15. |
| 3573 | Default: 3 = cyan. |
| 3574 | |
Randy Dunlap | 4724ba57 | 2010-05-03 11:42:52 -0700 | [diff] [blame] | 3575 | watchdog timers [HW,WDT] For information on watchdog timers, |
| 3576 | see Documentation/watchdog/watchdog-parameters.txt |
| 3577 | or other driver-specific files in the |
| 3578 | Documentation/watchdog/ directory. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3579 | |
Tejun Heo | d55262c | 2013-04-01 11:23:38 -0700 | [diff] [blame] | 3580 | workqueue.disable_numa |
| 3581 | By default, all work items queued to unbound |
| 3582 | workqueues are affine to the NUMA nodes they're |
| 3583 | issued on, which results in better behavior in |
| 3584 | general. If NUMA affinity needs to be disabled for |
| 3585 | whatever reason, this option can be used. Note |
| 3586 | that this also can be controlled per-workqueue for |
| 3587 | workqueues visible under /sys/bus/workqueue/. |
| 3588 | |
Viresh Kumar | cee22a1 | 2013-04-08 16:45:40 +0530 | [diff] [blame] | 3589 | workqueue.power_efficient |
| 3590 | Per-cpu workqueues are generally preferred because |
| 3591 | they show better performance thanks to cache |
| 3592 | locality; unfortunately, per-cpu workqueues tend to |
| 3593 | be more power hungry than unbound workqueues. |
| 3594 | |
| 3595 | Enabling this makes the per-cpu workqueues which |
| 3596 | were observed to contribute significantly to power |
| 3597 | consumption unbound, leading to measurably lower |
| 3598 | power usage at the cost of small performance |
| 3599 | overhead. |
| 3600 | |
| 3601 | The default value of this parameter is determined by |
| 3602 | the config option CONFIG_WQ_POWER_EFFICIENT_DEFAULT. |
| 3603 | |
Randy Dunlap | 0cb55ad | 2009-04-05 15:55:22 -0700 | [diff] [blame] | 3604 | x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of |
| 3605 | default x2apic cluster mode on platforms |
| 3606 | supporting x2apic. |
| 3607 | |
Kuppuswamy Sathyanarayanan | 712b6aa | 2013-10-17 15:35:29 -0700 | [diff] [blame] | 3608 | x86_intel_mid_timer= [X86-32,APBT] |
| 3609 | Choose timer option for x86 Intel MID platform. |
Jacob Pan | bb24c47 | 2009-09-02 07:37:17 -0700 | [diff] [blame] | 3610 | Two valid options are apbt timer only and lapic timer |
| 3611 | plus one apbt timer for broadcast timer. |
Kuppuswamy Sathyanarayanan | 712b6aa | 2013-10-17 15:35:29 -0700 | [diff] [blame] | 3612 | x86_intel_mid_timer=apbt_only | lapic_and_apbt |
Jacob Pan | bb24c47 | 2009-09-02 07:37:17 -0700 | [diff] [blame] | 3613 | |
Stefano Stabellini | c1c5413 | 2010-05-14 12:44:30 +0100 | [diff] [blame] | 3614 | xen_emul_unplug= [HW,X86,XEN] |
| 3615 | Unplug Xen emulated devices |
| 3616 | Format: [unplug0,][unplug1] |
| 3617 | ide-disks -- unplug primary master IDE devices |
| 3618 | aux-ide-disks -- unplug non-primary-master IDE devices |
| 3619 | nics -- unplug network devices |
| 3620 | all -- unplug all emulated devices (NICs and IDE disks) |
Ian Campbell | 1dc7ce9 | 2010-08-23 11:59:29 +0100 | [diff] [blame] | 3621 | unnecessary -- unplugging emulated devices is |
| 3622 | unnecessary even if the host did not respond to |
| 3623 | the unplug protocol |
Ian Campbell | c93a4df | 2010-08-23 11:59:28 +0100 | [diff] [blame] | 3624 | never -- do not unplug even if version check succeeds |
Stefano Stabellini | c1c5413 | 2010-05-14 12:44:30 +0100 | [diff] [blame] | 3625 | |
Konrad Rzeszutek Wilk | 15a3eac | 2013-09-25 10:07:20 -0400 | [diff] [blame] | 3626 | xen_nopvspin [X86,XEN] |
| 3627 | Disables the ticketlock slowpath using Xen PV |
| 3628 | optimizations. |
| 3629 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3630 | xirc2ps_cs= [NET,PCMCIA] |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 3631 | Format: |
| 3632 | <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3633 | |
Randy Dunlap | a991304 | 2005-10-23 12:57:11 -0700 | [diff] [blame] | 3634 | ______________________________________________________________________ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3635 | |
| 3636 | TODO: |
| 3637 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3638 | Add more DRM drivers. |