| # |
| # For a description of the syntax of this configuration file, |
| # see Documentation/kbuild/kconfig-language.txt. |
| # |
| |
| mainmenu "Linux Kernel Configuration" |
| |
| config X86_32 |
| bool |
| default y |
| help |
| This is Linux's home port. Linux was originally native to the Intel |
| 386, and runs on all the later x86 processors including the Intel |
| 486, 586, Pentiums, and various instruction-set-compatible chips by |
| AMD, Cyrix, and others. |
| |
| config GENERIC_TIME |
| bool |
| default y |
| |
| config GENERIC_CMOS_UPDATE |
| bool |
| default y |
| |
| config CLOCKSOURCE_WATCHDOG |
| bool |
| default y |
| |
| config GENERIC_CLOCKEVENTS |
| bool |
| default y |
| |
| config GENERIC_CLOCKEVENTS_BROADCAST |
| bool |
| default y |
| depends on X86_LOCAL_APIC |
| |
| config LOCKDEP_SUPPORT |
| bool |
| default y |
| |
| config STACKTRACE_SUPPORT |
| bool |
| default y |
| |
| config SEMAPHORE_SLEEPERS |
| bool |
| default y |
| |
| config X86 |
| bool |
| default y |
| |
| config MMU |
| bool |
| default y |
| |
| config ZONE_DMA |
| bool |
| default y |
| |
| config QUICKLIST |
| bool |
| default y |
| |
| config SBUS |
| bool |
| |
| config GENERIC_ISA_DMA |
| bool |
| default y |
| |
| config GENERIC_IOMAP |
| bool |
| default y |
| |
| config GENERIC_BUG |
| bool |
| default y |
| depends on BUG |
| |
| config GENERIC_HWEIGHT |
| bool |
| default y |
| |
| config ARCH_MAY_HAVE_PC_FDC |
| bool |
| default y |
| |
| config DMI |
| bool |
| default y |
| |
| source "init/Kconfig" |
| |
| menu "Processor type and features" |
| |
| source "kernel/time/Kconfig" |
| |
| config SMP |
| bool "Symmetric multi-processing support" |
| ---help--- |
| This enables support for systems with more than one CPU. If you have |
| a system with only one CPU, like most personal computers, say N. If |
| you have a system with more than one CPU, say Y. |
| |
| If you say N here, the kernel will run on single and multiprocessor |
| machines, but will use only one CPU of a multiprocessor machine. If |
| you say Y here, the kernel will run on many, but not all, |
| singleprocessor machines. On a singleprocessor machine, the kernel |
| will run faster if you say N here. |
| |
| Note that if you say Y here and choose architecture "586" or |
| "Pentium" under "Processor family", the kernel will not work on 486 |
| architectures. Similarly, multiprocessor kernels for the "PPro" |
| architecture may not work on all Pentium based boards. |
| |
| People using multiprocessor machines who say Y here should also say |
| Y to "Enhanced Real Time Clock Support", below. The "Advanced Power |
| Management" code will be disabled if you say Y here. |
| |
| See also the <file:Documentation/smp.txt>, |
| <file:Documentation/i386/IO-APIC.txt>, |
| <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at |
| <http://www.tldp.org/docs.html#howto>. |
| |
| If you don't know what to do here, say N. |
| |
| choice |
| prompt "Subarchitecture Type" |
| default X86_PC |
| |
| config X86_PC |
| bool "PC-compatible" |
| help |
| Choose this option if your computer is a standard PC or compatible. |
| |
| config X86_ELAN |
| bool "AMD Elan" |
| help |
| Select this for an AMD Elan processor. |
| |
| Do not use this option for K6/Athlon/Opteron processors! |
| |
| If unsure, choose "PC-compatible" instead. |
| |
| config X86_VOYAGER |
| bool "Voyager (NCR)" |
| select SMP if !BROKEN |
| help |
| Voyager is an MCA-based 32-way capable SMP architecture proprietary |
| to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based. |
| |
| *** WARNING *** |
| |
| If you do not specifically know you have a Voyager based machine, |
| say N here, otherwise the kernel you build will not be bootable. |
| |
| config X86_NUMAQ |
| bool "NUMAQ (IBM/Sequent)" |
| select SMP |
| select NUMA |
| help |
| This option is used for getting Linux to run on a (IBM/Sequent) NUMA |
| multiquad box. This changes the way that processors are bootstrapped, |
| and uses Clustered Logical APIC addressing mode instead of Flat Logical. |
| You will need a new lynxer.elf file to flash your firmware with - send |
| email to <Martin.Bligh@us.ibm.com>. |
| |
| config X86_SUMMIT |
| bool "Summit/EXA (IBM x440)" |
| depends on SMP |
| help |
| This option is needed for IBM systems that use the Summit/EXA chipset. |
| In particular, it is needed for the x440. |
| |
| If you don't have one of these computers, you should say N here. |
| If you want to build a NUMA kernel, you must select ACPI. |
| |
| config X86_BIGSMP |
| bool "Support for other sub-arch SMP systems with more than 8 CPUs" |
| depends on SMP |
| help |
| This option is needed for the systems that have more than 8 CPUs |
| and if the system is not of any sub-arch type above. |
| |
| If you don't have such a system, you should say N here. |
| |
| config X86_VISWS |
| bool "SGI 320/540 (Visual Workstation)" |
| help |
| The SGI Visual Workstation series is an IA32-based workstation |
| based on SGI systems chips with some legacy PC hardware attached. |
| |
| Say Y here to create a kernel to run on the SGI 320 or 540. |
| |
| A kernel compiled for the Visual Workstation will not run on PCs |
| and vice versa. See <file:Documentation/sgi-visws.txt> for details. |
| |
| config X86_GENERICARCH |
| bool "Generic architecture (Summit, bigsmp, ES7000, default)" |
| help |
| This option compiles in the Summit, bigsmp, ES7000, default subarchitectures. |
| It is intended for a generic binary kernel. |
| If you want a NUMA kernel, select ACPI. We need SRAT for NUMA. |
| |
| config X86_ES7000 |
| bool "Support for Unisys ES7000 IA32 series" |
| depends on SMP |
| help |
| Support for Unisys ES7000 systems. Say 'Y' here if this kernel is |
| supposed to run on an IA32-based Unisys ES7000 system. |
| Only choose this option if you have such a system, otherwise you |
| should say N here. |
| |
| endchoice |
| |
| config SCHED_NO_NO_OMIT_FRAME_POINTER |
| bool "Single-depth WCHAN output" |
| default y |
| help |
| Calculate simpler /proc/<PID>/wchan values. If this option |
| is disabled then wchan values will recurse back to the |
| caller function. This provides more accurate wchan values, |
| at the expense of slightly more scheduling overhead. |
| |
| If in doubt, say "Y". |
| |
| config PARAVIRT |
| bool |
| depends on !(X86_VISWS || X86_VOYAGER) |
| help |
| This changes the kernel so it can modify itself when it is run |
| under a hypervisor, potentially improving performance significantly |
| over full virtualization. However, when run without a hypervisor |
| the kernel is theoretically slower and slightly larger. |
| |
| menuconfig PARAVIRT_GUEST |
| bool "Paravirtualized guest support" |
| help |
| Say Y here to get to see options related to running Linux under |
| various hypervisors. This option alone does not add any kernel code. |
| |
| If you say N, all options in this submenu will be skipped and disabled. |
| |
| if PARAVIRT_GUEST |
| |
| source "arch/x86/xen/Kconfig" |
| |
| config VMI |
| bool "VMI Guest support" |
| select PARAVIRT |
| depends on !(X86_VISWS || X86_VOYAGER) |
| help |
| VMI provides a paravirtualized interface to the VMware ESX server |
| (it could be used by other hypervisors in theory too, but is not |
| at the moment), by linking the kernel to a GPL-ed ROM module |
| provided by the hypervisor. |
| |
| source "arch/x86/lguest/Kconfig" |
| |
| endif |
| |
| config ACPI_SRAT |
| bool |
| default y |
| depends on ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH) |
| select ACPI_NUMA |
| |
| config HAVE_ARCH_PARSE_SRAT |
| bool |
| default y |
| depends on ACPI_SRAT |
| |
| config X86_SUMMIT_NUMA |
| bool |
| default y |
| depends on NUMA && (X86_SUMMIT || X86_GENERICARCH) |
| |
| config X86_CYCLONE_TIMER |
| bool |
| default y |
| depends on X86_SUMMIT || X86_GENERICARCH |
| |
| config ES7000_CLUSTERED_APIC |
| bool |
| default y |
| depends on SMP && X86_ES7000 && MPENTIUMIII |
| |
| source "arch/x86/Kconfig.cpu" |
| |
| config HPET_TIMER |
| bool "HPET Timer Support" |
| help |
| This enables the use of the HPET for the kernel's internal timer. |
| HPET is the next generation timer replacing legacy 8254s. |
| You can safely choose Y here. However, HPET will only be |
| activated if the platform and the BIOS support this feature. |
| Otherwise the 8254 will be used for timing services. |
| |
| Choose N to continue using the legacy 8254 timer. |
| |
| config HPET_EMULATE_RTC |
| bool |
| depends on HPET_TIMER && RTC=y |
| default y |
| |
| config NR_CPUS |
| int "Maximum number of CPUs (2-255)" |
| range 2 255 |
| depends on SMP |
| default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000 |
| default "8" |
| help |
| This allows you to specify the maximum number of CPUs which this |
| kernel will support. The maximum supported value is 255 and the |
| minimum value which makes sense is 2. |
| |
| This is purely to save memory - each supported CPU adds |
| approximately eight kilobytes to the kernel image. |
| |
| config SCHED_SMT |
| bool "SMT (Hyperthreading) scheduler support" |
| depends on X86_HT |
| help |
| SMT scheduler support improves the CPU scheduler's decision making |
| when dealing with Intel Pentium 4 chips with HyperThreading at a |
| cost of slightly increased overhead in some places. If unsure say |
| N here. |
| |
| config SCHED_MC |
| bool "Multi-core scheduler support" |
| depends on X86_HT |
| default y |
| help |
| Multi-core scheduler support improves the CPU scheduler's decision |
| making when dealing with multi-core CPU chips at a cost of slightly |
| increased overhead in some places. If unsure say N here. |
| |
| source "kernel/Kconfig.preempt" |
| |
| config X86_UP_APIC |
| bool "Local APIC support on uniprocessors" |
| depends on !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH) |
| help |
| A local APIC (Advanced Programmable Interrupt Controller) is an |
| integrated interrupt controller in the CPU. If you have a single-CPU |
| system which has a processor with a local APIC, you can say Y here to |
| enable and use it. If you say Y here even though your machine doesn't |
| have a local APIC, then the kernel will still run with no slowdown at |
| all. The local APIC supports CPU-generated self-interrupts (timer, |
| performance counters), and the NMI watchdog which detects hard |
| lockups. |
| |
| config X86_UP_IOAPIC |
| bool "IO-APIC support on uniprocessors" |
| depends on X86_UP_APIC |
| help |
| An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an |
| SMP-capable replacement for PC-style interrupt controllers. Most |
| SMP systems and many recent uniprocessor systems have one. |
| |
| If you have a single-CPU system with an IO-APIC, you can say Y here |
| to use it. If you say Y here even though your machine doesn't have |
| an IO-APIC, then the kernel will still run with no slowdown at all. |
| |
| config X86_LOCAL_APIC |
| bool |
| depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH |
| default y |
| |
| config X86_IO_APIC |
| bool |
| depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH |
| default y |
| |
| config X86_VISWS_APIC |
| bool |
| depends on X86_VISWS |
| default y |
| |
| config X86_MCE |
| bool "Machine Check Exception" |
| depends on !X86_VOYAGER |
| ---help--- |
| Machine Check Exception support allows the processor to notify the |
| kernel if it detects a problem (e.g. overheating, component failure). |
| The action the kernel takes depends on the severity of the problem, |
| ranging from a warning message on the console, to halting the machine. |
| Your processor must be a Pentium or newer to support this - check the |
| flags in /proc/cpuinfo for mce. Note that some older Pentium systems |
| have a design flaw which leads to false MCE events - hence MCE is |
| disabled on all P5 processors, unless explicitly enabled with "mce" |
| as a boot argument. Similarly, if MCE is built in and creates a |
| problem on some new non-standard machine, you can boot with "nomce" |
| to disable it. MCE support simply ignores non-MCE processors like |
| the 386 and 486, so nearly everyone can say Y here. |
| |
| config X86_MCE_NONFATAL |
| tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4" |
| depends on X86_MCE |
| help |
| Enabling this feature starts a timer that triggers every 5 seconds which |
| will look at the machine check registers to see if anything happened. |
| Non-fatal problems automatically get corrected (but still logged). |
| Disable this if you don't want to see these messages. |
| Seeing the messages this option prints out may be indicative of dying |
| or out-of-spec (ie, overclocked) hardware. |
| This option only does something on certain CPUs. |
| (AMD Athlon/Duron and Intel Pentium 4) |
| |
| config X86_MCE_P4THERMAL |
| bool "check for P4 thermal throttling interrupt." |
| depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS |
| help |
| Enabling this feature will cause a message to be printed when the P4 |
| enters thermal throttling. |
| |
| config VM86 |
| default y |
| bool "Enable VM86 support" if EMBEDDED |
| help |
| This option is required by programs like DOSEMU to run 16-bit legacy |
| code on X86 processors. It also may be needed by software like |
| XFree86 to initialize some video cards via BIOS. Disabling this |
| option saves about 6k. |
| |
| config TOSHIBA |
| tristate "Toshiba Laptop support" |
| ---help--- |
| This adds a driver to safely access the System Management Mode of |
| the CPU on Toshiba portables with a genuine Toshiba BIOS. It does |
| not work on models with a Phoenix BIOS. The System Management Mode |
| is used to set the BIOS and power saving options on Toshiba portables. |
| |
| For information on utilities to make use of this driver see the |
| Toshiba Linux utilities web site at: |
| <http://www.buzzard.org.uk/toshiba/>. |
| |
| Say Y if you intend to run this kernel on a Toshiba portable. |
| Say N otherwise. |
| |
| config I8K |
| tristate "Dell laptop support" |
| ---help--- |
| This adds a driver to safely access the System Management Mode |
| of the CPU on the Dell Inspiron 8000. The System Management Mode |
| is used to read cpu temperature and cooling fan status and to |
| control the fans on the I8K portables. |
| |
| This driver has been tested only on the Inspiron 8000 but it may |
| also work with other Dell laptops. You can force loading on other |
| models by passing the parameter `force=1' to the module. Use at |
| your own risk. |
| |
| For information on utilities to make use of this driver see the |
| I8K Linux utilities web site at: |
| <http://people.debian.org/~dz/i8k/> |
| |
| Say Y if you intend to run this kernel on a Dell Inspiron 8000. |
| Say N otherwise. |
| |
| config X86_REBOOTFIXUPS |
| bool "Enable X86 board specific fixups for reboot" |
| depends on X86 |
| default n |
| ---help--- |
| This enables chipset and/or board specific fixups to be done |
| in order to get reboot to work correctly. This is only needed on |
| some combinations of hardware and BIOS. The symptom, for which |
| this config is intended, is when reboot ends with a stalled/hung |
| system. |
| |
| Currently, the only fixup is for the Geode machines using |
| CS5530A and CS5536 chipsets. |
| |
| Say Y if you want to enable the fixup. Currently, it's safe to |
| enable this option even if you don't need it. |
| Say N otherwise. |
| |
| config MICROCODE |
| tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support" |
| select FW_LOADER |
| ---help--- |
| If you say Y here, you will be able to update the microcode on |
| Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II, |
| Pentium III, Pentium 4, Xeon etc. You will obviously need the |
| actual microcode binary data itself which is not shipped with the |
| Linux kernel. |
| |
| For latest news and information on obtaining all the required |
| ingredients for this driver, check: |
| <http://www.urbanmyth.org/microcode/>. |
| |
| To compile this driver as a module, choose M here: the |
| module will be called microcode. |
| |
| config MICROCODE_OLD_INTERFACE |
| bool |
| depends on MICROCODE |
| default y |
| |
| config X86_MSR |
| tristate "/dev/cpu/*/msr - Model-specific register support" |
| help |
| This device gives privileged processes access to the x86 |
| Model-Specific Registers (MSRs). It is a character device with |
| major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. |
| MSR accesses are directed to a specific CPU on multi-processor |
| systems. |
| |
| config X86_CPUID |
| tristate "/dev/cpu/*/cpuid - CPU information support" |
| help |
| This device gives processes access to the x86 CPUID instruction to |
| be executed on a specific processor. It is a character device |
| with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to |
| /dev/cpu/31/cpuid. |
| |
| choice |
| prompt "High Memory Support" |
| default HIGHMEM4G if !X86_NUMAQ |
| default HIGHMEM64G if X86_NUMAQ |
| |
| config NOHIGHMEM |
| bool "off" |
| depends on !X86_NUMAQ |
| ---help--- |
| Linux can use up to 64 Gigabytes of physical memory on x86 systems. |
| However, the address space of 32-bit x86 processors is only 4 |
| Gigabytes large. That means that, if you have a large amount of |
| physical memory, not all of it can be "permanently mapped" by the |
| kernel. The physical memory that's not permanently mapped is called |
| "high memory". |
| |
| If you are compiling a kernel which will never run on a machine with |
| more than 1 Gigabyte total physical RAM, answer "off" here (default |
| choice and suitable for most users). This will result in a "3GB/1GB" |
| split: 3GB are mapped so that each process sees a 3GB virtual memory |
| space and the remaining part of the 4GB virtual memory space is used |
| by the kernel to permanently map as much physical memory as |
| possible. |
| |
| If the machine has between 1 and 4 Gigabytes physical RAM, then |
| answer "4GB" here. |
| |
| If more than 4 Gigabytes is used then answer "64GB" here. This |
| selection turns Intel PAE (Physical Address Extension) mode on. |
| PAE implements 3-level paging on IA32 processors. PAE is fully |
| supported by Linux, PAE mode is implemented on all recent Intel |
| processors (Pentium Pro and better). NOTE: If you say "64GB" here, |
| then the kernel will not boot on CPUs that don't support PAE! |
| |
| The actual amount of total physical memory will either be |
| auto detected or can be forced by using a kernel command line option |
| such as "mem=256M". (Try "man bootparam" or see the documentation of |
| your boot loader (lilo or loadlin) about how to pass options to the |
| kernel at boot time.) |
| |
| If unsure, say "off". |
| |
| config HIGHMEM4G |
| bool "4GB" |
| depends on !X86_NUMAQ |
| help |
| Select this if you have a 32-bit processor and between 1 and 4 |
| gigabytes of physical RAM. |
| |
| config HIGHMEM64G |
| bool "64GB" |
| depends on !M386 && !M486 |
| select X86_PAE |
| help |
| Select this if you have a 32-bit processor and more than 4 |
| gigabytes of physical RAM. |
| |
| endchoice |
| |
| choice |
| depends on EXPERIMENTAL |
| prompt "Memory split" if EMBEDDED |
| default VMSPLIT_3G |
| help |
| Select the desired split between kernel and user memory. |
| |
| If the address range available to the kernel is less than the |
| physical memory installed, the remaining memory will be available |
| as "high memory". Accessing high memory is a little more costly |
| than low memory, as it needs to be mapped into the kernel first. |
| Note that increasing the kernel address space limits the range |
| available to user programs, making the address space there |
| tighter. Selecting anything other than the default 3G/1G split |
| will also likely make your kernel incompatible with binary-only |
| kernel modules. |
| |
| If you are not absolutely sure what you are doing, leave this |
| option alone! |
| |
| config VMSPLIT_3G |
| bool "3G/1G user/kernel split" |
| config VMSPLIT_3G_OPT |
| depends on !X86_PAE |
| bool "3G/1G user/kernel split (for full 1G low memory)" |
| config VMSPLIT_2G |
| bool "2G/2G user/kernel split" |
| config VMSPLIT_2G_OPT |
| depends on !X86_PAE |
| bool "2G/2G user/kernel split (for full 2G low memory)" |
| config VMSPLIT_1G |
| bool "1G/3G user/kernel split" |
| endchoice |
| |
| config PAGE_OFFSET |
| hex |
| default 0xB0000000 if VMSPLIT_3G_OPT |
| default 0x80000000 if VMSPLIT_2G |
| default 0x78000000 if VMSPLIT_2G_OPT |
| default 0x40000000 if VMSPLIT_1G |
| default 0xC0000000 |
| |
| config HIGHMEM |
| bool |
| depends on HIGHMEM64G || HIGHMEM4G |
| default y |
| |
| config X86_PAE |
| bool "PAE (Physical Address Extension) Support" |
| default n |
| depends on !HIGHMEM4G |
| select RESOURCES_64BIT |
| help |
| PAE is required for NX support, and furthermore enables |
| larger swapspace support for non-overcommit purposes. It |
| has the cost of more pagetable lookup overhead, and also |
| consumes more pagetable space per process. |
| |
| # Common NUMA Features |
| config NUMA |
| bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)" |
| depends on SMP && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI) && EXPERIMENTAL |
| default n if X86_PC |
| default y if (X86_NUMAQ || X86_SUMMIT) |
| help |
| NUMA support for i386. This is currently highly experimental |
| and should be only used for kernel development. It might also |
| cause boot failures. |
| |
| comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI" |
| depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI) |
| |
| config NODES_SHIFT |
| int |
| default "4" if X86_NUMAQ |
| default "3" |
| depends on NEED_MULTIPLE_NODES |
| |
| config HAVE_ARCH_BOOTMEM_NODE |
| bool |
| depends on NUMA |
| default y |
| |
| config ARCH_HAVE_MEMORY_PRESENT |
| bool |
| depends on DISCONTIGMEM |
| default y |
| |
| config NEED_NODE_MEMMAP_SIZE |
| bool |
| depends on DISCONTIGMEM || SPARSEMEM |
| default y |
| |
| config HAVE_ARCH_ALLOC_REMAP |
| bool |
| depends on NUMA |
| default y |
| |
| config ARCH_FLATMEM_ENABLE |
| def_bool y |
| depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC) |
| |
| config ARCH_DISCONTIGMEM_ENABLE |
| def_bool y |
| depends on NUMA |
| |
| config ARCH_DISCONTIGMEM_DEFAULT |
| def_bool y |
| depends on NUMA |
| |
| config ARCH_SPARSEMEM_ENABLE |
| def_bool y |
| depends on (NUMA || (X86_PC && EXPERIMENTAL)) |
| select SPARSEMEM_STATIC |
| |
| config ARCH_SELECT_MEMORY_MODEL |
| def_bool y |
| depends on ARCH_SPARSEMEM_ENABLE |
| |
| config ARCH_POPULATES_NODE_MAP |
| def_bool y |
| |
| source "mm/Kconfig" |
| |
| config HIGHPTE |
| bool "Allocate 3rd-level pagetables from highmem" |
| depends on HIGHMEM4G || HIGHMEM64G |
| help |
| The VM uses one page table entry for each page of physical memory. |
| For systems with a lot of RAM, this can be wasteful of precious |
| low memory. Setting this option will put user-space page table |
| entries in high memory. |
| |
| config MATH_EMULATION |
| bool "Math emulation" |
| ---help--- |
| Linux can emulate a math coprocessor (used for floating point |
| operations) if you don't have one. 486DX and Pentium processors have |
| a math coprocessor built in, 486SX and 386 do not, unless you added |
| a 487DX or 387, respectively. (The messages during boot time can |
| give you some hints here ["man dmesg"].) Everyone needs either a |
| coprocessor or this emulation. |
| |
| If you don't have a math coprocessor, you need to say Y here; if you |
| say Y here even though you have a coprocessor, the coprocessor will |
| be used nevertheless. (This behavior can be changed with the kernel |
| command line option "no387", which comes handy if your coprocessor |
| is broken. Try "man bootparam" or see the documentation of your boot |
| loader (lilo or loadlin) about how to pass options to the kernel at |
| boot time.) This means that it is a good idea to say Y here if you |
| intend to use this kernel on different machines. |
| |
| More information about the internals of the Linux math coprocessor |
| emulation can be found in <file:arch/x86/math-emu/README>. |
| |
| If you are not sure, say Y; apart from resulting in a 66 KB bigger |
| kernel, it won't hurt. |
| |
| config MTRR |
| bool "MTRR (Memory Type Range Register) support" |
| ---help--- |
| On Intel P6 family processors (Pentium Pro, Pentium II and later) |
| the Memory Type Range Registers (MTRRs) may be used to control |
| processor access to memory ranges. This is most useful if you have |
| a video (VGA) card on a PCI or AGP bus. Enabling write-combining |
| allows bus write transfers to be combined into a larger transfer |
| before bursting over the PCI/AGP bus. This can increase performance |
| of image write operations 2.5 times or more. Saying Y here creates a |
| /proc/mtrr file which may be used to manipulate your processor's |
| MTRRs. Typically the X server should use this. |
| |
| This code has a reasonably generic interface so that similar |
| control registers on other processors can be easily supported |
| as well: |
| |
| The Cyrix 6x86, 6x86MX and M II processors have Address Range |
| Registers (ARRs) which provide a similar functionality to MTRRs. For |
| these, the ARRs are used to emulate the MTRRs. |
| The AMD K6-2 (stepping 8 and above) and K6-3 processors have two |
| MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing |
| write-combining. All of these processors are supported by this code |
| and it makes sense to say Y here if you have one of them. |
| |
| Saying Y here also fixes a problem with buggy SMP BIOSes which only |
| set the MTRRs for the boot CPU and not for the secondary CPUs. This |
| can lead to all sorts of problems, so it's good to say Y here. |
| |
| You can safely say Y even if your machine doesn't have MTRRs, you'll |
| just add about 9 KB to your kernel. |
| |
| See <file:Documentation/mtrr.txt> for more information. |
| |
| config EFI |
| bool "Boot from EFI support" |
| depends on ACPI |
| default n |
| ---help--- |
| This enables the kernel to boot on EFI platforms using |
| system configuration information passed to it from the firmware. |
| This also enables the kernel to use any EFI runtime services that are |
| available (such as the EFI variable services). |
| |
| This option is only useful on systems that have EFI firmware |
| and will result in a kernel image that is ~8k larger. In addition, |
| you must use the latest ELILO loader available at |
| <http://elilo.sourceforge.net> in order to take advantage of |
| kernel initialization using EFI information (neither GRUB nor LILO know |
| anything about EFI). However, even with this option, the resultant |
| kernel should continue to boot on existing non-EFI platforms. |
| |
| config IRQBALANCE |
| bool "Enable kernel irq balancing" |
| depends on SMP && X86_IO_APIC |
| default y |
| help |
| The default yes will allow the kernel to do irq load balancing. |
| Saying no will keep the kernel from doing irq load balancing. |
| |
| # turning this on wastes a bunch of space. |
| # Summit needs it only when NUMA is on |
| config BOOT_IOREMAP |
| bool |
| depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI)) |
| default y |
| |
| config SECCOMP |
| bool "Enable seccomp to safely compute untrusted bytecode" |
| depends on PROC_FS |
| default y |
| help |
| This kernel feature is useful for number crunching applications |
| that may need to compute untrusted bytecode during their |
| execution. By using pipes or other transports made available to |
| the process as file descriptors supporting the read/write |
| syscalls, it's possible to isolate those applications in |
| their own address space using seccomp. Once seccomp is |
| enabled via /proc/<pid>/seccomp, it cannot be disabled |
| and the task is only allowed to execute a few safe syscalls |
| defined by each seccomp mode. |
| |
| If unsure, say Y. Only embedded should say N here. |
| |
| source kernel/Kconfig.hz |
| |
| config KEXEC |
| bool "kexec system call" |
| help |
| kexec is a system call that implements the ability to shutdown your |
| current kernel, and to start another kernel. It is like a reboot |
| but it is independent of the system firmware. And like a reboot |
| you can start any kernel with it, not just Linux. |
| |
| The name comes from the similarity to the exec system call. |
| |
| It is an ongoing process to be certain the hardware in a machine |
| is properly shutdown, so do not be surprised if this code does not |
| initially work for you. It may help to enable device hotplugging |
| support. As of this writing the exact hardware interface is |
| strongly in flux, so no good recommendation can be made. |
| |
| config CRASH_DUMP |
| bool "kernel crash dumps (EXPERIMENTAL)" |
| depends on EXPERIMENTAL |
| depends on HIGHMEM |
| help |
| Generate crash dump after being started by kexec. |
| This should be normally only set in special crash dump kernels |
| which are loaded in the main kernel with kexec-tools into |
| a specially reserved region and then later executed after |
| a crash by kdump/kexec. The crash dump kernel must be compiled |
| to a memory address not used by the main kernel or BIOS using |
| PHYSICAL_START, or it must be built as a relocatable image |
| (CONFIG_RELOCATABLE=y). |
| For more details see Documentation/kdump/kdump.txt |
| |
| config PHYSICAL_START |
| hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP) |
| default "0x1000000" if X86_NUMAQ |
| default "0x100000" |
| help |
| This gives the physical address where the kernel is loaded. |
| |
| If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then |
| bzImage will decompress itself to above physical address and |
| run from there. Otherwise, bzImage will run from the address where |
| it has been loaded by the boot loader and will ignore above physical |
| address. |
| |
| In normal kdump cases one does not have to set/change this option |
| as now bzImage can be compiled as a completely relocatable image |
| (CONFIG_RELOCATABLE=y) and be used to load and run from a different |
| address. This option is mainly useful for the folks who don't want |
| to use a bzImage for capturing the crash dump and want to use a |
| vmlinux instead. vmlinux is not relocatable hence a kernel needs |
| to be specifically compiled to run from a specific memory area |
| (normally a reserved region) and this option comes handy. |
| |
| So if you are using bzImage for capturing the crash dump, leave |
| the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y. |
| Otherwise if you plan to use vmlinux for capturing the crash dump |
| change this value to start of the reserved region (Typically 16MB |
| 0x1000000). In other words, it can be set based on the "X" value as |
| specified in the "crashkernel=YM@XM" command line boot parameter |
| passed to the panic-ed kernel. Typically this parameter is set as |
| crashkernel=64M@16M. Please take a look at |
| Documentation/kdump/kdump.txt for more details about crash dumps. |
| |
| Usage of bzImage for capturing the crash dump is recommended as |
| one does not have to build two kernels. Same kernel can be used |
| as production kernel and capture kernel. Above option should have |
| gone away after relocatable bzImage support is introduced. But it |
| is present because there are users out there who continue to use |
| vmlinux for dump capture. This option should go away down the |
| line. |
| |
| Don't change this unless you know what you are doing. |
| |
| config RELOCATABLE |
| bool "Build a relocatable kernel (EXPERIMENTAL)" |
| depends on EXPERIMENTAL |
| help |
| This builds a kernel image that retains relocation information |
| so it can be loaded someplace besides the default 1MB. |
| The relocations tend to make the kernel binary about 10% larger, |
| but are discarded at runtime. |
| |
| One use is for the kexec on panic case where the recovery kernel |
| must live at a different physical address than the primary |
| kernel. |
| |
| config PHYSICAL_ALIGN |
| hex "Alignment value to which kernel should be aligned" |
| default "0x100000" |
| range 0x2000 0x400000 |
| help |
| This value puts the alignment restrictions on physical address |
| where kernel is loaded and run from. Kernel is compiled for an |
| address which meets above alignment restriction. |
| |
| If bootloader loads the kernel at a non-aligned address and |
| CONFIG_RELOCATABLE is set, kernel will move itself to nearest |
| address aligned to above value and run from there. |
| |
| If bootloader loads the kernel at a non-aligned address and |
| CONFIG_RELOCATABLE is not set, kernel will ignore the run time |
| load address and decompress itself to the address it has been |
| compiled for and run from there. The address for which kernel is |
| compiled already meets above alignment restrictions. Hence the |
| end result is that kernel runs from a physical address meeting |
| above alignment restrictions. |
| |
| Don't change this unless you know what you are doing. |
| |
| config HOTPLUG_CPU |
| bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)" |
| depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER |
| ---help--- |
| Say Y here to experiment with turning CPUs off and on, and to |
| enable suspend on SMP systems. CPUs can be controlled through |
| /sys/devices/system/cpu. |
| |
| config COMPAT_VDSO |
| bool "Compat VDSO support" |
| default y |
| help |
| Map the VDSO to the predictable old-style address too. |
| ---help--- |
| Say N here if you are running a sufficiently recent glibc |
| version (2.3.3 or later), to remove the high-mapped |
| VDSO mapping and to exclusively use the randomized VDSO. |
| |
| If unsure, say Y. |
| |
| endmenu |
| |
| config ARCH_ENABLE_MEMORY_HOTPLUG |
| def_bool y |
| depends on HIGHMEM |
| |
| |
| # |
| # Use the generic interrupt handling code in kernel/irq/: |
| # |
| config GENERIC_HARDIRQS |
| bool |
| default y |
| |
| config GENERIC_IRQ_PROBE |
| bool |
| default y |
| |
| config GENERIC_PENDING_IRQ |
| bool |
| depends on GENERIC_HARDIRQS && SMP |
| default y |
| |
| config X86_SMP |
| bool |
| depends on SMP && !X86_VOYAGER |
| default y |
| |
| config X86_HT |
| bool |
| depends on SMP && !(X86_VISWS || X86_VOYAGER) |
| default y |
| |
| config X86_BIOS_REBOOT |
| bool |
| depends on !(X86_VISWS || X86_VOYAGER) |
| default y |
| |
| config X86_TRAMPOLINE |
| bool |
| depends on X86_SMP || (X86_VOYAGER && SMP) |
| default y |
| |
| config KTIME_SCALAR |
| bool |
| default y |
| |
| source "arch/x86/Kconfig" |