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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#
2# For a description of the syntax of this configuration file,
3# see Documentation/kbuild/kconfig-language.txt.
4#
5
6mainmenu "Linux Kernel Configuration"
7
Brian Gerst0d078f62005-10-30 14:59:20 -08008config X86_32
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 bool
10 default y
11 help
12 This is Linux's home port. Linux was originally native to the Intel
13 386, and runs on all the later x86 processors including the Intel
14 486, 586, Pentiums, and various instruction-set-compatible chips by
15 AMD, Cyrix, and others.
16
john stultz6f84fa22006-06-26 00:25:11 -070017config GENERIC_TIME
18 bool
19 default y
20
Benjamin LaHaise52fdd082005-09-03 15:56:52 -070021config SEMAPHORE_SLEEPERS
22 bool
23 default y
24
Brian Gerst0d078f62005-10-30 14:59:20 -080025config X86
26 bool
27 default y
28
Linus Torvalds1da177e2005-04-16 15:20:36 -070029config MMU
30 bool
31 default y
32
33config SBUS
34 bool
35
Linus Torvalds1da177e2005-04-16 15:20:36 -070036config GENERIC_ISA_DMA
37 bool
38 default y
39
40config GENERIC_IOMAP
41 bool
42 default y
43
Akinobu Mita1cc2b992006-03-26 01:39:24 -080044config GENERIC_HWEIGHT
45 bool
46 default y
47
viro@ZenIV.linux.org.uka08b6b72005-09-06 01:48:42 +010048config ARCH_MAY_HAVE_PC_FDC
49 bool
50 default y
51
Andi Kleene9928672006-01-11 22:43:33 +010052config DMI
53 bool
54 default y
55
Linus Torvalds1da177e2005-04-16 15:20:36 -070056source "init/Kconfig"
57
58menu "Processor type and features"
59
Adrian Bunkedd711f2006-04-10 22:53:14 -070060config SMP
61 bool "Symmetric multi-processing support"
62 ---help---
63 This enables support for systems with more than one CPU. If you have
64 a system with only one CPU, like most personal computers, say N. If
65 you have a system with more than one CPU, say Y.
66
67 If you say N here, the kernel will run on single and multiprocessor
68 machines, but will use only one CPU of a multiprocessor machine. If
69 you say Y here, the kernel will run on many, but not all,
70 singleprocessor machines. On a singleprocessor machine, the kernel
71 will run faster if you say N here.
72
73 Note that if you say Y here and choose architecture "586" or
74 "Pentium" under "Processor family", the kernel will not work on 486
75 architectures. Similarly, multiprocessor kernels for the "PPro"
76 architecture may not work on all Pentium based boards.
77
78 People using multiprocessor machines who say Y here should also say
79 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
80 Management" code will be disabled if you say Y here.
81
82 See also the <file:Documentation/smp.txt>,
83 <file:Documentation/i386/IO-APIC.txt>,
84 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
85 <http://www.tldp.org/docs.html#howto>.
86
87 If you don't know what to do here, say N.
88
Linus Torvalds1da177e2005-04-16 15:20:36 -070089choice
90 prompt "Subarchitecture Type"
91 default X86_PC
92
93config X86_PC
94 bool "PC-compatible"
95 help
96 Choose this option if your computer is a standard PC or compatible.
97
98config X86_ELAN
99 bool "AMD Elan"
100 help
101 Select this for an AMD Elan processor.
102
103 Do not use this option for K6/Athlon/Opteron processors!
104
105 If unsure, choose "PC-compatible" instead.
106
107config X86_VOYAGER
108 bool "Voyager (NCR)"
109 help
110 Voyager is an MCA-based 32-way capable SMP architecture proprietary
111 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
112
113 *** WARNING ***
114
115 If you do not specifically know you have a Voyager based machine,
116 say N here, otherwise the kernel you build will not be bootable.
117
118config X86_NUMAQ
119 bool "NUMAQ (IBM/Sequent)"
Adrian Bunk905c3992006-03-23 02:59:55 -0800120 select SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 select NUMA
122 help
123 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
124 multiquad box. This changes the way that processors are bootstrapped,
125 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
126 You will need a new lynxer.elf file to flash your firmware with - send
127 email to <Martin.Bligh@us.ibm.com>.
128
129config X86_SUMMIT
130 bool "Summit/EXA (IBM x440)"
131 depends on SMP
132 help
133 This option is needed for IBM systems that use the Summit/EXA chipset.
134 In particular, it is needed for the x440.
135
136 If you don't have one of these computers, you should say N here.
137
138config X86_BIGSMP
139 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
140 depends on SMP
141 help
142 This option is needed for the systems that have more than 8 CPUs
143 and if the system is not of any sub-arch type above.
144
145 If you don't have such a system, you should say N here.
146
147config X86_VISWS
148 bool "SGI 320/540 (Visual Workstation)"
149 help
150 The SGI Visual Workstation series is an IA32-based workstation
151 based on SGI systems chips with some legacy PC hardware attached.
152
153 Say Y here to create a kernel to run on the SGI 320 or 540.
154
155 A kernel compiled for the Visual Workstation will not run on PCs
156 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
157
158config X86_GENERICARCH
159 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
160 depends on SMP
161 help
162 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
163 It is intended for a generic binary kernel.
164
165config X86_ES7000
166 bool "Support for Unisys ES7000 IA32 series"
167 depends on SMP
168 help
169 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
170 supposed to run on an IA32-based Unisys ES7000 system.
171 Only choose this option if you have such a system, otherwise you
172 should say N here.
173
174endchoice
175
176config ACPI_SRAT
177 bool
178 default y
179 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
Yasunori Goto762834e2006-06-23 02:03:19 -0700180 select ACPI_NUMA
181
182config HAVE_ARCH_PARSE_SRAT
183 bool
184 default y
185 depends on ACPI_SRAT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186
187config X86_SUMMIT_NUMA
188 bool
189 default y
190 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
191
192config X86_CYCLONE_TIMER
193 bool
194 default y
195 depends on X86_SUMMIT || X86_GENERICARCH
196
197config ES7000_CLUSTERED_APIC
198 bool
199 default y
200 depends on SMP && X86_ES7000 && MPENTIUMIII
201
Paolo 'Blaisorblade' Giarrusso96d55b82005-10-30 15:00:07 -0800202source "arch/i386/Kconfig.cpu"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203
204config HPET_TIMER
205 bool "HPET Timer Support"
206 help
207 This enables the use of the HPET for the kernel's internal timer.
208 HPET is the next generation timer replacing legacy 8254s.
209 You can safely choose Y here. However, HPET will only be
210 activated if the platform and the BIOS support this feature.
211 Otherwise the 8254 will be used for timing services.
212
213 Choose N to continue using the legacy 8254 timer.
214
215config HPET_EMULATE_RTC
Venkatesh Pallipadic91096d2005-08-04 15:36:10 -0700216 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 depends on HPET_TIMER && RTC=y
Venkatesh Pallipadic91096d2005-08-04 15:36:10 -0700218 default y
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220config NR_CPUS
221 int "Maximum number of CPUs (2-255)"
222 range 2 255
223 depends on SMP
224 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
225 default "8"
226 help
227 This allows you to specify the maximum number of CPUs which this
228 kernel will support. The maximum supported value is 255 and the
229 minimum value which makes sense is 2.
230
231 This is purely to save memory - each supported CPU adds
232 approximately eight kilobytes to the kernel image.
233
234config SCHED_SMT
235 bool "SMT (Hyperthreading) scheduler support"
236 depends on SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 help
238 SMT scheduler support improves the CPU scheduler's decision making
239 when dealing with Intel Pentium 4 chips with HyperThreading at a
240 cost of slightly increased overhead in some places. If unsure say
241 N here.
242
Siddha, Suresh B1e9f28f2006-03-27 01:15:22 -0800243config SCHED_MC
244 bool "Multi-core scheduler support"
245 depends on SMP
246 default y
247 help
248 Multi-core scheduler support improves the CPU scheduler's decision
249 making when dealing with multi-core CPU chips at a cost of slightly
250 increased overhead in some places. If unsure say N here.
251
Ingo Molnarcc19ca82005-06-25 14:57:36 -0700252source "kernel/Kconfig.preempt"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253
254config X86_UP_APIC
255 bool "Local APIC support on uniprocessors"
256 depends on !SMP && !(X86_VISWS || X86_VOYAGER)
257 help
258 A local APIC (Advanced Programmable Interrupt Controller) is an
259 integrated interrupt controller in the CPU. If you have a single-CPU
260 system which has a processor with a local APIC, you can say Y here to
261 enable and use it. If you say Y here even though your machine doesn't
262 have a local APIC, then the kernel will still run with no slowdown at
263 all. The local APIC supports CPU-generated self-interrupts (timer,
264 performance counters), and the NMI watchdog which detects hard
265 lockups.
266
267config X86_UP_IOAPIC
268 bool "IO-APIC support on uniprocessors"
269 depends on X86_UP_APIC
270 help
271 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
272 SMP-capable replacement for PC-style interrupt controllers. Most
273 SMP systems and many recent uniprocessor systems have one.
274
275 If you have a single-CPU system with an IO-APIC, you can say Y here
276 to use it. If you say Y here even though your machine doesn't have
277 an IO-APIC, then the kernel will still run with no slowdown at all.
278
279config X86_LOCAL_APIC
280 bool
281 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER)
282 default y
283
284config X86_IO_APIC
285 bool
286 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER))
287 default y
288
289config X86_VISWS_APIC
290 bool
291 depends on X86_VISWS
292 default y
293
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294config X86_MCE
295 bool "Machine Check Exception"
296 depends on !X86_VOYAGER
297 ---help---
298 Machine Check Exception support allows the processor to notify the
299 kernel if it detects a problem (e.g. overheating, component failure).
300 The action the kernel takes depends on the severity of the problem,
301 ranging from a warning message on the console, to halting the machine.
302 Your processor must be a Pentium or newer to support this - check the
303 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
304 have a design flaw which leads to false MCE events - hence MCE is
305 disabled on all P5 processors, unless explicitly enabled with "mce"
306 as a boot argument. Similarly, if MCE is built in and creates a
307 problem on some new non-standard machine, you can boot with "nomce"
308 to disable it. MCE support simply ignores non-MCE processors like
309 the 386 and 486, so nearly everyone can say Y here.
310
311config X86_MCE_NONFATAL
312 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
313 depends on X86_MCE
314 help
315 Enabling this feature starts a timer that triggers every 5 seconds which
316 will look at the machine check registers to see if anything happened.
317 Non-fatal problems automatically get corrected (but still logged).
318 Disable this if you don't want to see these messages.
319 Seeing the messages this option prints out may be indicative of dying hardware,
320 or out-of-spec (ie, overclocked) hardware.
321 This option only does something on certain CPUs.
322 (AMD Athlon/Duron and Intel Pentium 4)
323
324config X86_MCE_P4THERMAL
325 bool "check for P4 thermal throttling interrupt."
326 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
327 help
328 Enabling this feature will cause a message to be printed when the P4
329 enters thermal throttling.
330
331config TOSHIBA
332 tristate "Toshiba Laptop support"
333 ---help---
334 This adds a driver to safely access the System Management Mode of
335 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
336 not work on models with a Phoenix BIOS. The System Management Mode
337 is used to set the BIOS and power saving options on Toshiba portables.
338
339 For information on utilities to make use of this driver see the
340 Toshiba Linux utilities web site at:
341 <http://www.buzzard.org.uk/toshiba/>.
342
343 Say Y if you intend to run this kernel on a Toshiba portable.
344 Say N otherwise.
345
346config I8K
347 tristate "Dell laptop support"
348 ---help---
349 This adds a driver to safely access the System Management Mode
350 of the CPU on the Dell Inspiron 8000. The System Management Mode
351 is used to read cpu temperature and cooling fan status and to
352 control the fans on the I8K portables.
353
354 This driver has been tested only on the Inspiron 8000 but it may
355 also work with other Dell laptops. You can force loading on other
356 models by passing the parameter `force=1' to the module. Use at
357 your own risk.
358
359 For information on utilities to make use of this driver see the
360 I8K Linux utilities web site at:
361 <http://people.debian.org/~dz/i8k/>
362
363 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
364 Say N otherwise.
365
Jaya Kumara2f7c352005-05-01 08:58:49 -0700366config X86_REBOOTFIXUPS
367 bool "Enable X86 board specific fixups for reboot"
368 depends on X86
369 default n
370 ---help---
371 This enables chipset and/or board specific fixups to be done
372 in order to get reboot to work correctly. This is only needed on
373 some combinations of hardware and BIOS. The symptom, for which
374 this config is intended, is when reboot ends with a stalled/hung
375 system.
376
377 Currently, the only fixup is for the Geode GX1/CS5530A/TROM2.1.
378 combination.
379
380 Say Y if you want to enable the fixup. Currently, it's safe to
381 enable this option even if you don't need it.
382 Say N otherwise.
383
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384config MICROCODE
385 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
386 ---help---
387 If you say Y here and also to "/dev file system support" in the
388 'File systems' section, you will be able to update the microcode on
389 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
390 Pentium III, Pentium 4, Xeon etc. You will obviously need the
391 actual microcode binary data itself which is not shipped with the
392 Linux kernel.
393
394 For latest news and information on obtaining all the required
395 ingredients for this driver, check:
396 <http://www.urbanmyth.org/microcode/>.
397
398 To compile this driver as a module, choose M here: the
399 module will be called microcode.
400
401config X86_MSR
402 tristate "/dev/cpu/*/msr - Model-specific register support"
403 help
404 This device gives privileged processes access to the x86
405 Model-Specific Registers (MSRs). It is a character device with
406 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
407 MSR accesses are directed to a specific CPU on multi-processor
408 systems.
409
410config X86_CPUID
411 tristate "/dev/cpu/*/cpuid - CPU information support"
412 help
413 This device gives processes access to the x86 CPUID instruction to
414 be executed on a specific processor. It is a character device
415 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
416 /dev/cpu/31/cpuid.
417
418source "drivers/firmware/Kconfig"
419
420choice
421 prompt "High Memory Support"
422 default NOHIGHMEM
423
424config NOHIGHMEM
425 bool "off"
Adrian Bunk905c3992006-03-23 02:59:55 -0800426 depends on !X86_NUMAQ
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 ---help---
428 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
429 However, the address space of 32-bit x86 processors is only 4
430 Gigabytes large. That means that, if you have a large amount of
431 physical memory, not all of it can be "permanently mapped" by the
432 kernel. The physical memory that's not permanently mapped is called
433 "high memory".
434
435 If you are compiling a kernel which will never run on a machine with
436 more than 1 Gigabyte total physical RAM, answer "off" here (default
437 choice and suitable for most users). This will result in a "3GB/1GB"
438 split: 3GB are mapped so that each process sees a 3GB virtual memory
439 space and the remaining part of the 4GB virtual memory space is used
440 by the kernel to permanently map as much physical memory as
441 possible.
442
443 If the machine has between 1 and 4 Gigabytes physical RAM, then
444 answer "4GB" here.
445
446 If more than 4 Gigabytes is used then answer "64GB" here. This
447 selection turns Intel PAE (Physical Address Extension) mode on.
448 PAE implements 3-level paging on IA32 processors. PAE is fully
449 supported by Linux, PAE mode is implemented on all recent Intel
450 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
451 then the kernel will not boot on CPUs that don't support PAE!
452
453 The actual amount of total physical memory will either be
454 auto detected or can be forced by using a kernel command line option
455 such as "mem=256M". (Try "man bootparam" or see the documentation of
456 your boot loader (lilo or loadlin) about how to pass options to the
457 kernel at boot time.)
458
459 If unsure, say "off".
460
461config HIGHMEM4G
462 bool "4GB"
Adrian Bunk905c3992006-03-23 02:59:55 -0800463 depends on !X86_NUMAQ
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 help
465 Select this if you have a 32-bit processor and between 1 and 4
466 gigabytes of physical RAM.
467
468config HIGHMEM64G
469 bool "64GB"
Adrian Bunk4be68a72006-02-04 23:28:05 -0800470 depends on X86_CMPXCHG64
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 help
472 Select this if you have a 32-bit processor and more than 4
473 gigabytes of physical RAM.
474
475endchoice
476
Mark Lord975b3d32006-02-01 03:06:11 -0800477choice
478 depends on EXPERIMENTAL && !X86_PAE
Andi Kleen9539d4e2006-04-27 18:39:36 -0700479 prompt "Memory split" if EMBEDDED
Mark Lord975b3d32006-02-01 03:06:11 -0800480 default VMSPLIT_3G
481 help
482 Select the desired split between kernel and user memory.
483
484 If the address range available to the kernel is less than the
485 physical memory installed, the remaining memory will be available
486 as "high memory". Accessing high memory is a little more costly
487 than low memory, as it needs to be mapped into the kernel first.
488 Note that increasing the kernel address space limits the range
489 available to user programs, making the address space there
490 tighter. Selecting anything other than the default 3G/1G split
491 will also likely make your kernel incompatible with binary-only
492 kernel modules.
493
494 If you are not absolutely sure what you are doing, leave this
495 option alone!
496
497 config VMSPLIT_3G
498 bool "3G/1G user/kernel split"
499 config VMSPLIT_3G_OPT
500 bool "3G/1G user/kernel split (for full 1G low memory)"
501 config VMSPLIT_2G
502 bool "2G/2G user/kernel split"
503 config VMSPLIT_1G
504 bool "1G/3G user/kernel split"
505endchoice
506
507config PAGE_OFFSET
508 hex
509 default 0xB0000000 if VMSPLIT_3G_OPT
510 default 0x78000000 if VMSPLIT_2G
511 default 0x40000000 if VMSPLIT_1G
512 default 0xC0000000
513
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514config HIGHMEM
515 bool
516 depends on HIGHMEM64G || HIGHMEM4G
517 default y
518
519config X86_PAE
520 bool
521 depends on HIGHMEM64G
522 default y
523
524# Common NUMA Features
525config NUMA
526 bool "Numa Memory Allocation and Scheduler Support"
527 depends on SMP && HIGHMEM64G && (X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI))
528 default n if X86_PC
529 default y if (X86_NUMAQ || X86_SUMMIT)
530
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
532 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
533
Yasunori Gotoc80d79d2006-04-10 22:53:53 -0700534config NODES_SHIFT
535 int
536 default "4" if X86_NUMAQ
537 default "3"
538 depends on NEED_MULTIPLE_NODES
539
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540config HAVE_ARCH_BOOTMEM_NODE
541 bool
542 depends on NUMA
543 default y
544
Andy Whitcroftaf705362005-06-23 00:07:53 -0700545config ARCH_HAVE_MEMORY_PRESENT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 bool
547 depends on DISCONTIGMEM
548 default y
549
550config NEED_NODE_MEMMAP_SIZE
551 bool
Andy Whitcroft05b79bd2005-06-23 00:07:57 -0700552 depends on DISCONTIGMEM || SPARSEMEM
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 default y
554
Dave Hansen6f167ec2005-06-23 00:07:39 -0700555config HAVE_ARCH_ALLOC_REMAP
556 bool
557 depends on NUMA
558 default y
559
Andy Whitcroft215c3402006-01-06 00:12:06 -0800560config ARCH_FLATMEM_ENABLE
561 def_bool y
562 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
563
Andy Whitcroft05b79bd2005-06-23 00:07:57 -0700564config ARCH_DISCONTIGMEM_ENABLE
565 def_bool y
566 depends on NUMA
567
568config ARCH_DISCONTIGMEM_DEFAULT
569 def_bool y
570 depends on NUMA
571
572config ARCH_SPARSEMEM_ENABLE
573 def_bool y
Andy Whitcroft215c3402006-01-06 00:12:06 -0800574 depends on (NUMA || (X86_PC && EXPERIMENTAL))
575 select SPARSEMEM_STATIC
Andy Whitcroft05b79bd2005-06-23 00:07:57 -0700576
577config ARCH_SELECT_MEMORY_MODEL
578 def_bool y
579 depends on ARCH_SPARSEMEM_ENABLE
580
Dave Hansen3f22ab22005-06-23 00:07:43 -0700581source "mm/Kconfig"
582
Andy Whitcroftb159d432005-06-23 00:07:52 -0700583config HAVE_ARCH_EARLY_PFN_TO_NID
584 bool
585 default y
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700586 depends on NUMA
Andy Whitcroftb159d432005-06-23 00:07:52 -0700587
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588config HIGHPTE
589 bool "Allocate 3rd-level pagetables from highmem"
590 depends on HIGHMEM4G || HIGHMEM64G
591 help
592 The VM uses one page table entry for each page of physical memory.
593 For systems with a lot of RAM, this can be wasteful of precious
594 low memory. Setting this option will put user-space page table
595 entries in high memory.
596
597config MATH_EMULATION
598 bool "Math emulation"
599 ---help---
600 Linux can emulate a math coprocessor (used for floating point
601 operations) if you don't have one. 486DX and Pentium processors have
602 a math coprocessor built in, 486SX and 386 do not, unless you added
603 a 487DX or 387, respectively. (The messages during boot time can
604 give you some hints here ["man dmesg"].) Everyone needs either a
605 coprocessor or this emulation.
606
607 If you don't have a math coprocessor, you need to say Y here; if you
608 say Y here even though you have a coprocessor, the coprocessor will
609 be used nevertheless. (This behavior can be changed with the kernel
610 command line option "no387", which comes handy if your coprocessor
611 is broken. Try "man bootparam" or see the documentation of your boot
612 loader (lilo or loadlin) about how to pass options to the kernel at
613 boot time.) This means that it is a good idea to say Y here if you
614 intend to use this kernel on different machines.
615
616 More information about the internals of the Linux math coprocessor
617 emulation can be found in <file:arch/i386/math-emu/README>.
618
619 If you are not sure, say Y; apart from resulting in a 66 KB bigger
620 kernel, it won't hurt.
621
622config MTRR
623 bool "MTRR (Memory Type Range Register) support"
624 ---help---
625 On Intel P6 family processors (Pentium Pro, Pentium II and later)
626 the Memory Type Range Registers (MTRRs) may be used to control
627 processor access to memory ranges. This is most useful if you have
628 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
629 allows bus write transfers to be combined into a larger transfer
630 before bursting over the PCI/AGP bus. This can increase performance
631 of image write operations 2.5 times or more. Saying Y here creates a
632 /proc/mtrr file which may be used to manipulate your processor's
633 MTRRs. Typically the X server should use this.
634
635 This code has a reasonably generic interface so that similar
636 control registers on other processors can be easily supported
637 as well:
638
639 The Cyrix 6x86, 6x86MX and M II processors have Address Range
640 Registers (ARRs) which provide a similar functionality to MTRRs. For
641 these, the ARRs are used to emulate the MTRRs.
642 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
643 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
644 write-combining. All of these processors are supported by this code
645 and it makes sense to say Y here if you have one of them.
646
647 Saying Y here also fixes a problem with buggy SMP BIOSes which only
648 set the MTRRs for the boot CPU and not for the secondary CPUs. This
649 can lead to all sorts of problems, so it's good to say Y here.
650
651 You can safely say Y even if your machine doesn't have MTRRs, you'll
652 just add about 9 KB to your kernel.
653
654 See <file:Documentation/mtrr.txt> for more information.
655
656config EFI
657 bool "Boot from EFI support (EXPERIMENTAL)"
658 depends on ACPI
659 default n
660 ---help---
661 This enables the the kernel to boot on EFI platforms using
662 system configuration information passed to it from the firmware.
663 This also enables the kernel to use any EFI runtime services that are
664 available (such as the EFI variable services).
665
666 This option is only useful on systems that have EFI firmware
667 and will result in a kernel image that is ~8k larger. In addition,
668 you must use the latest ELILO loader available at
669 <http://elilo.sourceforge.net> in order to take advantage of
670 kernel initialization using EFI information (neither GRUB nor LILO know
671 anything about EFI). However, even with this option, the resultant
672 kernel should continue to boot on existing non-EFI platforms.
673
674config IRQBALANCE
675 bool "Enable kernel irq balancing"
676 depends on SMP && X86_IO_APIC
677 default y
678 help
679 The default yes will allow the kernel to do irq load balancing.
680 Saying no will keep the kernel from doing irq load balancing.
681
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682# turning this on wastes a bunch of space.
683# Summit needs it only when NUMA is on
684config BOOT_IOREMAP
685 bool
686 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
687 default y
688
689config REGPARM
Adrian Bunk69ef4142006-03-23 02:59:28 -0800690 bool "Use register arguments"
Ingo Molnarb824eb62006-03-23 02:59:29 -0800691 default y
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 help
Ingo Molnarb824eb62006-03-23 02:59:29 -0800693 Compile the kernel with -mregparm=3. This instructs gcc to use
694 a more efficient function call ABI which passes the first three
695 arguments of a function call via registers, which results in denser
696 and faster code.
697
698 If this option is disabled, then the default ABI of passing
699 arguments via the stack is used.
700
701 If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703config SECCOMP
704 bool "Enable seccomp to safely compute untrusted bytecode"
705 depends on PROC_FS
706 default y
707 help
708 This kernel feature is useful for number crunching applications
709 that may need to compute untrusted bytecode during their
710 execution. By using pipes or other transports made available to
711 the process as file descriptors supporting the read/write
712 syscalls, it's possible to isolate those applications in
713 their own address space using seccomp. Once seccomp is
714 enabled via /proc/<pid>/seccomp, it cannot be disabled
715 and the task is only allowed to execute a few safe syscalls
716 defined by each seccomp mode.
717
718 If unsure, say Y. Only embedded should say N here.
719
Christoph Lameter59121002005-06-23 00:08:25 -0700720source kernel/Kconfig.hz
721
Eric W. Biederman5033cba2005-06-25 14:57:56 -0700722config KEXEC
723 bool "kexec system call (EXPERIMENTAL)"
724 depends on EXPERIMENTAL
725 help
726 kexec is a system call that implements the ability to shutdown your
727 current kernel, and to start another kernel. It is like a reboot
728 but it is indepedent of the system firmware. And like a reboot
729 you can start any kernel with it, not just Linux.
730
731 The name comes from the similiarity to the exec system call.
732
733 It is an ongoing process to be certain the hardware in a machine
734 is properly shutdown, so do not be surprised if this code does not
735 initially work for you. It may help to enable device hotplugging
736 support. As of this writing the exact hardware interface is
737 strongly in flux, so no good recommendation can be made.
738
Vivek Goyal5f016452005-06-25 14:58:19 -0700739config CRASH_DUMP
740 bool "kernel crash dumps (EXPERIMENTAL)"
Vivek Goyal5f016452005-06-25 14:58:19 -0700741 depends on EXPERIMENTAL
742 depends on HIGHMEM
743 help
744 Generate crash dump after being started by kexec.
Maneesh Soni05970d42006-01-09 20:51:52 -0800745
746config PHYSICAL_START
747 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
748
749 default "0x1000000" if CRASH_DUMP
750 default "0x100000"
751 help
752 This gives the physical address where the kernel is loaded. Normally
753 for regular kernels this value is 0x100000 (1MB). But in the case
754 of kexec on panic the fail safe kernel needs to run at a different
755 address than the panic-ed kernel. This option is used to set the load
756 address for kernels used to capture crash dump on being kexec'ed
757 after panic. The default value for crash dump kernels is
758 0x1000000 (16MB). This can also be set based on the "X" value as
759 specified in the "crashkernel=YM@XM" command line boot parameter
760 passed to the panic-ed kernel. Typically this parameter is set as
761 crashkernel=64M@16M. Please take a look at
762 Documentation/kdump/kdump.txt for more details about crash dumps.
763
764 Don't change this unless you know what you are doing.
765
Randy Dunlapce63ad72006-01-14 13:20:51 -0800766config HOTPLUG_CPU
767 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
Ashok Raj35076bd2006-04-27 18:39:30 -0700768 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
Randy Dunlapce63ad72006-01-14 13:20:51 -0800769 ---help---
Pavel Machekb2d596d2006-05-15 09:44:34 -0700770 Say Y here to experiment with turning CPUs off and on, and to
771 enable suspend on SMP systems. CPUs can be controlled through
772 /sys/devices/system/cpu.
Randy Dunlapce63ad72006-01-14 13:20:51 -0800773
Randy Dunlapce63ad72006-01-14 13:20:51 -0800774
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775endmenu
776
777
778menu "Power management options (ACPI, APM)"
779 depends on !X86_VOYAGER
780
781source kernel/power/Kconfig
782
783source "drivers/acpi/Kconfig"
784
785menu "APM (Advanced Power Management) BIOS Support"
786depends on PM && !X86_VISWS
787
788config APM
789 tristate "APM (Advanced Power Management) BIOS support"
Dave Jones987d46132006-01-08 01:05:09 -0800790 depends on PM
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 ---help---
792 APM is a BIOS specification for saving power using several different
793 techniques. This is mostly useful for battery powered laptops with
794 APM compliant BIOSes. If you say Y here, the system time will be
795 reset after a RESUME operation, the /proc/apm device will provide
796 battery status information, and user-space programs will receive
797 notification of APM "events" (e.g. battery status change).
798
799 If you select "Y" here, you can disable actual use of the APM
800 BIOS by passing the "apm=off" option to the kernel at boot time.
801
802 Note that the APM support is almost completely disabled for
803 machines with more than one CPU.
804
805 In order to use APM, you will need supporting software. For location
806 and more information, read <file:Documentation/pm.txt> and the
807 Battery Powered Linux mini-HOWTO, available from
808 <http://www.tldp.org/docs.html#howto>.
809
810 This driver does not spin down disk drives (see the hdparm(8)
811 manpage ("man 8 hdparm") for that), and it doesn't turn off
812 VESA-compliant "green" monitors.
813
814 This driver does not support the TI 4000M TravelMate and the ACER
815 486/DX4/75 because they don't have compliant BIOSes. Many "green"
816 desktop machines also don't have compliant BIOSes, and this driver
817 may cause those machines to panic during the boot phase.
818
819 Generally, if you don't have a battery in your machine, there isn't
820 much point in using this driver and you should say N. If you get
821 random kernel OOPSes or reboots that don't seem to be related to
822 anything, try disabling/enabling this option (or disabling/enabling
823 APM in your BIOS).
824
825 Some other things you should try when experiencing seemingly random,
826 "weird" problems:
827
828 1) make sure that you have enough swap space and that it is
829 enabled.
830 2) pass the "no-hlt" option to the kernel
831 3) switch on floating point emulation in the kernel and pass
832 the "no387" option to the kernel
833 4) pass the "floppy=nodma" option to the kernel
834 5) pass the "mem=4M" option to the kernel (thereby disabling
835 all but the first 4 MB of RAM)
836 6) make sure that the CPU is not over clocked.
837 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
838 8) disable the cache from your BIOS settings
839 9) install a fan for the video card or exchange video RAM
840 10) install a better fan for the CPU
841 11) exchange RAM chips
842 12) exchange the motherboard.
843
844 To compile this driver as a module, choose M here: the
845 module will be called apm.
846
847config APM_IGNORE_USER_SUSPEND
848 bool "Ignore USER SUSPEND"
849 depends on APM
850 help
851 This option will ignore USER SUSPEND requests. On machines with a
852 compliant APM BIOS, you want to say N. However, on the NEC Versa M
853 series notebooks, it is necessary to say Y because of a BIOS bug.
854
855config APM_DO_ENABLE
856 bool "Enable PM at boot time"
857 depends on APM
858 ---help---
859 Enable APM features at boot time. From page 36 of the APM BIOS
860 specification: "When disabled, the APM BIOS does not automatically
861 power manage devices, enter the Standby State, enter the Suspend
862 State, or take power saving steps in response to CPU Idle calls."
863 This driver will make CPU Idle calls when Linux is idle (unless this
864 feature is turned off -- see "Do CPU IDLE calls", below). This
865 should always save battery power, but more complicated APM features
866 will be dependent on your BIOS implementation. You may need to turn
867 this option off if your computer hangs at boot time when using APM
868 support, or if it beeps continuously instead of suspending. Turn
869 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
870 T400CDT. This is off by default since most machines do fine without
871 this feature.
872
873config APM_CPU_IDLE
874 bool "Make CPU Idle calls when idle"
875 depends on APM
876 help
877 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
878 On some machines, this can activate improved power savings, such as
879 a slowed CPU clock rate, when the machine is idle. These idle calls
880 are made after the idle loop has run for some length of time (e.g.,
881 333 mS). On some machines, this will cause a hang at boot time or
882 whenever the CPU becomes idle. (On machines with more than one CPU,
883 this option does nothing.)
884
885config APM_DISPLAY_BLANK
886 bool "Enable console blanking using APM"
887 depends on APM
888 help
889 Enable console blanking using the APM. Some laptops can use this to
890 turn off the LCD backlight when the screen blanker of the Linux
891 virtual console blanks the screen. Note that this is only used by
892 the virtual console screen blanker, and won't turn off the backlight
893 when using the X Window system. This also doesn't have anything to
894 do with your VESA-compliant power-saving monitor. Further, this
895 option doesn't work for all laptops -- it might not turn off your
896 backlight at all, or it might print a lot of errors to the console,
897 especially if you are using gpm.
898
899config APM_RTC_IS_GMT
900 bool "RTC stores time in GMT"
901 depends on APM
902 help
903 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
904 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
905 stores localtime.
906
907 It is in fact recommended to store GMT in your RTC, because then you
908 don't have to worry about daylight savings time changes. The only
909 reason not to use GMT in your RTC is if you also run a broken OS
910 that doesn't understand GMT.
911
912config APM_ALLOW_INTS
913 bool "Allow interrupts during APM BIOS calls"
914 depends on APM
915 help
916 Normally we disable external interrupts while we are making calls to
917 the APM BIOS as a measure to lessen the effects of a badly behaving
918 BIOS implementation. The BIOS should reenable interrupts if it
919 needs to. Unfortunately, some BIOSes do not -- especially those in
920 many of the newer IBM Thinkpads. If you experience hangs when you
921 suspend, try setting this to Y. Otherwise, say N.
922
923config APM_REAL_MODE_POWER_OFF
924 bool "Use real mode APM BIOS call to power off"
925 depends on APM
926 help
927 Use real mode APM BIOS calls to switch off the computer. This is
928 a work-around for a number of buggy BIOSes. Switch this option on if
929 your computer crashes instead of powering off properly.
930
931endmenu
932
933source "arch/i386/kernel/cpu/cpufreq/Kconfig"
934
935endmenu
936
937menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
938
939config PCI
940 bool "PCI support" if !X86_VISWS
941 depends on !X86_VOYAGER
942 default y if X86_VISWS
943 help
944 Find out whether you have a PCI motherboard. PCI is the name of a
945 bus system, i.e. the way the CPU talks to the other stuff inside
946 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
947 VESA. If you have PCI, say Y, otherwise N.
948
949 The PCI-HOWTO, available from
950 <http://www.tldp.org/docs.html#howto>, contains valuable
951 information about which PCI hardware does work under Linux and which
952 doesn't.
953
954choice
955 prompt "PCI access mode"
956 depends on PCI && !X86_VISWS
957 default PCI_GOANY
958 ---help---
959 On PCI systems, the BIOS can be used to detect the PCI devices and
960 determine their configuration. However, some old PCI motherboards
961 have BIOS bugs and may crash if this is done. Also, some embedded
962 PCI-based systems don't have any BIOS at all. Linux can also try to
963 detect the PCI hardware directly without using the BIOS.
964
965 With this option, you can specify how Linux should detect the
966 PCI devices. If you choose "BIOS", the BIOS will be used,
967 if you choose "Direct", the BIOS won't be used, and if you
968 choose "MMConfig", then PCI Express MMCONFIG will be used.
969 If you choose "Any", the kernel will try MMCONFIG, then the
970 direct access method and falls back to the BIOS if that doesn't
971 work. If unsure, go with the default, which is "Any".
972
973config PCI_GOBIOS
974 bool "BIOS"
975
976config PCI_GOMMCONFIG
977 bool "MMConfig"
978
979config PCI_GODIRECT
980 bool "Direct"
981
982config PCI_GOANY
983 bool "Any"
984
985endchoice
986
987config PCI_BIOS
988 bool
989 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
990 default y
991
992config PCI_DIRECT
993 bool
994 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
995 default y
996
997config PCI_MMCONFIG
998 bool
Alexander Nyberg8aadff72005-05-27 12:48:50 +0200999 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000 default y
1001
1002source "drivers/pci/pcie/Kconfig"
1003
1004source "drivers/pci/Kconfig"
1005
Al Viro5cae8412005-05-04 05:39:22 +01001006config ISA_DMA_API
1007 bool
1008 default y
1009
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010config ISA
1011 bool "ISA support"
1012 depends on !(X86_VOYAGER || X86_VISWS)
1013 help
1014 Find out whether you have ISA slots on your motherboard. ISA is the
1015 name of a bus system, i.e. the way the CPU talks to the other stuff
1016 inside your box. Other bus systems are PCI, EISA, MicroChannel
1017 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1018 newer boards don't support it. If you have ISA, say Y, otherwise N.
1019
1020config EISA
1021 bool "EISA support"
1022 depends on ISA
1023 ---help---
1024 The Extended Industry Standard Architecture (EISA) bus was
1025 developed as an open alternative to the IBM MicroChannel bus.
1026
1027 The EISA bus provided some of the features of the IBM MicroChannel
1028 bus while maintaining backward compatibility with cards made for
1029 the older ISA bus. The EISA bus saw limited use between 1988 and
1030 1995 when it was made obsolete by the PCI bus.
1031
1032 Say Y here if you are building a kernel for an EISA-based machine.
1033
1034 Otherwise, say N.
1035
1036source "drivers/eisa/Kconfig"
1037
1038config MCA
1039 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1040 default y if X86_VOYAGER
1041 help
1042 MicroChannel Architecture is found in some IBM PS/2 machines and
1043 laptops. It is a bus system similar to PCI or ISA. See
1044 <file:Documentation/mca.txt> (and especially the web page given
1045 there) before attempting to build an MCA bus kernel.
1046
1047source "drivers/mca/Kconfig"
1048
1049config SCx200
1050 tristate "NatSemi SCx200 support"
1051 depends on !X86_VOYAGER
1052 help
1053 This provides basic support for the National Semiconductor SCx200
1054 processor. Right now this is just a driver for the GPIO pins.
1055
1056 If you don't know what to do here, say N.
1057
1058 This support is also available as a module. If compiled as a
1059 module, it will be called scx200.
1060
Linus Torvalds1da177e2005-04-16 15:20:36 -07001061source "drivers/pcmcia/Kconfig"
1062
1063source "drivers/pci/hotplug/Kconfig"
1064
1065endmenu
1066
1067menu "Executable file formats"
1068
1069source "fs/Kconfig.binfmt"
1070
1071endmenu
1072
Sam Ravnborgd5950b42005-07-11 21:03:49 -07001073source "net/Kconfig"
1074
Linus Torvalds1da177e2005-04-16 15:20:36 -07001075source "drivers/Kconfig"
1076
1077source "fs/Kconfig"
1078
Prasanna S Panchamukhicd6b0762005-11-07 00:59:14 -08001079menu "Instrumentation Support"
1080 depends on EXPERIMENTAL
1081
Linus Torvalds1da177e2005-04-16 15:20:36 -07001082source "arch/i386/oprofile/Kconfig"
1083
Prasanna S Panchamukhicd6b0762005-11-07 00:59:14 -08001084config KPROBES
1085 bool "Kprobes (EXPERIMENTAL)"
Linus Torvaldsadd2b6f2006-02-26 20:24:40 -08001086 depends on EXPERIMENTAL && MODULES
Prasanna S Panchamukhicd6b0762005-11-07 00:59:14 -08001087 help
1088 Kprobes allows you to trap at almost any kernel address and
1089 execute a callback function. register_kprobe() establishes
1090 a probepoint and specifies the callback. Kprobes is useful
1091 for kernel debugging, non-intrusive instrumentation and testing.
1092 If in doubt, say "N".
1093endmenu
1094
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095source "arch/i386/Kconfig.debug"
1096
1097source "security/Kconfig"
1098
1099source "crypto/Kconfig"
1100
1101source "lib/Kconfig"
1102
1103#
1104# Use the generic interrupt handling code in kernel/irq/:
1105#
1106config GENERIC_HARDIRQS
1107 bool
1108 default y
1109
1110config GENERIC_IRQ_PROBE
1111 bool
1112 default y
1113
Ashok Raj54d5d422005-09-06 15:16:15 -07001114config GENERIC_PENDING_IRQ
1115 bool
1116 depends on GENERIC_HARDIRQS && SMP
1117 default y
1118
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119config X86_SMP
1120 bool
1121 depends on SMP && !X86_VOYAGER
1122 default y
1123
1124config X86_HT
1125 bool
1126 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1127 default y
1128
1129config X86_BIOS_REBOOT
1130 bool
1131 depends on !(X86_VISWS || X86_VOYAGER)
1132 default y
1133
1134config X86_TRAMPOLINE
1135 bool
1136 depends on X86_SMP || (X86_VOYAGER && SMP)
1137 default y
Thomas Gleixner97fc79f2006-01-09 20:52:31 -08001138
1139config KTIME_SCALAR
1140 bool
1141 default y