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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
Benjamin LaHaise52fdd082005-09-03 15:56:52 -070017config SEMAPHORE_SLEEPERS
18 bool
19 default y
20
Brian Gerst0d078f62005-10-30 14:59:20 -080021config X86
22 bool
23 default y
24
Linus Torvalds1da177e2005-04-16 15:20:36 -070025config MMU
26 bool
27 default y
28
29config SBUS
30 bool
31
Linus Torvalds1da177e2005-04-16 15:20:36 -070032config GENERIC_ISA_DMA
33 bool
34 default y
35
36config GENERIC_IOMAP
37 bool
38 default y
39
Akinobu Mita1cc2b992006-03-26 01:39:24 -080040config GENERIC_HWEIGHT
41 bool
42 default y
43
viro@ZenIV.linux.org.uka08b6b72005-09-06 01:48:42 +010044config ARCH_MAY_HAVE_PC_FDC
45 bool
46 default y
47
Andi Kleene9928672006-01-11 22:43:33 +010048config DMI
49 bool
50 default y
51
Linus Torvalds1da177e2005-04-16 15:20:36 -070052source "init/Kconfig"
53
54menu "Processor type and features"
55
56choice
57 prompt "Subarchitecture Type"
58 default X86_PC
59
60config X86_PC
61 bool "PC-compatible"
62 help
63 Choose this option if your computer is a standard PC or compatible.
64
65config X86_ELAN
66 bool "AMD Elan"
67 help
68 Select this for an AMD Elan processor.
69
70 Do not use this option for K6/Athlon/Opteron processors!
71
72 If unsure, choose "PC-compatible" instead.
73
74config X86_VOYAGER
75 bool "Voyager (NCR)"
76 help
77 Voyager is an MCA-based 32-way capable SMP architecture proprietary
78 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
79
80 *** WARNING ***
81
82 If you do not specifically know you have a Voyager based machine,
83 say N here, otherwise the kernel you build will not be bootable.
84
85config X86_NUMAQ
86 bool "NUMAQ (IBM/Sequent)"
Adrian Bunk905c3992006-03-23 02:59:55 -080087 select SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 select NUMA
89 help
90 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
91 multiquad box. This changes the way that processors are bootstrapped,
92 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
93 You will need a new lynxer.elf file to flash your firmware with - send
94 email to <Martin.Bligh@us.ibm.com>.
95
96config X86_SUMMIT
97 bool "Summit/EXA (IBM x440)"
98 depends on SMP
99 help
100 This option is needed for IBM systems that use the Summit/EXA chipset.
101 In particular, it is needed for the x440.
102
103 If you don't have one of these computers, you should say N here.
104
105config X86_BIGSMP
106 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
107 depends on SMP
108 help
109 This option is needed for the systems that have more than 8 CPUs
110 and if the system is not of any sub-arch type above.
111
112 If you don't have such a system, you should say N here.
113
114config X86_VISWS
115 bool "SGI 320/540 (Visual Workstation)"
116 help
117 The SGI Visual Workstation series is an IA32-based workstation
118 based on SGI systems chips with some legacy PC hardware attached.
119
120 Say Y here to create a kernel to run on the SGI 320 or 540.
121
122 A kernel compiled for the Visual Workstation will not run on PCs
123 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
124
125config X86_GENERICARCH
126 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
127 depends on SMP
128 help
129 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
130 It is intended for a generic binary kernel.
131
132config X86_ES7000
133 bool "Support for Unisys ES7000 IA32 series"
134 depends on SMP
135 help
136 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
137 supposed to run on an IA32-based Unisys ES7000 system.
138 Only choose this option if you have such a system, otherwise you
139 should say N here.
140
141endchoice
142
143config ACPI_SRAT
144 bool
145 default y
146 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
147
148config X86_SUMMIT_NUMA
149 bool
150 default y
151 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
152
153config X86_CYCLONE_TIMER
154 bool
155 default y
156 depends on X86_SUMMIT || X86_GENERICARCH
157
158config ES7000_CLUSTERED_APIC
159 bool
160 default y
161 depends on SMP && X86_ES7000 && MPENTIUMIII
162
Paolo 'Blaisorblade' Giarrusso96d55b82005-10-30 15:00:07 -0800163source "arch/i386/Kconfig.cpu"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164
165config HPET_TIMER
166 bool "HPET Timer Support"
167 help
168 This enables the use of the HPET for the kernel's internal timer.
169 HPET is the next generation timer replacing legacy 8254s.
170 You can safely choose Y here. However, HPET will only be
171 activated if the platform and the BIOS support this feature.
172 Otherwise the 8254 will be used for timing services.
173
174 Choose N to continue using the legacy 8254 timer.
175
176config HPET_EMULATE_RTC
Venkatesh Pallipadic91096d2005-08-04 15:36:10 -0700177 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 depends on HPET_TIMER && RTC=y
Venkatesh Pallipadic91096d2005-08-04 15:36:10 -0700179 default y
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180
181config SMP
182 bool "Symmetric multi-processing support"
183 ---help---
184 This enables support for systems with more than one CPU. If you have
185 a system with only one CPU, like most personal computers, say N. If
186 you have a system with more than one CPU, say Y.
187
188 If you say N here, the kernel will run on single and multiprocessor
189 machines, but will use only one CPU of a multiprocessor machine. If
190 you say Y here, the kernel will run on many, but not all,
191 singleprocessor machines. On a singleprocessor machine, the kernel
192 will run faster if you say N here.
193
194 Note that if you say Y here and choose architecture "586" or
195 "Pentium" under "Processor family", the kernel will not work on 486
196 architectures. Similarly, multiprocessor kernels for the "PPro"
197 architecture may not work on all Pentium based boards.
198
199 People using multiprocessor machines who say Y here should also say
200 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
201 Management" code will be disabled if you say Y here.
202
203 See also the <file:Documentation/smp.txt>,
204 <file:Documentation/i386/IO-APIC.txt>,
205 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
206 <http://www.tldp.org/docs.html#howto>.
207
208 If you don't know what to do here, say N.
209
210config NR_CPUS
211 int "Maximum number of CPUs (2-255)"
212 range 2 255
213 depends on SMP
214 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
215 default "8"
216 help
217 This allows you to specify the maximum number of CPUs which this
218 kernel will support. The maximum supported value is 255 and the
219 minimum value which makes sense is 2.
220
221 This is purely to save memory - each supported CPU adds
222 approximately eight kilobytes to the kernel image.
223
224config SCHED_SMT
225 bool "SMT (Hyperthreading) scheduler support"
226 depends on SMP
227 default off
228 help
229 SMT scheduler support improves the CPU scheduler's decision making
230 when dealing with Intel Pentium 4 chips with HyperThreading at a
231 cost of slightly increased overhead in some places. If unsure say
232 N here.
233
Siddha, Suresh B1e9f28f2006-03-27 01:15:22 -0800234config SCHED_MC
235 bool "Multi-core scheduler support"
236 depends on SMP
237 default y
238 help
239 Multi-core scheduler support improves the CPU scheduler's decision
240 making when dealing with multi-core CPU chips at a cost of slightly
241 increased overhead in some places. If unsure say N here.
242
Ingo Molnarcc19ca82005-06-25 14:57:36 -0700243source "kernel/Kconfig.preempt"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244
245config X86_UP_APIC
246 bool "Local APIC support on uniprocessors"
247 depends on !SMP && !(X86_VISWS || X86_VOYAGER)
248 help
249 A local APIC (Advanced Programmable Interrupt Controller) is an
250 integrated interrupt controller in the CPU. If you have a single-CPU
251 system which has a processor with a local APIC, you can say Y here to
252 enable and use it. If you say Y here even though your machine doesn't
253 have a local APIC, then the kernel will still run with no slowdown at
254 all. The local APIC supports CPU-generated self-interrupts (timer,
255 performance counters), and the NMI watchdog which detects hard
256 lockups.
257
258config X86_UP_IOAPIC
259 bool "IO-APIC support on uniprocessors"
260 depends on X86_UP_APIC
261 help
262 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
263 SMP-capable replacement for PC-style interrupt controllers. Most
264 SMP systems and many recent uniprocessor systems have one.
265
266 If you have a single-CPU system with an IO-APIC, you can say Y here
267 to use it. If you say Y here even though your machine doesn't have
268 an IO-APIC, then the kernel will still run with no slowdown at all.
269
270config X86_LOCAL_APIC
271 bool
272 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER)
273 default y
274
275config X86_IO_APIC
276 bool
277 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER))
278 default y
279
280config X86_VISWS_APIC
281 bool
282 depends on X86_VISWS
283 default y
284
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285config X86_MCE
286 bool "Machine Check Exception"
287 depends on !X86_VOYAGER
288 ---help---
289 Machine Check Exception support allows the processor to notify the
290 kernel if it detects a problem (e.g. overheating, component failure).
291 The action the kernel takes depends on the severity of the problem,
292 ranging from a warning message on the console, to halting the machine.
293 Your processor must be a Pentium or newer to support this - check the
294 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
295 have a design flaw which leads to false MCE events - hence MCE is
296 disabled on all P5 processors, unless explicitly enabled with "mce"
297 as a boot argument. Similarly, if MCE is built in and creates a
298 problem on some new non-standard machine, you can boot with "nomce"
299 to disable it. MCE support simply ignores non-MCE processors like
300 the 386 and 486, so nearly everyone can say Y here.
301
302config X86_MCE_NONFATAL
303 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
304 depends on X86_MCE
305 help
306 Enabling this feature starts a timer that triggers every 5 seconds which
307 will look at the machine check registers to see if anything happened.
308 Non-fatal problems automatically get corrected (but still logged).
309 Disable this if you don't want to see these messages.
310 Seeing the messages this option prints out may be indicative of dying hardware,
311 or out-of-spec (ie, overclocked) hardware.
312 This option only does something on certain CPUs.
313 (AMD Athlon/Duron and Intel Pentium 4)
314
315config X86_MCE_P4THERMAL
316 bool "check for P4 thermal throttling interrupt."
317 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
318 help
319 Enabling this feature will cause a message to be printed when the P4
320 enters thermal throttling.
321
322config TOSHIBA
323 tristate "Toshiba Laptop support"
324 ---help---
325 This adds a driver to safely access the System Management Mode of
326 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
327 not work on models with a Phoenix BIOS. The System Management Mode
328 is used to set the BIOS and power saving options on Toshiba portables.
329
330 For information on utilities to make use of this driver see the
331 Toshiba Linux utilities web site at:
332 <http://www.buzzard.org.uk/toshiba/>.
333
334 Say Y if you intend to run this kernel on a Toshiba portable.
335 Say N otherwise.
336
337config I8K
338 tristate "Dell laptop support"
339 ---help---
340 This adds a driver to safely access the System Management Mode
341 of the CPU on the Dell Inspiron 8000. The System Management Mode
342 is used to read cpu temperature and cooling fan status and to
343 control the fans on the I8K portables.
344
345 This driver has been tested only on the Inspiron 8000 but it may
346 also work with other Dell laptops. You can force loading on other
347 models by passing the parameter `force=1' to the module. Use at
348 your own risk.
349
350 For information on utilities to make use of this driver see the
351 I8K Linux utilities web site at:
352 <http://people.debian.org/~dz/i8k/>
353
354 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
355 Say N otherwise.
356
Jaya Kumara2f7c352005-05-01 08:58:49 -0700357config X86_REBOOTFIXUPS
358 bool "Enable X86 board specific fixups for reboot"
359 depends on X86
360 default n
361 ---help---
362 This enables chipset and/or board specific fixups to be done
363 in order to get reboot to work correctly. This is only needed on
364 some combinations of hardware and BIOS. The symptom, for which
365 this config is intended, is when reboot ends with a stalled/hung
366 system.
367
368 Currently, the only fixup is for the Geode GX1/CS5530A/TROM2.1.
369 combination.
370
371 Say Y if you want to enable the fixup. Currently, it's safe to
372 enable this option even if you don't need it.
373 Say N otherwise.
374
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375config MICROCODE
376 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
377 ---help---
378 If you say Y here and also to "/dev file system support" in the
379 'File systems' section, you will be able to update the microcode on
380 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
381 Pentium III, Pentium 4, Xeon etc. You will obviously need the
382 actual microcode binary data itself which is not shipped with the
383 Linux kernel.
384
385 For latest news and information on obtaining all the required
386 ingredients for this driver, check:
387 <http://www.urbanmyth.org/microcode/>.
388
389 To compile this driver as a module, choose M here: the
390 module will be called microcode.
391
392config X86_MSR
393 tristate "/dev/cpu/*/msr - Model-specific register support"
394 help
395 This device gives privileged processes access to the x86
396 Model-Specific Registers (MSRs). It is a character device with
397 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
398 MSR accesses are directed to a specific CPU on multi-processor
399 systems.
400
401config X86_CPUID
402 tristate "/dev/cpu/*/cpuid - CPU information support"
403 help
404 This device gives processes access to the x86 CPUID instruction to
405 be executed on a specific processor. It is a character device
406 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
407 /dev/cpu/31/cpuid.
408
409source "drivers/firmware/Kconfig"
410
411choice
412 prompt "High Memory Support"
413 default NOHIGHMEM
414
415config NOHIGHMEM
416 bool "off"
Adrian Bunk905c3992006-03-23 02:59:55 -0800417 depends on !X86_NUMAQ
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 ---help---
419 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
420 However, the address space of 32-bit x86 processors is only 4
421 Gigabytes large. That means that, if you have a large amount of
422 physical memory, not all of it can be "permanently mapped" by the
423 kernel. The physical memory that's not permanently mapped is called
424 "high memory".
425
426 If you are compiling a kernel which will never run on a machine with
427 more than 1 Gigabyte total physical RAM, answer "off" here (default
428 choice and suitable for most users). This will result in a "3GB/1GB"
429 split: 3GB are mapped so that each process sees a 3GB virtual memory
430 space and the remaining part of the 4GB virtual memory space is used
431 by the kernel to permanently map as much physical memory as
432 possible.
433
434 If the machine has between 1 and 4 Gigabytes physical RAM, then
435 answer "4GB" here.
436
437 If more than 4 Gigabytes is used then answer "64GB" here. This
438 selection turns Intel PAE (Physical Address Extension) mode on.
439 PAE implements 3-level paging on IA32 processors. PAE is fully
440 supported by Linux, PAE mode is implemented on all recent Intel
441 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
442 then the kernel will not boot on CPUs that don't support PAE!
443
444 The actual amount of total physical memory will either be
445 auto detected or can be forced by using a kernel command line option
446 such as "mem=256M". (Try "man bootparam" or see the documentation of
447 your boot loader (lilo or loadlin) about how to pass options to the
448 kernel at boot time.)
449
450 If unsure, say "off".
451
452config HIGHMEM4G
453 bool "4GB"
Adrian Bunk905c3992006-03-23 02:59:55 -0800454 depends on !X86_NUMAQ
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 help
456 Select this if you have a 32-bit processor and between 1 and 4
457 gigabytes of physical RAM.
458
459config HIGHMEM64G
460 bool "64GB"
Adrian Bunk4be68a72006-02-04 23:28:05 -0800461 depends on X86_CMPXCHG64
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 help
463 Select this if you have a 32-bit processor and more than 4
464 gigabytes of physical RAM.
465
466endchoice
467
Mark Lord975b3d32006-02-01 03:06:11 -0800468choice
469 depends on EXPERIMENTAL && !X86_PAE
470 prompt "Memory split"
471 default VMSPLIT_3G
472 help
473 Select the desired split between kernel and user memory.
474
475 If the address range available to the kernel is less than the
476 physical memory installed, the remaining memory will be available
477 as "high memory". Accessing high memory is a little more costly
478 than low memory, as it needs to be mapped into the kernel first.
479 Note that increasing the kernel address space limits the range
480 available to user programs, making the address space there
481 tighter. Selecting anything other than the default 3G/1G split
482 will also likely make your kernel incompatible with binary-only
483 kernel modules.
484
485 If you are not absolutely sure what you are doing, leave this
486 option alone!
487
488 config VMSPLIT_3G
489 bool "3G/1G user/kernel split"
490 config VMSPLIT_3G_OPT
491 bool "3G/1G user/kernel split (for full 1G low memory)"
492 config VMSPLIT_2G
493 bool "2G/2G user/kernel split"
494 config VMSPLIT_1G
495 bool "1G/3G user/kernel split"
496endchoice
497
498config PAGE_OFFSET
499 hex
500 default 0xB0000000 if VMSPLIT_3G_OPT
501 default 0x78000000 if VMSPLIT_2G
502 default 0x40000000 if VMSPLIT_1G
503 default 0xC0000000
504
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505config HIGHMEM
506 bool
507 depends on HIGHMEM64G || HIGHMEM4G
508 default y
509
510config X86_PAE
511 bool
512 depends on HIGHMEM64G
513 default y
514
515# Common NUMA Features
516config NUMA
517 bool "Numa Memory Allocation and Scheduler Support"
518 depends on SMP && HIGHMEM64G && (X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI))
519 default n if X86_PC
520 default y if (X86_NUMAQ || X86_SUMMIT)
521
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
523 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
524
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525config HAVE_ARCH_BOOTMEM_NODE
526 bool
527 depends on NUMA
528 default y
529
Andy Whitcroftaf705362005-06-23 00:07:53 -0700530config ARCH_HAVE_MEMORY_PRESENT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 bool
532 depends on DISCONTIGMEM
533 default y
534
535config NEED_NODE_MEMMAP_SIZE
536 bool
Andy Whitcroft05b79bd2005-06-23 00:07:57 -0700537 depends on DISCONTIGMEM || SPARSEMEM
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 default y
539
Dave Hansen6f167ec2005-06-23 00:07:39 -0700540config HAVE_ARCH_ALLOC_REMAP
541 bool
542 depends on NUMA
543 default y
544
Andy Whitcroft215c3402006-01-06 00:12:06 -0800545config ARCH_FLATMEM_ENABLE
546 def_bool y
547 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
548
Andy Whitcroft05b79bd2005-06-23 00:07:57 -0700549config ARCH_DISCONTIGMEM_ENABLE
550 def_bool y
551 depends on NUMA
552
553config ARCH_DISCONTIGMEM_DEFAULT
554 def_bool y
555 depends on NUMA
556
557config ARCH_SPARSEMEM_ENABLE
558 def_bool y
Andy Whitcroft215c3402006-01-06 00:12:06 -0800559 depends on (NUMA || (X86_PC && EXPERIMENTAL))
560 select SPARSEMEM_STATIC
Andy Whitcroft05b79bd2005-06-23 00:07:57 -0700561
562config ARCH_SELECT_MEMORY_MODEL
563 def_bool y
564 depends on ARCH_SPARSEMEM_ENABLE
565
Dave Hansen3f22ab22005-06-23 00:07:43 -0700566source "mm/Kconfig"
567
Andy Whitcroftb159d432005-06-23 00:07:52 -0700568config HAVE_ARCH_EARLY_PFN_TO_NID
569 bool
570 default y
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700571 depends on NUMA
Andy Whitcroftb159d432005-06-23 00:07:52 -0700572
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573config HIGHPTE
574 bool "Allocate 3rd-level pagetables from highmem"
575 depends on HIGHMEM4G || HIGHMEM64G
576 help
577 The VM uses one page table entry for each page of physical memory.
578 For systems with a lot of RAM, this can be wasteful of precious
579 low memory. Setting this option will put user-space page table
580 entries in high memory.
581
582config MATH_EMULATION
583 bool "Math emulation"
584 ---help---
585 Linux can emulate a math coprocessor (used for floating point
586 operations) if you don't have one. 486DX and Pentium processors have
587 a math coprocessor built in, 486SX and 386 do not, unless you added
588 a 487DX or 387, respectively. (The messages during boot time can
589 give you some hints here ["man dmesg"].) Everyone needs either a
590 coprocessor or this emulation.
591
592 If you don't have a math coprocessor, you need to say Y here; if you
593 say Y here even though you have a coprocessor, the coprocessor will
594 be used nevertheless. (This behavior can be changed with the kernel
595 command line option "no387", which comes handy if your coprocessor
596 is broken. Try "man bootparam" or see the documentation of your boot
597 loader (lilo or loadlin) about how to pass options to the kernel at
598 boot time.) This means that it is a good idea to say Y here if you
599 intend to use this kernel on different machines.
600
601 More information about the internals of the Linux math coprocessor
602 emulation can be found in <file:arch/i386/math-emu/README>.
603
604 If you are not sure, say Y; apart from resulting in a 66 KB bigger
605 kernel, it won't hurt.
606
607config MTRR
608 bool "MTRR (Memory Type Range Register) support"
609 ---help---
610 On Intel P6 family processors (Pentium Pro, Pentium II and later)
611 the Memory Type Range Registers (MTRRs) may be used to control
612 processor access to memory ranges. This is most useful if you have
613 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
614 allows bus write transfers to be combined into a larger transfer
615 before bursting over the PCI/AGP bus. This can increase performance
616 of image write operations 2.5 times or more. Saying Y here creates a
617 /proc/mtrr file which may be used to manipulate your processor's
618 MTRRs. Typically the X server should use this.
619
620 This code has a reasonably generic interface so that similar
621 control registers on other processors can be easily supported
622 as well:
623
624 The Cyrix 6x86, 6x86MX and M II processors have Address Range
625 Registers (ARRs) which provide a similar functionality to MTRRs. For
626 these, the ARRs are used to emulate the MTRRs.
627 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
628 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
629 write-combining. All of these processors are supported by this code
630 and it makes sense to say Y here if you have one of them.
631
632 Saying Y here also fixes a problem with buggy SMP BIOSes which only
633 set the MTRRs for the boot CPU and not for the secondary CPUs. This
634 can lead to all sorts of problems, so it's good to say Y here.
635
636 You can safely say Y even if your machine doesn't have MTRRs, you'll
637 just add about 9 KB to your kernel.
638
639 See <file:Documentation/mtrr.txt> for more information.
640
641config EFI
642 bool "Boot from EFI support (EXPERIMENTAL)"
643 depends on ACPI
644 default n
645 ---help---
646 This enables the the kernel to boot on EFI platforms using
647 system configuration information passed to it from the firmware.
648 This also enables the kernel to use any EFI runtime services that are
649 available (such as the EFI variable services).
650
651 This option is only useful on systems that have EFI firmware
652 and will result in a kernel image that is ~8k larger. In addition,
653 you must use the latest ELILO loader available at
654 <http://elilo.sourceforge.net> in order to take advantage of
655 kernel initialization using EFI information (neither GRUB nor LILO know
656 anything about EFI). However, even with this option, the resultant
657 kernel should continue to boot on existing non-EFI platforms.
658
659config IRQBALANCE
660 bool "Enable kernel irq balancing"
661 depends on SMP && X86_IO_APIC
662 default y
663 help
664 The default yes will allow the kernel to do irq load balancing.
665 Saying no will keep the kernel from doing irq load balancing.
666
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667# turning this on wastes a bunch of space.
668# Summit needs it only when NUMA is on
669config BOOT_IOREMAP
670 bool
671 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
672 default y
673
674config REGPARM
Adrian Bunk69ef4142006-03-23 02:59:28 -0800675 bool "Use register arguments"
Ingo Molnarb824eb62006-03-23 02:59:29 -0800676 default y
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 help
Ingo Molnarb824eb62006-03-23 02:59:29 -0800678 Compile the kernel with -mregparm=3. This instructs gcc to use
679 a more efficient function call ABI which passes the first three
680 arguments of a function call via registers, which results in denser
681 and faster code.
682
683 If this option is disabled, then the default ABI of passing
684 arguments via the stack is used.
685
686 If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688config SECCOMP
689 bool "Enable seccomp to safely compute untrusted bytecode"
690 depends on PROC_FS
691 default y
692 help
693 This kernel feature is useful for number crunching applications
694 that may need to compute untrusted bytecode during their
695 execution. By using pipes or other transports made available to
696 the process as file descriptors supporting the read/write
697 syscalls, it's possible to isolate those applications in
698 their own address space using seccomp. Once seccomp is
699 enabled via /proc/<pid>/seccomp, it cannot be disabled
700 and the task is only allowed to execute a few safe syscalls
701 defined by each seccomp mode.
702
703 If unsure, say Y. Only embedded should say N here.
704
Christoph Lameter59121002005-06-23 00:08:25 -0700705source kernel/Kconfig.hz
706
Eric W. Biederman5033cba2005-06-25 14:57:56 -0700707config KEXEC
708 bool "kexec system call (EXPERIMENTAL)"
709 depends on EXPERIMENTAL
710 help
711 kexec is a system call that implements the ability to shutdown your
712 current kernel, and to start another kernel. It is like a reboot
713 but it is indepedent of the system firmware. And like a reboot
714 you can start any kernel with it, not just Linux.
715
716 The name comes from the similiarity to the exec system call.
717
718 It is an ongoing process to be certain the hardware in a machine
719 is properly shutdown, so do not be surprised if this code does not
720 initially work for you. It may help to enable device hotplugging
721 support. As of this writing the exact hardware interface is
722 strongly in flux, so no good recommendation can be made.
723
Vivek Goyal5f016452005-06-25 14:58:19 -0700724config CRASH_DUMP
725 bool "kernel crash dumps (EXPERIMENTAL)"
Vivek Goyal5f016452005-06-25 14:58:19 -0700726 depends on EXPERIMENTAL
727 depends on HIGHMEM
728 help
729 Generate crash dump after being started by kexec.
Maneesh Soni05970d42006-01-09 20:51:52 -0800730
731config PHYSICAL_START
732 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
733
734 default "0x1000000" if CRASH_DUMP
735 default "0x100000"
736 help
737 This gives the physical address where the kernel is loaded. Normally
738 for regular kernels this value is 0x100000 (1MB). But in the case
739 of kexec on panic the fail safe kernel needs to run at a different
740 address than the panic-ed kernel. This option is used to set the load
741 address for kernels used to capture crash dump on being kexec'ed
742 after panic. The default value for crash dump kernels is
743 0x1000000 (16MB). This can also be set based on the "X" value as
744 specified in the "crashkernel=YM@XM" command line boot parameter
745 passed to the panic-ed kernel. Typically this parameter is set as
746 crashkernel=64M@16M. Please take a look at
747 Documentation/kdump/kdump.txt for more details about crash dumps.
748
749 Don't change this unless you know what you are doing.
750
Randy Dunlapce63ad72006-01-14 13:20:51 -0800751config HOTPLUG_CPU
752 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
Ashok Rajd3f4aaa2006-03-25 03:06:50 -0800753 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER && !X86_PC
Randy Dunlapce63ad72006-01-14 13:20:51 -0800754 ---help---
755 Say Y here to experiment with turning CPUs off and on. CPUs
756 can be controlled through /sys/devices/system/cpu.
757
758 Say N.
759
Ingo Molnar389d1ea2006-02-01 03:04:35 -0800760config DOUBLEFAULT
761 default y
762 bool "Enable doublefault exception handler" if EMBEDDED
763 help
764 This option allows trapping of rare doublefault exceptions that
765 would otherwise cause a system to silently reboot. Disabling this
766 option saves about 4k and might cause you much additional grey
767 hair.
768
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769endmenu
770
771
772menu "Power management options (ACPI, APM)"
773 depends on !X86_VOYAGER
774
775source kernel/power/Kconfig
776
777source "drivers/acpi/Kconfig"
778
779menu "APM (Advanced Power Management) BIOS Support"
780depends on PM && !X86_VISWS
781
782config APM
783 tristate "APM (Advanced Power Management) BIOS support"
Dave Jones987d46132006-01-08 01:05:09 -0800784 depends on PM
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785 ---help---
786 APM is a BIOS specification for saving power using several different
787 techniques. This is mostly useful for battery powered laptops with
788 APM compliant BIOSes. If you say Y here, the system time will be
789 reset after a RESUME operation, the /proc/apm device will provide
790 battery status information, and user-space programs will receive
791 notification of APM "events" (e.g. battery status change).
792
793 If you select "Y" here, you can disable actual use of the APM
794 BIOS by passing the "apm=off" option to the kernel at boot time.
795
796 Note that the APM support is almost completely disabled for
797 machines with more than one CPU.
798
799 In order to use APM, you will need supporting software. For location
800 and more information, read <file:Documentation/pm.txt> and the
801 Battery Powered Linux mini-HOWTO, available from
802 <http://www.tldp.org/docs.html#howto>.
803
804 This driver does not spin down disk drives (see the hdparm(8)
805 manpage ("man 8 hdparm") for that), and it doesn't turn off
806 VESA-compliant "green" monitors.
807
808 This driver does not support the TI 4000M TravelMate and the ACER
809 486/DX4/75 because they don't have compliant BIOSes. Many "green"
810 desktop machines also don't have compliant BIOSes, and this driver
811 may cause those machines to panic during the boot phase.
812
813 Generally, if you don't have a battery in your machine, there isn't
814 much point in using this driver and you should say N. If you get
815 random kernel OOPSes or reboots that don't seem to be related to
816 anything, try disabling/enabling this option (or disabling/enabling
817 APM in your BIOS).
818
819 Some other things you should try when experiencing seemingly random,
820 "weird" problems:
821
822 1) make sure that you have enough swap space and that it is
823 enabled.
824 2) pass the "no-hlt" option to the kernel
825 3) switch on floating point emulation in the kernel and pass
826 the "no387" option to the kernel
827 4) pass the "floppy=nodma" option to the kernel
828 5) pass the "mem=4M" option to the kernel (thereby disabling
829 all but the first 4 MB of RAM)
830 6) make sure that the CPU is not over clocked.
831 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
832 8) disable the cache from your BIOS settings
833 9) install a fan for the video card or exchange video RAM
834 10) install a better fan for the CPU
835 11) exchange RAM chips
836 12) exchange the motherboard.
837
838 To compile this driver as a module, choose M here: the
839 module will be called apm.
840
841config APM_IGNORE_USER_SUSPEND
842 bool "Ignore USER SUSPEND"
843 depends on APM
844 help
845 This option will ignore USER SUSPEND requests. On machines with a
846 compliant APM BIOS, you want to say N. However, on the NEC Versa M
847 series notebooks, it is necessary to say Y because of a BIOS bug.
848
849config APM_DO_ENABLE
850 bool "Enable PM at boot time"
851 depends on APM
852 ---help---
853 Enable APM features at boot time. From page 36 of the APM BIOS
854 specification: "When disabled, the APM BIOS does not automatically
855 power manage devices, enter the Standby State, enter the Suspend
856 State, or take power saving steps in response to CPU Idle calls."
857 This driver will make CPU Idle calls when Linux is idle (unless this
858 feature is turned off -- see "Do CPU IDLE calls", below). This
859 should always save battery power, but more complicated APM features
860 will be dependent on your BIOS implementation. You may need to turn
861 this option off if your computer hangs at boot time when using APM
862 support, or if it beeps continuously instead of suspending. Turn
863 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
864 T400CDT. This is off by default since most machines do fine without
865 this feature.
866
867config APM_CPU_IDLE
868 bool "Make CPU Idle calls when idle"
869 depends on APM
870 help
871 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
872 On some machines, this can activate improved power savings, such as
873 a slowed CPU clock rate, when the machine is idle. These idle calls
874 are made after the idle loop has run for some length of time (e.g.,
875 333 mS). On some machines, this will cause a hang at boot time or
876 whenever the CPU becomes idle. (On machines with more than one CPU,
877 this option does nothing.)
878
879config APM_DISPLAY_BLANK
880 bool "Enable console blanking using APM"
881 depends on APM
882 help
883 Enable console blanking using the APM. Some laptops can use this to
884 turn off the LCD backlight when the screen blanker of the Linux
885 virtual console blanks the screen. Note that this is only used by
886 the virtual console screen blanker, and won't turn off the backlight
887 when using the X Window system. This also doesn't have anything to
888 do with your VESA-compliant power-saving monitor. Further, this
889 option doesn't work for all laptops -- it might not turn off your
890 backlight at all, or it might print a lot of errors to the console,
891 especially if you are using gpm.
892
893config APM_RTC_IS_GMT
894 bool "RTC stores time in GMT"
895 depends on APM
896 help
897 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
898 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
899 stores localtime.
900
901 It is in fact recommended to store GMT in your RTC, because then you
902 don't have to worry about daylight savings time changes. The only
903 reason not to use GMT in your RTC is if you also run a broken OS
904 that doesn't understand GMT.
905
906config APM_ALLOW_INTS
907 bool "Allow interrupts during APM BIOS calls"
908 depends on APM
909 help
910 Normally we disable external interrupts while we are making calls to
911 the APM BIOS as a measure to lessen the effects of a badly behaving
912 BIOS implementation. The BIOS should reenable interrupts if it
913 needs to. Unfortunately, some BIOSes do not -- especially those in
914 many of the newer IBM Thinkpads. If you experience hangs when you
915 suspend, try setting this to Y. Otherwise, say N.
916
917config APM_REAL_MODE_POWER_OFF
918 bool "Use real mode APM BIOS call to power off"
919 depends on APM
920 help
921 Use real mode APM BIOS calls to switch off the computer. This is
922 a work-around for a number of buggy BIOSes. Switch this option on if
923 your computer crashes instead of powering off properly.
924
925endmenu
926
927source "arch/i386/kernel/cpu/cpufreq/Kconfig"
928
929endmenu
930
931menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
932
933config PCI
934 bool "PCI support" if !X86_VISWS
935 depends on !X86_VOYAGER
936 default y if X86_VISWS
937 help
938 Find out whether you have a PCI motherboard. PCI is the name of a
939 bus system, i.e. the way the CPU talks to the other stuff inside
940 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
941 VESA. If you have PCI, say Y, otherwise N.
942
943 The PCI-HOWTO, available from
944 <http://www.tldp.org/docs.html#howto>, contains valuable
945 information about which PCI hardware does work under Linux and which
946 doesn't.
947
948choice
949 prompt "PCI access mode"
950 depends on PCI && !X86_VISWS
951 default PCI_GOANY
952 ---help---
953 On PCI systems, the BIOS can be used to detect the PCI devices and
954 determine their configuration. However, some old PCI motherboards
955 have BIOS bugs and may crash if this is done. Also, some embedded
956 PCI-based systems don't have any BIOS at all. Linux can also try to
957 detect the PCI hardware directly without using the BIOS.
958
959 With this option, you can specify how Linux should detect the
960 PCI devices. If you choose "BIOS", the BIOS will be used,
961 if you choose "Direct", the BIOS won't be used, and if you
962 choose "MMConfig", then PCI Express MMCONFIG will be used.
963 If you choose "Any", the kernel will try MMCONFIG, then the
964 direct access method and falls back to the BIOS if that doesn't
965 work. If unsure, go with the default, which is "Any".
966
967config PCI_GOBIOS
968 bool "BIOS"
969
970config PCI_GOMMCONFIG
971 bool "MMConfig"
972
973config PCI_GODIRECT
974 bool "Direct"
975
976config PCI_GOANY
977 bool "Any"
978
979endchoice
980
981config PCI_BIOS
982 bool
983 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
984 default y
985
986config PCI_DIRECT
987 bool
988 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
989 default y
990
991config PCI_MMCONFIG
992 bool
Alexander Nyberg8aadff72005-05-27 12:48:50 +0200993 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994 default y
995
996source "drivers/pci/pcie/Kconfig"
997
998source "drivers/pci/Kconfig"
999
Al Viro5cae8412005-05-04 05:39:22 +01001000config ISA_DMA_API
1001 bool
1002 default y
1003
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004config ISA
1005 bool "ISA support"
1006 depends on !(X86_VOYAGER || X86_VISWS)
1007 help
1008 Find out whether you have ISA slots on your motherboard. ISA is the
1009 name of a bus system, i.e. the way the CPU talks to the other stuff
1010 inside your box. Other bus systems are PCI, EISA, MicroChannel
1011 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1012 newer boards don't support it. If you have ISA, say Y, otherwise N.
1013
1014config EISA
1015 bool "EISA support"
1016 depends on ISA
1017 ---help---
1018 The Extended Industry Standard Architecture (EISA) bus was
1019 developed as an open alternative to the IBM MicroChannel bus.
1020
1021 The EISA bus provided some of the features of the IBM MicroChannel
1022 bus while maintaining backward compatibility with cards made for
1023 the older ISA bus. The EISA bus saw limited use between 1988 and
1024 1995 when it was made obsolete by the PCI bus.
1025
1026 Say Y here if you are building a kernel for an EISA-based machine.
1027
1028 Otherwise, say N.
1029
1030source "drivers/eisa/Kconfig"
1031
1032config MCA
1033 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1034 default y if X86_VOYAGER
1035 help
1036 MicroChannel Architecture is found in some IBM PS/2 machines and
1037 laptops. It is a bus system similar to PCI or ISA. See
1038 <file:Documentation/mca.txt> (and especially the web page given
1039 there) before attempting to build an MCA bus kernel.
1040
1041source "drivers/mca/Kconfig"
1042
1043config SCx200
1044 tristate "NatSemi SCx200 support"
1045 depends on !X86_VOYAGER
1046 help
1047 This provides basic support for the National Semiconductor SCx200
1048 processor. Right now this is just a driver for the GPIO pins.
1049
1050 If you don't know what to do here, say N.
1051
1052 This support is also available as a module. If compiled as a
1053 module, it will be called scx200.
1054
Linus Torvalds1da177e2005-04-16 15:20:36 -07001055source "drivers/pcmcia/Kconfig"
1056
1057source "drivers/pci/hotplug/Kconfig"
1058
1059endmenu
1060
1061menu "Executable file formats"
1062
1063source "fs/Kconfig.binfmt"
1064
1065endmenu
1066
Sam Ravnborgd5950b42005-07-11 21:03:49 -07001067source "net/Kconfig"
1068
Linus Torvalds1da177e2005-04-16 15:20:36 -07001069source "drivers/Kconfig"
1070
1071source "fs/Kconfig"
1072
Prasanna S Panchamukhicd6b0762005-11-07 00:59:14 -08001073menu "Instrumentation Support"
1074 depends on EXPERIMENTAL
1075
Linus Torvalds1da177e2005-04-16 15:20:36 -07001076source "arch/i386/oprofile/Kconfig"
1077
Prasanna S Panchamukhicd6b0762005-11-07 00:59:14 -08001078config KPROBES
1079 bool "Kprobes (EXPERIMENTAL)"
Linus Torvaldsadd2b6f2006-02-26 20:24:40 -08001080 depends on EXPERIMENTAL && MODULES
Prasanna S Panchamukhicd6b0762005-11-07 00:59:14 -08001081 help
1082 Kprobes allows you to trap at almost any kernel address and
1083 execute a callback function. register_kprobe() establishes
1084 a probepoint and specifies the callback. Kprobes is useful
1085 for kernel debugging, non-intrusive instrumentation and testing.
1086 If in doubt, say "N".
1087endmenu
1088
Linus Torvalds1da177e2005-04-16 15:20:36 -07001089source "arch/i386/Kconfig.debug"
1090
1091source "security/Kconfig"
1092
1093source "crypto/Kconfig"
1094
1095source "lib/Kconfig"
1096
1097#
1098# Use the generic interrupt handling code in kernel/irq/:
1099#
1100config GENERIC_HARDIRQS
1101 bool
1102 default y
1103
1104config GENERIC_IRQ_PROBE
1105 bool
1106 default y
1107
Ashok Raj54d5d422005-09-06 15:16:15 -07001108config GENERIC_PENDING_IRQ
1109 bool
1110 depends on GENERIC_HARDIRQS && SMP
1111 default y
1112
Linus Torvalds1da177e2005-04-16 15:20:36 -07001113config X86_SMP
1114 bool
1115 depends on SMP && !X86_VOYAGER
1116 default y
1117
1118config X86_HT
1119 bool
1120 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1121 default y
1122
1123config X86_BIOS_REBOOT
1124 bool
1125 depends on !(X86_VISWS || X86_VOYAGER)
1126 default y
1127
1128config X86_TRAMPOLINE
1129 bool
1130 depends on X86_SMP || (X86_VOYAGER && SMP)
1131 default y
Thomas Gleixner97fc79f2006-01-09 20:52:31 -08001132
1133config KTIME_SCALAR
1134 bool
1135 default y