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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
Adrian Bunkedd711f2006-04-10 22:53:14 -070056config SMP
57 bool "Symmetric multi-processing support"
58 ---help---
59 This enables support for systems with more than one CPU. If you have
60 a system with only one CPU, like most personal computers, say N. If
61 you have a system with more than one CPU, say Y.
62
63 If you say N here, the kernel will run on single and multiprocessor
64 machines, but will use only one CPU of a multiprocessor machine. If
65 you say Y here, the kernel will run on many, but not all,
66 singleprocessor machines. On a singleprocessor machine, the kernel
67 will run faster if you say N here.
68
69 Note that if you say Y here and choose architecture "586" or
70 "Pentium" under "Processor family", the kernel will not work on 486
71 architectures. Similarly, multiprocessor kernels for the "PPro"
72 architecture may not work on all Pentium based boards.
73
74 People using multiprocessor machines who say Y here should also say
75 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
76 Management" code will be disabled if you say Y here.
77
78 See also the <file:Documentation/smp.txt>,
79 <file:Documentation/i386/IO-APIC.txt>,
80 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
81 <http://www.tldp.org/docs.html#howto>.
82
83 If you don't know what to do here, say N.
84
Linus Torvalds1da177e2005-04-16 15:20:36 -070085choice
86 prompt "Subarchitecture Type"
87 default X86_PC
88
89config X86_PC
90 bool "PC-compatible"
91 help
92 Choose this option if your computer is a standard PC or compatible.
93
94config X86_ELAN
95 bool "AMD Elan"
96 help
97 Select this for an AMD Elan processor.
98
99 Do not use this option for K6/Athlon/Opteron processors!
100
101 If unsure, choose "PC-compatible" instead.
102
103config X86_VOYAGER
104 bool "Voyager (NCR)"
105 help
106 Voyager is an MCA-based 32-way capable SMP architecture proprietary
107 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
108
109 *** WARNING ***
110
111 If you do not specifically know you have a Voyager based machine,
112 say N here, otherwise the kernel you build will not be bootable.
113
114config X86_NUMAQ
115 bool "NUMAQ (IBM/Sequent)"
Adrian Bunk905c3992006-03-23 02:59:55 -0800116 select SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 select NUMA
118 help
119 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
120 multiquad box. This changes the way that processors are bootstrapped,
121 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
122 You will need a new lynxer.elf file to flash your firmware with - send
123 email to <Martin.Bligh@us.ibm.com>.
124
125config X86_SUMMIT
126 bool "Summit/EXA (IBM x440)"
127 depends on SMP
128 help
129 This option is needed for IBM systems that use the Summit/EXA chipset.
130 In particular, it is needed for the x440.
131
132 If you don't have one of these computers, you should say N here.
133
134config X86_BIGSMP
135 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
136 depends on SMP
137 help
138 This option is needed for the systems that have more than 8 CPUs
139 and if the system is not of any sub-arch type above.
140
141 If you don't have such a system, you should say N here.
142
143config X86_VISWS
144 bool "SGI 320/540 (Visual Workstation)"
145 help
146 The SGI Visual Workstation series is an IA32-based workstation
147 based on SGI systems chips with some legacy PC hardware attached.
148
149 Say Y here to create a kernel to run on the SGI 320 or 540.
150
151 A kernel compiled for the Visual Workstation will not run on PCs
152 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
153
154config X86_GENERICARCH
155 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
156 depends on SMP
157 help
158 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
159 It is intended for a generic binary kernel.
160
161config X86_ES7000
162 bool "Support for Unisys ES7000 IA32 series"
163 depends on SMP
164 help
165 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
166 supposed to run on an IA32-based Unisys ES7000 system.
167 Only choose this option if you have such a system, otherwise you
168 should say N here.
169
170endchoice
171
172config ACPI_SRAT
173 bool
174 default y
175 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
Yasunori Goto762834e2006-06-23 02:03:19 -0700176 select ACPI_NUMA
177
178config HAVE_ARCH_PARSE_SRAT
179 bool
180 default y
181 depends on ACPI_SRAT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
183config X86_SUMMIT_NUMA
184 bool
185 default y
186 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
187
188config X86_CYCLONE_TIMER
189 bool
190 default y
191 depends on X86_SUMMIT || X86_GENERICARCH
192
193config ES7000_CLUSTERED_APIC
194 bool
195 default y
196 depends on SMP && X86_ES7000 && MPENTIUMIII
197
Paolo 'Blaisorblade' Giarrusso96d55b82005-10-30 15:00:07 -0800198source "arch/i386/Kconfig.cpu"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199
200config HPET_TIMER
201 bool "HPET Timer Support"
202 help
203 This enables the use of the HPET for the kernel's internal timer.
204 HPET is the next generation timer replacing legacy 8254s.
205 You can safely choose Y here. However, HPET will only be
206 activated if the platform and the BIOS support this feature.
207 Otherwise the 8254 will be used for timing services.
208
209 Choose N to continue using the legacy 8254 timer.
210
211config HPET_EMULATE_RTC
Venkatesh Pallipadic91096d2005-08-04 15:36:10 -0700212 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 depends on HPET_TIMER && RTC=y
Venkatesh Pallipadic91096d2005-08-04 15:36:10 -0700214 default y
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216config NR_CPUS
217 int "Maximum number of CPUs (2-255)"
218 range 2 255
219 depends on SMP
220 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
221 default "8"
222 help
223 This allows you to specify the maximum number of CPUs which this
224 kernel will support. The maximum supported value is 255 and the
225 minimum value which makes sense is 2.
226
227 This is purely to save memory - each supported CPU adds
228 approximately eight kilobytes to the kernel image.
229
230config SCHED_SMT
231 bool "SMT (Hyperthreading) scheduler support"
232 depends on SMP
233 default off
234 help
235 SMT scheduler support improves the CPU scheduler's decision making
236 when dealing with Intel Pentium 4 chips with HyperThreading at a
237 cost of slightly increased overhead in some places. If unsure say
238 N here.
239
Siddha, Suresh B1e9f28f2006-03-27 01:15:22 -0800240config SCHED_MC
241 bool "Multi-core scheduler support"
242 depends on SMP
243 default y
244 help
245 Multi-core scheduler support improves the CPU scheduler's decision
246 making when dealing with multi-core CPU chips at a cost of slightly
247 increased overhead in some places. If unsure say N here.
248
Ingo Molnarcc19ca82005-06-25 14:57:36 -0700249source "kernel/Kconfig.preempt"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250
251config X86_UP_APIC
252 bool "Local APIC support on uniprocessors"
253 depends on !SMP && !(X86_VISWS || X86_VOYAGER)
254 help
255 A local APIC (Advanced Programmable Interrupt Controller) is an
256 integrated interrupt controller in the CPU. If you have a single-CPU
257 system which has a processor with a local APIC, you can say Y here to
258 enable and use it. If you say Y here even though your machine doesn't
259 have a local APIC, then the kernel will still run with no slowdown at
260 all. The local APIC supports CPU-generated self-interrupts (timer,
261 performance counters), and the NMI watchdog which detects hard
262 lockups.
263
264config X86_UP_IOAPIC
265 bool "IO-APIC support on uniprocessors"
266 depends on X86_UP_APIC
267 help
268 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
269 SMP-capable replacement for PC-style interrupt controllers. Most
270 SMP systems and many recent uniprocessor systems have one.
271
272 If you have a single-CPU system with an IO-APIC, you can say Y here
273 to use it. If you say Y here even though your machine doesn't have
274 an IO-APIC, then the kernel will still run with no slowdown at all.
275
276config X86_LOCAL_APIC
277 bool
278 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER)
279 default y
280
281config X86_IO_APIC
282 bool
283 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER))
284 default y
285
286config X86_VISWS_APIC
287 bool
288 depends on X86_VISWS
289 default y
290
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291config X86_MCE
292 bool "Machine Check Exception"
293 depends on !X86_VOYAGER
294 ---help---
295 Machine Check Exception support allows the processor to notify the
296 kernel if it detects a problem (e.g. overheating, component failure).
297 The action the kernel takes depends on the severity of the problem,
298 ranging from a warning message on the console, to halting the machine.
299 Your processor must be a Pentium or newer to support this - check the
300 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
301 have a design flaw which leads to false MCE events - hence MCE is
302 disabled on all P5 processors, unless explicitly enabled with "mce"
303 as a boot argument. Similarly, if MCE is built in and creates a
304 problem on some new non-standard machine, you can boot with "nomce"
305 to disable it. MCE support simply ignores non-MCE processors like
306 the 386 and 486, so nearly everyone can say Y here.
307
308config X86_MCE_NONFATAL
309 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
310 depends on X86_MCE
311 help
312 Enabling this feature starts a timer that triggers every 5 seconds which
313 will look at the machine check registers to see if anything happened.
314 Non-fatal problems automatically get corrected (but still logged).
315 Disable this if you don't want to see these messages.
316 Seeing the messages this option prints out may be indicative of dying hardware,
317 or out-of-spec (ie, overclocked) hardware.
318 This option only does something on certain CPUs.
319 (AMD Athlon/Duron and Intel Pentium 4)
320
321config X86_MCE_P4THERMAL
322 bool "check for P4 thermal throttling interrupt."
323 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
324 help
325 Enabling this feature will cause a message to be printed when the P4
326 enters thermal throttling.
327
328config TOSHIBA
329 tristate "Toshiba Laptop support"
330 ---help---
331 This adds a driver to safely access the System Management Mode of
332 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
333 not work on models with a Phoenix BIOS. The System Management Mode
334 is used to set the BIOS and power saving options on Toshiba portables.
335
336 For information on utilities to make use of this driver see the
337 Toshiba Linux utilities web site at:
338 <http://www.buzzard.org.uk/toshiba/>.
339
340 Say Y if you intend to run this kernel on a Toshiba portable.
341 Say N otherwise.
342
343config I8K
344 tristate "Dell laptop support"
345 ---help---
346 This adds a driver to safely access the System Management Mode
347 of the CPU on the Dell Inspiron 8000. The System Management Mode
348 is used to read cpu temperature and cooling fan status and to
349 control the fans on the I8K portables.
350
351 This driver has been tested only on the Inspiron 8000 but it may
352 also work with other Dell laptops. You can force loading on other
353 models by passing the parameter `force=1' to the module. Use at
354 your own risk.
355
356 For information on utilities to make use of this driver see the
357 I8K Linux utilities web site at:
358 <http://people.debian.org/~dz/i8k/>
359
360 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
361 Say N otherwise.
362
Jaya Kumara2f7c352005-05-01 08:58:49 -0700363config X86_REBOOTFIXUPS
364 bool "Enable X86 board specific fixups for reboot"
365 depends on X86
366 default n
367 ---help---
368 This enables chipset and/or board specific fixups to be done
369 in order to get reboot to work correctly. This is only needed on
370 some combinations of hardware and BIOS. The symptom, for which
371 this config is intended, is when reboot ends with a stalled/hung
372 system.
373
374 Currently, the only fixup is for the Geode GX1/CS5530A/TROM2.1.
375 combination.
376
377 Say Y if you want to enable the fixup. Currently, it's safe to
378 enable this option even if you don't need it.
379 Say N otherwise.
380
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381config MICROCODE
382 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
383 ---help---
384 If you say Y here and also to "/dev file system support" in the
385 'File systems' section, you will be able to update the microcode on
386 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
387 Pentium III, Pentium 4, Xeon etc. You will obviously need the
388 actual microcode binary data itself which is not shipped with the
389 Linux kernel.
390
391 For latest news and information on obtaining all the required
392 ingredients for this driver, check:
393 <http://www.urbanmyth.org/microcode/>.
394
395 To compile this driver as a module, choose M here: the
396 module will be called microcode.
397
398config X86_MSR
399 tristate "/dev/cpu/*/msr - Model-specific register support"
400 help
401 This device gives privileged processes access to the x86
402 Model-Specific Registers (MSRs). It is a character device with
403 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
404 MSR accesses are directed to a specific CPU on multi-processor
405 systems.
406
407config X86_CPUID
408 tristate "/dev/cpu/*/cpuid - CPU information support"
409 help
410 This device gives processes access to the x86 CPUID instruction to
411 be executed on a specific processor. It is a character device
412 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
413 /dev/cpu/31/cpuid.
414
415source "drivers/firmware/Kconfig"
416
417choice
418 prompt "High Memory Support"
419 default NOHIGHMEM
420
421config NOHIGHMEM
422 bool "off"
Adrian Bunk905c3992006-03-23 02:59:55 -0800423 depends on !X86_NUMAQ
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424 ---help---
425 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
426 However, the address space of 32-bit x86 processors is only 4
427 Gigabytes large. That means that, if you have a large amount of
428 physical memory, not all of it can be "permanently mapped" by the
429 kernel. The physical memory that's not permanently mapped is called
430 "high memory".
431
432 If you are compiling a kernel which will never run on a machine with
433 more than 1 Gigabyte total physical RAM, answer "off" here (default
434 choice and suitable for most users). This will result in a "3GB/1GB"
435 split: 3GB are mapped so that each process sees a 3GB virtual memory
436 space and the remaining part of the 4GB virtual memory space is used
437 by the kernel to permanently map as much physical memory as
438 possible.
439
440 If the machine has between 1 and 4 Gigabytes physical RAM, then
441 answer "4GB" here.
442
443 If more than 4 Gigabytes is used then answer "64GB" here. This
444 selection turns Intel PAE (Physical Address Extension) mode on.
445 PAE implements 3-level paging on IA32 processors. PAE is fully
446 supported by Linux, PAE mode is implemented on all recent Intel
447 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
448 then the kernel will not boot on CPUs that don't support PAE!
449
450 The actual amount of total physical memory will either be
451 auto detected or can be forced by using a kernel command line option
452 such as "mem=256M". (Try "man bootparam" or see the documentation of
453 your boot loader (lilo or loadlin) about how to pass options to the
454 kernel at boot time.)
455
456 If unsure, say "off".
457
458config HIGHMEM4G
459 bool "4GB"
Adrian Bunk905c3992006-03-23 02:59:55 -0800460 depends on !X86_NUMAQ
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 help
462 Select this if you have a 32-bit processor and between 1 and 4
463 gigabytes of physical RAM.
464
465config HIGHMEM64G
466 bool "64GB"
Adrian Bunk4be68a72006-02-04 23:28:05 -0800467 depends on X86_CMPXCHG64
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 help
469 Select this if you have a 32-bit processor and more than 4
470 gigabytes of physical RAM.
471
472endchoice
473
Mark Lord975b3d32006-02-01 03:06:11 -0800474choice
475 depends on EXPERIMENTAL && !X86_PAE
Andi Kleen9539d4e2006-04-27 18:39:36 -0700476 prompt "Memory split" if EMBEDDED
Mark Lord975b3d32006-02-01 03:06:11 -0800477 default VMSPLIT_3G
478 help
479 Select the desired split between kernel and user memory.
480
481 If the address range available to the kernel is less than the
482 physical memory installed, the remaining memory will be available
483 as "high memory". Accessing high memory is a little more costly
484 than low memory, as it needs to be mapped into the kernel first.
485 Note that increasing the kernel address space limits the range
486 available to user programs, making the address space there
487 tighter. Selecting anything other than the default 3G/1G split
488 will also likely make your kernel incompatible with binary-only
489 kernel modules.
490
491 If you are not absolutely sure what you are doing, leave this
492 option alone!
493
494 config VMSPLIT_3G
495 bool "3G/1G user/kernel split"
496 config VMSPLIT_3G_OPT
497 bool "3G/1G user/kernel split (for full 1G low memory)"
498 config VMSPLIT_2G
499 bool "2G/2G user/kernel split"
500 config VMSPLIT_1G
501 bool "1G/3G user/kernel split"
502endchoice
503
504config PAGE_OFFSET
505 hex
506 default 0xB0000000 if VMSPLIT_3G_OPT
507 default 0x78000000 if VMSPLIT_2G
508 default 0x40000000 if VMSPLIT_1G
509 default 0xC0000000
510
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511config HIGHMEM
512 bool
513 depends on HIGHMEM64G || HIGHMEM4G
514 default y
515
516config X86_PAE
517 bool
518 depends on HIGHMEM64G
519 default y
520
521# Common NUMA Features
522config NUMA
523 bool "Numa Memory Allocation and Scheduler Support"
524 depends on SMP && HIGHMEM64G && (X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI))
525 default n if X86_PC
526 default y if (X86_NUMAQ || X86_SUMMIT)
527
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
529 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
530
Yasunori Gotoc80d79d2006-04-10 22:53:53 -0700531config NODES_SHIFT
532 int
533 default "4" if X86_NUMAQ
534 default "3"
535 depends on NEED_MULTIPLE_NODES
536
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537config HAVE_ARCH_BOOTMEM_NODE
538 bool
539 depends on NUMA
540 default y
541
Andy Whitcroftaf705362005-06-23 00:07:53 -0700542config ARCH_HAVE_MEMORY_PRESENT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 bool
544 depends on DISCONTIGMEM
545 default y
546
547config NEED_NODE_MEMMAP_SIZE
548 bool
Andy Whitcroft05b79bd2005-06-23 00:07:57 -0700549 depends on DISCONTIGMEM || SPARSEMEM
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 default y
551
Dave Hansen6f167ec2005-06-23 00:07:39 -0700552config HAVE_ARCH_ALLOC_REMAP
553 bool
554 depends on NUMA
555 default y
556
Andy Whitcroft215c3402006-01-06 00:12:06 -0800557config ARCH_FLATMEM_ENABLE
558 def_bool y
559 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
560
Andy Whitcroft05b79bd2005-06-23 00:07:57 -0700561config ARCH_DISCONTIGMEM_ENABLE
562 def_bool y
563 depends on NUMA
564
565config ARCH_DISCONTIGMEM_DEFAULT
566 def_bool y
567 depends on NUMA
568
569config ARCH_SPARSEMEM_ENABLE
570 def_bool y
Andy Whitcroft215c3402006-01-06 00:12:06 -0800571 depends on (NUMA || (X86_PC && EXPERIMENTAL))
572 select SPARSEMEM_STATIC
Andy Whitcroft05b79bd2005-06-23 00:07:57 -0700573
574config ARCH_SELECT_MEMORY_MODEL
575 def_bool y
576 depends on ARCH_SPARSEMEM_ENABLE
577
Dave Hansen3f22ab22005-06-23 00:07:43 -0700578source "mm/Kconfig"
579
Andy Whitcroftb159d432005-06-23 00:07:52 -0700580config HAVE_ARCH_EARLY_PFN_TO_NID
581 bool
582 default y
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700583 depends on NUMA
Andy Whitcroftb159d432005-06-23 00:07:52 -0700584
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585config HIGHPTE
586 bool "Allocate 3rd-level pagetables from highmem"
587 depends on HIGHMEM4G || HIGHMEM64G
588 help
589 The VM uses one page table entry for each page of physical memory.
590 For systems with a lot of RAM, this can be wasteful of precious
591 low memory. Setting this option will put user-space page table
592 entries in high memory.
593
594config MATH_EMULATION
595 bool "Math emulation"
596 ---help---
597 Linux can emulate a math coprocessor (used for floating point
598 operations) if you don't have one. 486DX and Pentium processors have
599 a math coprocessor built in, 486SX and 386 do not, unless you added
600 a 487DX or 387, respectively. (The messages during boot time can
601 give you some hints here ["man dmesg"].) Everyone needs either a
602 coprocessor or this emulation.
603
604 If you don't have a math coprocessor, you need to say Y here; if you
605 say Y here even though you have a coprocessor, the coprocessor will
606 be used nevertheless. (This behavior can be changed with the kernel
607 command line option "no387", which comes handy if your coprocessor
608 is broken. Try "man bootparam" or see the documentation of your boot
609 loader (lilo or loadlin) about how to pass options to the kernel at
610 boot time.) This means that it is a good idea to say Y here if you
611 intend to use this kernel on different machines.
612
613 More information about the internals of the Linux math coprocessor
614 emulation can be found in <file:arch/i386/math-emu/README>.
615
616 If you are not sure, say Y; apart from resulting in a 66 KB bigger
617 kernel, it won't hurt.
618
619config MTRR
620 bool "MTRR (Memory Type Range Register) support"
621 ---help---
622 On Intel P6 family processors (Pentium Pro, Pentium II and later)
623 the Memory Type Range Registers (MTRRs) may be used to control
624 processor access to memory ranges. This is most useful if you have
625 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
626 allows bus write transfers to be combined into a larger transfer
627 before bursting over the PCI/AGP bus. This can increase performance
628 of image write operations 2.5 times or more. Saying Y here creates a
629 /proc/mtrr file which may be used to manipulate your processor's
630 MTRRs. Typically the X server should use this.
631
632 This code has a reasonably generic interface so that similar
633 control registers on other processors can be easily supported
634 as well:
635
636 The Cyrix 6x86, 6x86MX and M II processors have Address Range
637 Registers (ARRs) which provide a similar functionality to MTRRs. For
638 these, the ARRs are used to emulate the MTRRs.
639 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
640 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
641 write-combining. All of these processors are supported by this code
642 and it makes sense to say Y here if you have one of them.
643
644 Saying Y here also fixes a problem with buggy SMP BIOSes which only
645 set the MTRRs for the boot CPU and not for the secondary CPUs. This
646 can lead to all sorts of problems, so it's good to say Y here.
647
648 You can safely say Y even if your machine doesn't have MTRRs, you'll
649 just add about 9 KB to your kernel.
650
651 See <file:Documentation/mtrr.txt> for more information.
652
653config EFI
654 bool "Boot from EFI support (EXPERIMENTAL)"
655 depends on ACPI
656 default n
657 ---help---
658 This enables the the kernel to boot on EFI platforms using
659 system configuration information passed to it from the firmware.
660 This also enables the kernel to use any EFI runtime services that are
661 available (such as the EFI variable services).
662
663 This option is only useful on systems that have EFI firmware
664 and will result in a kernel image that is ~8k larger. In addition,
665 you must use the latest ELILO loader available at
666 <http://elilo.sourceforge.net> in order to take advantage of
667 kernel initialization using EFI information (neither GRUB nor LILO know
668 anything about EFI). However, even with this option, the resultant
669 kernel should continue to boot on existing non-EFI platforms.
670
671config IRQBALANCE
672 bool "Enable kernel irq balancing"
673 depends on SMP && X86_IO_APIC
674 default y
675 help
676 The default yes will allow the kernel to do irq load balancing.
677 Saying no will keep the kernel from doing irq load balancing.
678
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679# turning this on wastes a bunch of space.
680# Summit needs it only when NUMA is on
681config BOOT_IOREMAP
682 bool
683 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
684 default y
685
686config REGPARM
Adrian Bunk69ef4142006-03-23 02:59:28 -0800687 bool "Use register arguments"
Ingo Molnarb824eb62006-03-23 02:59:29 -0800688 default y
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 help
Ingo Molnarb824eb62006-03-23 02:59:29 -0800690 Compile the kernel with -mregparm=3. This instructs gcc to use
691 a more efficient function call ABI which passes the first three
692 arguments of a function call via registers, which results in denser
693 and faster code.
694
695 If this option is disabled, then the default ABI of passing
696 arguments via the stack is used.
697
698 If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700config SECCOMP
701 bool "Enable seccomp to safely compute untrusted bytecode"
702 depends on PROC_FS
703 default y
704 help
705 This kernel feature is useful for number crunching applications
706 that may need to compute untrusted bytecode during their
707 execution. By using pipes or other transports made available to
708 the process as file descriptors supporting the read/write
709 syscalls, it's possible to isolate those applications in
710 their own address space using seccomp. Once seccomp is
711 enabled via /proc/<pid>/seccomp, it cannot be disabled
712 and the task is only allowed to execute a few safe syscalls
713 defined by each seccomp mode.
714
715 If unsure, say Y. Only embedded should say N here.
716
Christoph Lameter59121002005-06-23 00:08:25 -0700717source kernel/Kconfig.hz
718
Eric W. Biederman5033cba2005-06-25 14:57:56 -0700719config KEXEC
720 bool "kexec system call (EXPERIMENTAL)"
721 depends on EXPERIMENTAL
722 help
723 kexec is a system call that implements the ability to shutdown your
724 current kernel, and to start another kernel. It is like a reboot
725 but it is indepedent of the system firmware. And like a reboot
726 you can start any kernel with it, not just Linux.
727
728 The name comes from the similiarity to the exec system call.
729
730 It is an ongoing process to be certain the hardware in a machine
731 is properly shutdown, so do not be surprised if this code does not
732 initially work for you. It may help to enable device hotplugging
733 support. As of this writing the exact hardware interface is
734 strongly in flux, so no good recommendation can be made.
735
Vivek Goyal5f016452005-06-25 14:58:19 -0700736config CRASH_DUMP
737 bool "kernel crash dumps (EXPERIMENTAL)"
Vivek Goyal5f016452005-06-25 14:58:19 -0700738 depends on EXPERIMENTAL
739 depends on HIGHMEM
740 help
741 Generate crash dump after being started by kexec.
Maneesh Soni05970d42006-01-09 20:51:52 -0800742
743config PHYSICAL_START
744 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
745
746 default "0x1000000" if CRASH_DUMP
747 default "0x100000"
748 help
749 This gives the physical address where the kernel is loaded. Normally
750 for regular kernels this value is 0x100000 (1MB). But in the case
751 of kexec on panic the fail safe kernel needs to run at a different
752 address than the panic-ed kernel. This option is used to set the load
753 address for kernels used to capture crash dump on being kexec'ed
754 after panic. The default value for crash dump kernels is
755 0x1000000 (16MB). This can also be set based on the "X" value as
756 specified in the "crashkernel=YM@XM" command line boot parameter
757 passed to the panic-ed kernel. Typically this parameter is set as
758 crashkernel=64M@16M. Please take a look at
759 Documentation/kdump/kdump.txt for more details about crash dumps.
760
761 Don't change this unless you know what you are doing.
762
Randy Dunlapce63ad72006-01-14 13:20:51 -0800763config HOTPLUG_CPU
764 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
Ashok Raj35076bd2006-04-27 18:39:30 -0700765 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
Randy Dunlapce63ad72006-01-14 13:20:51 -0800766 ---help---
Pavel Machekb2d596d2006-05-15 09:44:34 -0700767 Say Y here to experiment with turning CPUs off and on, and to
768 enable suspend on SMP systems. CPUs can be controlled through
769 /sys/devices/system/cpu.
Randy Dunlapce63ad72006-01-14 13:20:51 -0800770
Randy Dunlapce63ad72006-01-14 13:20:51 -0800771
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772endmenu
773
774
775menu "Power management options (ACPI, APM)"
776 depends on !X86_VOYAGER
777
778source kernel/power/Kconfig
779
780source "drivers/acpi/Kconfig"
781
782menu "APM (Advanced Power Management) BIOS Support"
783depends on PM && !X86_VISWS
784
785config APM
786 tristate "APM (Advanced Power Management) BIOS support"
Dave Jones987d46132006-01-08 01:05:09 -0800787 depends on PM
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 ---help---
789 APM is a BIOS specification for saving power using several different
790 techniques. This is mostly useful for battery powered laptops with
791 APM compliant BIOSes. If you say Y here, the system time will be
792 reset after a RESUME operation, the /proc/apm device will provide
793 battery status information, and user-space programs will receive
794 notification of APM "events" (e.g. battery status change).
795
796 If you select "Y" here, you can disable actual use of the APM
797 BIOS by passing the "apm=off" option to the kernel at boot time.
798
799 Note that the APM support is almost completely disabled for
800 machines with more than one CPU.
801
802 In order to use APM, you will need supporting software. For location
803 and more information, read <file:Documentation/pm.txt> and the
804 Battery Powered Linux mini-HOWTO, available from
805 <http://www.tldp.org/docs.html#howto>.
806
807 This driver does not spin down disk drives (see the hdparm(8)
808 manpage ("man 8 hdparm") for that), and it doesn't turn off
809 VESA-compliant "green" monitors.
810
811 This driver does not support the TI 4000M TravelMate and the ACER
812 486/DX4/75 because they don't have compliant BIOSes. Many "green"
813 desktop machines also don't have compliant BIOSes, and this driver
814 may cause those machines to panic during the boot phase.
815
816 Generally, if you don't have a battery in your machine, there isn't
817 much point in using this driver and you should say N. If you get
818 random kernel OOPSes or reboots that don't seem to be related to
819 anything, try disabling/enabling this option (or disabling/enabling
820 APM in your BIOS).
821
822 Some other things you should try when experiencing seemingly random,
823 "weird" problems:
824
825 1) make sure that you have enough swap space and that it is
826 enabled.
827 2) pass the "no-hlt" option to the kernel
828 3) switch on floating point emulation in the kernel and pass
829 the "no387" option to the kernel
830 4) pass the "floppy=nodma" option to the kernel
831 5) pass the "mem=4M" option to the kernel (thereby disabling
832 all but the first 4 MB of RAM)
833 6) make sure that the CPU is not over clocked.
834 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
835 8) disable the cache from your BIOS settings
836 9) install a fan for the video card or exchange video RAM
837 10) install a better fan for the CPU
838 11) exchange RAM chips
839 12) exchange the motherboard.
840
841 To compile this driver as a module, choose M here: the
842 module will be called apm.
843
844config APM_IGNORE_USER_SUSPEND
845 bool "Ignore USER SUSPEND"
846 depends on APM
847 help
848 This option will ignore USER SUSPEND requests. On machines with a
849 compliant APM BIOS, you want to say N. However, on the NEC Versa M
850 series notebooks, it is necessary to say Y because of a BIOS bug.
851
852config APM_DO_ENABLE
853 bool "Enable PM at boot time"
854 depends on APM
855 ---help---
856 Enable APM features at boot time. From page 36 of the APM BIOS
857 specification: "When disabled, the APM BIOS does not automatically
858 power manage devices, enter the Standby State, enter the Suspend
859 State, or take power saving steps in response to CPU Idle calls."
860 This driver will make CPU Idle calls when Linux is idle (unless this
861 feature is turned off -- see "Do CPU IDLE calls", below). This
862 should always save battery power, but more complicated APM features
863 will be dependent on your BIOS implementation. You may need to turn
864 this option off if your computer hangs at boot time when using APM
865 support, or if it beeps continuously instead of suspending. Turn
866 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
867 T400CDT. This is off by default since most machines do fine without
868 this feature.
869
870config APM_CPU_IDLE
871 bool "Make CPU Idle calls when idle"
872 depends on APM
873 help
874 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
875 On some machines, this can activate improved power savings, such as
876 a slowed CPU clock rate, when the machine is idle. These idle calls
877 are made after the idle loop has run for some length of time (e.g.,
878 333 mS). On some machines, this will cause a hang at boot time or
879 whenever the CPU becomes idle. (On machines with more than one CPU,
880 this option does nothing.)
881
882config APM_DISPLAY_BLANK
883 bool "Enable console blanking using APM"
884 depends on APM
885 help
886 Enable console blanking using the APM. Some laptops can use this to
887 turn off the LCD backlight when the screen blanker of the Linux
888 virtual console blanks the screen. Note that this is only used by
889 the virtual console screen blanker, and won't turn off the backlight
890 when using the X Window system. This also doesn't have anything to
891 do with your VESA-compliant power-saving monitor. Further, this
892 option doesn't work for all laptops -- it might not turn off your
893 backlight at all, or it might print a lot of errors to the console,
894 especially if you are using gpm.
895
896config APM_RTC_IS_GMT
897 bool "RTC stores time in GMT"
898 depends on APM
899 help
900 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
901 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
902 stores localtime.
903
904 It is in fact recommended to store GMT in your RTC, because then you
905 don't have to worry about daylight savings time changes. The only
906 reason not to use GMT in your RTC is if you also run a broken OS
907 that doesn't understand GMT.
908
909config APM_ALLOW_INTS
910 bool "Allow interrupts during APM BIOS calls"
911 depends on APM
912 help
913 Normally we disable external interrupts while we are making calls to
914 the APM BIOS as a measure to lessen the effects of a badly behaving
915 BIOS implementation. The BIOS should reenable interrupts if it
916 needs to. Unfortunately, some BIOSes do not -- especially those in
917 many of the newer IBM Thinkpads. If you experience hangs when you
918 suspend, try setting this to Y. Otherwise, say N.
919
920config APM_REAL_MODE_POWER_OFF
921 bool "Use real mode APM BIOS call to power off"
922 depends on APM
923 help
924 Use real mode APM BIOS calls to switch off the computer. This is
925 a work-around for a number of buggy BIOSes. Switch this option on if
926 your computer crashes instead of powering off properly.
927
928endmenu
929
930source "arch/i386/kernel/cpu/cpufreq/Kconfig"
931
932endmenu
933
934menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
935
936config PCI
937 bool "PCI support" if !X86_VISWS
938 depends on !X86_VOYAGER
939 default y if X86_VISWS
940 help
941 Find out whether you have a PCI motherboard. PCI is the name of a
942 bus system, i.e. the way the CPU talks to the other stuff inside
943 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
944 VESA. If you have PCI, say Y, otherwise N.
945
946 The PCI-HOWTO, available from
947 <http://www.tldp.org/docs.html#howto>, contains valuable
948 information about which PCI hardware does work under Linux and which
949 doesn't.
950
951choice
952 prompt "PCI access mode"
953 depends on PCI && !X86_VISWS
954 default PCI_GOANY
955 ---help---
956 On PCI systems, the BIOS can be used to detect the PCI devices and
957 determine their configuration. However, some old PCI motherboards
958 have BIOS bugs and may crash if this is done. Also, some embedded
959 PCI-based systems don't have any BIOS at all. Linux can also try to
960 detect the PCI hardware directly without using the BIOS.
961
962 With this option, you can specify how Linux should detect the
963 PCI devices. If you choose "BIOS", the BIOS will be used,
964 if you choose "Direct", the BIOS won't be used, and if you
965 choose "MMConfig", then PCI Express MMCONFIG will be used.
966 If you choose "Any", the kernel will try MMCONFIG, then the
967 direct access method and falls back to the BIOS if that doesn't
968 work. If unsure, go with the default, which is "Any".
969
970config PCI_GOBIOS
971 bool "BIOS"
972
973config PCI_GOMMCONFIG
974 bool "MMConfig"
975
976config PCI_GODIRECT
977 bool "Direct"
978
979config PCI_GOANY
980 bool "Any"
981
982endchoice
983
984config PCI_BIOS
985 bool
986 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
987 default y
988
989config PCI_DIRECT
990 bool
991 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
992 default y
993
994config PCI_MMCONFIG
995 bool
Alexander Nyberg8aadff72005-05-27 12:48:50 +0200996 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997 default y
998
999source "drivers/pci/pcie/Kconfig"
1000
1001source "drivers/pci/Kconfig"
1002
Al Viro5cae8412005-05-04 05:39:22 +01001003config ISA_DMA_API
1004 bool
1005 default y
1006
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007config ISA
1008 bool "ISA support"
1009 depends on !(X86_VOYAGER || X86_VISWS)
1010 help
1011 Find out whether you have ISA slots on your motherboard. ISA is the
1012 name of a bus system, i.e. the way the CPU talks to the other stuff
1013 inside your box. Other bus systems are PCI, EISA, MicroChannel
1014 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1015 newer boards don't support it. If you have ISA, say Y, otherwise N.
1016
1017config EISA
1018 bool "EISA support"
1019 depends on ISA
1020 ---help---
1021 The Extended Industry Standard Architecture (EISA) bus was
1022 developed as an open alternative to the IBM MicroChannel bus.
1023
1024 The EISA bus provided some of the features of the IBM MicroChannel
1025 bus while maintaining backward compatibility with cards made for
1026 the older ISA bus. The EISA bus saw limited use between 1988 and
1027 1995 when it was made obsolete by the PCI bus.
1028
1029 Say Y here if you are building a kernel for an EISA-based machine.
1030
1031 Otherwise, say N.
1032
1033source "drivers/eisa/Kconfig"
1034
1035config MCA
1036 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1037 default y if X86_VOYAGER
1038 help
1039 MicroChannel Architecture is found in some IBM PS/2 machines and
1040 laptops. It is a bus system similar to PCI or ISA. See
1041 <file:Documentation/mca.txt> (and especially the web page given
1042 there) before attempting to build an MCA bus kernel.
1043
1044source "drivers/mca/Kconfig"
1045
1046config SCx200
1047 tristate "NatSemi SCx200 support"
1048 depends on !X86_VOYAGER
1049 help
1050 This provides basic support for the National Semiconductor SCx200
1051 processor. Right now this is just a driver for the GPIO pins.
1052
1053 If you don't know what to do here, say N.
1054
1055 This support is also available as a module. If compiled as a
1056 module, it will be called scx200.
1057
Linus Torvalds1da177e2005-04-16 15:20:36 -07001058source "drivers/pcmcia/Kconfig"
1059
1060source "drivers/pci/hotplug/Kconfig"
1061
1062endmenu
1063
1064menu "Executable file formats"
1065
1066source "fs/Kconfig.binfmt"
1067
1068endmenu
1069
Sam Ravnborgd5950b42005-07-11 21:03:49 -07001070source "net/Kconfig"
1071
Linus Torvalds1da177e2005-04-16 15:20:36 -07001072source "drivers/Kconfig"
1073
1074source "fs/Kconfig"
1075
Prasanna S Panchamukhicd6b0762005-11-07 00:59:14 -08001076menu "Instrumentation Support"
1077 depends on EXPERIMENTAL
1078
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079source "arch/i386/oprofile/Kconfig"
1080
Prasanna S Panchamukhicd6b0762005-11-07 00:59:14 -08001081config KPROBES
1082 bool "Kprobes (EXPERIMENTAL)"
Linus Torvaldsadd2b6f2006-02-26 20:24:40 -08001083 depends on EXPERIMENTAL && MODULES
Prasanna S Panchamukhicd6b0762005-11-07 00:59:14 -08001084 help
1085 Kprobes allows you to trap at almost any kernel address and
1086 execute a callback function. register_kprobe() establishes
1087 a probepoint and specifies the callback. Kprobes is useful
1088 for kernel debugging, non-intrusive instrumentation and testing.
1089 If in doubt, say "N".
1090endmenu
1091
Linus Torvalds1da177e2005-04-16 15:20:36 -07001092source "arch/i386/Kconfig.debug"
1093
1094source "security/Kconfig"
1095
1096source "crypto/Kconfig"
1097
1098source "lib/Kconfig"
1099
1100#
1101# Use the generic interrupt handling code in kernel/irq/:
1102#
1103config GENERIC_HARDIRQS
1104 bool
1105 default y
1106
1107config GENERIC_IRQ_PROBE
1108 bool
1109 default y
1110
Ashok Raj54d5d422005-09-06 15:16:15 -07001111config GENERIC_PENDING_IRQ
1112 bool
1113 depends on GENERIC_HARDIRQS && SMP
1114 default y
1115
Linus Torvalds1da177e2005-04-16 15:20:36 -07001116config X86_SMP
1117 bool
1118 depends on SMP && !X86_VOYAGER
1119 default y
1120
1121config X86_HT
1122 bool
1123 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1124 default y
1125
1126config X86_BIOS_REBOOT
1127 bool
1128 depends on !(X86_VISWS || X86_VOYAGER)
1129 default y
1130
1131config X86_TRAMPOLINE
1132 bool
1133 depends on X86_SMP || (X86_VOYAGER && SMP)
1134 default y
Thomas Gleixner97fc79f2006-01-09 20:52:31 -08001135
1136config KTIME_SCALAR
1137 bool
1138 default y