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1 #
2 # For a description of the syntax of this configuration file,
3 # see Documentation/kbuild/kconfig-language.txt.
4 #
5
6 mainmenu "Linux Kernel Configuration"
7
8 config X86_32
9 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
17 config SEMAPHORE_SLEEPERS
18 bool
19 default y
20
21 config X86
22 bool
23 default y
24
25 config MMU
26 bool
27 default y
28
29 config SBUS
30 bool
31
32 config GENERIC_ISA_DMA
33 bool
34 default y
35
36 config GENERIC_IOMAP
37 bool
38 default y
39
40 config GENERIC_HWEIGHT
41 bool
42 default y
43
44 config ARCH_MAY_HAVE_PC_FDC
45 bool
46 default y
47
48 config DMI
49 bool
50 default y
51
52 source "init/Kconfig"
53
54 menu "Processor type and features"
55
56 config 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
85 choice
86 prompt "Subarchitecture Type"
87 default X86_PC
88
89 config X86_PC
90 bool "PC-compatible"
91 help
92 Choose this option if your computer is a standard PC or compatible.
93
94 config 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
103 config 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
114 config X86_NUMAQ
115 bool "NUMAQ (IBM/Sequent)"
116 select SMP
117 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
125 config 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
134 config 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
143 config 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
154 config 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
161 config 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
170 endchoice
171
172 config ACPI_SRAT
173 bool
174 default y
175 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
176
177 config X86_SUMMIT_NUMA
178 bool
179 default y
180 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
181
182 config X86_CYCLONE_TIMER
183 bool
184 default y
185 depends on X86_SUMMIT || X86_GENERICARCH
186
187 config ES7000_CLUSTERED_APIC
188 bool
189 default y
190 depends on SMP && X86_ES7000 && MPENTIUMIII
191
192 source "arch/i386/Kconfig.cpu"
193
194 config HPET_TIMER
195 bool "HPET Timer Support"
196 help
197 This enables the use of the HPET for the kernel's internal timer.
198 HPET is the next generation timer replacing legacy 8254s.
199 You can safely choose Y here. However, HPET will only be
200 activated if the platform and the BIOS support this feature.
201 Otherwise the 8254 will be used for timing services.
202
203 Choose N to continue using the legacy 8254 timer.
204
205 config HPET_EMULATE_RTC
206 bool
207 depends on HPET_TIMER && RTC=y
208 default y
209
210 config 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
224 config 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
234 config 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
243 source "kernel/Kconfig.preempt"
244
245 config 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
258 config 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
270 config X86_LOCAL_APIC
271 bool
272 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER)
273 default y
274
275 config X86_IO_APIC
276 bool
277 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER))
278 default y
279
280 config X86_VISWS_APIC
281 bool
282 depends on X86_VISWS
283 default y
284
285 config 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
302 config 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
315 config 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
322 config 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
337 config 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
357 config 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
375 config 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
392 config 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
401 config 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
409 source "drivers/firmware/Kconfig"
410
411 choice
412 prompt "High Memory Support"
413 default NOHIGHMEM
414
415 config NOHIGHMEM
416 bool "off"
417 depends on !X86_NUMAQ
418 ---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
452 config HIGHMEM4G
453 bool "4GB"
454 depends on !X86_NUMAQ
455 help
456 Select this if you have a 32-bit processor and between 1 and 4
457 gigabytes of physical RAM.
458
459 config HIGHMEM64G
460 bool "64GB"
461 depends on X86_CMPXCHG64
462 help
463 Select this if you have a 32-bit processor and more than 4
464 gigabytes of physical RAM.
465
466 endchoice
467
468 choice
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"
496 endchoice
497
498 config 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
505 config HIGHMEM
506 bool
507 depends on HIGHMEM64G || HIGHMEM4G
508 default y
509
510 config X86_PAE
511 bool
512 depends on HIGHMEM64G
513 default y
514
515 # Common NUMA Features
516 config 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
522 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
523 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
524
525 config NODES_SHIFT
526 int
527 default "4" if X86_NUMAQ
528 default "3"
529 depends on NEED_MULTIPLE_NODES
530
531 config HAVE_ARCH_BOOTMEM_NODE
532 bool
533 depends on NUMA
534 default y
535
536 config ARCH_HAVE_MEMORY_PRESENT
537 bool
538 depends on DISCONTIGMEM
539 default y
540
541 config NEED_NODE_MEMMAP_SIZE
542 bool
543 depends on DISCONTIGMEM || SPARSEMEM
544 default y
545
546 config HAVE_ARCH_ALLOC_REMAP
547 bool
548 depends on NUMA
549 default y
550
551 config ARCH_FLATMEM_ENABLE
552 def_bool y
553 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
554
555 config ARCH_DISCONTIGMEM_ENABLE
556 def_bool y
557 depends on NUMA
558
559 config ARCH_DISCONTIGMEM_DEFAULT
560 def_bool y
561 depends on NUMA
562
563 config ARCH_SPARSEMEM_ENABLE
564 def_bool y
565 depends on (NUMA || (X86_PC && EXPERIMENTAL))
566 select SPARSEMEM_STATIC
567
568 config ARCH_SELECT_MEMORY_MODEL
569 def_bool y
570 depends on ARCH_SPARSEMEM_ENABLE
571
572 source "mm/Kconfig"
573
574 config HAVE_ARCH_EARLY_PFN_TO_NID
575 bool
576 default y
577 depends on NUMA
578
579 config HIGHPTE
580 bool "Allocate 3rd-level pagetables from highmem"
581 depends on HIGHMEM4G || HIGHMEM64G
582 help
583 The VM uses one page table entry for each page of physical memory.
584 For systems with a lot of RAM, this can be wasteful of precious
585 low memory. Setting this option will put user-space page table
586 entries in high memory.
587
588 config MATH_EMULATION
589 bool "Math emulation"
590 ---help---
591 Linux can emulate a math coprocessor (used for floating point
592 operations) if you don't have one. 486DX and Pentium processors have
593 a math coprocessor built in, 486SX and 386 do not, unless you added
594 a 487DX or 387, respectively. (The messages during boot time can
595 give you some hints here ["man dmesg"].) Everyone needs either a
596 coprocessor or this emulation.
597
598 If you don't have a math coprocessor, you need to say Y here; if you
599 say Y here even though you have a coprocessor, the coprocessor will
600 be used nevertheless. (This behavior can be changed with the kernel
601 command line option "no387", which comes handy if your coprocessor
602 is broken. Try "man bootparam" or see the documentation of your boot
603 loader (lilo or loadlin) about how to pass options to the kernel at
604 boot time.) This means that it is a good idea to say Y here if you
605 intend to use this kernel on different machines.
606
607 More information about the internals of the Linux math coprocessor
608 emulation can be found in <file:arch/i386/math-emu/README>.
609
610 If you are not sure, say Y; apart from resulting in a 66 KB bigger
611 kernel, it won't hurt.
612
613 config MTRR
614 bool "MTRR (Memory Type Range Register) support"
615 ---help---
616 On Intel P6 family processors (Pentium Pro, Pentium II and later)
617 the Memory Type Range Registers (MTRRs) may be used to control
618 processor access to memory ranges. This is most useful if you have
619 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
620 allows bus write transfers to be combined into a larger transfer
621 before bursting over the PCI/AGP bus. This can increase performance
622 of image write operations 2.5 times or more. Saying Y here creates a
623 /proc/mtrr file which may be used to manipulate your processor's
624 MTRRs. Typically the X server should use this.
625
626 This code has a reasonably generic interface so that similar
627 control registers on other processors can be easily supported
628 as well:
629
630 The Cyrix 6x86, 6x86MX and M II processors have Address Range
631 Registers (ARRs) which provide a similar functionality to MTRRs. For
632 these, the ARRs are used to emulate the MTRRs.
633 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
634 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
635 write-combining. All of these processors are supported by this code
636 and it makes sense to say Y here if you have one of them.
637
638 Saying Y here also fixes a problem with buggy SMP BIOSes which only
639 set the MTRRs for the boot CPU and not for the secondary CPUs. This
640 can lead to all sorts of problems, so it's good to say Y here.
641
642 You can safely say Y even if your machine doesn't have MTRRs, you'll
643 just add about 9 KB to your kernel.
644
645 See <file:Documentation/mtrr.txt> for more information.
646
647 config EFI
648 bool "Boot from EFI support (EXPERIMENTAL)"
649 depends on ACPI
650 default n
651 ---help---
652 This enables the the kernel to boot on EFI platforms using
653 system configuration information passed to it from the firmware.
654 This also enables the kernel to use any EFI runtime services that are
655 available (such as the EFI variable services).
656
657 This option is only useful on systems that have EFI firmware
658 and will result in a kernel image that is ~8k larger. In addition,
659 you must use the latest ELILO loader available at
660 <http://elilo.sourceforge.net> in order to take advantage of
661 kernel initialization using EFI information (neither GRUB nor LILO know
662 anything about EFI). However, even with this option, the resultant
663 kernel should continue to boot on existing non-EFI platforms.
664
665 config IRQBALANCE
666 bool "Enable kernel irq balancing"
667 depends on SMP && X86_IO_APIC
668 default y
669 help
670 The default yes will allow the kernel to do irq load balancing.
671 Saying no will keep the kernel from doing irq load balancing.
672
673 # turning this on wastes a bunch of space.
674 # Summit needs it only when NUMA is on
675 config BOOT_IOREMAP
676 bool
677 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
678 default y
679
680 config REGPARM
681 bool "Use register arguments"
682 default y
683 help
684 Compile the kernel with -mregparm=3. This instructs gcc to use
685 a more efficient function call ABI which passes the first three
686 arguments of a function call via registers, which results in denser
687 and faster code.
688
689 If this option is disabled, then the default ABI of passing
690 arguments via the stack is used.
691
692 If unsure, say Y.
693
694 config SECCOMP
695 bool "Enable seccomp to safely compute untrusted bytecode"
696 depends on PROC_FS
697 default y
698 help
699 This kernel feature is useful for number crunching applications
700 that may need to compute untrusted bytecode during their
701 execution. By using pipes or other transports made available to
702 the process as file descriptors supporting the read/write
703 syscalls, it's possible to isolate those applications in
704 their own address space using seccomp. Once seccomp is
705 enabled via /proc/<pid>/seccomp, it cannot be disabled
706 and the task is only allowed to execute a few safe syscalls
707 defined by each seccomp mode.
708
709 If unsure, say Y. Only embedded should say N here.
710
711 source kernel/Kconfig.hz
712
713 config KEXEC
714 bool "kexec system call (EXPERIMENTAL)"
715 depends on EXPERIMENTAL
716 help
717 kexec is a system call that implements the ability to shutdown your
718 current kernel, and to start another kernel. It is like a reboot
719 but it is indepedent of the system firmware. And like a reboot
720 you can start any kernel with it, not just Linux.
721
722 The name comes from the similiarity to the exec system call.
723
724 It is an ongoing process to be certain the hardware in a machine
725 is properly shutdown, so do not be surprised if this code does not
726 initially work for you. It may help to enable device hotplugging
727 support. As of this writing the exact hardware interface is
728 strongly in flux, so no good recommendation can be made.
729
730 config CRASH_DUMP
731 bool "kernel crash dumps (EXPERIMENTAL)"
732 depends on EXPERIMENTAL
733 depends on HIGHMEM
734 help
735 Generate crash dump after being started by kexec.
736
737 config PHYSICAL_START
738 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
739
740 default "0x1000000" if CRASH_DUMP
741 default "0x100000"
742 help
743 This gives the physical address where the kernel is loaded. Normally
744 for regular kernels this value is 0x100000 (1MB). But in the case
745 of kexec on panic the fail safe kernel needs to run at a different
746 address than the panic-ed kernel. This option is used to set the load
747 address for kernels used to capture crash dump on being kexec'ed
748 after panic. The default value for crash dump kernels is
749 0x1000000 (16MB). This can also be set based on the "X" value as
750 specified in the "crashkernel=YM@XM" command line boot parameter
751 passed to the panic-ed kernel. Typically this parameter is set as
752 crashkernel=64M@16M. Please take a look at
753 Documentation/kdump/kdump.txt for more details about crash dumps.
754
755 Don't change this unless you know what you are doing.
756
757 config HOTPLUG_CPU
758 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
759 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER && !X86_PC
760 ---help---
761 Say Y here to experiment with turning CPUs off and on. CPUs
762 can be controlled through /sys/devices/system/cpu.
763
764 Say N.
765
766 endmenu
767
768
769 menu "Power management options (ACPI, APM)"
770 depends on !X86_VOYAGER
771
772 source kernel/power/Kconfig
773
774 source "drivers/acpi/Kconfig"
775
776 menu "APM (Advanced Power Management) BIOS Support"
777 depends on PM && !X86_VISWS
778
779 config APM
780 tristate "APM (Advanced Power Management) BIOS support"
781 depends on PM
782 ---help---
783 APM is a BIOS specification for saving power using several different
784 techniques. This is mostly useful for battery powered laptops with
785 APM compliant BIOSes. If you say Y here, the system time will be
786 reset after a RESUME operation, the /proc/apm device will provide
787 battery status information, and user-space programs will receive
788 notification of APM "events" (e.g. battery status change).
789
790 If you select "Y" here, you can disable actual use of the APM
791 BIOS by passing the "apm=off" option to the kernel at boot time.
792
793 Note that the APM support is almost completely disabled for
794 machines with more than one CPU.
795
796 In order to use APM, you will need supporting software. For location
797 and more information, read <file:Documentation/pm.txt> and the
798 Battery Powered Linux mini-HOWTO, available from
799 <http://www.tldp.org/docs.html#howto>.
800
801 This driver does not spin down disk drives (see the hdparm(8)
802 manpage ("man 8 hdparm") for that), and it doesn't turn off
803 VESA-compliant "green" monitors.
804
805 This driver does not support the TI 4000M TravelMate and the ACER
806 486/DX4/75 because they don't have compliant BIOSes. Many "green"
807 desktop machines also don't have compliant BIOSes, and this driver
808 may cause those machines to panic during the boot phase.
809
810 Generally, if you don't have a battery in your machine, there isn't
811 much point in using this driver and you should say N. If you get
812 random kernel OOPSes or reboots that don't seem to be related to
813 anything, try disabling/enabling this option (or disabling/enabling
814 APM in your BIOS).
815
816 Some other things you should try when experiencing seemingly random,
817 "weird" problems:
818
819 1) make sure that you have enough swap space and that it is
820 enabled.
821 2) pass the "no-hlt" option to the kernel
822 3) switch on floating point emulation in the kernel and pass
823 the "no387" option to the kernel
824 4) pass the "floppy=nodma" option to the kernel
825 5) pass the "mem=4M" option to the kernel (thereby disabling
826 all but the first 4 MB of RAM)
827 6) make sure that the CPU is not over clocked.
828 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
829 8) disable the cache from your BIOS settings
830 9) install a fan for the video card or exchange video RAM
831 10) install a better fan for the CPU
832 11) exchange RAM chips
833 12) exchange the motherboard.
834
835 To compile this driver as a module, choose M here: the
836 module will be called apm.
837
838 config APM_IGNORE_USER_SUSPEND
839 bool "Ignore USER SUSPEND"
840 depends on APM
841 help
842 This option will ignore USER SUSPEND requests. On machines with a
843 compliant APM BIOS, you want to say N. However, on the NEC Versa M
844 series notebooks, it is necessary to say Y because of a BIOS bug.
845
846 config APM_DO_ENABLE
847 bool "Enable PM at boot time"
848 depends on APM
849 ---help---
850 Enable APM features at boot time. From page 36 of the APM BIOS
851 specification: "When disabled, the APM BIOS does not automatically
852 power manage devices, enter the Standby State, enter the Suspend
853 State, or take power saving steps in response to CPU Idle calls."
854 This driver will make CPU Idle calls when Linux is idle (unless this
855 feature is turned off -- see "Do CPU IDLE calls", below). This
856 should always save battery power, but more complicated APM features
857 will be dependent on your BIOS implementation. You may need to turn
858 this option off if your computer hangs at boot time when using APM
859 support, or if it beeps continuously instead of suspending. Turn
860 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
861 T400CDT. This is off by default since most machines do fine without
862 this feature.
863
864 config APM_CPU_IDLE
865 bool "Make CPU Idle calls when idle"
866 depends on APM
867 help
868 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
869 On some machines, this can activate improved power savings, such as
870 a slowed CPU clock rate, when the machine is idle. These idle calls
871 are made after the idle loop has run for some length of time (e.g.,
872 333 mS). On some machines, this will cause a hang at boot time or
873 whenever the CPU becomes idle. (On machines with more than one CPU,
874 this option does nothing.)
875
876 config APM_DISPLAY_BLANK
877 bool "Enable console blanking using APM"
878 depends on APM
879 help
880 Enable console blanking using the APM. Some laptops can use this to
881 turn off the LCD backlight when the screen blanker of the Linux
882 virtual console blanks the screen. Note that this is only used by
883 the virtual console screen blanker, and won't turn off the backlight
884 when using the X Window system. This also doesn't have anything to
885 do with your VESA-compliant power-saving monitor. Further, this
886 option doesn't work for all laptops -- it might not turn off your
887 backlight at all, or it might print a lot of errors to the console,
888 especially if you are using gpm.
889
890 config APM_RTC_IS_GMT
891 bool "RTC stores time in GMT"
892 depends on APM
893 help
894 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
895 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
896 stores localtime.
897
898 It is in fact recommended to store GMT in your RTC, because then you
899 don't have to worry about daylight savings time changes. The only
900 reason not to use GMT in your RTC is if you also run a broken OS
901 that doesn't understand GMT.
902
903 config APM_ALLOW_INTS
904 bool "Allow interrupts during APM BIOS calls"
905 depends on APM
906 help
907 Normally we disable external interrupts while we are making calls to
908 the APM BIOS as a measure to lessen the effects of a badly behaving
909 BIOS implementation. The BIOS should reenable interrupts if it
910 needs to. Unfortunately, some BIOSes do not -- especially those in
911 many of the newer IBM Thinkpads. If you experience hangs when you
912 suspend, try setting this to Y. Otherwise, say N.
913
914 config APM_REAL_MODE_POWER_OFF
915 bool "Use real mode APM BIOS call to power off"
916 depends on APM
917 help
918 Use real mode APM BIOS calls to switch off the computer. This is
919 a work-around for a number of buggy BIOSes. Switch this option on if
920 your computer crashes instead of powering off properly.
921
922 endmenu
923
924 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
925
926 endmenu
927
928 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
929
930 config PCI
931 bool "PCI support" if !X86_VISWS
932 depends on !X86_VOYAGER
933 default y if X86_VISWS
934 help
935 Find out whether you have a PCI motherboard. PCI is the name of a
936 bus system, i.e. the way the CPU talks to the other stuff inside
937 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
938 VESA. If you have PCI, say Y, otherwise N.
939
940 The PCI-HOWTO, available from
941 <http://www.tldp.org/docs.html#howto>, contains valuable
942 information about which PCI hardware does work under Linux and which
943 doesn't.
944
945 choice
946 prompt "PCI access mode"
947 depends on PCI && !X86_VISWS
948 default PCI_GOANY
949 ---help---
950 On PCI systems, the BIOS can be used to detect the PCI devices and
951 determine their configuration. However, some old PCI motherboards
952 have BIOS bugs and may crash if this is done. Also, some embedded
953 PCI-based systems don't have any BIOS at all. Linux can also try to
954 detect the PCI hardware directly without using the BIOS.
955
956 With this option, you can specify how Linux should detect the
957 PCI devices. If you choose "BIOS", the BIOS will be used,
958 if you choose "Direct", the BIOS won't be used, and if you
959 choose "MMConfig", then PCI Express MMCONFIG will be used.
960 If you choose "Any", the kernel will try MMCONFIG, then the
961 direct access method and falls back to the BIOS if that doesn't
962 work. If unsure, go with the default, which is "Any".
963
964 config PCI_GOBIOS
965 bool "BIOS"
966
967 config PCI_GOMMCONFIG
968 bool "MMConfig"
969
970 config PCI_GODIRECT
971 bool "Direct"
972
973 config PCI_GOANY
974 bool "Any"
975
976 endchoice
977
978 config PCI_BIOS
979 bool
980 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
981 default y
982
983 config PCI_DIRECT
984 bool
985 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
986 default y
987
988 config PCI_MMCONFIG
989 bool
990 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
991 default y
992
993 source "drivers/pci/pcie/Kconfig"
994
995 source "drivers/pci/Kconfig"
996
997 config ISA_DMA_API
998 bool
999 default y
1000
1001 config ISA
1002 bool "ISA support"
1003 depends on !(X86_VOYAGER || X86_VISWS)
1004 help
1005 Find out whether you have ISA slots on your motherboard. ISA is the
1006 name of a bus system, i.e. the way the CPU talks to the other stuff
1007 inside your box. Other bus systems are PCI, EISA, MicroChannel
1008 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1009 newer boards don't support it. If you have ISA, say Y, otherwise N.
1010
1011 config EISA
1012 bool "EISA support"
1013 depends on ISA
1014 ---help---
1015 The Extended Industry Standard Architecture (EISA) bus was
1016 developed as an open alternative to the IBM MicroChannel bus.
1017
1018 The EISA bus provided some of the features of the IBM MicroChannel
1019 bus while maintaining backward compatibility with cards made for
1020 the older ISA bus. The EISA bus saw limited use between 1988 and
1021 1995 when it was made obsolete by the PCI bus.
1022
1023 Say Y here if you are building a kernel for an EISA-based machine.
1024
1025 Otherwise, say N.
1026
1027 source "drivers/eisa/Kconfig"
1028
1029 config MCA
1030 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1031 default y if X86_VOYAGER
1032 help
1033 MicroChannel Architecture is found in some IBM PS/2 machines and
1034 laptops. It is a bus system similar to PCI or ISA. See
1035 <file:Documentation/mca.txt> (and especially the web page given
1036 there) before attempting to build an MCA bus kernel.
1037
1038 source "drivers/mca/Kconfig"
1039
1040 config SCx200
1041 tristate "NatSemi SCx200 support"
1042 depends on !X86_VOYAGER
1043 help
1044 This provides basic support for the National Semiconductor SCx200
1045 processor. Right now this is just a driver for the GPIO pins.
1046
1047 If you don't know what to do here, say N.
1048
1049 This support is also available as a module. If compiled as a
1050 module, it will be called scx200.
1051
1052 source "drivers/pcmcia/Kconfig"
1053
1054 source "drivers/pci/hotplug/Kconfig"
1055
1056 endmenu
1057
1058 menu "Executable file formats"
1059
1060 source "fs/Kconfig.binfmt"
1061
1062 endmenu
1063
1064 source "net/Kconfig"
1065
1066 source "drivers/Kconfig"
1067
1068 source "fs/Kconfig"
1069
1070 menu "Instrumentation Support"
1071 depends on EXPERIMENTAL
1072
1073 source "arch/i386/oprofile/Kconfig"
1074
1075 config KPROBES
1076 bool "Kprobes (EXPERIMENTAL)"
1077 depends on EXPERIMENTAL && MODULES
1078 help
1079 Kprobes allows you to trap at almost any kernel address and
1080 execute a callback function. register_kprobe() establishes
1081 a probepoint and specifies the callback. Kprobes is useful
1082 for kernel debugging, non-intrusive instrumentation and testing.
1083 If in doubt, say "N".
1084 endmenu
1085
1086 source "arch/i386/Kconfig.debug"
1087
1088 source "security/Kconfig"
1089
1090 source "crypto/Kconfig"
1091
1092 source "lib/Kconfig"
1093
1094 #
1095 # Use the generic interrupt handling code in kernel/irq/:
1096 #
1097 config GENERIC_HARDIRQS
1098 bool
1099 default y
1100
1101 config GENERIC_IRQ_PROBE
1102 bool
1103 default y
1104
1105 config GENERIC_PENDING_IRQ
1106 bool
1107 depends on GENERIC_HARDIRQS && SMP
1108 default y
1109
1110 config X86_SMP
1111 bool
1112 depends on SMP && !X86_VOYAGER
1113 default y
1114
1115 config X86_HT
1116 bool
1117 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1118 default y
1119
1120 config X86_BIOS_REBOOT
1121 bool
1122 depends on !(X86_VISWS || X86_VOYAGER)
1123 default y
1124
1125 config X86_TRAMPOLINE
1126 bool
1127 depends on X86_SMP || (X86_VOYAGER && SMP)
1128 default y
1129
1130 config KTIME_SCALAR
1131 bool
1132 default y