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1 #
2 # For a description of the syntax of this configuration file,
3 # see Documentation/kbuild/kconfig-language.txt.
4 #
6 mainmenu "Linux Kernel Configuration"
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.
17 config SEMAPHORE_SLEEPERS
18 bool
19 default y
21 config X86
22 bool
23 default y
25 config MMU
26 bool
27 default y
29 config SBUS
30 bool
32 config GENERIC_ISA_DMA
33 bool
34 default y
36 config GENERIC_IOMAP
37 bool
38 default y
40 config ARCH_MAY_HAVE_PC_FDC
41 bool
42 default y
44 config DMI
45 bool
46 default y
48 source "init/Kconfig"
50 menu "Processor type and features"
52 choice
53 prompt "Subarchitecture Type"
54 default X86_PC
56 config X86_PC
57 bool "PC-compatible"
58 help
59 Choose this option if your computer is a standard PC or compatible.
61 config X86_ELAN
62 bool "AMD Elan"
63 help
64 Select this for an AMD Elan processor.
66 Do not use this option for K6/Athlon/Opteron processors!
68 If unsure, choose "PC-compatible" instead.
70 config X86_VOYAGER
71 bool "Voyager (NCR)"
72 help
73 Voyager is an MCA-based 32-way capable SMP architecture proprietary
74 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
76 *** WARNING ***
78 If you do not specifically know you have a Voyager based machine,
79 say N here, otherwise the kernel you build will not be bootable.
81 config X86_NUMAQ
82 bool "NUMAQ (IBM/Sequent)"
83 select NUMA
84 help
85 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
86 multiquad box. This changes the way that processors are bootstrapped,
87 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
88 You will need a new lynxer.elf file to flash your firmware with - send
89 email to <Martin.Bligh@us.ibm.com>.
91 config X86_SUMMIT
92 bool "Summit/EXA (IBM x440)"
93 depends on SMP
94 help
95 This option is needed for IBM systems that use the Summit/EXA chipset.
96 In particular, it is needed for the x440.
98 If you don't have one of these computers, you should say N here.
100 config X86_BIGSMP
101 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
102 depends on SMP
103 help
104 This option is needed for the systems that have more than 8 CPUs
105 and if the system is not of any sub-arch type above.
107 If you don't have such a system, you should say N here.
109 config X86_VISWS
110 bool "SGI 320/540 (Visual Workstation)"
111 help
112 The SGI Visual Workstation series is an IA32-based workstation
113 based on SGI systems chips with some legacy PC hardware attached.
115 Say Y here to create a kernel to run on the SGI 320 or 540.
117 A kernel compiled for the Visual Workstation will not run on PCs
118 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
120 config X86_GENERICARCH
121 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
122 depends on SMP
123 help
124 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
125 It is intended for a generic binary kernel.
127 config X86_ES7000
128 bool "Support for Unisys ES7000 IA32 series"
129 depends on SMP
130 help
131 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
132 supposed to run on an IA32-based Unisys ES7000 system.
133 Only choose this option if you have such a system, otherwise you
134 should say N here.
136 endchoice
138 config ACPI_SRAT
139 bool
140 default y
141 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
143 config X86_SUMMIT_NUMA
144 bool
145 default y
146 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
148 config X86_CYCLONE_TIMER
149 bool
150 default y
151 depends on X86_SUMMIT || X86_GENERICARCH
153 config ES7000_CLUSTERED_APIC
154 bool
155 default y
156 depends on SMP && X86_ES7000 && MPENTIUMIII
158 source "arch/i386/Kconfig.cpu"
160 config HPET_TIMER
161 bool "HPET Timer Support"
162 help
163 This enables the use of the HPET for the kernel's internal timer.
164 HPET is the next generation timer replacing legacy 8254s.
165 You can safely choose Y here. However, HPET will only be
166 activated if the platform and the BIOS support this feature.
167 Otherwise the 8254 will be used for timing services.
169 Choose N to continue using the legacy 8254 timer.
171 config HPET_EMULATE_RTC
172 bool
173 depends on HPET_TIMER && RTC=y
174 default y
176 config SMP
177 bool "Symmetric multi-processing support"
178 ---help---
179 This enables support for systems with more than one CPU. If you have
180 a system with only one CPU, like most personal computers, say N. If
181 you have a system with more than one CPU, say Y.
183 If you say N here, the kernel will run on single and multiprocessor
184 machines, but will use only one CPU of a multiprocessor machine. If
185 you say Y here, the kernel will run on many, but not all,
186 singleprocessor machines. On a singleprocessor machine, the kernel
187 will run faster if you say N here.
189 Note that if you say Y here and choose architecture "586" or
190 "Pentium" under "Processor family", the kernel will not work on 486
191 architectures. Similarly, multiprocessor kernels for the "PPro"
192 architecture may not work on all Pentium based boards.
194 People using multiprocessor machines who say Y here should also say
195 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
196 Management" code will be disabled if you say Y here.
198 See also the <file:Documentation/smp.txt>,
199 <file:Documentation/i386/IO-APIC.txt>,
200 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
201 <http://www.tldp.org/docs.html#howto>.
203 If you don't know what to do here, say N.
205 config NR_CPUS
206 int "Maximum number of CPUs (2-255)"
207 range 2 255
208 depends on SMP
209 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
210 default "8"
211 help
212 This allows you to specify the maximum number of CPUs which this
213 kernel will support. The maximum supported value is 255 and the
214 minimum value which makes sense is 2.
216 This is purely to save memory - each supported CPU adds
217 approximately eight kilobytes to the kernel image.
219 config SCHED_SMT
220 bool "SMT (Hyperthreading) scheduler support"
221 depends on SMP
222 default off
223 help
224 SMT scheduler support improves the CPU scheduler's decision making
225 when dealing with Intel Pentium 4 chips with HyperThreading at a
226 cost of slightly increased overhead in some places. If unsure say
227 N here.
229 source "kernel/Kconfig.preempt"
231 config X86_UP_APIC
232 bool "Local APIC support on uniprocessors"
233 depends on !SMP && !(X86_VISWS || X86_VOYAGER)
234 help
235 A local APIC (Advanced Programmable Interrupt Controller) is an
236 integrated interrupt controller in the CPU. If you have a single-CPU
237 system which has a processor with a local APIC, you can say Y here to
238 enable and use it. If you say Y here even though your machine doesn't
239 have a local APIC, then the kernel will still run with no slowdown at
240 all. The local APIC supports CPU-generated self-interrupts (timer,
241 performance counters), and the NMI watchdog which detects hard
242 lockups.
244 config X86_UP_IOAPIC
245 bool "IO-APIC support on uniprocessors"
246 depends on X86_UP_APIC
247 help
248 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
249 SMP-capable replacement for PC-style interrupt controllers. Most
250 SMP systems and many recent uniprocessor systems have one.
252 If you have a single-CPU system with an IO-APIC, you can say Y here
253 to use it. If you say Y here even though your machine doesn't have
254 an IO-APIC, then the kernel will still run with no slowdown at all.
256 config X86_LOCAL_APIC
257 bool
258 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER)
259 default y
261 config X86_IO_APIC
262 bool
263 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER))
264 default y
266 config X86_VISWS_APIC
267 bool
268 depends on X86_VISWS
269 default y
271 config X86_MCE
272 bool "Machine Check Exception"
273 depends on !X86_VOYAGER
274 ---help---
275 Machine Check Exception support allows the processor to notify the
276 kernel if it detects a problem (e.g. overheating, component failure).
277 The action the kernel takes depends on the severity of the problem,
278 ranging from a warning message on the console, to halting the machine.
279 Your processor must be a Pentium or newer to support this - check the
280 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
281 have a design flaw which leads to false MCE events - hence MCE is
282 disabled on all P5 processors, unless explicitly enabled with "mce"
283 as a boot argument. Similarly, if MCE is built in and creates a
284 problem on some new non-standard machine, you can boot with "nomce"
285 to disable it. MCE support simply ignores non-MCE processors like
286 the 386 and 486, so nearly everyone can say Y here.
288 config X86_MCE_NONFATAL
289 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
290 depends on X86_MCE
291 help
292 Enabling this feature starts a timer that triggers every 5 seconds which
293 will look at the machine check registers to see if anything happened.
294 Non-fatal problems automatically get corrected (but still logged).
295 Disable this if you don't want to see these messages.
296 Seeing the messages this option prints out may be indicative of dying hardware,
297 or out-of-spec (ie, overclocked) hardware.
298 This option only does something on certain CPUs.
299 (AMD Athlon/Duron and Intel Pentium 4)
301 config X86_MCE_P4THERMAL
302 bool "check for P4 thermal throttling interrupt."
303 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
304 help
305 Enabling this feature will cause a message to be printed when the P4
306 enters thermal throttling.
308 config TOSHIBA
309 tristate "Toshiba Laptop support"
310 ---help---
311 This adds a driver to safely access the System Management Mode of
312 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
313 not work on models with a Phoenix BIOS. The System Management Mode
314 is used to set the BIOS and power saving options on Toshiba portables.
316 For information on utilities to make use of this driver see the
317 Toshiba Linux utilities web site at:
318 <http://www.buzzard.org.uk/toshiba/>.
320 Say Y if you intend to run this kernel on a Toshiba portable.
321 Say N otherwise.
323 config I8K
324 tristate "Dell laptop support"
325 ---help---
326 This adds a driver to safely access the System Management Mode
327 of the CPU on the Dell Inspiron 8000. The System Management Mode
328 is used to read cpu temperature and cooling fan status and to
329 control the fans on the I8K portables.
331 This driver has been tested only on the Inspiron 8000 but it may
332 also work with other Dell laptops. You can force loading on other
333 models by passing the parameter `force=1' to the module. Use at
334 your own risk.
336 For information on utilities to make use of this driver see the
337 I8K Linux utilities web site at:
338 <http://people.debian.org/~dz/i8k/>
340 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
341 Say N otherwise.
343 config X86_REBOOTFIXUPS
344 bool "Enable X86 board specific fixups for reboot"
345 depends on X86
346 default n
347 ---help---
348 This enables chipset and/or board specific fixups to be done
349 in order to get reboot to work correctly. This is only needed on
350 some combinations of hardware and BIOS. The symptom, for which
351 this config is intended, is when reboot ends with a stalled/hung
352 system.
354 Currently, the only fixup is for the Geode GX1/CS5530A/TROM2.1.
355 combination.
357 Say Y if you want to enable the fixup. Currently, it's safe to
358 enable this option even if you don't need it.
359 Say N otherwise.
361 config MICROCODE
362 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
363 ---help---
364 If you say Y here and also to "/dev file system support" in the
365 'File systems' section, you will be able to update the microcode on
366 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
367 Pentium III, Pentium 4, Xeon etc. You will obviously need the
368 actual microcode binary data itself which is not shipped with the
369 Linux kernel.
371 For latest news and information on obtaining all the required
372 ingredients for this driver, check:
373 <http://www.urbanmyth.org/microcode/>.
375 To compile this driver as a module, choose M here: the
376 module will be called microcode.
378 config X86_MSR
379 tristate "/dev/cpu/*/msr - Model-specific register support"
380 help
381 This device gives privileged processes access to the x86
382 Model-Specific Registers (MSRs). It is a character device with
383 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
384 MSR accesses are directed to a specific CPU on multi-processor
385 systems.
387 config X86_CPUID
388 tristate "/dev/cpu/*/cpuid - CPU information support"
389 help
390 This device gives processes access to the x86 CPUID instruction to
391 be executed on a specific processor. It is a character device
392 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
393 /dev/cpu/31/cpuid.
395 source "drivers/firmware/Kconfig"
397 choice
398 prompt "High Memory Support"
399 default NOHIGHMEM
401 config NOHIGHMEM
402 bool "off"
403 ---help---
404 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
405 However, the address space of 32-bit x86 processors is only 4
406 Gigabytes large. That means that, if you have a large amount of
407 physical memory, not all of it can be "permanently mapped" by the
408 kernel. The physical memory that's not permanently mapped is called
409 "high memory".
411 If you are compiling a kernel which will never run on a machine with
412 more than 1 Gigabyte total physical RAM, answer "off" here (default
413 choice and suitable for most users). This will result in a "3GB/1GB"
414 split: 3GB are mapped so that each process sees a 3GB virtual memory
415 space and the remaining part of the 4GB virtual memory space is used
416 by the kernel to permanently map as much physical memory as
417 possible.
419 If the machine has between 1 and 4 Gigabytes physical RAM, then
420 answer "4GB" here.
422 If more than 4 Gigabytes is used then answer "64GB" here. This
423 selection turns Intel PAE (Physical Address Extension) mode on.
424 PAE implements 3-level paging on IA32 processors. PAE is fully
425 supported by Linux, PAE mode is implemented on all recent Intel
426 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
427 then the kernel will not boot on CPUs that don't support PAE!
429 The actual amount of total physical memory will either be
430 auto detected or can be forced by using a kernel command line option
431 such as "mem=256M". (Try "man bootparam" or see the documentation of
432 your boot loader (lilo or loadlin) about how to pass options to the
433 kernel at boot time.)
435 If unsure, say "off".
437 config HIGHMEM4G
438 bool "4GB"
439 help
440 Select this if you have a 32-bit processor and between 1 and 4
441 gigabytes of physical RAM.
443 config HIGHMEM64G
444 bool "64GB"
445 depends on X86_CMPXCHG64
446 help
447 Select this if you have a 32-bit processor and more than 4
448 gigabytes of physical RAM.
450 endchoice
452 choice
453 depends on EXPERIMENTAL && !X86_PAE
454 prompt "Memory split"
455 default VMSPLIT_3G
456 help
457 Select the desired split between kernel and user memory.
459 If the address range available to the kernel is less than the
460 physical memory installed, the remaining memory will be available
461 as "high memory". Accessing high memory is a little more costly
462 than low memory, as it needs to be mapped into the kernel first.
463 Note that increasing the kernel address space limits the range
464 available to user programs, making the address space there
465 tighter. Selecting anything other than the default 3G/1G split
466 will also likely make your kernel incompatible with binary-only
467 kernel modules.
469 If you are not absolutely sure what you are doing, leave this
470 option alone!
472 config VMSPLIT_3G
473 bool "3G/1G user/kernel split"
474 config VMSPLIT_3G_OPT
475 bool "3G/1G user/kernel split (for full 1G low memory)"
476 config VMSPLIT_2G
477 bool "2G/2G user/kernel split"
478 config VMSPLIT_1G
479 bool "1G/3G user/kernel split"
480 endchoice
482 config PAGE_OFFSET
483 hex
484 default 0xB0000000 if VMSPLIT_3G_OPT
485 default 0x78000000 if VMSPLIT_2G
486 default 0x40000000 if VMSPLIT_1G
487 default 0xC0000000
489 config HIGHMEM
490 bool
491 depends on HIGHMEM64G || HIGHMEM4G
492 default y
494 config X86_PAE
495 bool
496 depends on HIGHMEM64G
497 default y
499 # Common NUMA Features
500 config NUMA
501 bool "Numa Memory Allocation and Scheduler Support"
502 depends on SMP && HIGHMEM64G && (X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI))
503 default n if X86_PC
504 default y if (X86_NUMAQ || X86_SUMMIT)
506 # Need comments to help the hapless user trying to turn on NUMA support
507 comment "NUMA (NUMA-Q) requires SMP, 64GB highmem support"
508 depends on X86_NUMAQ && (!HIGHMEM64G || !SMP)
510 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
511 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
513 config HAVE_ARCH_BOOTMEM_NODE
514 bool
515 depends on NUMA
516 default y
518 config ARCH_HAVE_MEMORY_PRESENT
519 bool
520 depends on DISCONTIGMEM
521 default y
523 config NEED_NODE_MEMMAP_SIZE
524 bool
525 depends on DISCONTIGMEM || SPARSEMEM
526 default y
528 config HAVE_ARCH_ALLOC_REMAP
529 bool
530 depends on NUMA
531 default y
533 config ARCH_FLATMEM_ENABLE
534 def_bool y
535 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
537 config ARCH_DISCONTIGMEM_ENABLE
538 def_bool y
539 depends on NUMA
541 config ARCH_DISCONTIGMEM_DEFAULT
542 def_bool y
543 depends on NUMA
545 config ARCH_SPARSEMEM_ENABLE
546 def_bool y
547 depends on (NUMA || (X86_PC && EXPERIMENTAL))
548 select SPARSEMEM_STATIC
550 config ARCH_SELECT_MEMORY_MODEL
551 def_bool y
552 depends on ARCH_SPARSEMEM_ENABLE
554 source "mm/Kconfig"
556 config HAVE_ARCH_EARLY_PFN_TO_NID
557 bool
558 default y
559 depends on NUMA
561 config HIGHPTE
562 bool "Allocate 3rd-level pagetables from highmem"
563 depends on HIGHMEM4G || HIGHMEM64G
564 help
565 The VM uses one page table entry for each page of physical memory.
566 For systems with a lot of RAM, this can be wasteful of precious
567 low memory. Setting this option will put user-space page table
568 entries in high memory.
570 config MATH_EMULATION
571 bool "Math emulation"
572 ---help---
573 Linux can emulate a math coprocessor (used for floating point
574 operations) if you don't have one. 486DX and Pentium processors have
575 a math coprocessor built in, 486SX and 386 do not, unless you added
576 a 487DX or 387, respectively. (The messages during boot time can
577 give you some hints here ["man dmesg"].) Everyone needs either a
578 coprocessor or this emulation.
580 If you don't have a math coprocessor, you need to say Y here; if you
581 say Y here even though you have a coprocessor, the coprocessor will
582 be used nevertheless. (This behavior can be changed with the kernel
583 command line option "no387", which comes handy if your coprocessor
584 is broken. Try "man bootparam" or see the documentation of your boot
585 loader (lilo or loadlin) about how to pass options to the kernel at
586 boot time.) This means that it is a good idea to say Y here if you
587 intend to use this kernel on different machines.
589 More information about the internals of the Linux math coprocessor
590 emulation can be found in <file:arch/i386/math-emu/README>.
592 If you are not sure, say Y; apart from resulting in a 66 KB bigger
593 kernel, it won't hurt.
595 config MTRR
596 bool "MTRR (Memory Type Range Register) support"
597 ---help---
598 On Intel P6 family processors (Pentium Pro, Pentium II and later)
599 the Memory Type Range Registers (MTRRs) may be used to control
600 processor access to memory ranges. This is most useful if you have
601 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
602 allows bus write transfers to be combined into a larger transfer
603 before bursting over the PCI/AGP bus. This can increase performance
604 of image write operations 2.5 times or more. Saying Y here creates a
605 /proc/mtrr file which may be used to manipulate your processor's
606 MTRRs. Typically the X server should use this.
608 This code has a reasonably generic interface so that similar
609 control registers on other processors can be easily supported
610 as well:
612 The Cyrix 6x86, 6x86MX and M II processors have Address Range
613 Registers (ARRs) which provide a similar functionality to MTRRs. For
614 these, the ARRs are used to emulate the MTRRs.
615 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
616 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
617 write-combining. All of these processors are supported by this code
618 and it makes sense to say Y here if you have one of them.
620 Saying Y here also fixes a problem with buggy SMP BIOSes which only
621 set the MTRRs for the boot CPU and not for the secondary CPUs. This
622 can lead to all sorts of problems, so it's good to say Y here.
624 You can safely say Y even if your machine doesn't have MTRRs, you'll
625 just add about 9 KB to your kernel.
627 See <file:Documentation/mtrr.txt> for more information.
629 config EFI
630 bool "Boot from EFI support (EXPERIMENTAL)"
631 depends on ACPI
632 default n
633 ---help---
634 This enables the the kernel to boot on EFI platforms using
635 system configuration information passed to it from the firmware.
636 This also enables the kernel to use any EFI runtime services that are
637 available (such as the EFI variable services).
639 This option is only useful on systems that have EFI firmware
640 and will result in a kernel image that is ~8k larger. In addition,
641 you must use the latest ELILO loader available at
642 <http://elilo.sourceforge.net> in order to take advantage of
643 kernel initialization using EFI information (neither GRUB nor LILO know
644 anything about EFI). However, even with this option, the resultant
645 kernel should continue to boot on existing non-EFI platforms.
647 config IRQBALANCE
648 bool "Enable kernel irq balancing"
649 depends on SMP && X86_IO_APIC
650 default y
651 help
652 The default yes will allow the kernel to do irq load balancing.
653 Saying no will keep the kernel from doing irq load balancing.
655 # turning this on wastes a bunch of space.
656 # Summit needs it only when NUMA is on
657 config BOOT_IOREMAP
658 bool
659 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
660 default y
662 config REGPARM
663 bool "Use register arguments (EXPERIMENTAL)"
664 depends on EXPERIMENTAL
665 default n
666 help
667 Compile the kernel with -mregparm=3. This uses a different ABI
668 and passes the first three arguments of a function call in registers.
669 This will probably break binary only modules.
671 config SECCOMP
672 bool "Enable seccomp to safely compute untrusted bytecode"
673 depends on PROC_FS
674 default y
675 help
676 This kernel feature is useful for number crunching applications
677 that may need to compute untrusted bytecode during their
678 execution. By using pipes or other transports made available to
679 the process as file descriptors supporting the read/write
680 syscalls, it's possible to isolate those applications in
681 their own address space using seccomp. Once seccomp is
682 enabled via /proc/<pid>/seccomp, it cannot be disabled
683 and the task is only allowed to execute a few safe syscalls
684 defined by each seccomp mode.
686 If unsure, say Y. Only embedded should say N here.
688 source kernel/Kconfig.hz
690 config KEXEC
691 bool "kexec system call (EXPERIMENTAL)"
692 depends on EXPERIMENTAL
693 help
694 kexec is a system call that implements the ability to shutdown your
695 current kernel, and to start another kernel. It is like a reboot
696 but it is indepedent of the system firmware. And like a reboot
697 you can start any kernel with it, not just Linux.
699 The name comes from the similiarity to the exec system call.
701 It is an ongoing process to be certain the hardware in a machine
702 is properly shutdown, so do not be surprised if this code does not
703 initially work for you. It may help to enable device hotplugging
704 support. As of this writing the exact hardware interface is
705 strongly in flux, so no good recommendation can be made.
707 config CRASH_DUMP
708 bool "kernel crash dumps (EXPERIMENTAL)"
709 depends on EXPERIMENTAL
710 depends on HIGHMEM
711 help
712 Generate crash dump after being started by kexec.
714 config PHYSICAL_START
715 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
717 default "0x1000000" if CRASH_DUMP
718 default "0x100000"
719 help
720 This gives the physical address where the kernel is loaded. Normally
721 for regular kernels this value is 0x100000 (1MB). But in the case
722 of kexec on panic the fail safe kernel needs to run at a different
723 address than the panic-ed kernel. This option is used to set the load
724 address for kernels used to capture crash dump on being kexec'ed
725 after panic. The default value for crash dump kernels is
726 0x1000000 (16MB). This can also be set based on the "X" value as
727 specified in the "crashkernel=YM@XM" command line boot parameter
728 passed to the panic-ed kernel. Typically this parameter is set as
729 crashkernel=64M@16M. Please take a look at
730 Documentation/kdump/kdump.txt for more details about crash dumps.
732 Don't change this unless you know what you are doing.
734 config HOTPLUG_CPU
735 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
736 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
737 ---help---
738 Say Y here to experiment with turning CPUs off and on. CPUs
739 can be controlled through /sys/devices/system/cpu.
741 Say N.
743 config DOUBLEFAULT
744 default y
745 bool "Enable doublefault exception handler" if EMBEDDED
746 help
747 This option allows trapping of rare doublefault exceptions that
748 would otherwise cause a system to silently reboot. Disabling this
749 option saves about 4k and might cause you much additional grey
750 hair.
752 endmenu
754 config ARCH_ENABLE_MEMORY_HOTPLUG
755 def_bool y
756 depends on HIGHMEM
758 menu "Power management options (ACPI, APM)"
759 depends on !X86_VOYAGER
761 source kernel/power/Kconfig
763 source "drivers/acpi/Kconfig"
765 menu "APM (Advanced Power Management) BIOS Support"
766 depends on PM && !X86_VISWS
768 config APM
769 tristate "APM (Advanced Power Management) BIOS support"
770 depends on PM
771 ---help---
772 APM is a BIOS specification for saving power using several different
773 techniques. This is mostly useful for battery powered laptops with
774 APM compliant BIOSes. If you say Y here, the system time will be
775 reset after a RESUME operation, the /proc/apm device will provide
776 battery status information, and user-space programs will receive
777 notification of APM "events" (e.g. battery status change).
779 If you select "Y" here, you can disable actual use of the APM
780 BIOS by passing the "apm=off" option to the kernel at boot time.
782 Note that the APM support is almost completely disabled for
783 machines with more than one CPU.
785 In order to use APM, you will need supporting software. For location
786 and more information, read <file:Documentation/pm.txt> and the
787 Battery Powered Linux mini-HOWTO, available from
788 <http://www.tldp.org/docs.html#howto>.
790 This driver does not spin down disk drives (see the hdparm(8)
791 manpage ("man 8 hdparm") for that), and it doesn't turn off
792 VESA-compliant "green" monitors.
794 This driver does not support the TI 4000M TravelMate and the ACER
795 486/DX4/75 because they don't have compliant BIOSes. Many "green"
796 desktop machines also don't have compliant BIOSes, and this driver
797 may cause those machines to panic during the boot phase.
799 Generally, if you don't have a battery in your machine, there isn't
800 much point in using this driver and you should say N. If you get
801 random kernel OOPSes or reboots that don't seem to be related to
802 anything, try disabling/enabling this option (or disabling/enabling
803 APM in your BIOS).
805 Some other things you should try when experiencing seemingly random,
806 "weird" problems:
808 1) make sure that you have enough swap space and that it is
809 enabled.
810 2) pass the "no-hlt" option to the kernel
811 3) switch on floating point emulation in the kernel and pass
812 the "no387" option to the kernel
813 4) pass the "floppy=nodma" option to the kernel
814 5) pass the "mem=4M" option to the kernel (thereby disabling
815 all but the first 4 MB of RAM)
816 6) make sure that the CPU is not over clocked.
817 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
818 8) disable the cache from your BIOS settings
819 9) install a fan for the video card or exchange video RAM
820 10) install a better fan for the CPU
821 11) exchange RAM chips
822 12) exchange the motherboard.
824 To compile this driver as a module, choose M here: the
825 module will be called apm.
827 config APM_IGNORE_USER_SUSPEND
828 bool "Ignore USER SUSPEND"
829 depends on APM
830 help
831 This option will ignore USER SUSPEND requests. On machines with a
832 compliant APM BIOS, you want to say N. However, on the NEC Versa M
833 series notebooks, it is necessary to say Y because of a BIOS bug.
835 config APM_DO_ENABLE
836 bool "Enable PM at boot time"
837 depends on APM
838 ---help---
839 Enable APM features at boot time. From page 36 of the APM BIOS
840 specification: "When disabled, the APM BIOS does not automatically
841 power manage devices, enter the Standby State, enter the Suspend
842 State, or take power saving steps in response to CPU Idle calls."
843 This driver will make CPU Idle calls when Linux is idle (unless this
844 feature is turned off -- see "Do CPU IDLE calls", below). This
845 should always save battery power, but more complicated APM features
846 will be dependent on your BIOS implementation. You may need to turn
847 this option off if your computer hangs at boot time when using APM
848 support, or if it beeps continuously instead of suspending. Turn
849 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
850 T400CDT. This is off by default since most machines do fine without
851 this feature.
853 config APM_CPU_IDLE
854 bool "Make CPU Idle calls when idle"
855 depends on APM
856 help
857 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
858 On some machines, this can activate improved power savings, such as
859 a slowed CPU clock rate, when the machine is idle. These idle calls
860 are made after the idle loop has run for some length of time (e.g.,
861 333 mS). On some machines, this will cause a hang at boot time or
862 whenever the CPU becomes idle. (On machines with more than one CPU,
863 this option does nothing.)
865 config APM_DISPLAY_BLANK
866 bool "Enable console blanking using APM"
867 depends on APM
868 help
869 Enable console blanking using the APM. Some laptops can use this to
870 turn off the LCD backlight when the screen blanker of the Linux
871 virtual console blanks the screen. Note that this is only used by
872 the virtual console screen blanker, and won't turn off the backlight
873 when using the X Window system. This also doesn't have anything to
874 do with your VESA-compliant power-saving monitor. Further, this
875 option doesn't work for all laptops -- it might not turn off your
876 backlight at all, or it might print a lot of errors to the console,
877 especially if you are using gpm.
879 config APM_RTC_IS_GMT
880 bool "RTC stores time in GMT"
881 depends on APM
882 help
883 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
884 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
885 stores localtime.
887 It is in fact recommended to store GMT in your RTC, because then you
888 don't have to worry about daylight savings time changes. The only
889 reason not to use GMT in your RTC is if you also run a broken OS
890 that doesn't understand GMT.
892 config APM_ALLOW_INTS
893 bool "Allow interrupts during APM BIOS calls"
894 depends on APM
895 help
896 Normally we disable external interrupts while we are making calls to
897 the APM BIOS as a measure to lessen the effects of a badly behaving
898 BIOS implementation. The BIOS should reenable interrupts if it
899 needs to. Unfortunately, some BIOSes do not -- especially those in
900 many of the newer IBM Thinkpads. If you experience hangs when you
901 suspend, try setting this to Y. Otherwise, say N.
903 config APM_REAL_MODE_POWER_OFF
904 bool "Use real mode APM BIOS call to power off"
905 depends on APM
906 help
907 Use real mode APM BIOS calls to switch off the computer. This is
908 a work-around for a number of buggy BIOSes. Switch this option on if
909 your computer crashes instead of powering off properly.
911 endmenu
913 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
915 endmenu
917 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
919 config PCI
920 bool "PCI support" if !X86_VISWS
921 depends on !X86_VOYAGER
922 default y if X86_VISWS
923 help
924 Find out whether you have a PCI motherboard. PCI is the name of a
925 bus system, i.e. the way the CPU talks to the other stuff inside
926 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
927 VESA. If you have PCI, say Y, otherwise N.
929 The PCI-HOWTO, available from
930 <http://www.tldp.org/docs.html#howto>, contains valuable
931 information about which PCI hardware does work under Linux and which
932 doesn't.
934 choice
935 prompt "PCI access mode"
936 depends on PCI && !X86_VISWS
937 default PCI_GOANY
938 ---help---
939 On PCI systems, the BIOS can be used to detect the PCI devices and
940 determine their configuration. However, some old PCI motherboards
941 have BIOS bugs and may crash if this is done. Also, some embedded
942 PCI-based systems don't have any BIOS at all. Linux can also try to
943 detect the PCI hardware directly without using the BIOS.
945 With this option, you can specify how Linux should detect the
946 PCI devices. If you choose "BIOS", the BIOS will be used,
947 if you choose "Direct", the BIOS won't be used, and if you
948 choose "MMConfig", then PCI Express MMCONFIG will be used.
949 If you choose "Any", the kernel will try MMCONFIG, then the
950 direct access method and falls back to the BIOS if that doesn't
951 work. If unsure, go with the default, which is "Any".
953 config PCI_GOBIOS
954 bool "BIOS"
956 config PCI_GOMMCONFIG
957 bool "MMConfig"
959 config PCI_GODIRECT
960 bool "Direct"
962 config PCI_GOANY
963 bool "Any"
965 endchoice
967 config PCI_BIOS
968 bool
969 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
970 default y
972 config PCI_DIRECT
973 bool
974 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
975 default y
977 config PCI_MMCONFIG
978 bool
979 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
980 default y
982 source "drivers/pci/pcie/Kconfig"
984 source "drivers/pci/Kconfig"
986 config ISA_DMA_API
987 bool
988 default y
990 config ISA
991 bool "ISA support"
992 depends on !(X86_VOYAGER || X86_VISWS)
993 help
994 Find out whether you have ISA slots on your motherboard. ISA is the
995 name of a bus system, i.e. the way the CPU talks to the other stuff
996 inside your box. Other bus systems are PCI, EISA, MicroChannel
997 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
998 newer boards don't support it. If you have ISA, say Y, otherwise N.
1000 config EISA
1001 bool "EISA support"
1002 depends on ISA
1003 ---help---
1004 The Extended Industry Standard Architecture (EISA) bus was
1005 developed as an open alternative to the IBM MicroChannel bus.
1007 The EISA bus provided some of the features of the IBM MicroChannel
1008 bus while maintaining backward compatibility with cards made for
1009 the older ISA bus. The EISA bus saw limited use between 1988 and
1010 1995 when it was made obsolete by the PCI bus.
1012 Say Y here if you are building a kernel for an EISA-based machine.
1014 Otherwise, say N.
1016 source "drivers/eisa/Kconfig"
1018 config MCA
1019 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1020 default y if X86_VOYAGER
1021 help
1022 MicroChannel Architecture is found in some IBM PS/2 machines and
1023 laptops. It is a bus system similar to PCI or ISA. See
1024 <file:Documentation/mca.txt> (and especially the web page given
1025 there) before attempting to build an MCA bus kernel.
1027 source "drivers/mca/Kconfig"
1029 config SCx200
1030 tristate "NatSemi SCx200 support"
1031 depends on !X86_VOYAGER
1032 help
1033 This provides basic support for the National Semiconductor SCx200
1034 processor. Right now this is just a driver for the GPIO pins.
1036 If you don't know what to do here, say N.
1038 This support is also available as a module. If compiled as a
1039 module, it will be called scx200.
1041 source "drivers/pcmcia/Kconfig"
1043 source "drivers/pci/hotplug/Kconfig"
1045 endmenu
1047 menu "Executable file formats"
1049 source "fs/Kconfig.binfmt"
1051 endmenu
1053 source "net/Kconfig"
1055 source "drivers/Kconfig"
1057 source "fs/Kconfig"
1059 menu "Instrumentation Support"
1060 depends on EXPERIMENTAL
1062 source "arch/i386/oprofile/Kconfig"
1064 config KPROBES
1065 bool "Kprobes (EXPERIMENTAL)"
1066 depends on EXPERIMENTAL && MODULES
1067 help
1068 Kprobes allows you to trap at almost any kernel address and
1069 execute a callback function. register_kprobe() establishes
1070 a probepoint and specifies the callback. Kprobes is useful
1071 for kernel debugging, non-intrusive instrumentation and testing.
1072 If in doubt, say "N".
1073 endmenu
1075 source "arch/i386/Kconfig.debug"
1077 source "security/Kconfig"
1079 source "crypto/Kconfig"
1081 source "lib/Kconfig"
1083 #
1084 # Use the generic interrupt handling code in kernel/irq/:
1085 #
1086 config GENERIC_HARDIRQS
1087 bool
1088 default y
1090 config GENERIC_IRQ_PROBE
1091 bool
1092 default y
1094 config GENERIC_PENDING_IRQ
1095 bool
1096 depends on GENERIC_HARDIRQS && SMP
1097 default y
1099 config X86_SMP
1100 bool
1101 depends on SMP && !X86_VOYAGER
1102 default y
1104 config X86_HT
1105 bool
1106 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1107 default y
1109 config X86_BIOS_REBOOT
1110 bool
1111 depends on !(X86_VISWS || X86_VOYAGER)
1112 default y
1114 config X86_TRAMPOLINE
1115 bool
1116 depends on X86_SMP || (X86_VOYAGER && SMP)
1117 default y
1119 config KTIME_SCALAR
1120 bool
1121 default y