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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 help
446 Select this if you have a 32-bit processor and more than 4
447 gigabytes of physical RAM.
449 endchoice
451 choice
452 depends on EXPERIMENTAL && !X86_PAE
453 prompt "Memory split"
454 default VMSPLIT_3G
455 help
456 Select the desired split between kernel and user memory.
458 If the address range available to the kernel is less than the
459 physical memory installed, the remaining memory will be available
460 as "high memory". Accessing high memory is a little more costly
461 than low memory, as it needs to be mapped into the kernel first.
462 Note that increasing the kernel address space limits the range
463 available to user programs, making the address space there
464 tighter. Selecting anything other than the default 3G/1G split
465 will also likely make your kernel incompatible with binary-only
466 kernel modules.
468 If you are not absolutely sure what you are doing, leave this
469 option alone!
471 config VMSPLIT_3G
472 bool "3G/1G user/kernel split"
473 config VMSPLIT_3G_OPT
474 bool "3G/1G user/kernel split (for full 1G low memory)"
475 config VMSPLIT_2G
476 bool "2G/2G user/kernel split"
477 config VMSPLIT_1G
478 bool "1G/3G user/kernel split"
479 endchoice
481 config PAGE_OFFSET
482 hex
483 default 0xB0000000 if VMSPLIT_3G_OPT
484 default 0x78000000 if VMSPLIT_2G
485 default 0x40000000 if VMSPLIT_1G
486 default 0xC0000000
488 config HIGHMEM
489 bool
490 depends on HIGHMEM64G || HIGHMEM4G
491 default y
493 config X86_PAE
494 bool
495 depends on HIGHMEM64G
496 default y
498 # Common NUMA Features
499 config NUMA
500 bool "Numa Memory Allocation and Scheduler Support"
501 depends on SMP && HIGHMEM64G && (X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI))
502 default n if X86_PC
503 default y if (X86_NUMAQ || X86_SUMMIT)
505 # Need comments to help the hapless user trying to turn on NUMA support
506 comment "NUMA (NUMA-Q) requires SMP, 64GB highmem support"
507 depends on X86_NUMAQ && (!HIGHMEM64G || !SMP)
509 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
510 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
512 config HAVE_ARCH_BOOTMEM_NODE
513 bool
514 depends on NUMA
515 default y
517 config ARCH_HAVE_MEMORY_PRESENT
518 bool
519 depends on DISCONTIGMEM
520 default y
522 config NEED_NODE_MEMMAP_SIZE
523 bool
524 depends on DISCONTIGMEM || SPARSEMEM
525 default y
527 config HAVE_ARCH_ALLOC_REMAP
528 bool
529 depends on NUMA
530 default y
532 config ARCH_FLATMEM_ENABLE
533 def_bool y
534 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
536 config ARCH_DISCONTIGMEM_ENABLE
537 def_bool y
538 depends on NUMA
540 config ARCH_DISCONTIGMEM_DEFAULT
541 def_bool y
542 depends on NUMA
544 config ARCH_SPARSEMEM_ENABLE
545 def_bool y
546 depends on (NUMA || (X86_PC && EXPERIMENTAL))
547 select SPARSEMEM_STATIC
549 config ARCH_SELECT_MEMORY_MODEL
550 def_bool y
551 depends on ARCH_SPARSEMEM_ENABLE
553 source "mm/Kconfig"
555 config HAVE_ARCH_EARLY_PFN_TO_NID
556 bool
557 default y
558 depends on NUMA
560 config HIGHPTE
561 bool "Allocate 3rd-level pagetables from highmem"
562 depends on HIGHMEM4G || HIGHMEM64G
563 help
564 The VM uses one page table entry for each page of physical memory.
565 For systems with a lot of RAM, this can be wasteful of precious
566 low memory. Setting this option will put user-space page table
567 entries in high memory.
569 config MATH_EMULATION
570 bool "Math emulation"
571 ---help---
572 Linux can emulate a math coprocessor (used for floating point
573 operations) if you don't have one. 486DX and Pentium processors have
574 a math coprocessor built in, 486SX and 386 do not, unless you added
575 a 487DX or 387, respectively. (The messages during boot time can
576 give you some hints here ["man dmesg"].) Everyone needs either a
577 coprocessor or this emulation.
579 If you don't have a math coprocessor, you need to say Y here; if you
580 say Y here even though you have a coprocessor, the coprocessor will
581 be used nevertheless. (This behavior can be changed with the kernel
582 command line option "no387", which comes handy if your coprocessor
583 is broken. Try "man bootparam" or see the documentation of your boot
584 loader (lilo or loadlin) about how to pass options to the kernel at
585 boot time.) This means that it is a good idea to say Y here if you
586 intend to use this kernel on different machines.
588 More information about the internals of the Linux math coprocessor
589 emulation can be found in <file:arch/i386/math-emu/README>.
591 If you are not sure, say Y; apart from resulting in a 66 KB bigger
592 kernel, it won't hurt.
594 config MTRR
595 bool "MTRR (Memory Type Range Register) support"
596 ---help---
597 On Intel P6 family processors (Pentium Pro, Pentium II and later)
598 the Memory Type Range Registers (MTRRs) may be used to control
599 processor access to memory ranges. This is most useful if you have
600 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
601 allows bus write transfers to be combined into a larger transfer
602 before bursting over the PCI/AGP bus. This can increase performance
603 of image write operations 2.5 times or more. Saying Y here creates a
604 /proc/mtrr file which may be used to manipulate your processor's
605 MTRRs. Typically the X server should use this.
607 This code has a reasonably generic interface so that similar
608 control registers on other processors can be easily supported
609 as well:
611 The Cyrix 6x86, 6x86MX and M II processors have Address Range
612 Registers (ARRs) which provide a similar functionality to MTRRs. For
613 these, the ARRs are used to emulate the MTRRs.
614 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
615 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
616 write-combining. All of these processors are supported by this code
617 and it makes sense to say Y here if you have one of them.
619 Saying Y here also fixes a problem with buggy SMP BIOSes which only
620 set the MTRRs for the boot CPU and not for the secondary CPUs. This
621 can lead to all sorts of problems, so it's good to say Y here.
623 You can safely say Y even if your machine doesn't have MTRRs, you'll
624 just add about 9 KB to your kernel.
626 See <file:Documentation/mtrr.txt> for more information.
628 config EFI
629 bool "Boot from EFI support (EXPERIMENTAL)"
630 depends on ACPI
631 default n
632 ---help---
633 This enables the the kernel to boot on EFI platforms using
634 system configuration information passed to it from the firmware.
635 This also enables the kernel to use any EFI runtime services that are
636 available (such as the EFI variable services).
638 This option is only useful on systems that have EFI firmware
639 and will result in a kernel image that is ~8k larger. In addition,
640 you must use the latest ELILO loader available at
641 <http://elilo.sourceforge.net> in order to take advantage of
642 kernel initialization using EFI information (neither GRUB nor LILO know
643 anything about EFI). However, even with this option, the resultant
644 kernel should continue to boot on existing non-EFI platforms.
646 config IRQBALANCE
647 bool "Enable kernel irq balancing"
648 depends on SMP && X86_IO_APIC
649 default y
650 help
651 The default yes will allow the kernel to do irq load balancing.
652 Saying no will keep the kernel from doing irq load balancing.
654 # turning this on wastes a bunch of space.
655 # Summit needs it only when NUMA is on
656 config BOOT_IOREMAP
657 bool
658 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
659 default y
661 config REGPARM
662 bool "Use register arguments (EXPERIMENTAL)"
663 depends on EXPERIMENTAL
664 default n
665 help
666 Compile the kernel with -mregparm=3. This uses a different ABI
667 and passes the first three arguments of a function call in registers.
668 This will probably break binary only modules.
670 config SECCOMP
671 bool "Enable seccomp to safely compute untrusted bytecode"
672 depends on PROC_FS
673 default y
674 help
675 This kernel feature is useful for number crunching applications
676 that may need to compute untrusted bytecode during their
677 execution. By using pipes or other transports made available to
678 the process as file descriptors supporting the read/write
679 syscalls, it's possible to isolate those applications in
680 their own address space using seccomp. Once seccomp is
681 enabled via /proc/<pid>/seccomp, it cannot be disabled
682 and the task is only allowed to execute a few safe syscalls
683 defined by each seccomp mode.
685 If unsure, say Y. Only embedded should say N here.
687 source kernel/Kconfig.hz
689 config KEXEC
690 bool "kexec system call (EXPERIMENTAL)"
691 depends on EXPERIMENTAL
692 help
693 kexec is a system call that implements the ability to shutdown your
694 current kernel, and to start another kernel. It is like a reboot
695 but it is indepedent of the system firmware. And like a reboot
696 you can start any kernel with it, not just Linux.
698 The name comes from the similiarity to the exec system call.
700 It is an ongoing process to be certain the hardware in a machine
701 is properly shutdown, so do not be surprised if this code does not
702 initially work for you. It may help to enable device hotplugging
703 support. As of this writing the exact hardware interface is
704 strongly in flux, so no good recommendation can be made.
706 config CRASH_DUMP
707 bool "kernel crash dumps (EXPERIMENTAL)"
708 depends on EXPERIMENTAL
709 depends on HIGHMEM
710 help
711 Generate crash dump after being started by kexec.
713 config PHYSICAL_START
714 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
716 default "0x1000000" if CRASH_DUMP
717 default "0x100000"
718 help
719 This gives the physical address where the kernel is loaded. Normally
720 for regular kernels this value is 0x100000 (1MB). But in the case
721 of kexec on panic the fail safe kernel needs to run at a different
722 address than the panic-ed kernel. This option is used to set the load
723 address for kernels used to capture crash dump on being kexec'ed
724 after panic. The default value for crash dump kernels is
725 0x1000000 (16MB). This can also be set based on the "X" value as
726 specified in the "crashkernel=YM@XM" command line boot parameter
727 passed to the panic-ed kernel. Typically this parameter is set as
728 crashkernel=64M@16M. Please take a look at
729 Documentation/kdump/kdump.txt for more details about crash dumps.
731 Don't change this unless you know what you are doing.
733 config HOTPLUG_CPU
734 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
735 depends on SMP && HOTPLUG && EXPERIMENTAL
736 ---help---
737 Say Y here to experiment with turning CPUs off and on. CPUs
738 can be controlled through /sys/devices/system/cpu.
740 Say N.
742 config DOUBLEFAULT
743 default y
744 bool "Enable doublefault exception handler" if EMBEDDED
745 help
746 This option allows trapping of rare doublefault exceptions that
747 would otherwise cause a system to silently reboot. Disabling this
748 option saves about 4k and might cause you much additional grey
749 hair.
751 endmenu
754 menu "Power management options (ACPI, APM)"
755 depends on !X86_VOYAGER
757 source kernel/power/Kconfig
759 source "drivers/acpi/Kconfig"
761 menu "APM (Advanced Power Management) BIOS Support"
762 depends on PM && !X86_VISWS
764 config APM
765 tristate "APM (Advanced Power Management) BIOS support"
766 depends on PM
767 ---help---
768 APM is a BIOS specification for saving power using several different
769 techniques. This is mostly useful for battery powered laptops with
770 APM compliant BIOSes. If you say Y here, the system time will be
771 reset after a RESUME operation, the /proc/apm device will provide
772 battery status information, and user-space programs will receive
773 notification of APM "events" (e.g. battery status change).
775 If you select "Y" here, you can disable actual use of the APM
776 BIOS by passing the "apm=off" option to the kernel at boot time.
778 Note that the APM support is almost completely disabled for
779 machines with more than one CPU.
781 In order to use APM, you will need supporting software. For location
782 and more information, read <file:Documentation/pm.txt> and the
783 Battery Powered Linux mini-HOWTO, available from
784 <http://www.tldp.org/docs.html#howto>.
786 This driver does not spin down disk drives (see the hdparm(8)
787 manpage ("man 8 hdparm") for that), and it doesn't turn off
788 VESA-compliant "green" monitors.
790 This driver does not support the TI 4000M TravelMate and the ACER
791 486/DX4/75 because they don't have compliant BIOSes. Many "green"
792 desktop machines also don't have compliant BIOSes, and this driver
793 may cause those machines to panic during the boot phase.
795 Generally, if you don't have a battery in your machine, there isn't
796 much point in using this driver and you should say N. If you get
797 random kernel OOPSes or reboots that don't seem to be related to
798 anything, try disabling/enabling this option (or disabling/enabling
799 APM in your BIOS).
801 Some other things you should try when experiencing seemingly random,
802 "weird" problems:
804 1) make sure that you have enough swap space and that it is
805 enabled.
806 2) pass the "no-hlt" option to the kernel
807 3) switch on floating point emulation in the kernel and pass
808 the "no387" option to the kernel
809 4) pass the "floppy=nodma" option to the kernel
810 5) pass the "mem=4M" option to the kernel (thereby disabling
811 all but the first 4 MB of RAM)
812 6) make sure that the CPU is not over clocked.
813 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
814 8) disable the cache from your BIOS settings
815 9) install a fan for the video card or exchange video RAM
816 10) install a better fan for the CPU
817 11) exchange RAM chips
818 12) exchange the motherboard.
820 To compile this driver as a module, choose M here: the
821 module will be called apm.
823 config APM_IGNORE_USER_SUSPEND
824 bool "Ignore USER SUSPEND"
825 depends on APM
826 help
827 This option will ignore USER SUSPEND requests. On machines with a
828 compliant APM BIOS, you want to say N. However, on the NEC Versa M
829 series notebooks, it is necessary to say Y because of a BIOS bug.
831 config APM_DO_ENABLE
832 bool "Enable PM at boot time"
833 depends on APM
834 ---help---
835 Enable APM features at boot time. From page 36 of the APM BIOS
836 specification: "When disabled, the APM BIOS does not automatically
837 power manage devices, enter the Standby State, enter the Suspend
838 State, or take power saving steps in response to CPU Idle calls."
839 This driver will make CPU Idle calls when Linux is idle (unless this
840 feature is turned off -- see "Do CPU IDLE calls", below). This
841 should always save battery power, but more complicated APM features
842 will be dependent on your BIOS implementation. You may need to turn
843 this option off if your computer hangs at boot time when using APM
844 support, or if it beeps continuously instead of suspending. Turn
845 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
846 T400CDT. This is off by default since most machines do fine without
847 this feature.
849 config APM_CPU_IDLE
850 bool "Make CPU Idle calls when idle"
851 depends on APM
852 help
853 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
854 On some machines, this can activate improved power savings, such as
855 a slowed CPU clock rate, when the machine is idle. These idle calls
856 are made after the idle loop has run for some length of time (e.g.,
857 333 mS). On some machines, this will cause a hang at boot time or
858 whenever the CPU becomes idle. (On machines with more than one CPU,
859 this option does nothing.)
861 config APM_DISPLAY_BLANK
862 bool "Enable console blanking using APM"
863 depends on APM
864 help
865 Enable console blanking using the APM. Some laptops can use this to
866 turn off the LCD backlight when the screen blanker of the Linux
867 virtual console blanks the screen. Note that this is only used by
868 the virtual console screen blanker, and won't turn off the backlight
869 when using the X Window system. This also doesn't have anything to
870 do with your VESA-compliant power-saving monitor. Further, this
871 option doesn't work for all laptops -- it might not turn off your
872 backlight at all, or it might print a lot of errors to the console,
873 especially if you are using gpm.
875 config APM_RTC_IS_GMT
876 bool "RTC stores time in GMT"
877 depends on APM
878 help
879 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
880 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
881 stores localtime.
883 It is in fact recommended to store GMT in your RTC, because then you
884 don't have to worry about daylight savings time changes. The only
885 reason not to use GMT in your RTC is if you also run a broken OS
886 that doesn't understand GMT.
888 config APM_ALLOW_INTS
889 bool "Allow interrupts during APM BIOS calls"
890 depends on APM
891 help
892 Normally we disable external interrupts while we are making calls to
893 the APM BIOS as a measure to lessen the effects of a badly behaving
894 BIOS implementation. The BIOS should reenable interrupts if it
895 needs to. Unfortunately, some BIOSes do not -- especially those in
896 many of the newer IBM Thinkpads. If you experience hangs when you
897 suspend, try setting this to Y. Otherwise, say N.
899 config APM_REAL_MODE_POWER_OFF
900 bool "Use real mode APM BIOS call to power off"
901 depends on APM
902 help
903 Use real mode APM BIOS calls to switch off the computer. This is
904 a work-around for a number of buggy BIOSes. Switch this option on if
905 your computer crashes instead of powering off properly.
907 endmenu
909 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
911 endmenu
913 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
915 config PCI
916 bool "PCI support" if !X86_VISWS
917 depends on !X86_VOYAGER
918 default y if X86_VISWS
919 help
920 Find out whether you have a PCI motherboard. PCI is the name of a
921 bus system, i.e. the way the CPU talks to the other stuff inside
922 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
923 VESA. If you have PCI, say Y, otherwise N.
925 The PCI-HOWTO, available from
926 <http://www.tldp.org/docs.html#howto>, contains valuable
927 information about which PCI hardware does work under Linux and which
928 doesn't.
930 choice
931 prompt "PCI access mode"
932 depends on PCI && !X86_VISWS
933 default PCI_GOANY
934 ---help---
935 On PCI systems, the BIOS can be used to detect the PCI devices and
936 determine their configuration. However, some old PCI motherboards
937 have BIOS bugs and may crash if this is done. Also, some embedded
938 PCI-based systems don't have any BIOS at all. Linux can also try to
939 detect the PCI hardware directly without using the BIOS.
941 With this option, you can specify how Linux should detect the
942 PCI devices. If you choose "BIOS", the BIOS will be used,
943 if you choose "Direct", the BIOS won't be used, and if you
944 choose "MMConfig", then PCI Express MMCONFIG will be used.
945 If you choose "Any", the kernel will try MMCONFIG, then the
946 direct access method and falls back to the BIOS if that doesn't
947 work. If unsure, go with the default, which is "Any".
949 config PCI_GOBIOS
950 bool "BIOS"
952 config PCI_GOMMCONFIG
953 bool "MMConfig"
955 config PCI_GODIRECT
956 bool "Direct"
958 config PCI_GOANY
959 bool "Any"
961 endchoice
963 config PCI_BIOS
964 bool
965 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
966 default y
968 config PCI_DIRECT
969 bool
970 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
971 default y
973 config PCI_MMCONFIG
974 bool
975 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
976 default y
978 source "drivers/pci/pcie/Kconfig"
980 source "drivers/pci/Kconfig"
982 config ISA_DMA_API
983 bool
984 default y
986 config ISA
987 bool "ISA support"
988 depends on !(X86_VOYAGER || X86_VISWS)
989 help
990 Find out whether you have ISA slots on your motherboard. ISA is the
991 name of a bus system, i.e. the way the CPU talks to the other stuff
992 inside your box. Other bus systems are PCI, EISA, MicroChannel
993 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
994 newer boards don't support it. If you have ISA, say Y, otherwise N.
996 config EISA
997 bool "EISA support"
998 depends on ISA
999 ---help---
1000 The Extended Industry Standard Architecture (EISA) bus was
1001 developed as an open alternative to the IBM MicroChannel bus.
1003 The EISA bus provided some of the features of the IBM MicroChannel
1004 bus while maintaining backward compatibility with cards made for
1005 the older ISA bus. The EISA bus saw limited use between 1988 and
1006 1995 when it was made obsolete by the PCI bus.
1008 Say Y here if you are building a kernel for an EISA-based machine.
1010 Otherwise, say N.
1012 source "drivers/eisa/Kconfig"
1014 config MCA
1015 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1016 default y if X86_VOYAGER
1017 help
1018 MicroChannel Architecture is found in some IBM PS/2 machines and
1019 laptops. It is a bus system similar to PCI or ISA. See
1020 <file:Documentation/mca.txt> (and especially the web page given
1021 there) before attempting to build an MCA bus kernel.
1023 source "drivers/mca/Kconfig"
1025 config SCx200
1026 tristate "NatSemi SCx200 support"
1027 depends on !X86_VOYAGER
1028 help
1029 This provides basic support for the National Semiconductor SCx200
1030 processor. Right now this is just a driver for the GPIO pins.
1032 If you don't know what to do here, say N.
1034 This support is also available as a module. If compiled as a
1035 module, it will be called scx200.
1037 source "drivers/pcmcia/Kconfig"
1039 source "drivers/pci/hotplug/Kconfig"
1041 endmenu
1043 menu "Executable file formats"
1045 source "fs/Kconfig.binfmt"
1047 endmenu
1049 source "net/Kconfig"
1051 source "drivers/Kconfig"
1053 source "fs/Kconfig"
1055 menu "Instrumentation Support"
1056 depends on EXPERIMENTAL
1058 source "arch/i386/oprofile/Kconfig"
1060 config KPROBES
1061 bool "Kprobes (EXPERIMENTAL)"
1062 help
1063 Kprobes allows you to trap at almost any kernel address and
1064 execute a callback function. register_kprobe() establishes
1065 a probepoint and specifies the callback. Kprobes is useful
1066 for kernel debugging, non-intrusive instrumentation and testing.
1067 If in doubt, say "N".
1068 endmenu
1070 source "arch/i386/Kconfig.debug"
1072 source "security/Kconfig"
1074 source "crypto/Kconfig"
1076 source "lib/Kconfig"
1078 #
1079 # Use the generic interrupt handling code in kernel/irq/:
1080 #
1081 config GENERIC_HARDIRQS
1082 bool
1083 default y
1085 config GENERIC_IRQ_PROBE
1086 bool
1087 default y
1089 config GENERIC_PENDING_IRQ
1090 bool
1091 depends on GENERIC_HARDIRQS && SMP
1092 default y
1094 config X86_SMP
1095 bool
1096 depends on SMP && !X86_VOYAGER
1097 default y
1099 config X86_HT
1100 bool
1101 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1102 default y
1104 config X86_BIOS_REBOOT
1105 bool
1106 depends on !(X86_VISWS || X86_VOYAGER)
1107 default y
1109 config X86_TRAMPOLINE
1110 bool
1111 depends on X86_SMP || (X86_VOYAGER && SMP)
1112 default y
1114 config KTIME_SCALAR
1115 bool
1116 default y