| blob | 3bb221db164a65c0425fdb5b01e299e331ccd99a |
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 GENERIC_TIME
18 bool
19 default y
21 config SEMAPHORE_SLEEPERS
22 bool
23 default y
25 config X86
26 bool
27 default y
29 config MMU
30 bool
31 default y
33 config SBUS
34 bool
36 config GENERIC_ISA_DMA
37 bool
38 default y
40 config GENERIC_IOMAP
41 bool
42 default y
44 config GENERIC_HWEIGHT
45 bool
46 default y
48 config ARCH_MAY_HAVE_PC_FDC
49 bool
50 default y
52 config DMI
53 bool
54 default y
56 source "init/Kconfig"
58 menu "Processor type and features"
60 config SMP
61 bool "Symmetric multi-processing support"
62 ---help---
63 This enables support for systems with more than one CPU. If you have
64 a system with only one CPU, like most personal computers, say N. If
65 you have a system with more than one CPU, say Y.
67 If you say N here, the kernel will run on single and multiprocessor
68 machines, but will use only one CPU of a multiprocessor machine. If
69 you say Y here, the kernel will run on many, but not all,
70 singleprocessor machines. On a singleprocessor machine, the kernel
71 will run faster if you say N here.
73 Note that if you say Y here and choose architecture "586" or
74 "Pentium" under "Processor family", the kernel will not work on 486
75 architectures. Similarly, multiprocessor kernels for the "PPro"
76 architecture may not work on all Pentium based boards.
78 People using multiprocessor machines who say Y here should also say
79 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
80 Management" code will be disabled if you say Y here.
82 See also the <file:Documentation/smp.txt>,
83 <file:Documentation/i386/IO-APIC.txt>,
84 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
85 <http://www.tldp.org/docs.html#howto>.
87 If you don't know what to do here, say N.
89 choice
90 prompt "Subarchitecture Type"
91 default X86_PC
93 config X86_PC
94 bool "PC-compatible"
95 help
96 Choose this option if your computer is a standard PC or compatible.
98 config X86_ELAN
99 bool "AMD Elan"
100 help
101 Select this for an AMD Elan processor.
103 Do not use this option for K6/Athlon/Opteron processors!
105 If unsure, choose "PC-compatible" instead.
107 config X86_VOYAGER
108 bool "Voyager (NCR)"
109 help
110 Voyager is an MCA-based 32-way capable SMP architecture proprietary
111 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
113 *** WARNING ***
115 If you do not specifically know you have a Voyager based machine,
116 say N here, otherwise the kernel you build will not be bootable.
118 config X86_NUMAQ
119 bool "NUMAQ (IBM/Sequent)"
120 select SMP
121 select NUMA
122 help
123 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
124 multiquad box. This changes the way that processors are bootstrapped,
125 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
126 You will need a new lynxer.elf file to flash your firmware with - send
127 email to <Martin.Bligh@us.ibm.com>.
129 config X86_SUMMIT
130 bool "Summit/EXA (IBM x440)"
131 depends on SMP
132 help
133 This option is needed for IBM systems that use the Summit/EXA chipset.
134 In particular, it is needed for the x440.
136 If you don't have one of these computers, you should say N here.
138 config X86_BIGSMP
139 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
140 depends on SMP
141 help
142 This option is needed for the systems that have more than 8 CPUs
143 and if the system is not of any sub-arch type above.
145 If you don't have such a system, you should say N here.
147 config X86_VISWS
148 bool "SGI 320/540 (Visual Workstation)"
149 help
150 The SGI Visual Workstation series is an IA32-based workstation
151 based on SGI systems chips with some legacy PC hardware attached.
153 Say Y here to create a kernel to run on the SGI 320 or 540.
155 A kernel compiled for the Visual Workstation will not run on PCs
156 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
158 config X86_GENERICARCH
159 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
160 depends on SMP
161 help
162 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
163 It is intended for a generic binary kernel.
165 config X86_ES7000
166 bool "Support for Unisys ES7000 IA32 series"
167 depends on SMP
168 help
169 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
170 supposed to run on an IA32-based Unisys ES7000 system.
171 Only choose this option if you have such a system, otherwise you
172 should say N here.
174 endchoice
176 config ACPI_SRAT
177 bool
178 default y
179 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
180 select ACPI_NUMA
182 config HAVE_ARCH_PARSE_SRAT
183 bool
184 default y
185 depends on ACPI_SRAT
187 config X86_SUMMIT_NUMA
188 bool
189 default y
190 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
192 config X86_CYCLONE_TIMER
193 bool
194 default y
195 depends on X86_SUMMIT || X86_GENERICARCH
197 config ES7000_CLUSTERED_APIC
198 bool
199 default y
200 depends on SMP && X86_ES7000 && MPENTIUMIII
202 source "arch/i386/Kconfig.cpu"
204 config HPET_TIMER
205 bool "HPET Timer Support"
206 help
207 This enables the use of the HPET for the kernel's internal timer.
208 HPET is the next generation timer replacing legacy 8254s.
209 You can safely choose Y here. However, HPET will only be
210 activated if the platform and the BIOS support this feature.
211 Otherwise the 8254 will be used for timing services.
213 Choose N to continue using the legacy 8254 timer.
215 config HPET_EMULATE_RTC
216 bool
217 depends on HPET_TIMER && RTC=y
218 default y
220 config NR_CPUS
221 int "Maximum number of CPUs (2-255)"
222 range 2 255
223 depends on SMP
224 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
225 default "8"
226 help
227 This allows you to specify the maximum number of CPUs which this
228 kernel will support. The maximum supported value is 255 and the
229 minimum value which makes sense is 2.
231 This is purely to save memory - each supported CPU adds
232 approximately eight kilobytes to the kernel image.
234 config SCHED_SMT
235 bool "SMT (Hyperthreading) scheduler support"
236 depends on X86_HT
237 help
238 SMT scheduler support improves the CPU scheduler's decision making
239 when dealing with Intel Pentium 4 chips with HyperThreading at a
240 cost of slightly increased overhead in some places. If unsure say
241 N here.
243 config SCHED_MC
244 bool "Multi-core scheduler support"
245 depends on X86_HT
246 default y
247 help
248 Multi-core scheduler support improves the CPU scheduler's decision
249 making when dealing with multi-core CPU chips at a cost of slightly
250 increased overhead in some places. If unsure say N here.
252 source "kernel/Kconfig.preempt"
254 config X86_UP_APIC
255 bool "Local APIC support on uniprocessors"
256 depends on !SMP && !(X86_VISWS || X86_VOYAGER)
257 help
258 A local APIC (Advanced Programmable Interrupt Controller) is an
259 integrated interrupt controller in the CPU. If you have a single-CPU
260 system which has a processor with a local APIC, you can say Y here to
261 enable and use it. If you say Y here even though your machine doesn't
262 have a local APIC, then the kernel will still run with no slowdown at
263 all. The local APIC supports CPU-generated self-interrupts (timer,
264 performance counters), and the NMI watchdog which detects hard
265 lockups.
267 config X86_UP_IOAPIC
268 bool "IO-APIC support on uniprocessors"
269 depends on X86_UP_APIC
270 help
271 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
272 SMP-capable replacement for PC-style interrupt controllers. Most
273 SMP systems and many recent uniprocessor systems have one.
275 If you have a single-CPU system with an IO-APIC, you can say Y here
276 to use it. If you say Y here even though your machine doesn't have
277 an IO-APIC, then the kernel will still run with no slowdown at all.
279 config X86_LOCAL_APIC
280 bool
281 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER)
282 default y
284 config X86_IO_APIC
285 bool
286 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER))
287 default y
289 config X86_VISWS_APIC
290 bool
291 depends on X86_VISWS
292 default y
294 config X86_MCE
295 bool "Machine Check Exception"
296 depends on !X86_VOYAGER
297 ---help---
298 Machine Check Exception support allows the processor to notify the
299 kernel if it detects a problem (e.g. overheating, component failure).
300 The action the kernel takes depends on the severity of the problem,
301 ranging from a warning message on the console, to halting the machine.
302 Your processor must be a Pentium or newer to support this - check the
303 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
304 have a design flaw which leads to false MCE events - hence MCE is
305 disabled on all P5 processors, unless explicitly enabled with "mce"
306 as a boot argument. Similarly, if MCE is built in and creates a
307 problem on some new non-standard machine, you can boot with "nomce"
308 to disable it. MCE support simply ignores non-MCE processors like
309 the 386 and 486, so nearly everyone can say Y here.
311 config X86_MCE_NONFATAL
312 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
313 depends on X86_MCE
314 help
315 Enabling this feature starts a timer that triggers every 5 seconds which
316 will look at the machine check registers to see if anything happened.
317 Non-fatal problems automatically get corrected (but still logged).
318 Disable this if you don't want to see these messages.
319 Seeing the messages this option prints out may be indicative of dying hardware,
320 or out-of-spec (ie, overclocked) hardware.
321 This option only does something on certain CPUs.
322 (AMD Athlon/Duron and Intel Pentium 4)
324 config X86_MCE_P4THERMAL
325 bool "check for P4 thermal throttling interrupt."
326 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
327 help
328 Enabling this feature will cause a message to be printed when the P4
329 enters thermal throttling.
331 config VM86
332 default y
333 bool "Enable VM86 support" if EMBEDDED
334 help
335 This option is required by programs like DOSEMU to run 16-bit legacy
336 code on X86 processors. It also may be needed by software like
337 XFree86 to initialize some video cards via BIOS. Disabling this
338 option saves about 6k.
340 config TOSHIBA
341 tristate "Toshiba Laptop support"
342 ---help---
343 This adds a driver to safely access the System Management Mode of
344 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
345 not work on models with a Phoenix BIOS. The System Management Mode
346 is used to set the BIOS and power saving options on Toshiba portables.
348 For information on utilities to make use of this driver see the
349 Toshiba Linux utilities web site at:
350 <http://www.buzzard.org.uk/toshiba/>.
352 Say Y if you intend to run this kernel on a Toshiba portable.
353 Say N otherwise.
355 config I8K
356 tristate "Dell laptop support"
357 ---help---
358 This adds a driver to safely access the System Management Mode
359 of the CPU on the Dell Inspiron 8000. The System Management Mode
360 is used to read cpu temperature and cooling fan status and to
361 control the fans on the I8K portables.
363 This driver has been tested only on the Inspiron 8000 but it may
364 also work with other Dell laptops. You can force loading on other
365 models by passing the parameter `force=1' to the module. Use at
366 your own risk.
368 For information on utilities to make use of this driver see the
369 I8K Linux utilities web site at:
370 <http://people.debian.org/~dz/i8k/>
372 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
373 Say N otherwise.
375 config X86_REBOOTFIXUPS
376 bool "Enable X86 board specific fixups for reboot"
377 depends on X86
378 default n
379 ---help---
380 This enables chipset and/or board specific fixups to be done
381 in order to get reboot to work correctly. This is only needed on
382 some combinations of hardware and BIOS. The symptom, for which
383 this config is intended, is when reboot ends with a stalled/hung
384 system.
386 Currently, the only fixup is for the Geode GX1/CS5530A/TROM2.1.
387 combination.
389 Say Y if you want to enable the fixup. Currently, it's safe to
390 enable this option even if you don't need it.
391 Say N otherwise.
393 config MICROCODE
394 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
395 ---help---
396 If you say Y here and also to "/dev file system support" in the
397 'File systems' section, you will be able to update the microcode on
398 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
399 Pentium III, Pentium 4, Xeon etc. You will obviously need the
400 actual microcode binary data itself which is not shipped with the
401 Linux kernel.
403 For latest news and information on obtaining all the required
404 ingredients for this driver, check:
405 <http://www.urbanmyth.org/microcode/>.
407 To compile this driver as a module, choose M here: the
408 module will be called microcode.
410 config X86_MSR
411 tristate "/dev/cpu/*/msr - Model-specific register support"
412 help
413 This device gives privileged processes access to the x86
414 Model-Specific Registers (MSRs). It is a character device with
415 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
416 MSR accesses are directed to a specific CPU on multi-processor
417 systems.
419 config X86_CPUID
420 tristate "/dev/cpu/*/cpuid - CPU information support"
421 help
422 This device gives processes access to the x86 CPUID instruction to
423 be executed on a specific processor. It is a character device
424 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
425 /dev/cpu/31/cpuid.
427 source "drivers/firmware/Kconfig"
429 choice
430 prompt "High Memory Support"
431 default NOHIGHMEM
433 config NOHIGHMEM
434 bool "off"
435 depends on !X86_NUMAQ
436 ---help---
437 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
438 However, the address space of 32-bit x86 processors is only 4
439 Gigabytes large. That means that, if you have a large amount of
440 physical memory, not all of it can be "permanently mapped" by the
441 kernel. The physical memory that's not permanently mapped is called
442 "high memory".
444 If you are compiling a kernel which will never run on a machine with
445 more than 1 Gigabyte total physical RAM, answer "off" here (default
446 choice and suitable for most users). This will result in a "3GB/1GB"
447 split: 3GB are mapped so that each process sees a 3GB virtual memory
448 space and the remaining part of the 4GB virtual memory space is used
449 by the kernel to permanently map as much physical memory as
450 possible.
452 If the machine has between 1 and 4 Gigabytes physical RAM, then
453 answer "4GB" here.
455 If more than 4 Gigabytes is used then answer "64GB" here. This
456 selection turns Intel PAE (Physical Address Extension) mode on.
457 PAE implements 3-level paging on IA32 processors. PAE is fully
458 supported by Linux, PAE mode is implemented on all recent Intel
459 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
460 then the kernel will not boot on CPUs that don't support PAE!
462 The actual amount of total physical memory will either be
463 auto detected or can be forced by using a kernel command line option
464 such as "mem=256M". (Try "man bootparam" or see the documentation of
465 your boot loader (lilo or loadlin) about how to pass options to the
466 kernel at boot time.)
468 If unsure, say "off".
470 config HIGHMEM4G
471 bool "4GB"
472 depends on !X86_NUMAQ
473 help
474 Select this if you have a 32-bit processor and between 1 and 4
475 gigabytes of physical RAM.
477 config HIGHMEM64G
478 bool "64GB"
479 depends on X86_CMPXCHG64
480 help
481 Select this if you have a 32-bit processor and more than 4
482 gigabytes of physical RAM.
484 endchoice
486 choice
487 depends on EXPERIMENTAL && !X86_PAE
488 prompt "Memory split" if EMBEDDED
489 default VMSPLIT_3G
490 help
491 Select the desired split between kernel and user memory.
493 If the address range available to the kernel is less than the
494 physical memory installed, the remaining memory will be available
495 as "high memory". Accessing high memory is a little more costly
496 than low memory, as it needs to be mapped into the kernel first.
497 Note that increasing the kernel address space limits the range
498 available to user programs, making the address space there
499 tighter. Selecting anything other than the default 3G/1G split
500 will also likely make your kernel incompatible with binary-only
501 kernel modules.
503 If you are not absolutely sure what you are doing, leave this
504 option alone!
506 config VMSPLIT_3G
507 bool "3G/1G user/kernel split"
508 config VMSPLIT_3G_OPT
509 bool "3G/1G user/kernel split (for full 1G low memory)"
510 config VMSPLIT_2G
511 bool "2G/2G user/kernel split"
512 config VMSPLIT_1G
513 bool "1G/3G user/kernel split"
514 endchoice
516 config PAGE_OFFSET
517 hex
518 default 0xB0000000 if VMSPLIT_3G_OPT
519 default 0x78000000 if VMSPLIT_2G
520 default 0x40000000 if VMSPLIT_1G
521 default 0xC0000000
523 config HIGHMEM
524 bool
525 depends on HIGHMEM64G || HIGHMEM4G
526 default y
528 config X86_PAE
529 bool
530 depends on HIGHMEM64G
531 default y
533 # Common NUMA Features
534 config NUMA
535 bool "Numa Memory Allocation and Scheduler Support"
536 depends on SMP && HIGHMEM64G && (X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI))
537 default n if X86_PC
538 default y if (X86_NUMAQ || X86_SUMMIT)
540 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
541 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
543 config NODES_SHIFT
544 int
545 default "4" if X86_NUMAQ
546 default "3"
547 depends on NEED_MULTIPLE_NODES
549 config HAVE_ARCH_BOOTMEM_NODE
550 bool
551 depends on NUMA
552 default y
554 config ARCH_HAVE_MEMORY_PRESENT
555 bool
556 depends on DISCONTIGMEM
557 default y
559 config NEED_NODE_MEMMAP_SIZE
560 bool
561 depends on DISCONTIGMEM || SPARSEMEM
562 default y
564 config HAVE_ARCH_ALLOC_REMAP
565 bool
566 depends on NUMA
567 default y
569 config ARCH_FLATMEM_ENABLE
570 def_bool y
571 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
573 config ARCH_DISCONTIGMEM_ENABLE
574 def_bool y
575 depends on NUMA
577 config ARCH_DISCONTIGMEM_DEFAULT
578 def_bool y
579 depends on NUMA
581 config ARCH_SPARSEMEM_ENABLE
582 def_bool y
583 depends on (NUMA || (X86_PC && EXPERIMENTAL))
584 select SPARSEMEM_STATIC
586 config ARCH_SELECT_MEMORY_MODEL
587 def_bool y
588 depends on ARCH_SPARSEMEM_ENABLE
590 source "mm/Kconfig"
592 config HAVE_ARCH_EARLY_PFN_TO_NID
593 bool
594 default y
595 depends on NUMA
597 config HIGHPTE
598 bool "Allocate 3rd-level pagetables from highmem"
599 depends on HIGHMEM4G || HIGHMEM64G
600 help
601 The VM uses one page table entry for each page of physical memory.
602 For systems with a lot of RAM, this can be wasteful of precious
603 low memory. Setting this option will put user-space page table
604 entries in high memory.
606 config MATH_EMULATION
607 bool "Math emulation"
608 ---help---
609 Linux can emulate a math coprocessor (used for floating point
610 operations) if you don't have one. 486DX and Pentium processors have
611 a math coprocessor built in, 486SX and 386 do not, unless you added
612 a 487DX or 387, respectively. (The messages during boot time can
613 give you some hints here ["man dmesg"].) Everyone needs either a
614 coprocessor or this emulation.
616 If you don't have a math coprocessor, you need to say Y here; if you
617 say Y here even though you have a coprocessor, the coprocessor will
618 be used nevertheless. (This behavior can be changed with the kernel
619 command line option "no387", which comes handy if your coprocessor
620 is broken. Try "man bootparam" or see the documentation of your boot
621 loader (lilo or loadlin) about how to pass options to the kernel at
622 boot time.) This means that it is a good idea to say Y here if you
623 intend to use this kernel on different machines.
625 More information about the internals of the Linux math coprocessor
626 emulation can be found in <file:arch/i386/math-emu/README>.
628 If you are not sure, say Y; apart from resulting in a 66 KB bigger
629 kernel, it won't hurt.
631 config MTRR
632 bool "MTRR (Memory Type Range Register) support"
633 ---help---
634 On Intel P6 family processors (Pentium Pro, Pentium II and later)
635 the Memory Type Range Registers (MTRRs) may be used to control
636 processor access to memory ranges. This is most useful if you have
637 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
638 allows bus write transfers to be combined into a larger transfer
639 before bursting over the PCI/AGP bus. This can increase performance
640 of image write operations 2.5 times or more. Saying Y here creates a
641 /proc/mtrr file which may be used to manipulate your processor's
642 MTRRs. Typically the X server should use this.
644 This code has a reasonably generic interface so that similar
645 control registers on other processors can be easily supported
646 as well:
648 The Cyrix 6x86, 6x86MX and M II processors have Address Range
649 Registers (ARRs) which provide a similar functionality to MTRRs. For
650 these, the ARRs are used to emulate the MTRRs.
651 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
652 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
653 write-combining. All of these processors are supported by this code
654 and it makes sense to say Y here if you have one of them.
656 Saying Y here also fixes a problem with buggy SMP BIOSes which only
657 set the MTRRs for the boot CPU and not for the secondary CPUs. This
658 can lead to all sorts of problems, so it's good to say Y here.
660 You can safely say Y even if your machine doesn't have MTRRs, you'll
661 just add about 9 KB to your kernel.
663 See <file:Documentation/mtrr.txt> for more information.
665 config EFI
666 bool "Boot from EFI support (EXPERIMENTAL)"
667 depends on ACPI
668 default n
669 ---help---
670 This enables the the kernel to boot on EFI platforms using
671 system configuration information passed to it from the firmware.
672 This also enables the kernel to use any EFI runtime services that are
673 available (such as the EFI variable services).
675 This option is only useful on systems that have EFI firmware
676 and will result in a kernel image that is ~8k larger. In addition,
677 you must use the latest ELILO loader available at
678 <http://elilo.sourceforge.net> in order to take advantage of
679 kernel initialization using EFI information (neither GRUB nor LILO know
680 anything about EFI). However, even with this option, the resultant
681 kernel should continue to boot on existing non-EFI platforms.
683 config IRQBALANCE
684 bool "Enable kernel irq balancing"
685 depends on SMP && X86_IO_APIC
686 default y
687 help
688 The default yes will allow the kernel to do irq load balancing.
689 Saying no will keep the kernel from doing irq load balancing.
691 # turning this on wastes a bunch of space.
692 # Summit needs it only when NUMA is on
693 config BOOT_IOREMAP
694 bool
695 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
696 default y
698 config REGPARM
699 bool "Use register arguments"
700 default y
701 help
702 Compile the kernel with -mregparm=3. This instructs gcc to use
703 a more efficient function call ABI which passes the first three
704 arguments of a function call via registers, which results in denser
705 and faster code.
707 If this option is disabled, then the default ABI of passing
708 arguments via the stack is used.
710 If unsure, say Y.
712 config SECCOMP
713 bool "Enable seccomp to safely compute untrusted bytecode"
714 depends on PROC_FS
715 default y
716 help
717 This kernel feature is useful for number crunching applications
718 that may need to compute untrusted bytecode during their
719 execution. By using pipes or other transports made available to
720 the process as file descriptors supporting the read/write
721 syscalls, it's possible to isolate those applications in
722 their own address space using seccomp. Once seccomp is
723 enabled via /proc/<pid>/seccomp, it cannot be disabled
724 and the task is only allowed to execute a few safe syscalls
725 defined by each seccomp mode.
727 If unsure, say Y. Only embedded should say N here.
729 source kernel/Kconfig.hz
731 config KEXEC
732 bool "kexec system call (EXPERIMENTAL)"
733 depends on EXPERIMENTAL
734 help
735 kexec is a system call that implements the ability to shutdown your
736 current kernel, and to start another kernel. It is like a reboot
737 but it is independent of the system firmware. And like a reboot
738 you can start any kernel with it, not just Linux.
740 The name comes from the similiarity to the exec system call.
742 It is an ongoing process to be certain the hardware in a machine
743 is properly shutdown, so do not be surprised if this code does not
744 initially work for you. It may help to enable device hotplugging
745 support. As of this writing the exact hardware interface is
746 strongly in flux, so no good recommendation can be made.
748 config CRASH_DUMP
749 bool "kernel crash dumps (EXPERIMENTAL)"
750 depends on EXPERIMENTAL
751 depends on HIGHMEM
752 help
753 Generate crash dump after being started by kexec.
755 config PHYSICAL_START
756 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
758 default "0x1000000" if CRASH_DUMP
759 default "0x100000"
760 help
761 This gives the physical address where the kernel is loaded. Normally
762 for regular kernels this value is 0x100000 (1MB). But in the case
763 of kexec on panic the fail safe kernel needs to run at a different
764 address than the panic-ed kernel. This option is used to set the load
765 address for kernels used to capture crash dump on being kexec'ed
766 after panic. The default value for crash dump kernels is
767 0x1000000 (16MB). This can also be set based on the "X" value as
768 specified in the "crashkernel=YM@XM" command line boot parameter
769 passed to the panic-ed kernel. Typically this parameter is set as
770 crashkernel=64M@16M. Please take a look at
771 Documentation/kdump/kdump.txt for more details about crash dumps.
773 Don't change this unless you know what you are doing.
775 config HOTPLUG_CPU
776 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
777 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
778 ---help---
779 Say Y here to experiment with turning CPUs off and on, and to
780 enable suspend on SMP systems. CPUs can be controlled through
781 /sys/devices/system/cpu.
783 config COMPAT_VDSO
784 bool "Compat VDSO support"
785 default y
786 help
787 Map the VDSO to the predictable old-style address too.
788 ---help---
789 Say N here if you are running a sufficiently recent glibc
790 version (2.3.3 or later), to remove the high-mapped
791 VDSO mapping and to exclusively use the randomized VDSO.
793 If unsure, say Y.
795 endmenu
798 menu "Power management options (ACPI, APM)"
799 depends on !X86_VOYAGER
801 source kernel/power/Kconfig
803 source "drivers/acpi/Kconfig"
805 menu "APM (Advanced Power Management) BIOS Support"
806 depends on PM && !X86_VISWS
808 config APM
809 tristate "APM (Advanced Power Management) BIOS support"
810 depends on PM
811 ---help---
812 APM is a BIOS specification for saving power using several different
813 techniques. This is mostly useful for battery powered laptops with
814 APM compliant BIOSes. If you say Y here, the system time will be
815 reset after a RESUME operation, the /proc/apm device will provide
816 battery status information, and user-space programs will receive
817 notification of APM "events" (e.g. battery status change).
819 If you select "Y" here, you can disable actual use of the APM
820 BIOS by passing the "apm=off" option to the kernel at boot time.
822 Note that the APM support is almost completely disabled for
823 machines with more than one CPU.
825 In order to use APM, you will need supporting software. For location
826 and more information, read <file:Documentation/pm.txt> and the
827 Battery Powered Linux mini-HOWTO, available from
828 <http://www.tldp.org/docs.html#howto>.
830 This driver does not spin down disk drives (see the hdparm(8)
831 manpage ("man 8 hdparm") for that), and it doesn't turn off
832 VESA-compliant "green" monitors.
834 This driver does not support the TI 4000M TravelMate and the ACER
835 486/DX4/75 because they don't have compliant BIOSes. Many "green"
836 desktop machines also don't have compliant BIOSes, and this driver
837 may cause those machines to panic during the boot phase.
839 Generally, if you don't have a battery in your machine, there isn't
840 much point in using this driver and you should say N. If you get
841 random kernel OOPSes or reboots that don't seem to be related to
842 anything, try disabling/enabling this option (or disabling/enabling
843 APM in your BIOS).
845 Some other things you should try when experiencing seemingly random,
846 "weird" problems:
848 1) make sure that you have enough swap space and that it is
849 enabled.
850 2) pass the "no-hlt" option to the kernel
851 3) switch on floating point emulation in the kernel and pass
852 the "no387" option to the kernel
853 4) pass the "floppy=nodma" option to the kernel
854 5) pass the "mem=4M" option to the kernel (thereby disabling
855 all but the first 4 MB of RAM)
856 6) make sure that the CPU is not over clocked.
857 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
858 8) disable the cache from your BIOS settings
859 9) install a fan for the video card or exchange video RAM
860 10) install a better fan for the CPU
861 11) exchange RAM chips
862 12) exchange the motherboard.
864 To compile this driver as a module, choose M here: the
865 module will be called apm.
867 config APM_IGNORE_USER_SUSPEND
868 bool "Ignore USER SUSPEND"
869 depends on APM
870 help
871 This option will ignore USER SUSPEND requests. On machines with a
872 compliant APM BIOS, you want to say N. However, on the NEC Versa M
873 series notebooks, it is necessary to say Y because of a BIOS bug.
875 config APM_DO_ENABLE
876 bool "Enable PM at boot time"
877 depends on APM
878 ---help---
879 Enable APM features at boot time. From page 36 of the APM BIOS
880 specification: "When disabled, the APM BIOS does not automatically
881 power manage devices, enter the Standby State, enter the Suspend
882 State, or take power saving steps in response to CPU Idle calls."
883 This driver will make CPU Idle calls when Linux is idle (unless this
884 feature is turned off -- see "Do CPU IDLE calls", below). This
885 should always save battery power, but more complicated APM features
886 will be dependent on your BIOS implementation. You may need to turn
887 this option off if your computer hangs at boot time when using APM
888 support, or if it beeps continuously instead of suspending. Turn
889 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
890 T400CDT. This is off by default since most machines do fine without
891 this feature.
893 config APM_CPU_IDLE
894 bool "Make CPU Idle calls when idle"
895 depends on APM
896 help
897 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
898 On some machines, this can activate improved power savings, such as
899 a slowed CPU clock rate, when the machine is idle. These idle calls
900 are made after the idle loop has run for some length of time (e.g.,
901 333 mS). On some machines, this will cause a hang at boot time or
902 whenever the CPU becomes idle. (On machines with more than one CPU,
903 this option does nothing.)
905 config APM_DISPLAY_BLANK
906 bool "Enable console blanking using APM"
907 depends on APM
908 help
909 Enable console blanking using the APM. Some laptops can use this to
910 turn off the LCD backlight when the screen blanker of the Linux
911 virtual console blanks the screen. Note that this is only used by
912 the virtual console screen blanker, and won't turn off the backlight
913 when using the X Window system. This also doesn't have anything to
914 do with your VESA-compliant power-saving monitor. Further, this
915 option doesn't work for all laptops -- it might not turn off your
916 backlight at all, or it might print a lot of errors to the console,
917 especially if you are using gpm.
919 config APM_RTC_IS_GMT
920 bool "RTC stores time in GMT"
921 depends on APM
922 help
923 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
924 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
925 stores localtime.
927 It is in fact recommended to store GMT in your RTC, because then you
928 don't have to worry about daylight savings time changes. The only
929 reason not to use GMT in your RTC is if you also run a broken OS
930 that doesn't understand GMT.
932 config APM_ALLOW_INTS
933 bool "Allow interrupts during APM BIOS calls"
934 depends on APM
935 help
936 Normally we disable external interrupts while we are making calls to
937 the APM BIOS as a measure to lessen the effects of a badly behaving
938 BIOS implementation. The BIOS should reenable interrupts if it
939 needs to. Unfortunately, some BIOSes do not -- especially those in
940 many of the newer IBM Thinkpads. If you experience hangs when you
941 suspend, try setting this to Y. Otherwise, say N.
943 config APM_REAL_MODE_POWER_OFF
944 bool "Use real mode APM BIOS call to power off"
945 depends on APM
946 help
947 Use real mode APM BIOS calls to switch off the computer. This is
948 a work-around for a number of buggy BIOSes. Switch this option on if
949 your computer crashes instead of powering off properly.
951 endmenu
953 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
955 endmenu
957 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
959 config PCI
960 bool "PCI support" if !X86_VISWS
961 depends on !X86_VOYAGER
962 default y if X86_VISWS
963 help
964 Find out whether you have a PCI motherboard. PCI is the name of a
965 bus system, i.e. the way the CPU talks to the other stuff inside
966 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
967 VESA. If you have PCI, say Y, otherwise N.
969 The PCI-HOWTO, available from
970 <http://www.tldp.org/docs.html#howto>, contains valuable
971 information about which PCI hardware does work under Linux and which
972 doesn't.
974 choice
975 prompt "PCI access mode"
976 depends on PCI && !X86_VISWS
977 default PCI_GOANY
978 ---help---
979 On PCI systems, the BIOS can be used to detect the PCI devices and
980 determine their configuration. However, some old PCI motherboards
981 have BIOS bugs and may crash if this is done. Also, some embedded
982 PCI-based systems don't have any BIOS at all. Linux can also try to
983 detect the PCI hardware directly without using the BIOS.
985 With this option, you can specify how Linux should detect the
986 PCI devices. If you choose "BIOS", the BIOS will be used,
987 if you choose "Direct", the BIOS won't be used, and if you
988 choose "MMConfig", then PCI Express MMCONFIG will be used.
989 If you choose "Any", the kernel will try MMCONFIG, then the
990 direct access method and falls back to the BIOS if that doesn't
991 work. If unsure, go with the default, which is "Any".
993 config PCI_GOBIOS
994 bool "BIOS"
996 config PCI_GOMMCONFIG
997 bool "MMConfig"
999 config PCI_GODIRECT
1000 bool "Direct"
1002 config PCI_GOANY
1003 bool "Any"
1005 endchoice
1007 config PCI_BIOS
1008 bool
1009 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1010 default y
1012 config PCI_DIRECT
1013 bool
1014 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1015 default y
1017 config PCI_MMCONFIG
1018 bool
1019 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1020 default y
1022 source "drivers/pci/pcie/Kconfig"
1024 source "drivers/pci/Kconfig"
1026 config ISA_DMA_API
1027 bool
1028 default y
1030 config ISA
1031 bool "ISA support"
1032 depends on !(X86_VOYAGER || X86_VISWS)
1033 help
1034 Find out whether you have ISA slots on your motherboard. ISA is the
1035 name of a bus system, i.e. the way the CPU talks to the other stuff
1036 inside your box. Other bus systems are PCI, EISA, MicroChannel
1037 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1038 newer boards don't support it. If you have ISA, say Y, otherwise N.
1040 config EISA
1041 bool "EISA support"
1042 depends on ISA
1043 ---help---
1044 The Extended Industry Standard Architecture (EISA) bus was
1045 developed as an open alternative to the IBM MicroChannel bus.
1047 The EISA bus provided some of the features of the IBM MicroChannel
1048 bus while maintaining backward compatibility with cards made for
1049 the older ISA bus. The EISA bus saw limited use between 1988 and
1050 1995 when it was made obsolete by the PCI bus.
1052 Say Y here if you are building a kernel for an EISA-based machine.
1054 Otherwise, say N.
1056 source "drivers/eisa/Kconfig"
1058 config MCA
1059 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1060 default y if X86_VOYAGER
1061 help
1062 MicroChannel Architecture is found in some IBM PS/2 machines and
1063 laptops. It is a bus system similar to PCI or ISA. See
1064 <file:Documentation/mca.txt> (and especially the web page given
1065 there) before attempting to build an MCA bus kernel.
1067 source "drivers/mca/Kconfig"
1069 config SCx200
1070 tristate "NatSemi SCx200 support"
1071 depends on !X86_VOYAGER
1072 help
1073 This provides basic support for National Semiconductor's
1074 (now AMD's) Geode processors. The driver probes for the
1075 PCI-IDs of several on-chip devices, so its a good dependency
1076 for other scx200_* drivers.
1078 If compiled as a module, the driver is named scx200.
1080 config SCx200HR_TIMER
1081 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1082 depends on SCx200 && GENERIC_TIME
1083 default y
1084 help
1085 This driver provides a clocksource built upon the on-chip
1086 27MHz high-resolution timer. Its also a workaround for
1087 NSC Geode SC-1100's buggy TSC, which loses time when the
1088 processor goes idle (as is done by the scheduler). The
1089 other workaround is idle=poll boot option.
1091 config K8_NB
1092 def_bool y
1093 depends on AGP_AMD64
1095 source "drivers/pcmcia/Kconfig"
1097 source "drivers/pci/hotplug/Kconfig"
1099 endmenu
1101 menu "Executable file formats"
1103 source "fs/Kconfig.binfmt"
1105 endmenu
1107 source "net/Kconfig"
1109 source "drivers/Kconfig"
1111 source "fs/Kconfig"
1113 menu "Instrumentation Support"
1114 depends on EXPERIMENTAL
1116 source "arch/i386/oprofile/Kconfig"
1118 config KPROBES
1119 bool "Kprobes (EXPERIMENTAL)"
1120 depends on EXPERIMENTAL && MODULES
1121 help
1122 Kprobes allows you to trap at almost any kernel address and
1123 execute a callback function. register_kprobe() establishes
1124 a probepoint and specifies the callback. Kprobes is useful
1125 for kernel debugging, non-intrusive instrumentation and testing.
1126 If in doubt, say "N".
1127 endmenu
1129 source "arch/i386/Kconfig.debug"
1131 source "security/Kconfig"
1133 source "crypto/Kconfig"
1135 source "lib/Kconfig"
1137 #
1138 # Use the generic interrupt handling code in kernel/irq/:
1139 #
1140 config GENERIC_HARDIRQS
1141 bool
1142 default y
1144 config GENERIC_IRQ_PROBE
1145 bool
1146 default y
1148 config GENERIC_PENDING_IRQ
1149 bool
1150 depends on GENERIC_HARDIRQS && SMP
1151 default y
1153 config X86_SMP
1154 bool
1155 depends on SMP && !X86_VOYAGER
1156 default y
1158 config X86_HT
1159 bool
1160 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1161 default y
1163 config X86_BIOS_REBOOT
1164 bool
1165 depends on !(X86_VISWS || X86_VOYAGER)
1166 default y
1168 config X86_TRAMPOLINE
1169 bool
1170 depends on X86_SMP || (X86_VOYAGER && SMP)
1171 default y
1173 config KTIME_SCALAR
1174 bool
1175 default y