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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 GENERIC_TIME
18 bool
19 default y
21 config LOCKDEP_SUPPORT
22 bool
23 default y
25 config STACKTRACE_SUPPORT
26 bool
27 default y
29 config SEMAPHORE_SLEEPERS
30 bool
31 default y
33 config X86
34 bool
35 default y
37 config MMU
38 bool
39 default y
41 config SBUS
42 bool
44 config GENERIC_ISA_DMA
45 bool
46 default y
48 config GENERIC_IOMAP
49 bool
50 default y
52 config GENERIC_HWEIGHT
53 bool
54 default y
56 config ARCH_MAY_HAVE_PC_FDC
57 bool
58 default y
60 config DMI
61 bool
62 default y
64 source "init/Kconfig"
66 menu "Processor type and features"
68 config SMP
69 bool "Symmetric multi-processing support"
70 ---help---
71 This enables support for systems with more than one CPU. If you have
72 a system with only one CPU, like most personal computers, say N. If
73 you have a system with more than one CPU, say Y.
75 If you say N here, the kernel will run on single and multiprocessor
76 machines, but will use only one CPU of a multiprocessor machine. If
77 you say Y here, the kernel will run on many, but not all,
78 singleprocessor machines. On a singleprocessor machine, the kernel
79 will run faster if you say N here.
81 Note that if you say Y here and choose architecture "586" or
82 "Pentium" under "Processor family", the kernel will not work on 486
83 architectures. Similarly, multiprocessor kernels for the "PPro"
84 architecture may not work on all Pentium based boards.
86 People using multiprocessor machines who say Y here should also say
87 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
88 Management" code will be disabled if you say Y here.
90 See also the <file:Documentation/smp.txt>,
91 <file:Documentation/i386/IO-APIC.txt>,
92 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
93 <http://www.tldp.org/docs.html#howto>.
95 If you don't know what to do here, say N.
97 choice
98 prompt "Subarchitecture Type"
99 default X86_PC
101 config X86_PC
102 bool "PC-compatible"
103 help
104 Choose this option if your computer is a standard PC or compatible.
106 config X86_ELAN
107 bool "AMD Elan"
108 help
109 Select this for an AMD Elan processor.
111 Do not use this option for K6/Athlon/Opteron processors!
113 If unsure, choose "PC-compatible" instead.
115 config X86_VOYAGER
116 bool "Voyager (NCR)"
117 help
118 Voyager is an MCA-based 32-way capable SMP architecture proprietary
119 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
121 *** WARNING ***
123 If you do not specifically know you have a Voyager based machine,
124 say N here, otherwise the kernel you build will not be bootable.
126 config X86_NUMAQ
127 bool "NUMAQ (IBM/Sequent)"
128 select SMP
129 select NUMA
130 help
131 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
132 multiquad box. This changes the way that processors are bootstrapped,
133 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
134 You will need a new lynxer.elf file to flash your firmware with - send
135 email to <Martin.Bligh@us.ibm.com>.
137 config X86_SUMMIT
138 bool "Summit/EXA (IBM x440)"
139 depends on SMP
140 help
141 This option is needed for IBM systems that use the Summit/EXA chipset.
142 In particular, it is needed for the x440.
144 If you don't have one of these computers, you should say N here.
145 If you want to build a NUMA kernel, you must select ACPI.
147 config X86_BIGSMP
148 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
149 depends on SMP
150 help
151 This option is needed for the systems that have more than 8 CPUs
152 and if the system is not of any sub-arch type above.
154 If you don't have such a system, you should say N here.
156 config X86_VISWS
157 bool "SGI 320/540 (Visual Workstation)"
158 help
159 The SGI Visual Workstation series is an IA32-based workstation
160 based on SGI systems chips with some legacy PC hardware attached.
162 Say Y here to create a kernel to run on the SGI 320 or 540.
164 A kernel compiled for the Visual Workstation will not run on PCs
165 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
167 config X86_GENERICARCH
168 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
169 help
170 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
171 It is intended for a generic binary kernel.
172 If you want a NUMA kernel, select ACPI. We need SRAT for NUMA.
174 config X86_ES7000
175 bool "Support for Unisys ES7000 IA32 series"
176 depends on SMP
177 help
178 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
179 supposed to run on an IA32-based Unisys ES7000 system.
180 Only choose this option if you have such a system, otherwise you
181 should say N here.
183 endchoice
185 config ACPI_SRAT
186 bool
187 default y
188 depends on ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH)
189 select ACPI_NUMA
191 config HAVE_ARCH_PARSE_SRAT
192 bool
193 default y
194 depends on ACPI_SRAT
196 config X86_SUMMIT_NUMA
197 bool
198 default y
199 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
201 config X86_CYCLONE_TIMER
202 bool
203 default y
204 depends on X86_SUMMIT || X86_GENERICARCH
206 config ES7000_CLUSTERED_APIC
207 bool
208 default y
209 depends on SMP && X86_ES7000 && MPENTIUMIII
211 source "arch/i386/Kconfig.cpu"
213 config HPET_TIMER
214 bool "HPET Timer Support"
215 help
216 This enables the use of the HPET for the kernel's internal timer.
217 HPET is the next generation timer replacing legacy 8254s.
218 You can safely choose Y here. However, HPET will only be
219 activated if the platform and the BIOS support this feature.
220 Otherwise the 8254 will be used for timing services.
222 Choose N to continue using the legacy 8254 timer.
224 config HPET_EMULATE_RTC
225 bool
226 depends on HPET_TIMER && RTC=y
227 default y
229 config NR_CPUS
230 int "Maximum number of CPUs (2-255)"
231 range 2 255
232 depends on SMP
233 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
234 default "8"
235 help
236 This allows you to specify the maximum number of CPUs which this
237 kernel will support. The maximum supported value is 255 and the
238 minimum value which makes sense is 2.
240 This is purely to save memory - each supported CPU adds
241 approximately eight kilobytes to the kernel image.
243 config SCHED_SMT
244 bool "SMT (Hyperthreading) scheduler support"
245 depends on X86_HT
246 help
247 SMT scheduler support improves the CPU scheduler's decision making
248 when dealing with Intel Pentium 4 chips with HyperThreading at a
249 cost of slightly increased overhead in some places. If unsure say
250 N here.
252 config SCHED_MC
253 bool "Multi-core scheduler support"
254 depends on X86_HT
255 default y
256 help
257 Multi-core scheduler support improves the CPU scheduler's decision
258 making when dealing with multi-core CPU chips at a cost of slightly
259 increased overhead in some places. If unsure say N here.
261 source "kernel/Kconfig.preempt"
263 config X86_UP_APIC
264 bool "Local APIC support on uniprocessors"
265 depends on !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH)
266 help
267 A local APIC (Advanced Programmable Interrupt Controller) is an
268 integrated interrupt controller in the CPU. If you have a single-CPU
269 system which has a processor with a local APIC, you can say Y here to
270 enable and use it. If you say Y here even though your machine doesn't
271 have a local APIC, then the kernel will still run with no slowdown at
272 all. The local APIC supports CPU-generated self-interrupts (timer,
273 performance counters), and the NMI watchdog which detects hard
274 lockups.
276 config X86_UP_IOAPIC
277 bool "IO-APIC support on uniprocessors"
278 depends on X86_UP_APIC
279 help
280 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
281 SMP-capable replacement for PC-style interrupt controllers. Most
282 SMP systems and many recent uniprocessor systems have one.
284 If you have a single-CPU system with an IO-APIC, you can say Y here
285 to use it. If you say Y here even though your machine doesn't have
286 an IO-APIC, then the kernel will still run with no slowdown at all.
288 config X86_LOCAL_APIC
289 bool
290 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH
291 default y
293 config X86_IO_APIC
294 bool
295 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH
296 default y
298 config X86_VISWS_APIC
299 bool
300 depends on X86_VISWS
301 default y
303 config X86_MCE
304 bool "Machine Check Exception"
305 depends on !X86_VOYAGER
306 ---help---
307 Machine Check Exception support allows the processor to notify the
308 kernel if it detects a problem (e.g. overheating, component failure).
309 The action the kernel takes depends on the severity of the problem,
310 ranging from a warning message on the console, to halting the machine.
311 Your processor must be a Pentium or newer to support this - check the
312 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
313 have a design flaw which leads to false MCE events - hence MCE is
314 disabled on all P5 processors, unless explicitly enabled with "mce"
315 as a boot argument. Similarly, if MCE is built in and creates a
316 problem on some new non-standard machine, you can boot with "nomce"
317 to disable it. MCE support simply ignores non-MCE processors like
318 the 386 and 486, so nearly everyone can say Y here.
320 config X86_MCE_NONFATAL
321 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
322 depends on X86_MCE
323 help
324 Enabling this feature starts a timer that triggers every 5 seconds which
325 will look at the machine check registers to see if anything happened.
326 Non-fatal problems automatically get corrected (but still logged).
327 Disable this if you don't want to see these messages.
328 Seeing the messages this option prints out may be indicative of dying hardware,
329 or out-of-spec (ie, overclocked) hardware.
330 This option only does something on certain CPUs.
331 (AMD Athlon/Duron and Intel Pentium 4)
333 config X86_MCE_P4THERMAL
334 bool "check for P4 thermal throttling interrupt."
335 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
336 help
337 Enabling this feature will cause a message to be printed when the P4
338 enters thermal throttling.
340 config VM86
341 default y
342 bool "Enable VM86 support" if EMBEDDED
343 help
344 This option is required by programs like DOSEMU to run 16-bit legacy
345 code on X86 processors. It also may be needed by software like
346 XFree86 to initialize some video cards via BIOS. Disabling this
347 option saves about 6k.
349 config TOSHIBA
350 tristate "Toshiba Laptop support"
351 ---help---
352 This adds a driver to safely access the System Management Mode of
353 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
354 not work on models with a Phoenix BIOS. The System Management Mode
355 is used to set the BIOS and power saving options on Toshiba portables.
357 For information on utilities to make use of this driver see the
358 Toshiba Linux utilities web site at:
359 <http://www.buzzard.org.uk/toshiba/>.
361 Say Y if you intend to run this kernel on a Toshiba portable.
362 Say N otherwise.
364 config I8K
365 tristate "Dell laptop support"
366 ---help---
367 This adds a driver to safely access the System Management Mode
368 of the CPU on the Dell Inspiron 8000. The System Management Mode
369 is used to read cpu temperature and cooling fan status and to
370 control the fans on the I8K portables.
372 This driver has been tested only on the Inspiron 8000 but it may
373 also work with other Dell laptops. You can force loading on other
374 models by passing the parameter `force=1' to the module. Use at
375 your own risk.
377 For information on utilities to make use of this driver see the
378 I8K Linux utilities web site at:
379 <http://people.debian.org/~dz/i8k/>
381 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
382 Say N otherwise.
384 config X86_REBOOTFIXUPS
385 bool "Enable X86 board specific fixups for reboot"
386 depends on X86
387 default n
388 ---help---
389 This enables chipset and/or board specific fixups to be done
390 in order to get reboot to work correctly. This is only needed on
391 some combinations of hardware and BIOS. The symptom, for which
392 this config is intended, is when reboot ends with a stalled/hung
393 system.
395 Currently, the only fixup is for the Geode GX1/CS5530A/TROM2.1.
396 combination.
398 Say Y if you want to enable the fixup. Currently, it's safe to
399 enable this option even if you don't need it.
400 Say N otherwise.
402 config MICROCODE
403 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
404 ---help---
405 If you say Y here and also to "/dev file system support" in the
406 'File systems' section, you will be able to update the microcode on
407 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
408 Pentium III, Pentium 4, Xeon etc. You will obviously need the
409 actual microcode binary data itself which is not shipped with the
410 Linux kernel.
412 For latest news and information on obtaining all the required
413 ingredients for this driver, check:
414 <http://www.urbanmyth.org/microcode/>.
416 To compile this driver as a module, choose M here: the
417 module will be called microcode.
419 config X86_MSR
420 tristate "/dev/cpu/*/msr - Model-specific register support"
421 help
422 This device gives privileged processes access to the x86
423 Model-Specific Registers (MSRs). It is a character device with
424 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
425 MSR accesses are directed to a specific CPU on multi-processor
426 systems.
428 config X86_CPUID
429 tristate "/dev/cpu/*/cpuid - CPU information support"
430 help
431 This device gives processes access to the x86 CPUID instruction to
432 be executed on a specific processor. It is a character device
433 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
434 /dev/cpu/31/cpuid.
436 source "drivers/firmware/Kconfig"
438 choice
439 prompt "High Memory Support"
440 default NOHIGHMEM
442 config NOHIGHMEM
443 bool "off"
444 depends on !X86_NUMAQ
445 ---help---
446 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
447 However, the address space of 32-bit x86 processors is only 4
448 Gigabytes large. That means that, if you have a large amount of
449 physical memory, not all of it can be "permanently mapped" by the
450 kernel. The physical memory that's not permanently mapped is called
451 "high memory".
453 If you are compiling a kernel which will never run on a machine with
454 more than 1 Gigabyte total physical RAM, answer "off" here (default
455 choice and suitable for most users). This will result in a "3GB/1GB"
456 split: 3GB are mapped so that each process sees a 3GB virtual memory
457 space and the remaining part of the 4GB virtual memory space is used
458 by the kernel to permanently map as much physical memory as
459 possible.
461 If the machine has between 1 and 4 Gigabytes physical RAM, then
462 answer "4GB" here.
464 If more than 4 Gigabytes is used then answer "64GB" here. This
465 selection turns Intel PAE (Physical Address Extension) mode on.
466 PAE implements 3-level paging on IA32 processors. PAE is fully
467 supported by Linux, PAE mode is implemented on all recent Intel
468 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
469 then the kernel will not boot on CPUs that don't support PAE!
471 The actual amount of total physical memory will either be
472 auto detected or can be forced by using a kernel command line option
473 such as "mem=256M". (Try "man bootparam" or see the documentation of
474 your boot loader (lilo or loadlin) about how to pass options to the
475 kernel at boot time.)
477 If unsure, say "off".
479 config HIGHMEM4G
480 bool "4GB"
481 depends on !X86_NUMAQ
482 help
483 Select this if you have a 32-bit processor and between 1 and 4
484 gigabytes of physical RAM.
486 config HIGHMEM64G
487 bool "64GB"
488 depends on X86_CMPXCHG64
489 help
490 Select this if you have a 32-bit processor and more than 4
491 gigabytes of physical RAM.
493 endchoice
495 choice
496 depends on EXPERIMENTAL
497 prompt "Memory split" if EMBEDDED
498 default VMSPLIT_3G
499 help
500 Select the desired split between kernel and user memory.
502 If the address range available to the kernel is less than the
503 physical memory installed, the remaining memory will be available
504 as "high memory". Accessing high memory is a little more costly
505 than low memory, as it needs to be mapped into the kernel first.
506 Note that increasing the kernel address space limits the range
507 available to user programs, making the address space there
508 tighter. Selecting anything other than the default 3G/1G split
509 will also likely make your kernel incompatible with binary-only
510 kernel modules.
512 If you are not absolutely sure what you are doing, leave this
513 option alone!
515 config VMSPLIT_3G
516 bool "3G/1G user/kernel split"
517 config VMSPLIT_3G_OPT
518 depends on !HIGHMEM
519 bool "3G/1G user/kernel split (for full 1G low memory)"
520 config VMSPLIT_2G
521 bool "2G/2G user/kernel split"
522 config VMSPLIT_1G
523 bool "1G/3G user/kernel split"
524 endchoice
526 config PAGE_OFFSET
527 hex
528 default 0xB0000000 if VMSPLIT_3G_OPT
529 default 0x78000000 if VMSPLIT_2G
530 default 0x40000000 if VMSPLIT_1G
531 default 0xC0000000
533 config HIGHMEM
534 bool
535 depends on HIGHMEM64G || HIGHMEM4G
536 default y
538 config X86_PAE
539 bool
540 depends on HIGHMEM64G
541 default y
542 select RESOURCES_64BIT
544 # Common NUMA Features
545 config NUMA
546 bool "Numa Memory Allocation and Scheduler Support"
547 depends on SMP && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI)
548 default n if X86_PC
549 default y if (X86_NUMAQ || X86_SUMMIT)
551 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
552 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
554 config NODES_SHIFT
555 int
556 default "4" if X86_NUMAQ
557 default "3"
558 depends on NEED_MULTIPLE_NODES
560 config HAVE_ARCH_BOOTMEM_NODE
561 bool
562 depends on NUMA
563 default y
565 config ARCH_HAVE_MEMORY_PRESENT
566 bool
567 depends on DISCONTIGMEM
568 default y
570 config NEED_NODE_MEMMAP_SIZE
571 bool
572 depends on DISCONTIGMEM || SPARSEMEM
573 default y
575 config HAVE_ARCH_ALLOC_REMAP
576 bool
577 depends on NUMA
578 default y
580 config ARCH_FLATMEM_ENABLE
581 def_bool y
582 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
584 config ARCH_DISCONTIGMEM_ENABLE
585 def_bool y
586 depends on NUMA
588 config ARCH_DISCONTIGMEM_DEFAULT
589 def_bool y
590 depends on NUMA
592 config ARCH_SPARSEMEM_ENABLE
593 def_bool y
594 depends on (NUMA || (X86_PC && EXPERIMENTAL))
595 select SPARSEMEM_STATIC
597 config ARCH_SELECT_MEMORY_MODEL
598 def_bool y
599 depends on ARCH_SPARSEMEM_ENABLE
601 source "mm/Kconfig"
603 config HAVE_ARCH_EARLY_PFN_TO_NID
604 bool
605 default y
606 depends on NUMA
608 config HIGHPTE
609 bool "Allocate 3rd-level pagetables from highmem"
610 depends on HIGHMEM4G || HIGHMEM64G
611 help
612 The VM uses one page table entry for each page of physical memory.
613 For systems with a lot of RAM, this can be wasteful of precious
614 low memory. Setting this option will put user-space page table
615 entries in high memory.
617 config MATH_EMULATION
618 bool "Math emulation"
619 ---help---
620 Linux can emulate a math coprocessor (used for floating point
621 operations) if you don't have one. 486DX and Pentium processors have
622 a math coprocessor built in, 486SX and 386 do not, unless you added
623 a 487DX or 387, respectively. (The messages during boot time can
624 give you some hints here ["man dmesg"].) Everyone needs either a
625 coprocessor or this emulation.
627 If you don't have a math coprocessor, you need to say Y here; if you
628 say Y here even though you have a coprocessor, the coprocessor will
629 be used nevertheless. (This behavior can be changed with the kernel
630 command line option "no387", which comes handy if your coprocessor
631 is broken. Try "man bootparam" or see the documentation of your boot
632 loader (lilo or loadlin) about how to pass options to the kernel at
633 boot time.) This means that it is a good idea to say Y here if you
634 intend to use this kernel on different machines.
636 More information about the internals of the Linux math coprocessor
637 emulation can be found in <file:arch/i386/math-emu/README>.
639 If you are not sure, say Y; apart from resulting in a 66 KB bigger
640 kernel, it won't hurt.
642 config MTRR
643 bool "MTRR (Memory Type Range Register) support"
644 ---help---
645 On Intel P6 family processors (Pentium Pro, Pentium II and later)
646 the Memory Type Range Registers (MTRRs) may be used to control
647 processor access to memory ranges. This is most useful if you have
648 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
649 allows bus write transfers to be combined into a larger transfer
650 before bursting over the PCI/AGP bus. This can increase performance
651 of image write operations 2.5 times or more. Saying Y here creates a
652 /proc/mtrr file which may be used to manipulate your processor's
653 MTRRs. Typically the X server should use this.
655 This code has a reasonably generic interface so that similar
656 control registers on other processors can be easily supported
657 as well:
659 The Cyrix 6x86, 6x86MX and M II processors have Address Range
660 Registers (ARRs) which provide a similar functionality to MTRRs. For
661 these, the ARRs are used to emulate the MTRRs.
662 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
663 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
664 write-combining. All of these processors are supported by this code
665 and it makes sense to say Y here if you have one of them.
667 Saying Y here also fixes a problem with buggy SMP BIOSes which only
668 set the MTRRs for the boot CPU and not for the secondary CPUs. This
669 can lead to all sorts of problems, so it's good to say Y here.
671 You can safely say Y even if your machine doesn't have MTRRs, you'll
672 just add about 9 KB to your kernel.
674 See <file:Documentation/mtrr.txt> for more information.
676 config EFI
677 bool "Boot from EFI support"
678 depends on ACPI
679 default n
680 ---help---
681 This enables the the kernel to boot on EFI platforms using
682 system configuration information passed to it from the firmware.
683 This also enables the kernel to use any EFI runtime services that are
684 available (such as the EFI variable services).
686 This option is only useful on systems that have EFI firmware
687 and will result in a kernel image that is ~8k larger. In addition,
688 you must use the latest ELILO loader available at
689 <http://elilo.sourceforge.net> in order to take advantage of
690 kernel initialization using EFI information (neither GRUB nor LILO know
691 anything about EFI). However, even with this option, the resultant
692 kernel should continue to boot on existing non-EFI platforms.
694 config IRQBALANCE
695 bool "Enable kernel irq balancing"
696 depends on SMP && X86_IO_APIC
697 default y
698 help
699 The default yes will allow the kernel to do irq load balancing.
700 Saying no will keep the kernel from doing irq load balancing.
702 # turning this on wastes a bunch of space.
703 # Summit needs it only when NUMA is on
704 config BOOT_IOREMAP
705 bool
706 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
707 default y
709 config REGPARM
710 bool "Use register arguments"
711 default y
712 help
713 Compile the kernel with -mregparm=3. This instructs gcc to use
714 a more efficient function call ABI which passes the first three
715 arguments of a function call via registers, which results in denser
716 and faster code.
718 If this option is disabled, then the default ABI of passing
719 arguments via the stack is used.
721 If unsure, say Y.
723 config SECCOMP
724 bool "Enable seccomp to safely compute untrusted bytecode"
725 depends on PROC_FS
726 default y
727 help
728 This kernel feature is useful for number crunching applications
729 that may need to compute untrusted bytecode during their
730 execution. By using pipes or other transports made available to
731 the process as file descriptors supporting the read/write
732 syscalls, it's possible to isolate those applications in
733 their own address space using seccomp. Once seccomp is
734 enabled via /proc/<pid>/seccomp, it cannot be disabled
735 and the task is only allowed to execute a few safe syscalls
736 defined by each seccomp mode.
738 If unsure, say Y. Only embedded should say N here.
740 source kernel/Kconfig.hz
742 config KEXEC
743 bool "kexec system call"
744 help
745 kexec is a system call that implements the ability to shutdown your
746 current kernel, and to start another kernel. It is like a reboot
747 but it is independent of the system firmware. And like a reboot
748 you can start any kernel with it, not just Linux.
750 The name comes from the similarity to the exec system call.
752 It is an ongoing process to be certain the hardware in a machine
753 is properly shutdown, so do not be surprised if this code does not
754 initially work for you. It may help to enable device hotplugging
755 support. As of this writing the exact hardware interface is
756 strongly in flux, so no good recommendation can be made.
758 config CRASH_DUMP
759 bool "kernel crash dumps (EXPERIMENTAL)"
760 depends on EXPERIMENTAL
761 depends on HIGHMEM
762 help
763 Generate crash dump after being started by kexec.
764 This should be normally only set in special crash dump kernels
765 which are loaded in the main kernel with kexec-tools into
766 a specially reserved region and then later executed after
767 a crash by kdump/kexec. The crash dump kernel must be compiled
768 to a memory address not used by the main kernel or BIOS using
769 PHYSICAL_START.
770 For more details see Documentation/kdump/kdump.txt
772 config PHYSICAL_START
773 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
775 default "0x1000000" if CRASH_DUMP
776 default "0x100000"
777 help
778 This gives the physical address where the kernel is loaded. Normally
779 for regular kernels this value is 0x100000 (1MB). But in the case
780 of kexec on panic the fail safe kernel needs to run at a different
781 address than the panic-ed kernel. This option is used to set the load
782 address for kernels used to capture crash dump on being kexec'ed
783 after panic. The default value for crash dump kernels is
784 0x1000000 (16MB). This can also be set based on the "X" value as
785 specified in the "crashkernel=YM@XM" command line boot parameter
786 passed to the panic-ed kernel. Typically this parameter is set as
787 crashkernel=64M@16M. Please take a look at
788 Documentation/kdump/kdump.txt for more details about crash dumps.
790 Don't change this unless you know what you are doing.
792 config HOTPLUG_CPU
793 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
794 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
795 ---help---
796 Say Y here to experiment with turning CPUs off and on, and to
797 enable suspend on SMP systems. CPUs can be controlled through
798 /sys/devices/system/cpu.
800 config COMPAT_VDSO
801 bool "Compat VDSO support"
802 default y
803 depends on !PARAVIRT
804 help
805 Map the VDSO to the predictable old-style address too.
806 ---help---
807 Say N here if you are running a sufficiently recent glibc
808 version (2.3.3 or later), to remove the high-mapped
809 VDSO mapping and to exclusively use the randomized VDSO.
811 If unsure, say Y.
813 endmenu
815 config ARCH_ENABLE_MEMORY_HOTPLUG
816 def_bool y
817 depends on HIGHMEM
819 menu "Power management options (ACPI, APM)"
820 depends on !X86_VOYAGER
822 source kernel/power/Kconfig
824 source "drivers/acpi/Kconfig"
826 menu "APM (Advanced Power Management) BIOS Support"
827 depends on PM && !X86_VISWS
829 config APM
830 tristate "APM (Advanced Power Management) BIOS support"
831 depends on PM
832 ---help---
833 APM is a BIOS specification for saving power using several different
834 techniques. This is mostly useful for battery powered laptops with
835 APM compliant BIOSes. If you say Y here, the system time will be
836 reset after a RESUME operation, the /proc/apm device will provide
837 battery status information, and user-space programs will receive
838 notification of APM "events" (e.g. battery status change).
840 If you select "Y" here, you can disable actual use of the APM
841 BIOS by passing the "apm=off" option to the kernel at boot time.
843 Note that the APM support is almost completely disabled for
844 machines with more than one CPU.
846 In order to use APM, you will need supporting software. For location
847 and more information, read <file:Documentation/pm.txt> and the
848 Battery Powered Linux mini-HOWTO, available from
849 <http://www.tldp.org/docs.html#howto>.
851 This driver does not spin down disk drives (see the hdparm(8)
852 manpage ("man 8 hdparm") for that), and it doesn't turn off
853 VESA-compliant "green" monitors.
855 This driver does not support the TI 4000M TravelMate and the ACER
856 486/DX4/75 because they don't have compliant BIOSes. Many "green"
857 desktop machines also don't have compliant BIOSes, and this driver
858 may cause those machines to panic during the boot phase.
860 Generally, if you don't have a battery in your machine, there isn't
861 much point in using this driver and you should say N. If you get
862 random kernel OOPSes or reboots that don't seem to be related to
863 anything, try disabling/enabling this option (or disabling/enabling
864 APM in your BIOS).
866 Some other things you should try when experiencing seemingly random,
867 "weird" problems:
869 1) make sure that you have enough swap space and that it is
870 enabled.
871 2) pass the "no-hlt" option to the kernel
872 3) switch on floating point emulation in the kernel and pass
873 the "no387" option to the kernel
874 4) pass the "floppy=nodma" option to the kernel
875 5) pass the "mem=4M" option to the kernel (thereby disabling
876 all but the first 4 MB of RAM)
877 6) make sure that the CPU is not over clocked.
878 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
879 8) disable the cache from your BIOS settings
880 9) install a fan for the video card or exchange video RAM
881 10) install a better fan for the CPU
882 11) exchange RAM chips
883 12) exchange the motherboard.
885 To compile this driver as a module, choose M here: the
886 module will be called apm.
888 config APM_IGNORE_USER_SUSPEND
889 bool "Ignore USER SUSPEND"
890 depends on APM
891 help
892 This option will ignore USER SUSPEND requests. On machines with a
893 compliant APM BIOS, you want to say N. However, on the NEC Versa M
894 series notebooks, it is necessary to say Y because of a BIOS bug.
896 config APM_DO_ENABLE
897 bool "Enable PM at boot time"
898 depends on APM
899 ---help---
900 Enable APM features at boot time. From page 36 of the APM BIOS
901 specification: "When disabled, the APM BIOS does not automatically
902 power manage devices, enter the Standby State, enter the Suspend
903 State, or take power saving steps in response to CPU Idle calls."
904 This driver will make CPU Idle calls when Linux is idle (unless this
905 feature is turned off -- see "Do CPU IDLE calls", below). This
906 should always save battery power, but more complicated APM features
907 will be dependent on your BIOS implementation. You may need to turn
908 this option off if your computer hangs at boot time when using APM
909 support, or if it beeps continuously instead of suspending. Turn
910 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
911 T400CDT. This is off by default since most machines do fine without
912 this feature.
914 config APM_CPU_IDLE
915 bool "Make CPU Idle calls when idle"
916 depends on APM
917 help
918 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
919 On some machines, this can activate improved power savings, such as
920 a slowed CPU clock rate, when the machine is idle. These idle calls
921 are made after the idle loop has run for some length of time (e.g.,
922 333 mS). On some machines, this will cause a hang at boot time or
923 whenever the CPU becomes idle. (On machines with more than one CPU,
924 this option does nothing.)
926 config APM_DISPLAY_BLANK
927 bool "Enable console blanking using APM"
928 depends on APM
929 help
930 Enable console blanking using the APM. Some laptops can use this to
931 turn off the LCD backlight when the screen blanker of the Linux
932 virtual console blanks the screen. Note that this is only used by
933 the virtual console screen blanker, and won't turn off the backlight
934 when using the X Window system. This also doesn't have anything to
935 do with your VESA-compliant power-saving monitor. Further, this
936 option doesn't work for all laptops -- it might not turn off your
937 backlight at all, or it might print a lot of errors to the console,
938 especially if you are using gpm.
940 config APM_RTC_IS_GMT
941 bool "RTC stores time in GMT"
942 depends on APM
943 help
944 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
945 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
946 stores localtime.
948 It is in fact recommended to store GMT in your RTC, because then you
949 don't have to worry about daylight savings time changes. The only
950 reason not to use GMT in your RTC is if you also run a broken OS
951 that doesn't understand GMT.
953 config APM_ALLOW_INTS
954 bool "Allow interrupts during APM BIOS calls"
955 depends on APM
956 help
957 Normally we disable external interrupts while we are making calls to
958 the APM BIOS as a measure to lessen the effects of a badly behaving
959 BIOS implementation. The BIOS should reenable interrupts if it
960 needs to. Unfortunately, some BIOSes do not -- especially those in
961 many of the newer IBM Thinkpads. If you experience hangs when you
962 suspend, try setting this to Y. Otherwise, say N.
964 config APM_REAL_MODE_POWER_OFF
965 bool "Use real mode APM BIOS call to power off"
966 depends on APM
967 help
968 Use real mode APM BIOS calls to switch off the computer. This is
969 a work-around for a number of buggy BIOSes. Switch this option on if
970 your computer crashes instead of powering off properly.
972 endmenu
974 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
976 endmenu
978 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
980 config PCI
981 bool "PCI support" if !X86_VISWS
982 depends on !X86_VOYAGER
983 default y if X86_VISWS
984 help
985 Find out whether you have a PCI motherboard. PCI is the name of a
986 bus system, i.e. the way the CPU talks to the other stuff inside
987 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
988 VESA. If you have PCI, say Y, otherwise N.
990 The PCI-HOWTO, available from
991 <http://www.tldp.org/docs.html#howto>, contains valuable
992 information about which PCI hardware does work under Linux and which
993 doesn't.
995 choice
996 prompt "PCI access mode"
997 depends on PCI && !X86_VISWS
998 default PCI_GOANY
999 ---help---
1000 On PCI systems, the BIOS can be used to detect the PCI devices and
1001 determine their configuration. However, some old PCI motherboards
1002 have BIOS bugs and may crash if this is done. Also, some embedded
1003 PCI-based systems don't have any BIOS at all. Linux can also try to
1004 detect the PCI hardware directly without using the BIOS.
1006 With this option, you can specify how Linux should detect the
1007 PCI devices. If you choose "BIOS", the BIOS will be used,
1008 if you choose "Direct", the BIOS won't be used, and if you
1009 choose "MMConfig", then PCI Express MMCONFIG will be used.
1010 If you choose "Any", the kernel will try MMCONFIG, then the
1011 direct access method and falls back to the BIOS if that doesn't
1012 work. If unsure, go with the default, which is "Any".
1014 config PCI_GOBIOS
1015 bool "BIOS"
1017 config PCI_GOMMCONFIG
1018 bool "MMConfig"
1020 config PCI_GODIRECT
1021 bool "Direct"
1023 config PCI_GOANY
1024 bool "Any"
1026 endchoice
1028 config PCI_BIOS
1029 bool
1030 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1031 default y
1033 config PCI_DIRECT
1034 bool
1035 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1036 default y
1038 config PCI_MMCONFIG
1039 bool
1040 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1041 default y
1043 source "drivers/pci/pcie/Kconfig"
1045 source "drivers/pci/Kconfig"
1047 config ISA_DMA_API
1048 bool
1049 default y
1051 config ISA
1052 bool "ISA support"
1053 depends on !(X86_VOYAGER || X86_VISWS)
1054 help
1055 Find out whether you have ISA slots on your motherboard. ISA is the
1056 name of a bus system, i.e. the way the CPU talks to the other stuff
1057 inside your box. Other bus systems are PCI, EISA, MicroChannel
1058 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1059 newer boards don't support it. If you have ISA, say Y, otherwise N.
1061 config EISA
1062 bool "EISA support"
1063 depends on ISA
1064 ---help---
1065 The Extended Industry Standard Architecture (EISA) bus was
1066 developed as an open alternative to the IBM MicroChannel bus.
1068 The EISA bus provided some of the features of the IBM MicroChannel
1069 bus while maintaining backward compatibility with cards made for
1070 the older ISA bus. The EISA bus saw limited use between 1988 and
1071 1995 when it was made obsolete by the PCI bus.
1073 Say Y here if you are building a kernel for an EISA-based machine.
1075 Otherwise, say N.
1077 source "drivers/eisa/Kconfig"
1079 config MCA
1080 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1081 default y if X86_VOYAGER
1082 help
1083 MicroChannel Architecture is found in some IBM PS/2 machines and
1084 laptops. It is a bus system similar to PCI or ISA. See
1085 <file:Documentation/mca.txt> (and especially the web page given
1086 there) before attempting to build an MCA bus kernel.
1088 source "drivers/mca/Kconfig"
1090 config SCx200
1091 tristate "NatSemi SCx200 support"
1092 depends on !X86_VOYAGER
1093 help
1094 This provides basic support for National Semiconductor's
1095 (now AMD's) Geode processors. The driver probes for the
1096 PCI-IDs of several on-chip devices, so its a good dependency
1097 for other scx200_* drivers.
1099 If compiled as a module, the driver is named scx200.
1101 config SCx200HR_TIMER
1102 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1103 depends on SCx200 && GENERIC_TIME
1104 default y
1105 help
1106 This driver provides a clocksource built upon the on-chip
1107 27MHz high-resolution timer. Its also a workaround for
1108 NSC Geode SC-1100's buggy TSC, which loses time when the
1109 processor goes idle (as is done by the scheduler). The
1110 other workaround is idle=poll boot option.
1112 config K8_NB
1113 def_bool y
1114 depends on AGP_AMD64
1116 source "drivers/pcmcia/Kconfig"
1118 source "drivers/pci/hotplug/Kconfig"
1120 endmenu
1122 menu "Executable file formats"
1124 source "fs/Kconfig.binfmt"
1126 endmenu
1128 source "net/Kconfig"
1130 source "drivers/Kconfig"
1132 source "fs/Kconfig"
1134 menu "Instrumentation Support"
1135 depends on EXPERIMENTAL
1137 source "arch/i386/oprofile/Kconfig"
1139 config KPROBES
1140 bool "Kprobes (EXPERIMENTAL)"
1141 depends on EXPERIMENTAL && MODULES
1142 help
1143 Kprobes allows you to trap at almost any kernel address and
1144 execute a callback function. register_kprobe() establishes
1145 a probepoint and specifies the callback. Kprobes is useful
1146 for kernel debugging, non-intrusive instrumentation and testing.
1147 If in doubt, say "N".
1148 endmenu
1150 source "arch/i386/Kconfig.debug"
1152 source "security/Kconfig"
1154 source "crypto/Kconfig"
1156 source "lib/Kconfig"
1158 #
1159 # Use the generic interrupt handling code in kernel/irq/:
1160 #
1161 config GENERIC_HARDIRQS
1162 bool
1163 default y
1165 config GENERIC_IRQ_PROBE
1166 bool
1167 default y
1169 config GENERIC_PENDING_IRQ
1170 bool
1171 depends on GENERIC_HARDIRQS && SMP
1172 default y
1174 config X86_SMP
1175 bool
1176 depends on SMP && !X86_VOYAGER
1177 default y
1179 config X86_HT
1180 bool
1181 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1182 default y
1184 config X86_BIOS_REBOOT
1185 bool
1186 depends on !(X86_VISWS || X86_VOYAGER)
1187 default y
1189 config X86_TRAMPOLINE
1190 bool
1191 depends on X86_SMP || (X86_VOYAGER && SMP)
1192 default y
1194 config KTIME_SCALAR
1195 bool
1196 default y