| blob | 0cbeb26ac3fbd9ae30df0b536074709537943f86 |
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 MICROCODE_OLD_INTERFACE
420 bool
421 depends on MICROCODE
422 default y
424 config X86_MSR
425 tristate "/dev/cpu/*/msr - Model-specific register support"
426 help
427 This device gives privileged processes access to the x86
428 Model-Specific Registers (MSRs). It is a character device with
429 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
430 MSR accesses are directed to a specific CPU on multi-processor
431 systems.
433 config X86_CPUID
434 tristate "/dev/cpu/*/cpuid - CPU information support"
435 help
436 This device gives processes access to the x86 CPUID instruction to
437 be executed on a specific processor. It is a character device
438 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
439 /dev/cpu/31/cpuid.
441 source "drivers/firmware/Kconfig"
443 choice
444 prompt "High Memory Support"
445 default NOHIGHMEM
447 config NOHIGHMEM
448 bool "off"
449 depends on !X86_NUMAQ
450 ---help---
451 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
452 However, the address space of 32-bit x86 processors is only 4
453 Gigabytes large. That means that, if you have a large amount of
454 physical memory, not all of it can be "permanently mapped" by the
455 kernel. The physical memory that's not permanently mapped is called
456 "high memory".
458 If you are compiling a kernel which will never run on a machine with
459 more than 1 Gigabyte total physical RAM, answer "off" here (default
460 choice and suitable for most users). This will result in a "3GB/1GB"
461 split: 3GB are mapped so that each process sees a 3GB virtual memory
462 space and the remaining part of the 4GB virtual memory space is used
463 by the kernel to permanently map as much physical memory as
464 possible.
466 If the machine has between 1 and 4 Gigabytes physical RAM, then
467 answer "4GB" here.
469 If more than 4 Gigabytes is used then answer "64GB" here. This
470 selection turns Intel PAE (Physical Address Extension) mode on.
471 PAE implements 3-level paging on IA32 processors. PAE is fully
472 supported by Linux, PAE mode is implemented on all recent Intel
473 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
474 then the kernel will not boot on CPUs that don't support PAE!
476 The actual amount of total physical memory will either be
477 auto detected or can be forced by using a kernel command line option
478 such as "mem=256M". (Try "man bootparam" or see the documentation of
479 your boot loader (lilo or loadlin) about how to pass options to the
480 kernel at boot time.)
482 If unsure, say "off".
484 config HIGHMEM4G
485 bool "4GB"
486 depends on !X86_NUMAQ
487 help
488 Select this if you have a 32-bit processor and between 1 and 4
489 gigabytes of physical RAM.
491 config HIGHMEM64G
492 bool "64GB"
493 depends on X86_CMPXCHG64
494 help
495 Select this if you have a 32-bit processor and more than 4
496 gigabytes of physical RAM.
498 endchoice
500 choice
501 depends on EXPERIMENTAL
502 prompt "Memory split" if EMBEDDED
503 default VMSPLIT_3G
504 help
505 Select the desired split between kernel and user memory.
507 If the address range available to the kernel is less than the
508 physical memory installed, the remaining memory will be available
509 as "high memory". Accessing high memory is a little more costly
510 than low memory, as it needs to be mapped into the kernel first.
511 Note that increasing the kernel address space limits the range
512 available to user programs, making the address space there
513 tighter. Selecting anything other than the default 3G/1G split
514 will also likely make your kernel incompatible with binary-only
515 kernel modules.
517 If you are not absolutely sure what you are doing, leave this
518 option alone!
520 config VMSPLIT_3G
521 bool "3G/1G user/kernel split"
522 config VMSPLIT_3G_OPT
523 depends on !HIGHMEM
524 bool "3G/1G user/kernel split (for full 1G low memory)"
525 config VMSPLIT_2G
526 bool "2G/2G user/kernel split"
527 config VMSPLIT_1G
528 bool "1G/3G user/kernel split"
529 endchoice
531 config PAGE_OFFSET
532 hex
533 default 0xB0000000 if VMSPLIT_3G_OPT
534 default 0x78000000 if VMSPLIT_2G
535 default 0x40000000 if VMSPLIT_1G
536 default 0xC0000000
538 config HIGHMEM
539 bool
540 depends on HIGHMEM64G || HIGHMEM4G
541 default y
543 config X86_PAE
544 bool
545 depends on HIGHMEM64G
546 default y
547 select RESOURCES_64BIT
549 # Common NUMA Features
550 config NUMA
551 bool "Numa Memory Allocation and Scheduler Support"
552 depends on SMP && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI)
553 default n if X86_PC
554 default y if (X86_NUMAQ || X86_SUMMIT)
556 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
557 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
559 config NODES_SHIFT
560 int
561 default "4" if X86_NUMAQ
562 default "3"
563 depends on NEED_MULTIPLE_NODES
565 config HAVE_ARCH_BOOTMEM_NODE
566 bool
567 depends on NUMA
568 default y
570 config ARCH_HAVE_MEMORY_PRESENT
571 bool
572 depends on DISCONTIGMEM
573 default y
575 config NEED_NODE_MEMMAP_SIZE
576 bool
577 depends on DISCONTIGMEM || SPARSEMEM
578 default y
580 config HAVE_ARCH_ALLOC_REMAP
581 bool
582 depends on NUMA
583 default y
585 config ARCH_FLATMEM_ENABLE
586 def_bool y
587 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
589 config ARCH_DISCONTIGMEM_ENABLE
590 def_bool y
591 depends on NUMA
593 config ARCH_DISCONTIGMEM_DEFAULT
594 def_bool y
595 depends on NUMA
597 config ARCH_SPARSEMEM_ENABLE
598 def_bool y
599 depends on (NUMA || (X86_PC && EXPERIMENTAL))
600 select SPARSEMEM_STATIC
602 config ARCH_SELECT_MEMORY_MODEL
603 def_bool y
604 depends on ARCH_SPARSEMEM_ENABLE
606 config ARCH_POPULATES_NODE_MAP
607 def_bool y
609 source "mm/Kconfig"
611 config HIGHPTE
612 bool "Allocate 3rd-level pagetables from highmem"
613 depends on HIGHMEM4G || HIGHMEM64G
614 help
615 The VM uses one page table entry for each page of physical memory.
616 For systems with a lot of RAM, this can be wasteful of precious
617 low memory. Setting this option will put user-space page table
618 entries in high memory.
620 config MATH_EMULATION
621 bool "Math emulation"
622 ---help---
623 Linux can emulate a math coprocessor (used for floating point
624 operations) if you don't have one. 486DX and Pentium processors have
625 a math coprocessor built in, 486SX and 386 do not, unless you added
626 a 487DX or 387, respectively. (The messages during boot time can
627 give you some hints here ["man dmesg"].) Everyone needs either a
628 coprocessor or this emulation.
630 If you don't have a math coprocessor, you need to say Y here; if you
631 say Y here even though you have a coprocessor, the coprocessor will
632 be used nevertheless. (This behavior can be changed with the kernel
633 command line option "no387", which comes handy if your coprocessor
634 is broken. Try "man bootparam" or see the documentation of your boot
635 loader (lilo or loadlin) about how to pass options to the kernel at
636 boot time.) This means that it is a good idea to say Y here if you
637 intend to use this kernel on different machines.
639 More information about the internals of the Linux math coprocessor
640 emulation can be found in <file:arch/i386/math-emu/README>.
642 If you are not sure, say Y; apart from resulting in a 66 KB bigger
643 kernel, it won't hurt.
645 config MTRR
646 bool "MTRR (Memory Type Range Register) support"
647 ---help---
648 On Intel P6 family processors (Pentium Pro, Pentium II and later)
649 the Memory Type Range Registers (MTRRs) may be used to control
650 processor access to memory ranges. This is most useful if you have
651 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
652 allows bus write transfers to be combined into a larger transfer
653 before bursting over the PCI/AGP bus. This can increase performance
654 of image write operations 2.5 times or more. Saying Y here creates a
655 /proc/mtrr file which may be used to manipulate your processor's
656 MTRRs. Typically the X server should use this.
658 This code has a reasonably generic interface so that similar
659 control registers on other processors can be easily supported
660 as well:
662 The Cyrix 6x86, 6x86MX and M II processors have Address Range
663 Registers (ARRs) which provide a similar functionality to MTRRs. For
664 these, the ARRs are used to emulate the MTRRs.
665 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
666 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
667 write-combining. All of these processors are supported by this code
668 and it makes sense to say Y here if you have one of them.
670 Saying Y here also fixes a problem with buggy SMP BIOSes which only
671 set the MTRRs for the boot CPU and not for the secondary CPUs. This
672 can lead to all sorts of problems, so it's good to say Y here.
674 You can safely say Y even if your machine doesn't have MTRRs, you'll
675 just add about 9 KB to your kernel.
677 See <file:Documentation/mtrr.txt> for more information.
679 config EFI
680 bool "Boot from EFI support"
681 depends on ACPI
682 default n
683 ---help---
684 This enables the the kernel to boot on EFI platforms using
685 system configuration information passed to it from the firmware.
686 This also enables the kernel to use any EFI runtime services that are
687 available (such as the EFI variable services).
689 This option is only useful on systems that have EFI firmware
690 and will result in a kernel image that is ~8k larger. In addition,
691 you must use the latest ELILO loader available at
692 <http://elilo.sourceforge.net> in order to take advantage of
693 kernel initialization using EFI information (neither GRUB nor LILO know
694 anything about EFI). However, even with this option, the resultant
695 kernel should continue to boot on existing non-EFI platforms.
697 config IRQBALANCE
698 bool "Enable kernel irq balancing"
699 depends on SMP && X86_IO_APIC
700 default y
701 help
702 The default yes will allow the kernel to do irq load balancing.
703 Saying no will keep the kernel from doing irq load balancing.
705 # turning this on wastes a bunch of space.
706 # Summit needs it only when NUMA is on
707 config BOOT_IOREMAP
708 bool
709 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
710 default y
712 config REGPARM
713 bool "Use register arguments"
714 default y
715 help
716 Compile the kernel with -mregparm=3. This instructs gcc to use
717 a more efficient function call ABI which passes the first three
718 arguments of a function call via registers, which results in denser
719 and faster code.
721 If this option is disabled, then the default ABI of passing
722 arguments via the stack is used.
724 If unsure, say Y.
726 config SECCOMP
727 bool "Enable seccomp to safely compute untrusted bytecode"
728 depends on PROC_FS
729 default y
730 help
731 This kernel feature is useful for number crunching applications
732 that may need to compute untrusted bytecode during their
733 execution. By using pipes or other transports made available to
734 the process as file descriptors supporting the read/write
735 syscalls, it's possible to isolate those applications in
736 their own address space using seccomp. Once seccomp is
737 enabled via /proc/<pid>/seccomp, it cannot be disabled
738 and the task is only allowed to execute a few safe syscalls
739 defined by each seccomp mode.
741 If unsure, say Y. Only embedded should say N here.
743 source kernel/Kconfig.hz
745 config KEXEC
746 bool "kexec system call"
747 help
748 kexec is a system call that implements the ability to shutdown your
749 current kernel, and to start another kernel. It is like a reboot
750 but it is independent of the system firmware. And like a reboot
751 you can start any kernel with it, not just Linux.
753 The name comes from the similarity to the exec system call.
755 It is an ongoing process to be certain the hardware in a machine
756 is properly shutdown, so do not be surprised if this code does not
757 initially work for you. It may help to enable device hotplugging
758 support. As of this writing the exact hardware interface is
759 strongly in flux, so no good recommendation can be made.
761 config CRASH_DUMP
762 bool "kernel crash dumps (EXPERIMENTAL)"
763 depends on EXPERIMENTAL
764 depends on HIGHMEM
765 help
766 Generate crash dump after being started by kexec.
767 This should be normally only set in special crash dump kernels
768 which are loaded in the main kernel with kexec-tools into
769 a specially reserved region and then later executed after
770 a crash by kdump/kexec. The crash dump kernel must be compiled
771 to a memory address not used by the main kernel or BIOS using
772 PHYSICAL_START.
773 For more details see Documentation/kdump/kdump.txt
775 config PHYSICAL_START
776 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
778 default "0x1000000" if CRASH_DUMP
779 default "0x100000"
780 help
781 This gives the physical address where the kernel is loaded. Normally
782 for regular kernels this value is 0x100000 (1MB). But in the case
783 of kexec on panic the fail safe kernel needs to run at a different
784 address than the panic-ed kernel. This option is used to set the load
785 address for kernels used to capture crash dump on being kexec'ed
786 after panic. The default value for crash dump kernels is
787 0x1000000 (16MB). This can also be set based on the "X" value as
788 specified in the "crashkernel=YM@XM" command line boot parameter
789 passed to the panic-ed kernel. Typically this parameter is set as
790 crashkernel=64M@16M. Please take a look at
791 Documentation/kdump/kdump.txt for more details about crash dumps.
793 Don't change this unless you know what you are doing.
795 config HOTPLUG_CPU
796 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
797 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
798 ---help---
799 Say Y here to experiment with turning CPUs off and on, and to
800 enable suspend on SMP systems. CPUs can be controlled through
801 /sys/devices/system/cpu.
803 config COMPAT_VDSO
804 bool "Compat VDSO support"
805 default y
806 depends on !PARAVIRT
807 help
808 Map the VDSO to the predictable old-style address too.
809 ---help---
810 Say N here if you are running a sufficiently recent glibc
811 version (2.3.3 or later), to remove the high-mapped
812 VDSO mapping and to exclusively use the randomized VDSO.
814 If unsure, say Y.
816 endmenu
818 config ARCH_ENABLE_MEMORY_HOTPLUG
819 def_bool y
820 depends on HIGHMEM
822 menu "Power management options (ACPI, APM)"
823 depends on !X86_VOYAGER
825 source kernel/power/Kconfig
827 source "drivers/acpi/Kconfig"
829 menu "APM (Advanced Power Management) BIOS Support"
830 depends on PM && !X86_VISWS
832 config APM
833 tristate "APM (Advanced Power Management) BIOS support"
834 depends on PM
835 ---help---
836 APM is a BIOS specification for saving power using several different
837 techniques. This is mostly useful for battery powered laptops with
838 APM compliant BIOSes. If you say Y here, the system time will be
839 reset after a RESUME operation, the /proc/apm device will provide
840 battery status information, and user-space programs will receive
841 notification of APM "events" (e.g. battery status change).
843 If you select "Y" here, you can disable actual use of the APM
844 BIOS by passing the "apm=off" option to the kernel at boot time.
846 Note that the APM support is almost completely disabled for
847 machines with more than one CPU.
849 In order to use APM, you will need supporting software. For location
850 and more information, read <file:Documentation/pm.txt> and the
851 Battery Powered Linux mini-HOWTO, available from
852 <http://www.tldp.org/docs.html#howto>.
854 This driver does not spin down disk drives (see the hdparm(8)
855 manpage ("man 8 hdparm") for that), and it doesn't turn off
856 VESA-compliant "green" monitors.
858 This driver does not support the TI 4000M TravelMate and the ACER
859 486/DX4/75 because they don't have compliant BIOSes. Many "green"
860 desktop machines also don't have compliant BIOSes, and this driver
861 may cause those machines to panic during the boot phase.
863 Generally, if you don't have a battery in your machine, there isn't
864 much point in using this driver and you should say N. If you get
865 random kernel OOPSes or reboots that don't seem to be related to
866 anything, try disabling/enabling this option (or disabling/enabling
867 APM in your BIOS).
869 Some other things you should try when experiencing seemingly random,
870 "weird" problems:
872 1) make sure that you have enough swap space and that it is
873 enabled.
874 2) pass the "no-hlt" option to the kernel
875 3) switch on floating point emulation in the kernel and pass
876 the "no387" option to the kernel
877 4) pass the "floppy=nodma" option to the kernel
878 5) pass the "mem=4M" option to the kernel (thereby disabling
879 all but the first 4 MB of RAM)
880 6) make sure that the CPU is not over clocked.
881 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
882 8) disable the cache from your BIOS settings
883 9) install a fan for the video card or exchange video RAM
884 10) install a better fan for the CPU
885 11) exchange RAM chips
886 12) exchange the motherboard.
888 To compile this driver as a module, choose M here: the
889 module will be called apm.
891 config APM_IGNORE_USER_SUSPEND
892 bool "Ignore USER SUSPEND"
893 depends on APM
894 help
895 This option will ignore USER SUSPEND requests. On machines with a
896 compliant APM BIOS, you want to say N. However, on the NEC Versa M
897 series notebooks, it is necessary to say Y because of a BIOS bug.
899 config APM_DO_ENABLE
900 bool "Enable PM at boot time"
901 depends on APM
902 ---help---
903 Enable APM features at boot time. From page 36 of the APM BIOS
904 specification: "When disabled, the APM BIOS does not automatically
905 power manage devices, enter the Standby State, enter the Suspend
906 State, or take power saving steps in response to CPU Idle calls."
907 This driver will make CPU Idle calls when Linux is idle (unless this
908 feature is turned off -- see "Do CPU IDLE calls", below). This
909 should always save battery power, but more complicated APM features
910 will be dependent on your BIOS implementation. You may need to turn
911 this option off if your computer hangs at boot time when using APM
912 support, or if it beeps continuously instead of suspending. Turn
913 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
914 T400CDT. This is off by default since most machines do fine without
915 this feature.
917 config APM_CPU_IDLE
918 bool "Make CPU Idle calls when idle"
919 depends on APM
920 help
921 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
922 On some machines, this can activate improved power savings, such as
923 a slowed CPU clock rate, when the machine is idle. These idle calls
924 are made after the idle loop has run for some length of time (e.g.,
925 333 mS). On some machines, this will cause a hang at boot time or
926 whenever the CPU becomes idle. (On machines with more than one CPU,
927 this option does nothing.)
929 config APM_DISPLAY_BLANK
930 bool "Enable console blanking using APM"
931 depends on APM
932 help
933 Enable console blanking using the APM. Some laptops can use this to
934 turn off the LCD backlight when the screen blanker of the Linux
935 virtual console blanks the screen. Note that this is only used by
936 the virtual console screen blanker, and won't turn off the backlight
937 when using the X Window system. This also doesn't have anything to
938 do with your VESA-compliant power-saving monitor. Further, this
939 option doesn't work for all laptops -- it might not turn off your
940 backlight at all, or it might print a lot of errors to the console,
941 especially if you are using gpm.
943 config APM_RTC_IS_GMT
944 bool "RTC stores time in GMT"
945 depends on APM
946 help
947 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
948 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
949 stores localtime.
951 It is in fact recommended to store GMT in your RTC, because then you
952 don't have to worry about daylight savings time changes. The only
953 reason not to use GMT in your RTC is if you also run a broken OS
954 that doesn't understand GMT.
956 config APM_ALLOW_INTS
957 bool "Allow interrupts during APM BIOS calls"
958 depends on APM
959 help
960 Normally we disable external interrupts while we are making calls to
961 the APM BIOS as a measure to lessen the effects of a badly behaving
962 BIOS implementation. The BIOS should reenable interrupts if it
963 needs to. Unfortunately, some BIOSes do not -- especially those in
964 many of the newer IBM Thinkpads. If you experience hangs when you
965 suspend, try setting this to Y. Otherwise, say N.
967 config APM_REAL_MODE_POWER_OFF
968 bool "Use real mode APM BIOS call to power off"
969 depends on APM
970 help
971 Use real mode APM BIOS calls to switch off the computer. This is
972 a work-around for a number of buggy BIOSes. Switch this option on if
973 your computer crashes instead of powering off properly.
975 endmenu
977 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
979 endmenu
981 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
983 config PCI
984 bool "PCI support" if !X86_VISWS
985 depends on !X86_VOYAGER
986 default y if X86_VISWS
987 help
988 Find out whether you have a PCI motherboard. PCI is the name of a
989 bus system, i.e. the way the CPU talks to the other stuff inside
990 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
991 VESA. If you have PCI, say Y, otherwise N.
993 The PCI-HOWTO, available from
994 <http://www.tldp.org/docs.html#howto>, contains valuable
995 information about which PCI hardware does work under Linux and which
996 doesn't.
998 choice
999 prompt "PCI access mode"
1000 depends on PCI && !X86_VISWS
1001 default PCI_GOANY
1002 ---help---
1003 On PCI systems, the BIOS can be used to detect the PCI devices and
1004 determine their configuration. However, some old PCI motherboards
1005 have BIOS bugs and may crash if this is done. Also, some embedded
1006 PCI-based systems don't have any BIOS at all. Linux can also try to
1007 detect the PCI hardware directly without using the BIOS.
1009 With this option, you can specify how Linux should detect the
1010 PCI devices. If you choose "BIOS", the BIOS will be used,
1011 if you choose "Direct", the BIOS won't be used, and if you
1012 choose "MMConfig", then PCI Express MMCONFIG will be used.
1013 If you choose "Any", the kernel will try MMCONFIG, then the
1014 direct access method and falls back to the BIOS if that doesn't
1015 work. If unsure, go with the default, which is "Any".
1017 config PCI_GOBIOS
1018 bool "BIOS"
1020 config PCI_GOMMCONFIG
1021 bool "MMConfig"
1023 config PCI_GODIRECT
1024 bool "Direct"
1026 config PCI_GOANY
1027 bool "Any"
1029 endchoice
1031 config PCI_BIOS
1032 bool
1033 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1034 default y
1036 config PCI_DIRECT
1037 bool
1038 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1039 default y
1041 config PCI_MMCONFIG
1042 bool
1043 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1044 default y
1046 source "drivers/pci/pcie/Kconfig"
1048 source "drivers/pci/Kconfig"
1050 config ISA_DMA_API
1051 bool
1052 default y
1054 config ISA
1055 bool "ISA support"
1056 depends on !(X86_VOYAGER || X86_VISWS)
1057 help
1058 Find out whether you have ISA slots on your motherboard. ISA is the
1059 name of a bus system, i.e. the way the CPU talks to the other stuff
1060 inside your box. Other bus systems are PCI, EISA, MicroChannel
1061 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1062 newer boards don't support it. If you have ISA, say Y, otherwise N.
1064 config EISA
1065 bool "EISA support"
1066 depends on ISA
1067 ---help---
1068 The Extended Industry Standard Architecture (EISA) bus was
1069 developed as an open alternative to the IBM MicroChannel bus.
1071 The EISA bus provided some of the features of the IBM MicroChannel
1072 bus while maintaining backward compatibility with cards made for
1073 the older ISA bus. The EISA bus saw limited use between 1988 and
1074 1995 when it was made obsolete by the PCI bus.
1076 Say Y here if you are building a kernel for an EISA-based machine.
1078 Otherwise, say N.
1080 source "drivers/eisa/Kconfig"
1082 config MCA
1083 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1084 default y if X86_VOYAGER
1085 help
1086 MicroChannel Architecture is found in some IBM PS/2 machines and
1087 laptops. It is a bus system similar to PCI or ISA. See
1088 <file:Documentation/mca.txt> (and especially the web page given
1089 there) before attempting to build an MCA bus kernel.
1091 source "drivers/mca/Kconfig"
1093 config SCx200
1094 tristate "NatSemi SCx200 support"
1095 depends on !X86_VOYAGER
1096 help
1097 This provides basic support for National Semiconductor's
1098 (now AMD's) Geode processors. The driver probes for the
1099 PCI-IDs of several on-chip devices, so its a good dependency
1100 for other scx200_* drivers.
1102 If compiled as a module, the driver is named scx200.
1104 config SCx200HR_TIMER
1105 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1106 depends on SCx200 && GENERIC_TIME
1107 default y
1108 help
1109 This driver provides a clocksource built upon the on-chip
1110 27MHz high-resolution timer. Its also a workaround for
1111 NSC Geode SC-1100's buggy TSC, which loses time when the
1112 processor goes idle (as is done by the scheduler). The
1113 other workaround is idle=poll boot option.
1115 config K8_NB
1116 def_bool y
1117 depends on AGP_AMD64
1119 source "drivers/pcmcia/Kconfig"
1121 source "drivers/pci/hotplug/Kconfig"
1123 endmenu
1125 menu "Executable file formats"
1127 source "fs/Kconfig.binfmt"
1129 endmenu
1131 source "net/Kconfig"
1133 source "drivers/Kconfig"
1135 source "fs/Kconfig"
1137 menu "Instrumentation Support"
1138 depends on EXPERIMENTAL
1140 source "arch/i386/oprofile/Kconfig"
1142 config KPROBES
1143 bool "Kprobes (EXPERIMENTAL)"
1144 depends on EXPERIMENTAL && MODULES
1145 help
1146 Kprobes allows you to trap at almost any kernel address and
1147 execute a callback function. register_kprobe() establishes
1148 a probepoint and specifies the callback. Kprobes is useful
1149 for kernel debugging, non-intrusive instrumentation and testing.
1150 If in doubt, say "N".
1151 endmenu
1153 source "arch/i386/Kconfig.debug"
1155 source "security/Kconfig"
1157 source "crypto/Kconfig"
1159 source "lib/Kconfig"
1161 #
1162 # Use the generic interrupt handling code in kernel/irq/:
1163 #
1164 config GENERIC_HARDIRQS
1165 bool
1166 default y
1168 config GENERIC_IRQ_PROBE
1169 bool
1170 default y
1172 config GENERIC_PENDING_IRQ
1173 bool
1174 depends on GENERIC_HARDIRQS && SMP
1175 default y
1177 config X86_SMP
1178 bool
1179 depends on SMP && !X86_VOYAGER
1180 default y
1182 config X86_HT
1183 bool
1184 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1185 default y
1187 config X86_BIOS_REBOOT
1188 bool
1189 depends on !(X86_VISWS || X86_VOYAGER)
1190 default y
1192 config X86_TRAMPOLINE
1193 bool
1194 depends on X86_SMP || (X86_VOYAGER && SMP)
1195 default y
1197 config KTIME_SCALAR
1198 bool
1199 default y