2 # For a description of the syntax of this configuration file,
3 # see Documentation/kbuild/kconfig-language.txt.
6 mainmenu "Linux Kernel Configuration"
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.
21 config LOCKDEP_SUPPORT
25 config STACKTRACE_SUPPORT
29 config SEMAPHORE_SLEEPERS
44 config GENERIC_ISA_DMA
52 config GENERIC_HWEIGHT
56 config ARCH_MAY_HAVE_PC_FDC
66 menu "Processor type and features"
69 bool "Symmetric multi-processing support"
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.
98 prompt "Subarchitecture Type"
104 Choose this option if your computer is a standard PC or compatible.
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.
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.
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.
127 bool "NUMAQ (IBM/Sequent)"
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>.
138 bool "Summit/EXA (IBM x440)"
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.
148 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
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.
157 bool "SGI 320/540 (Visual Workstation)"
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)"
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.
175 bool "Support for Unisys ES7000 IA32 series"
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
188 depends on ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH)
191 config HAVE_ARCH_PARSE_SRAT
196 config X86_SUMMIT_NUMA
199 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
201 config X86_CYCLONE_TIMER
204 depends on X86_SUMMIT || X86_GENERICARCH
206 config ES7000_CLUSTERED_APIC
209 depends on SMP && X86_ES7000 && MPENTIUMIII
211 source "arch/i386/Kconfig.cpu"
214 bool "HPET Timer Support"
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
226 depends on HPET_TIMER && RTC=y
230 int "Maximum number of CPUs (2-255)"
233 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
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.
244 bool "SMT (Hyperthreading) scheduler support"
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
253 bool "Multi-core scheduler support"
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"
264 bool "Local APIC support on uniprocessors"
265 depends on !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH)
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
277 bool "IO-APIC support on uniprocessors"
278 depends on X86_UP_APIC
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
290 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH
295 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH
298 config X86_VISWS_APIC
304 bool "Machine Check Exception"
305 depends on !X86_VOYAGER
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"
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
337 Enabling this feature will cause a message to be printed when the P4
338 enters thermal throttling.
342 bool "Enable VM86 support" if EMBEDDED
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.
350 tristate "Toshiba Laptop support"
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.
365 tristate "Dell laptop support"
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
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.
384 config X86_REBOOTFIXUPS
385 bool "Enable X86 board specific fixups for reboot"
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
395 Currently, the only fixup is for the Geode GX1/CS5530A/TROM2.1.
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.
403 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
406 If you say Y here and also to "/dev file system support" in the
407 'File systems' section, you will be able to update the microcode on
408 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
409 Pentium III, Pentium 4, Xeon etc. You will obviously need the
410 actual microcode binary data itself which is not shipped with the
413 For latest news and information on obtaining all the required
414 ingredients for this driver, check:
415 <http://www.urbanmyth.org/microcode/>.
417 To compile this driver as a module, choose M here: the
418 module will be called microcode.
420 config MICROCODE_OLD_INTERFACE
426 tristate "/dev/cpu/*/msr - Model-specific register support"
428 This device gives privileged processes access to the x86
429 Model-Specific Registers (MSRs). It is a character device with
430 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
431 MSR accesses are directed to a specific CPU on multi-processor
435 tristate "/dev/cpu/*/cpuid - CPU information support"
437 This device gives processes access to the x86 CPUID instruction to
438 be executed on a specific processor. It is a character device
439 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
442 source "drivers/firmware/Kconfig"
445 prompt "High Memory Support"
450 depends on !X86_NUMAQ
452 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
453 However, the address space of 32-bit x86 processors is only 4
454 Gigabytes large. That means that, if you have a large amount of
455 physical memory, not all of it can be "permanently mapped" by the
456 kernel. The physical memory that's not permanently mapped is called
459 If you are compiling a kernel which will never run on a machine with
460 more than 1 Gigabyte total physical RAM, answer "off" here (default
461 choice and suitable for most users). This will result in a "3GB/1GB"
462 split: 3GB are mapped so that each process sees a 3GB virtual memory
463 space and the remaining part of the 4GB virtual memory space is used
464 by the kernel to permanently map as much physical memory as
467 If the machine has between 1 and 4 Gigabytes physical RAM, then
470 If more than 4 Gigabytes is used then answer "64GB" here. This
471 selection turns Intel PAE (Physical Address Extension) mode on.
472 PAE implements 3-level paging on IA32 processors. PAE is fully
473 supported by Linux, PAE mode is implemented on all recent Intel
474 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
475 then the kernel will not boot on CPUs that don't support PAE!
477 The actual amount of total physical memory will either be
478 auto detected or can be forced by using a kernel command line option
479 such as "mem=256M". (Try "man bootparam" or see the documentation of
480 your boot loader (lilo or loadlin) about how to pass options to the
481 kernel at boot time.)
483 If unsure, say "off".
487 depends on !X86_NUMAQ
489 Select this if you have a 32-bit processor and between 1 and 4
490 gigabytes of physical RAM.
494 depends on X86_CMPXCHG64
496 Select this if you have a 32-bit processor and more than 4
497 gigabytes of physical RAM.
502 depends on EXPERIMENTAL
503 prompt "Memory split" if EMBEDDED
506 Select the desired split between kernel and user memory.
508 If the address range available to the kernel is less than the
509 physical memory installed, the remaining memory will be available
510 as "high memory". Accessing high memory is a little more costly
511 than low memory, as it needs to be mapped into the kernel first.
512 Note that increasing the kernel address space limits the range
513 available to user programs, making the address space there
514 tighter. Selecting anything other than the default 3G/1G split
515 will also likely make your kernel incompatible with binary-only
518 If you are not absolutely sure what you are doing, leave this
522 bool "3G/1G user/kernel split"
523 config VMSPLIT_3G_OPT
525 bool "3G/1G user/kernel split (for full 1G low memory)"
527 bool "2G/2G user/kernel split"
529 bool "1G/3G user/kernel split"
534 default 0xB0000000 if VMSPLIT_3G_OPT
535 default 0x78000000 if VMSPLIT_2G
536 default 0x40000000 if VMSPLIT_1G
541 depends on HIGHMEM64G || HIGHMEM4G
546 depends on HIGHMEM64G
548 select RESOURCES_64BIT
550 # Common NUMA Features
552 bool "Numa Memory Allocation and Scheduler Support"
553 depends on SMP && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI)
555 default y if (X86_NUMAQ || X86_SUMMIT)
557 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
558 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
562 default "4" if X86_NUMAQ
564 depends on NEED_MULTIPLE_NODES
566 config HAVE_ARCH_BOOTMEM_NODE
571 config ARCH_HAVE_MEMORY_PRESENT
573 depends on DISCONTIGMEM
576 config NEED_NODE_MEMMAP_SIZE
578 depends on DISCONTIGMEM || SPARSEMEM
581 config HAVE_ARCH_ALLOC_REMAP
586 config ARCH_FLATMEM_ENABLE
588 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
590 config ARCH_DISCONTIGMEM_ENABLE
594 config ARCH_DISCONTIGMEM_DEFAULT
598 config ARCH_SPARSEMEM_ENABLE
600 depends on (NUMA || (X86_PC && EXPERIMENTAL))
601 select SPARSEMEM_STATIC
603 config ARCH_SELECT_MEMORY_MODEL
605 depends on ARCH_SPARSEMEM_ENABLE
607 config ARCH_POPULATES_NODE_MAP
613 bool "Allocate 3rd-level pagetables from highmem"
614 depends on HIGHMEM4G || HIGHMEM64G
616 The VM uses one page table entry for each page of physical memory.
617 For systems with a lot of RAM, this can be wasteful of precious
618 low memory. Setting this option will put user-space page table
619 entries in high memory.
621 config MATH_EMULATION
622 bool "Math emulation"
624 Linux can emulate a math coprocessor (used for floating point
625 operations) if you don't have one. 486DX and Pentium processors have
626 a math coprocessor built in, 486SX and 386 do not, unless you added
627 a 487DX or 387, respectively. (The messages during boot time can
628 give you some hints here ["man dmesg"].) Everyone needs either a
629 coprocessor or this emulation.
631 If you don't have a math coprocessor, you need to say Y here; if you
632 say Y here even though you have a coprocessor, the coprocessor will
633 be used nevertheless. (This behavior can be changed with the kernel
634 command line option "no387", which comes handy if your coprocessor
635 is broken. Try "man bootparam" or see the documentation of your boot
636 loader (lilo or loadlin) about how to pass options to the kernel at
637 boot time.) This means that it is a good idea to say Y here if you
638 intend to use this kernel on different machines.
640 More information about the internals of the Linux math coprocessor
641 emulation can be found in <file:arch/i386/math-emu/README>.
643 If you are not sure, say Y; apart from resulting in a 66 KB bigger
644 kernel, it won't hurt.
647 bool "MTRR (Memory Type Range Register) support"
649 On Intel P6 family processors (Pentium Pro, Pentium II and later)
650 the Memory Type Range Registers (MTRRs) may be used to control
651 processor access to memory ranges. This is most useful if you have
652 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
653 allows bus write transfers to be combined into a larger transfer
654 before bursting over the PCI/AGP bus. This can increase performance
655 of image write operations 2.5 times or more. Saying Y here creates a
656 /proc/mtrr file which may be used to manipulate your processor's
657 MTRRs. Typically the X server should use this.
659 This code has a reasonably generic interface so that similar
660 control registers on other processors can be easily supported
663 The Cyrix 6x86, 6x86MX and M II processors have Address Range
664 Registers (ARRs) which provide a similar functionality to MTRRs. For
665 these, the ARRs are used to emulate the MTRRs.
666 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
667 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
668 write-combining. All of these processors are supported by this code
669 and it makes sense to say Y here if you have one of them.
671 Saying Y here also fixes a problem with buggy SMP BIOSes which only
672 set the MTRRs for the boot CPU and not for the secondary CPUs. This
673 can lead to all sorts of problems, so it's good to say Y here.
675 You can safely say Y even if your machine doesn't have MTRRs, you'll
676 just add about 9 KB to your kernel.
678 See <file:Documentation/mtrr.txt> for more information.
681 bool "Boot from EFI support"
685 This enables the kernel to boot on EFI platforms using
686 system configuration information passed to it from the firmware.
687 This also enables the kernel to use any EFI runtime services that are
688 available (such as the EFI variable services).
690 This option is only useful on systems that have EFI firmware
691 and will result in a kernel image that is ~8k larger. In addition,
692 you must use the latest ELILO loader available at
693 <http://elilo.sourceforge.net> in order to take advantage of
694 kernel initialization using EFI information (neither GRUB nor LILO know
695 anything about EFI). However, even with this option, the resultant
696 kernel should continue to boot on existing non-EFI platforms.
699 bool "Enable kernel irq balancing"
700 depends on SMP && X86_IO_APIC
703 The default yes will allow the kernel to do irq load balancing.
704 Saying no will keep the kernel from doing irq load balancing.
706 # turning this on wastes a bunch of space.
707 # Summit needs it only when NUMA is on
710 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
714 bool "Use register arguments"
717 Compile the kernel with -mregparm=3. This instructs gcc to use
718 a more efficient function call ABI which passes the first three
719 arguments of a function call via registers, which results in denser
722 If this option is disabled, then the default ABI of passing
723 arguments via the stack is used.
728 bool "Enable seccomp to safely compute untrusted bytecode"
732 This kernel feature is useful for number crunching applications
733 that may need to compute untrusted bytecode during their
734 execution. By using pipes or other transports made available to
735 the process as file descriptors supporting the read/write
736 syscalls, it's possible to isolate those applications in
737 their own address space using seccomp. Once seccomp is
738 enabled via /proc/<pid>/seccomp, it cannot be disabled
739 and the task is only allowed to execute a few safe syscalls
740 defined by each seccomp mode.
742 If unsure, say Y. Only embedded should say N here.
744 source kernel/Kconfig.hz
747 bool "kexec system call"
749 kexec is a system call that implements the ability to shutdown your
750 current kernel, and to start another kernel. It is like a reboot
751 but it is independent of the system firmware. And like a reboot
752 you can start any kernel with it, not just Linux.
754 The name comes from the similarity to the exec system call.
756 It is an ongoing process to be certain the hardware in a machine
757 is properly shutdown, so do not be surprised if this code does not
758 initially work for you. It may help to enable device hotplugging
759 support. As of this writing the exact hardware interface is
760 strongly in flux, so no good recommendation can be made.
763 bool "kernel crash dumps (EXPERIMENTAL)"
764 depends on EXPERIMENTAL
767 Generate crash dump after being started by kexec.
768 This should be normally only set in special crash dump kernels
769 which are loaded in the main kernel with kexec-tools into
770 a specially reserved region and then later executed after
771 a crash by kdump/kexec. The crash dump kernel must be compiled
772 to a memory address not used by the main kernel or BIOS using
774 For more details see Documentation/kdump/kdump.txt
777 bool "Build a relocatable kernel(EXPERIMENTAL)"
778 depends on EXPERIMENTAL
780 This build a kernel image that retains relocation information
781 so it can be loaded someplace besides the default 1MB.
782 The relocations tend to the kernel binary about 10% larger,
783 but are discarded at runtime.
785 One use is for the kexec on panic case where the recovery kernel
786 must live at a different physical address than the primary
789 config PHYSICAL_ALIGN
790 hex "Alignment value to which kernel should be aligned"
792 range 0x2000 0x400000
794 This value puts the alignment restrictions on physical address
795 where kernel is loaded and run from. Kernel is compiled for an
796 address which meets above alignment restriction.
798 If bootloader loads the kernel at a non-aligned address and
799 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
800 address aligned to above value and run from there.
802 If bootloader loads the kernel at a non-aligned address and
803 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
804 load address and decompress itself to the address it has been
805 compiled for and run from there. The address for which kernel is
806 compiled already meets above alignment restrictions. Hence the
807 end result is that kernel runs from a physical address meeting
808 above alignment restrictions.
810 Don't change this unless you know what you are doing.
813 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
814 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
816 Say Y here to experiment with turning CPUs off and on, and to
817 enable suspend on SMP systems. CPUs can be controlled through
818 /sys/devices/system/cpu.
821 bool "Compat VDSO support"
825 Map the VDSO to the predictable old-style address too.
827 Say N here if you are running a sufficiently recent glibc
828 version (2.3.3 or later), to remove the high-mapped
829 VDSO mapping and to exclusively use the randomized VDSO.
835 config ARCH_ENABLE_MEMORY_HOTPLUG
839 menu "Power management options (ACPI, APM)"
840 depends on !X86_VOYAGER
842 source kernel/power/Kconfig
844 source "drivers/acpi/Kconfig"
846 menu "APM (Advanced Power Management) BIOS Support"
847 depends on PM && !X86_VISWS
850 tristate "APM (Advanced Power Management) BIOS support"
853 APM is a BIOS specification for saving power using several different
854 techniques. This is mostly useful for battery powered laptops with
855 APM compliant BIOSes. If you say Y here, the system time will be
856 reset after a RESUME operation, the /proc/apm device will provide
857 battery status information, and user-space programs will receive
858 notification of APM "events" (e.g. battery status change).
860 If you select "Y" here, you can disable actual use of the APM
861 BIOS by passing the "apm=off" option to the kernel at boot time.
863 Note that the APM support is almost completely disabled for
864 machines with more than one CPU.
866 In order to use APM, you will need supporting software. For location
867 and more information, read <file:Documentation/pm.txt> and the
868 Battery Powered Linux mini-HOWTO, available from
869 <http://www.tldp.org/docs.html#howto>.
871 This driver does not spin down disk drives (see the hdparm(8)
872 manpage ("man 8 hdparm") for that), and it doesn't turn off
873 VESA-compliant "green" monitors.
875 This driver does not support the TI 4000M TravelMate and the ACER
876 486/DX4/75 because they don't have compliant BIOSes. Many "green"
877 desktop machines also don't have compliant BIOSes, and this driver
878 may cause those machines to panic during the boot phase.
880 Generally, if you don't have a battery in your machine, there isn't
881 much point in using this driver and you should say N. If you get
882 random kernel OOPSes or reboots that don't seem to be related to
883 anything, try disabling/enabling this option (or disabling/enabling
886 Some other things you should try when experiencing seemingly random,
889 1) make sure that you have enough swap space and that it is
891 2) pass the "no-hlt" option to the kernel
892 3) switch on floating point emulation in the kernel and pass
893 the "no387" option to the kernel
894 4) pass the "floppy=nodma" option to the kernel
895 5) pass the "mem=4M" option to the kernel (thereby disabling
896 all but the first 4 MB of RAM)
897 6) make sure that the CPU is not over clocked.
898 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
899 8) disable the cache from your BIOS settings
900 9) install a fan for the video card or exchange video RAM
901 10) install a better fan for the CPU
902 11) exchange RAM chips
903 12) exchange the motherboard.
905 To compile this driver as a module, choose M here: the
906 module will be called apm.
908 config APM_IGNORE_USER_SUSPEND
909 bool "Ignore USER SUSPEND"
912 This option will ignore USER SUSPEND requests. On machines with a
913 compliant APM BIOS, you want to say N. However, on the NEC Versa M
914 series notebooks, it is necessary to say Y because of a BIOS bug.
917 bool "Enable PM at boot time"
920 Enable APM features at boot time. From page 36 of the APM BIOS
921 specification: "When disabled, the APM BIOS does not automatically
922 power manage devices, enter the Standby State, enter the Suspend
923 State, or take power saving steps in response to CPU Idle calls."
924 This driver will make CPU Idle calls when Linux is idle (unless this
925 feature is turned off -- see "Do CPU IDLE calls", below). This
926 should always save battery power, but more complicated APM features
927 will be dependent on your BIOS implementation. You may need to turn
928 this option off if your computer hangs at boot time when using APM
929 support, or if it beeps continuously instead of suspending. Turn
930 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
931 T400CDT. This is off by default since most machines do fine without
935 bool "Make CPU Idle calls when idle"
938 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
939 On some machines, this can activate improved power savings, such as
940 a slowed CPU clock rate, when the machine is idle. These idle calls
941 are made after the idle loop has run for some length of time (e.g.,
942 333 mS). On some machines, this will cause a hang at boot time or
943 whenever the CPU becomes idle. (On machines with more than one CPU,
944 this option does nothing.)
946 config APM_DISPLAY_BLANK
947 bool "Enable console blanking using APM"
950 Enable console blanking using the APM. Some laptops can use this to
951 turn off the LCD backlight when the screen blanker of the Linux
952 virtual console blanks the screen. Note that this is only used by
953 the virtual console screen blanker, and won't turn off the backlight
954 when using the X Window system. This also doesn't have anything to
955 do with your VESA-compliant power-saving monitor. Further, this
956 option doesn't work for all laptops -- it might not turn off your
957 backlight at all, or it might print a lot of errors to the console,
958 especially if you are using gpm.
960 config APM_RTC_IS_GMT
961 bool "RTC stores time in GMT"
964 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
965 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
968 It is in fact recommended to store GMT in your RTC, because then you
969 don't have to worry about daylight savings time changes. The only
970 reason not to use GMT in your RTC is if you also run a broken OS
971 that doesn't understand GMT.
973 config APM_ALLOW_INTS
974 bool "Allow interrupts during APM BIOS calls"
977 Normally we disable external interrupts while we are making calls to
978 the APM BIOS as a measure to lessen the effects of a badly behaving
979 BIOS implementation. The BIOS should reenable interrupts if it
980 needs to. Unfortunately, some BIOSes do not -- especially those in
981 many of the newer IBM Thinkpads. If you experience hangs when you
982 suspend, try setting this to Y. Otherwise, say N.
984 config APM_REAL_MODE_POWER_OFF
985 bool "Use real mode APM BIOS call to power off"
988 Use real mode APM BIOS calls to switch off the computer. This is
989 a work-around for a number of buggy BIOSes. Switch this option on if
990 your computer crashes instead of powering off properly.
994 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
998 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
1001 bool "PCI support" if !X86_VISWS
1002 depends on !X86_VOYAGER
1003 default y if X86_VISWS
1005 Find out whether you have a PCI motherboard. PCI is the name of a
1006 bus system, i.e. the way the CPU talks to the other stuff inside
1007 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1008 VESA. If you have PCI, say Y, otherwise N.
1010 The PCI-HOWTO, available from
1011 <http://www.tldp.org/docs.html#howto>, contains valuable
1012 information about which PCI hardware does work under Linux and which
1016 prompt "PCI access mode"
1017 depends on PCI && !X86_VISWS
1020 On PCI systems, the BIOS can be used to detect the PCI devices and
1021 determine their configuration. However, some old PCI motherboards
1022 have BIOS bugs and may crash if this is done. Also, some embedded
1023 PCI-based systems don't have any BIOS at all. Linux can also try to
1024 detect the PCI hardware directly without using the BIOS.
1026 With this option, you can specify how Linux should detect the
1027 PCI devices. If you choose "BIOS", the BIOS will be used,
1028 if you choose "Direct", the BIOS won't be used, and if you
1029 choose "MMConfig", then PCI Express MMCONFIG will be used.
1030 If you choose "Any", the kernel will try MMCONFIG, then the
1031 direct access method and falls back to the BIOS if that doesn't
1032 work. If unsure, go with the default, which is "Any".
1037 config PCI_GOMMCONFIG
1050 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1055 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1060 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1063 source "drivers/pci/pcie/Kconfig"
1065 source "drivers/pci/Kconfig"
1073 depends on !(X86_VOYAGER || X86_VISWS)
1075 Find out whether you have ISA slots on your motherboard. ISA is the
1076 name of a bus system, i.e. the way the CPU talks to the other stuff
1077 inside your box. Other bus systems are PCI, EISA, MicroChannel
1078 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1079 newer boards don't support it. If you have ISA, say Y, otherwise N.
1085 The Extended Industry Standard Architecture (EISA) bus was
1086 developed as an open alternative to the IBM MicroChannel bus.
1088 The EISA bus provided some of the features of the IBM MicroChannel
1089 bus while maintaining backward compatibility with cards made for
1090 the older ISA bus. The EISA bus saw limited use between 1988 and
1091 1995 when it was made obsolete by the PCI bus.
1093 Say Y here if you are building a kernel for an EISA-based machine.
1097 source "drivers/eisa/Kconfig"
1100 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1101 default y if X86_VOYAGER
1103 MicroChannel Architecture is found in some IBM PS/2 machines and
1104 laptops. It is a bus system similar to PCI or ISA. See
1105 <file:Documentation/mca.txt> (and especially the web page given
1106 there) before attempting to build an MCA bus kernel.
1108 source "drivers/mca/Kconfig"
1111 tristate "NatSemi SCx200 support"
1112 depends on !X86_VOYAGER
1114 This provides basic support for National Semiconductor's
1115 (now AMD's) Geode processors. The driver probes for the
1116 PCI-IDs of several on-chip devices, so its a good dependency
1117 for other scx200_* drivers.
1119 If compiled as a module, the driver is named scx200.
1121 config SCx200HR_TIMER
1122 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1123 depends on SCx200 && GENERIC_TIME
1126 This driver provides a clocksource built upon the on-chip
1127 27MHz high-resolution timer. Its also a workaround for
1128 NSC Geode SC-1100's buggy TSC, which loses time when the
1129 processor goes idle (as is done by the scheduler). The
1130 other workaround is idle=poll boot option.
1134 depends on AGP_AMD64
1136 source "drivers/pcmcia/Kconfig"
1138 source "drivers/pci/hotplug/Kconfig"
1142 menu "Executable file formats"
1144 source "fs/Kconfig.binfmt"
1148 source "net/Kconfig"
1150 source "drivers/Kconfig"
1154 menu "Instrumentation Support"
1155 depends on EXPERIMENTAL
1157 source "arch/i386/oprofile/Kconfig"
1160 bool "Kprobes (EXPERIMENTAL)"
1161 depends on KALLSYMS && EXPERIMENTAL && MODULES
1163 Kprobes allows you to trap at almost any kernel address and
1164 execute a callback function. register_kprobe() establishes
1165 a probepoint and specifies the callback. Kprobes is useful
1166 for kernel debugging, non-intrusive instrumentation and testing.
1167 If in doubt, say "N".
1170 source "arch/i386/Kconfig.debug"
1172 source "security/Kconfig"
1174 source "crypto/Kconfig"
1176 source "lib/Kconfig"
1179 # Use the generic interrupt handling code in kernel/irq/:
1181 config GENERIC_HARDIRQS
1185 config GENERIC_IRQ_PROBE
1189 config GENERIC_PENDING_IRQ
1191 depends on GENERIC_HARDIRQS && SMP
1196 depends on SMP && !X86_VOYAGER
1201 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1204 config X86_BIOS_REBOOT
1206 depends on !(X86_VISWS || X86_VOYAGER)
1209 config X86_TRAMPOLINE
1211 depends on X86_SMP || (X86_VOYAGER && SMP)
projects / linux-2.6 / blob