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
57 config GENERIC_HWEIGHT
61 config ARCH_MAY_HAVE_PC_FDC
71 menu "Processor type and features"
74 bool "Symmetric multi-processing support"
76 This enables support for systems with more than one CPU. If you have
77 a system with only one CPU, like most personal computers, say N. If
78 you have a system with more than one CPU, say Y.
80 If you say N here, the kernel will run on single and multiprocessor
81 machines, but will use only one CPU of a multiprocessor machine. If
82 you say Y here, the kernel will run on many, but not all,
83 singleprocessor machines. On a singleprocessor machine, the kernel
84 will run faster if you say N here.
86 Note that if you say Y here and choose architecture "586" or
87 "Pentium" under "Processor family", the kernel will not work on 486
88 architectures. Similarly, multiprocessor kernels for the "PPro"
89 architecture may not work on all Pentium based boards.
91 People using multiprocessor machines who say Y here should also say
92 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
93 Management" code will be disabled if you say Y here.
95 See also the <file:Documentation/smp.txt>,
96 <file:Documentation/i386/IO-APIC.txt>,
97 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
98 <http://www.tldp.org/docs.html#howto>.
100 If you don't know what to do here, say N.
103 prompt "Subarchitecture Type"
109 Choose this option if your computer is a standard PC or compatible.
114 Select this for an AMD Elan processor.
116 Do not use this option for K6/Athlon/Opteron processors!
118 If unsure, choose "PC-compatible" instead.
123 Voyager is an MCA-based 32-way capable SMP architecture proprietary
124 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
128 If you do not specifically know you have a Voyager based machine,
129 say N here, otherwise the kernel you build will not be bootable.
132 bool "NUMAQ (IBM/Sequent)"
136 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
137 multiquad box. This changes the way that processors are bootstrapped,
138 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
139 You will need a new lynxer.elf file to flash your firmware with - send
140 email to <Martin.Bligh@us.ibm.com>.
143 bool "Summit/EXA (IBM x440)"
146 This option is needed for IBM systems that use the Summit/EXA chipset.
147 In particular, it is needed for the x440.
149 If you don't have one of these computers, you should say N here.
150 If you want to build a NUMA kernel, you must select ACPI.
153 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
156 This option is needed for the systems that have more than 8 CPUs
157 and if the system is not of any sub-arch type above.
159 If you don't have such a system, you should say N here.
162 bool "SGI 320/540 (Visual Workstation)"
164 The SGI Visual Workstation series is an IA32-based workstation
165 based on SGI systems chips with some legacy PC hardware attached.
167 Say Y here to create a kernel to run on the SGI 320 or 540.
169 A kernel compiled for the Visual Workstation will not run on PCs
170 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
172 config X86_GENERICARCH
173 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
175 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
176 It is intended for a generic binary kernel.
177 If you want a NUMA kernel, select ACPI. We need SRAT for NUMA.
180 bool "Support for Unisys ES7000 IA32 series"
183 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
184 supposed to run on an IA32-based Unisys ES7000 system.
185 Only choose this option if you have such a system, otherwise you
191 bool "Paravirtualization support (EXPERIMENTAL)"
192 depends on EXPERIMENTAL
194 Paravirtualization is a way of running multiple instances of
195 Linux on the same machine, under a hypervisor. This option
196 changes the kernel so it can modify itself when it is run
197 under a hypervisor, improving performance significantly.
198 However, when run without a hypervisor the kernel is
199 theoretically slower. If in doubt, say N.
204 depends on ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH)
207 config HAVE_ARCH_PARSE_SRAT
212 config X86_SUMMIT_NUMA
215 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
217 config X86_CYCLONE_TIMER
220 depends on X86_SUMMIT || X86_GENERICARCH
222 config ES7000_CLUSTERED_APIC
225 depends on SMP && X86_ES7000 && MPENTIUMIII
227 source "arch/i386/Kconfig.cpu"
230 bool "HPET Timer Support"
232 This enables the use of the HPET for the kernel's internal timer.
233 HPET is the next generation timer replacing legacy 8254s.
234 You can safely choose Y here. However, HPET will only be
235 activated if the platform and the BIOS support this feature.
236 Otherwise the 8254 will be used for timing services.
238 Choose N to continue using the legacy 8254 timer.
240 config HPET_EMULATE_RTC
242 depends on HPET_TIMER && RTC=y
246 int "Maximum number of CPUs (2-255)"
249 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
252 This allows you to specify the maximum number of CPUs which this
253 kernel will support. The maximum supported value is 255 and the
254 minimum value which makes sense is 2.
256 This is purely to save memory - each supported CPU adds
257 approximately eight kilobytes to the kernel image.
260 bool "SMT (Hyperthreading) scheduler support"
263 SMT scheduler support improves the CPU scheduler's decision making
264 when dealing with Intel Pentium 4 chips with HyperThreading at a
265 cost of slightly increased overhead in some places. If unsure say
269 bool "Multi-core scheduler support"
273 Multi-core scheduler support improves the CPU scheduler's decision
274 making when dealing with multi-core CPU chips at a cost of slightly
275 increased overhead in some places. If unsure say N here.
277 source "kernel/Kconfig.preempt"
280 bool "Local APIC support on uniprocessors"
281 depends on !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH)
283 A local APIC (Advanced Programmable Interrupt Controller) is an
284 integrated interrupt controller in the CPU. If you have a single-CPU
285 system which has a processor with a local APIC, you can say Y here to
286 enable and use it. If you say Y here even though your machine doesn't
287 have a local APIC, then the kernel will still run with no slowdown at
288 all. The local APIC supports CPU-generated self-interrupts (timer,
289 performance counters), and the NMI watchdog which detects hard
293 bool "IO-APIC support on uniprocessors"
294 depends on X86_UP_APIC
296 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
297 SMP-capable replacement for PC-style interrupt controllers. Most
298 SMP systems and many recent uniprocessor systems have one.
300 If you have a single-CPU system with an IO-APIC, you can say Y here
301 to use it. If you say Y here even though your machine doesn't have
302 an IO-APIC, then the kernel will still run with no slowdown at all.
304 config X86_LOCAL_APIC
306 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH
311 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH
314 config X86_VISWS_APIC
320 bool "Machine Check Exception"
321 depends on !X86_VOYAGER
323 Machine Check Exception support allows the processor to notify the
324 kernel if it detects a problem (e.g. overheating, component failure).
325 The action the kernel takes depends on the severity of the problem,
326 ranging from a warning message on the console, to halting the machine.
327 Your processor must be a Pentium or newer to support this - check the
328 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
329 have a design flaw which leads to false MCE events - hence MCE is
330 disabled on all P5 processors, unless explicitly enabled with "mce"
331 as a boot argument. Similarly, if MCE is built in and creates a
332 problem on some new non-standard machine, you can boot with "nomce"
333 to disable it. MCE support simply ignores non-MCE processors like
334 the 386 and 486, so nearly everyone can say Y here.
336 config X86_MCE_NONFATAL
337 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
340 Enabling this feature starts a timer that triggers every 5 seconds which
341 will look at the machine check registers to see if anything happened.
342 Non-fatal problems automatically get corrected (but still logged).
343 Disable this if you don't want to see these messages.
344 Seeing the messages this option prints out may be indicative of dying hardware,
345 or out-of-spec (ie, overclocked) hardware.
346 This option only does something on certain CPUs.
347 (AMD Athlon/Duron and Intel Pentium 4)
349 config X86_MCE_P4THERMAL
350 bool "check for P4 thermal throttling interrupt."
351 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
353 Enabling this feature will cause a message to be printed when the P4
354 enters thermal throttling.
358 bool "Enable VM86 support" if EMBEDDED
360 This option is required by programs like DOSEMU to run 16-bit legacy
361 code on X86 processors. It also may be needed by software like
362 XFree86 to initialize some video cards via BIOS. Disabling this
363 option saves about 6k.
366 tristate "Toshiba Laptop support"
368 This adds a driver to safely access the System Management Mode of
369 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
370 not work on models with a Phoenix BIOS. The System Management Mode
371 is used to set the BIOS and power saving options on Toshiba portables.
373 For information on utilities to make use of this driver see the
374 Toshiba Linux utilities web site at:
375 <http://www.buzzard.org.uk/toshiba/>.
377 Say Y if you intend to run this kernel on a Toshiba portable.
381 tristate "Dell laptop support"
383 This adds a driver to safely access the System Management Mode
384 of the CPU on the Dell Inspiron 8000. The System Management Mode
385 is used to read cpu temperature and cooling fan status and to
386 control the fans on the I8K portables.
388 This driver has been tested only on the Inspiron 8000 but it may
389 also work with other Dell laptops. You can force loading on other
390 models by passing the parameter `force=1' to the module. Use at
393 For information on utilities to make use of this driver see the
394 I8K Linux utilities web site at:
395 <http://people.debian.org/~dz/i8k/>
397 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
400 config X86_REBOOTFIXUPS
401 bool "Enable X86 board specific fixups for reboot"
405 This enables chipset and/or board specific fixups to be done
406 in order to get reboot to work correctly. This is only needed on
407 some combinations of hardware and BIOS. The symptom, for which
408 this config is intended, is when reboot ends with a stalled/hung
411 Currently, the only fixup is for the Geode GX1/CS5530A/TROM2.1.
414 Say Y if you want to enable the fixup. Currently, it's safe to
415 enable this option even if you don't need it.
419 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
422 If you say Y here and also to "/dev file system support" in the
423 'File systems' section, you will be able to update the microcode on
424 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
425 Pentium III, Pentium 4, Xeon etc. You will obviously need the
426 actual microcode binary data itself which is not shipped with the
429 For latest news and information on obtaining all the required
430 ingredients for this driver, check:
431 <http://www.urbanmyth.org/microcode/>.
433 To compile this driver as a module, choose M here: the
434 module will be called microcode.
436 config MICROCODE_OLD_INTERFACE
442 tristate "/dev/cpu/*/msr - Model-specific register support"
444 This device gives privileged processes access to the x86
445 Model-Specific Registers (MSRs). It is a character device with
446 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
447 MSR accesses are directed to a specific CPU on multi-processor
451 tristate "/dev/cpu/*/cpuid - CPU information support"
453 This device gives processes access to the x86 CPUID instruction to
454 be executed on a specific processor. It is a character device
455 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
458 source "drivers/firmware/Kconfig"
461 prompt "High Memory Support"
462 default HIGHMEM4G if !X86_NUMAQ
463 default HIGHMEM64G if X86_NUMAQ
467 depends on !X86_NUMAQ
469 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
470 However, the address space of 32-bit x86 processors is only 4
471 Gigabytes large. That means that, if you have a large amount of
472 physical memory, not all of it can be "permanently mapped" by the
473 kernel. The physical memory that's not permanently mapped is called
476 If you are compiling a kernel which will never run on a machine with
477 more than 1 Gigabyte total physical RAM, answer "off" here (default
478 choice and suitable for most users). This will result in a "3GB/1GB"
479 split: 3GB are mapped so that each process sees a 3GB virtual memory
480 space and the remaining part of the 4GB virtual memory space is used
481 by the kernel to permanently map as much physical memory as
484 If the machine has between 1 and 4 Gigabytes physical RAM, then
487 If more than 4 Gigabytes is used then answer "64GB" here. This
488 selection turns Intel PAE (Physical Address Extension) mode on.
489 PAE implements 3-level paging on IA32 processors. PAE is fully
490 supported by Linux, PAE mode is implemented on all recent Intel
491 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
492 then the kernel will not boot on CPUs that don't support PAE!
494 The actual amount of total physical memory will either be
495 auto detected or can be forced by using a kernel command line option
496 such as "mem=256M". (Try "man bootparam" or see the documentation of
497 your boot loader (lilo or loadlin) about how to pass options to the
498 kernel at boot time.)
500 If unsure, say "off".
504 depends on !X86_NUMAQ
506 Select this if you have a 32-bit processor and between 1 and 4
507 gigabytes of physical RAM.
511 depends on X86_CMPXCHG64
513 Select this if you have a 32-bit processor and more than 4
514 gigabytes of physical RAM.
519 depends on EXPERIMENTAL
520 prompt "Memory split" if EMBEDDED
523 Select the desired split between kernel and user memory.
525 If the address range available to the kernel is less than the
526 physical memory installed, the remaining memory will be available
527 as "high memory". Accessing high memory is a little more costly
528 than low memory, as it needs to be mapped into the kernel first.
529 Note that increasing the kernel address space limits the range
530 available to user programs, making the address space there
531 tighter. Selecting anything other than the default 3G/1G split
532 will also likely make your kernel incompatible with binary-only
535 If you are not absolutely sure what you are doing, leave this
539 bool "3G/1G user/kernel split"
540 config VMSPLIT_3G_OPT
542 bool "3G/1G user/kernel split (for full 1G low memory)"
544 bool "2G/2G user/kernel split"
546 bool "1G/3G user/kernel split"
551 default 0xB0000000 if VMSPLIT_3G_OPT
552 default 0x78000000 if VMSPLIT_2G
553 default 0x40000000 if VMSPLIT_1G
558 depends on HIGHMEM64G || HIGHMEM4G
563 depends on HIGHMEM64G
565 select RESOURCES_64BIT
567 # Common NUMA Features
569 bool "Numa Memory Allocation and Scheduler Support"
570 depends on SMP && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI)
572 default y if (X86_NUMAQ || X86_SUMMIT)
574 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
575 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
579 default "4" if X86_NUMAQ
581 depends on NEED_MULTIPLE_NODES
583 config HAVE_ARCH_BOOTMEM_NODE
588 config ARCH_HAVE_MEMORY_PRESENT
590 depends on DISCONTIGMEM
593 config NEED_NODE_MEMMAP_SIZE
595 depends on DISCONTIGMEM || SPARSEMEM
598 config HAVE_ARCH_ALLOC_REMAP
603 config ARCH_FLATMEM_ENABLE
605 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
607 config ARCH_DISCONTIGMEM_ENABLE
611 config ARCH_DISCONTIGMEM_DEFAULT
615 config ARCH_SPARSEMEM_ENABLE
617 depends on (NUMA || (X86_PC && EXPERIMENTAL))
618 select SPARSEMEM_STATIC
620 config ARCH_SELECT_MEMORY_MODEL
622 depends on ARCH_SPARSEMEM_ENABLE
624 config ARCH_POPULATES_NODE_MAP
630 bool "Allocate 3rd-level pagetables from highmem"
631 depends on HIGHMEM4G || HIGHMEM64G
633 The VM uses one page table entry for each page of physical memory.
634 For systems with a lot of RAM, this can be wasteful of precious
635 low memory. Setting this option will put user-space page table
636 entries in high memory.
638 config MATH_EMULATION
639 bool "Math emulation"
641 Linux can emulate a math coprocessor (used for floating point
642 operations) if you don't have one. 486DX and Pentium processors have
643 a math coprocessor built in, 486SX and 386 do not, unless you added
644 a 487DX or 387, respectively. (The messages during boot time can
645 give you some hints here ["man dmesg"].) Everyone needs either a
646 coprocessor or this emulation.
648 If you don't have a math coprocessor, you need to say Y here; if you
649 say Y here even though you have a coprocessor, the coprocessor will
650 be used nevertheless. (This behavior can be changed with the kernel
651 command line option "no387", which comes handy if your coprocessor
652 is broken. Try "man bootparam" or see the documentation of your boot
653 loader (lilo or loadlin) about how to pass options to the kernel at
654 boot time.) This means that it is a good idea to say Y here if you
655 intend to use this kernel on different machines.
657 More information about the internals of the Linux math coprocessor
658 emulation can be found in <file:arch/i386/math-emu/README>.
660 If you are not sure, say Y; apart from resulting in a 66 KB bigger
661 kernel, it won't hurt.
664 bool "MTRR (Memory Type Range Register) support"
666 On Intel P6 family processors (Pentium Pro, Pentium II and later)
667 the Memory Type Range Registers (MTRRs) may be used to control
668 processor access to memory ranges. This is most useful if you have
669 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
670 allows bus write transfers to be combined into a larger transfer
671 before bursting over the PCI/AGP bus. This can increase performance
672 of image write operations 2.5 times or more. Saying Y here creates a
673 /proc/mtrr file which may be used to manipulate your processor's
674 MTRRs. Typically the X server should use this.
676 This code has a reasonably generic interface so that similar
677 control registers on other processors can be easily supported
680 The Cyrix 6x86, 6x86MX and M II processors have Address Range
681 Registers (ARRs) which provide a similar functionality to MTRRs. For
682 these, the ARRs are used to emulate the MTRRs.
683 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
684 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
685 write-combining. All of these processors are supported by this code
686 and it makes sense to say Y here if you have one of them.
688 Saying Y here also fixes a problem with buggy SMP BIOSes which only
689 set the MTRRs for the boot CPU and not for the secondary CPUs. This
690 can lead to all sorts of problems, so it's good to say Y here.
692 You can safely say Y even if your machine doesn't have MTRRs, you'll
693 just add about 9 KB to your kernel.
695 See <file:Documentation/mtrr.txt> for more information.
698 bool "Boot from EFI support"
702 This enables the kernel to boot on EFI platforms using
703 system configuration information passed to it from the firmware.
704 This also enables the kernel to use any EFI runtime services that are
705 available (such as the EFI variable services).
707 This option is only useful on systems that have EFI firmware
708 and will result in a kernel image that is ~8k larger. In addition,
709 you must use the latest ELILO loader available at
710 <http://elilo.sourceforge.net> in order to take advantage of
711 kernel initialization using EFI information (neither GRUB nor LILO know
712 anything about EFI). However, even with this option, the resultant
713 kernel should continue to boot on existing non-EFI platforms.
716 bool "Enable kernel irq balancing"
717 depends on SMP && X86_IO_APIC
720 The default yes will allow the kernel to do irq load balancing.
721 Saying no will keep the kernel from doing irq load balancing.
723 # turning this on wastes a bunch of space.
724 # Summit needs it only when NUMA is on
727 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
731 bool "Enable seccomp to safely compute untrusted bytecode"
735 This kernel feature is useful for number crunching applications
736 that may need to compute untrusted bytecode during their
737 execution. By using pipes or other transports made available to
738 the process as file descriptors supporting the read/write
739 syscalls, it's possible to isolate those applications in
740 their own address space using seccomp. Once seccomp is
741 enabled via /proc/<pid>/seccomp, it cannot be disabled
742 and the task is only allowed to execute a few safe syscalls
743 defined by each seccomp mode.
745 If unsure, say Y. Only embedded should say N here.
747 source kernel/Kconfig.hz
750 bool "kexec system call"
752 kexec is a system call that implements the ability to shutdown your
753 current kernel, and to start another kernel. It is like a reboot
754 but it is independent of the system firmware. And like a reboot
755 you can start any kernel with it, not just Linux.
757 The name comes from the similarity to the exec system call.
759 It is an ongoing process to be certain the hardware in a machine
760 is properly shutdown, so do not be surprised if this code does not
761 initially work for you. It may help to enable device hotplugging
762 support. As of this writing the exact hardware interface is
763 strongly in flux, so no good recommendation can be made.
766 bool "kernel crash dumps (EXPERIMENTAL)"
767 depends on EXPERIMENTAL
770 Generate crash dump after being started by kexec.
771 This should be normally only set in special crash dump kernels
772 which are loaded in the main kernel with kexec-tools into
773 a specially reserved region and then later executed after
774 a crash by kdump/kexec. The crash dump kernel must be compiled
775 to a memory address not used by the main kernel or BIOS using
777 For more details see Documentation/kdump/kdump.txt
780 bool "Build a relocatable kernel(EXPERIMENTAL)"
781 depends on EXPERIMENTAL
783 This build a kernel image that retains relocation information
784 so it can be loaded someplace besides the default 1MB.
785 The relocations tend to the kernel binary about 10% larger,
786 but are discarded at runtime.
788 One use is for the kexec on panic case where the recovery kernel
789 must live at a different physical address than the primary
792 config PHYSICAL_ALIGN
793 hex "Alignment value to which kernel should be aligned"
795 range 0x2000 0x400000
797 This value puts the alignment restrictions on physical address
798 where kernel is loaded and run from. Kernel is compiled for an
799 address which meets above alignment restriction.
801 If bootloader loads the kernel at a non-aligned address and
802 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
803 address aligned to above value and run from there.
805 If bootloader loads the kernel at a non-aligned address and
806 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
807 load address and decompress itself to the address it has been
808 compiled for and run from there. The address for which kernel is
809 compiled already meets above alignment restrictions. Hence the
810 end result is that kernel runs from a physical address meeting
811 above alignment restrictions.
813 Don't change this unless you know what you are doing.
816 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
817 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
819 Say Y here to experiment with turning CPUs off and on, and to
820 enable suspend on SMP systems. CPUs can be controlled through
821 /sys/devices/system/cpu.
824 bool "Compat VDSO support"
828 Map the VDSO to the predictable old-style address too.
830 Say N here if you are running a sufficiently recent glibc
831 version (2.3.3 or later), to remove the high-mapped
832 VDSO mapping and to exclusively use the randomized VDSO.
838 config ARCH_ENABLE_MEMORY_HOTPLUG
842 menu "Power management options (ACPI, APM)"
843 depends on !X86_VOYAGER
845 source kernel/power/Kconfig
847 source "drivers/acpi/Kconfig"
849 menu "APM (Advanced Power Management) BIOS Support"
850 depends on PM && !X86_VISWS
853 tristate "APM (Advanced Power Management) BIOS support"
856 APM is a BIOS specification for saving power using several different
857 techniques. This is mostly useful for battery powered laptops with
858 APM compliant BIOSes. If you say Y here, the system time will be
859 reset after a RESUME operation, the /proc/apm device will provide
860 battery status information, and user-space programs will receive
861 notification of APM "events" (e.g. battery status change).
863 If you select "Y" here, you can disable actual use of the APM
864 BIOS by passing the "apm=off" option to the kernel at boot time.
866 Note that the APM support is almost completely disabled for
867 machines with more than one CPU.
869 In order to use APM, you will need supporting software. For location
870 and more information, read <file:Documentation/pm.txt> and the
871 Battery Powered Linux mini-HOWTO, available from
872 <http://www.tldp.org/docs.html#howto>.
874 This driver does not spin down disk drives (see the hdparm(8)
875 manpage ("man 8 hdparm") for that), and it doesn't turn off
876 VESA-compliant "green" monitors.
878 This driver does not support the TI 4000M TravelMate and the ACER
879 486/DX4/75 because they don't have compliant BIOSes. Many "green"
880 desktop machines also don't have compliant BIOSes, and this driver
881 may cause those machines to panic during the boot phase.
883 Generally, if you don't have a battery in your machine, there isn't
884 much point in using this driver and you should say N. If you get
885 random kernel OOPSes or reboots that don't seem to be related to
886 anything, try disabling/enabling this option (or disabling/enabling
889 Some other things you should try when experiencing seemingly random,
892 1) make sure that you have enough swap space and that it is
894 2) pass the "no-hlt" option to the kernel
895 3) switch on floating point emulation in the kernel and pass
896 the "no387" option to the kernel
897 4) pass the "floppy=nodma" option to the kernel
898 5) pass the "mem=4M" option to the kernel (thereby disabling
899 all but the first 4 MB of RAM)
900 6) make sure that the CPU is not over clocked.
901 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
902 8) disable the cache from your BIOS settings
903 9) install a fan for the video card or exchange video RAM
904 10) install a better fan for the CPU
905 11) exchange RAM chips
906 12) exchange the motherboard.
908 To compile this driver as a module, choose M here: the
909 module will be called apm.
911 config APM_IGNORE_USER_SUSPEND
912 bool "Ignore USER SUSPEND"
915 This option will ignore USER SUSPEND requests. On machines with a
916 compliant APM BIOS, you want to say N. However, on the NEC Versa M
917 series notebooks, it is necessary to say Y because of a BIOS bug.
920 bool "Enable PM at boot time"
923 Enable APM features at boot time. From page 36 of the APM BIOS
924 specification: "When disabled, the APM BIOS does not automatically
925 power manage devices, enter the Standby State, enter the Suspend
926 State, or take power saving steps in response to CPU Idle calls."
927 This driver will make CPU Idle calls when Linux is idle (unless this
928 feature is turned off -- see "Do CPU IDLE calls", below). This
929 should always save battery power, but more complicated APM features
930 will be dependent on your BIOS implementation. You may need to turn
931 this option off if your computer hangs at boot time when using APM
932 support, or if it beeps continuously instead of suspending. Turn
933 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
934 T400CDT. This is off by default since most machines do fine without
938 bool "Make CPU Idle calls when idle"
941 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
942 On some machines, this can activate improved power savings, such as
943 a slowed CPU clock rate, when the machine is idle. These idle calls
944 are made after the idle loop has run for some length of time (e.g.,
945 333 mS). On some machines, this will cause a hang at boot time or
946 whenever the CPU becomes idle. (On machines with more than one CPU,
947 this option does nothing.)
949 config APM_DISPLAY_BLANK
950 bool "Enable console blanking using APM"
953 Enable console blanking using the APM. Some laptops can use this to
954 turn off the LCD backlight when the screen blanker of the Linux
955 virtual console blanks the screen. Note that this is only used by
956 the virtual console screen blanker, and won't turn off the backlight
957 when using the X Window system. This also doesn't have anything to
958 do with your VESA-compliant power-saving monitor. Further, this
959 option doesn't work for all laptops -- it might not turn off your
960 backlight at all, or it might print a lot of errors to the console,
961 especially if you are using gpm.
963 config APM_RTC_IS_GMT
964 bool "RTC stores time in GMT"
967 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
968 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
971 It is in fact recommended to store GMT in your RTC, because then you
972 don't have to worry about daylight savings time changes. The only
973 reason not to use GMT in your RTC is if you also run a broken OS
974 that doesn't understand GMT.
976 config APM_ALLOW_INTS
977 bool "Allow interrupts during APM BIOS calls"
980 Normally we disable external interrupts while we are making calls to
981 the APM BIOS as a measure to lessen the effects of a badly behaving
982 BIOS implementation. The BIOS should reenable interrupts if it
983 needs to. Unfortunately, some BIOSes do not -- especially those in
984 many of the newer IBM Thinkpads. If you experience hangs when you
985 suspend, try setting this to Y. Otherwise, say N.
987 config APM_REAL_MODE_POWER_OFF
988 bool "Use real mode APM BIOS call to power off"
991 Use real mode APM BIOS calls to switch off the computer. This is
992 a work-around for a number of buggy BIOSes. Switch this option on if
993 your computer crashes instead of powering off properly.
997 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
1001 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
1004 bool "PCI support" if !X86_VISWS
1005 depends on !X86_VOYAGER
1006 default y if X86_VISWS
1008 Find out whether you have a PCI motherboard. PCI is the name of a
1009 bus system, i.e. the way the CPU talks to the other stuff inside
1010 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1011 VESA. If you have PCI, say Y, otherwise N.
1013 The PCI-HOWTO, available from
1014 <http://www.tldp.org/docs.html#howto>, contains valuable
1015 information about which PCI hardware does work under Linux and which
1019 prompt "PCI access mode"
1020 depends on PCI && !X86_VISWS
1023 On PCI systems, the BIOS can be used to detect the PCI devices and
1024 determine their configuration. However, some old PCI motherboards
1025 have BIOS bugs and may crash if this is done. Also, some embedded
1026 PCI-based systems don't have any BIOS at all. Linux can also try to
1027 detect the PCI hardware directly without using the BIOS.
1029 With this option, you can specify how Linux should detect the
1030 PCI devices. If you choose "BIOS", the BIOS will be used,
1031 if you choose "Direct", the BIOS won't be used, and if you
1032 choose "MMConfig", then PCI Express MMCONFIG will be used.
1033 If you choose "Any", the kernel will try MMCONFIG, then the
1034 direct access method and falls back to the BIOS if that doesn't
1035 work. If unsure, go with the default, which is "Any".
1040 config PCI_GOMMCONFIG
1053 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1058 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1063 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1066 source "drivers/pci/pcie/Kconfig"
1068 source "drivers/pci/Kconfig"
1076 depends on !(X86_VOYAGER || X86_VISWS)
1078 Find out whether you have ISA slots on your motherboard. ISA is the
1079 name of a bus system, i.e. the way the CPU talks to the other stuff
1080 inside your box. Other bus systems are PCI, EISA, MicroChannel
1081 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1082 newer boards don't support it. If you have ISA, say Y, otherwise N.
1088 The Extended Industry Standard Architecture (EISA) bus was
1089 developed as an open alternative to the IBM MicroChannel bus.
1091 The EISA bus provided some of the features of the IBM MicroChannel
1092 bus while maintaining backward compatibility with cards made for
1093 the older ISA bus. The EISA bus saw limited use between 1988 and
1094 1995 when it was made obsolete by the PCI bus.
1096 Say Y here if you are building a kernel for an EISA-based machine.
1100 source "drivers/eisa/Kconfig"
1103 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1104 default y if X86_VOYAGER
1106 MicroChannel Architecture is found in some IBM PS/2 machines and
1107 laptops. It is a bus system similar to PCI or ISA. See
1108 <file:Documentation/mca.txt> (and especially the web page given
1109 there) before attempting to build an MCA bus kernel.
1111 source "drivers/mca/Kconfig"
1114 tristate "NatSemi SCx200 support"
1115 depends on !X86_VOYAGER
1117 This provides basic support for National Semiconductor's
1118 (now AMD's) Geode processors. The driver probes for the
1119 PCI-IDs of several on-chip devices, so its a good dependency
1120 for other scx200_* drivers.
1122 If compiled as a module, the driver is named scx200.
1124 config SCx200HR_TIMER
1125 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1126 depends on SCx200 && GENERIC_TIME
1129 This driver provides a clocksource built upon the on-chip
1130 27MHz high-resolution timer. Its also a workaround for
1131 NSC Geode SC-1100's buggy TSC, which loses time when the
1132 processor goes idle (as is done by the scheduler). The
1133 other workaround is idle=poll boot option.
1137 depends on AGP_AMD64
1139 source "drivers/pcmcia/Kconfig"
1141 source "drivers/pci/hotplug/Kconfig"
1145 menu "Executable file formats"
1147 source "fs/Kconfig.binfmt"
1151 source "net/Kconfig"
1153 source "drivers/Kconfig"
1157 menu "Instrumentation Support"
1158 depends on EXPERIMENTAL
1160 source "arch/i386/oprofile/Kconfig"
1163 bool "Kprobes (EXPERIMENTAL)"
1164 depends on KALLSYMS && EXPERIMENTAL && MODULES
1166 Kprobes allows you to trap at almost any kernel address and
1167 execute a callback function. register_kprobe() establishes
1168 a probepoint and specifies the callback. Kprobes is useful
1169 for kernel debugging, non-intrusive instrumentation and testing.
1170 If in doubt, say "N".
1173 source "arch/i386/Kconfig.debug"
1175 source "security/Kconfig"
1177 source "crypto/Kconfig"
1179 source "lib/Kconfig"
1182 # Use the generic interrupt handling code in kernel/irq/:
1184 config GENERIC_HARDIRQS
1188 config GENERIC_IRQ_PROBE
1192 config GENERIC_PENDING_IRQ
1194 depends on GENERIC_HARDIRQS && SMP
1199 depends on SMP && !X86_VOYAGER
1204 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1207 config X86_BIOS_REBOOT
1209 depends on !(X86_VISWS || X86_VOYAGER)
1212 config X86_TRAMPOLINE
1214 depends on X86_SMP || (X86_VOYAGER && SMP)
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