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 SEMAPHORE_SLEEPERS
36 config GENERIC_ISA_DMA
44 config GENERIC_HWEIGHT
48 config ARCH_MAY_HAVE_PC_FDC
58 menu "Processor type and features"
61 bool "Symmetric multi-processing support"
63 This enables support for systems with more than one CPU. If you have
64 a system with only one CPU, like most personal computers, say N. If
65 you have a system with more than one CPU, say Y.
67 If you say N here, the kernel will run on single and multiprocessor
68 machines, but will use only one CPU of a multiprocessor machine. If
69 you say Y here, the kernel will run on many, but not all,
70 singleprocessor machines. On a singleprocessor machine, the kernel
71 will run faster if you say N here.
73 Note that if you say Y here and choose architecture "586" or
74 "Pentium" under "Processor family", the kernel will not work on 486
75 architectures. Similarly, multiprocessor kernels for the "PPro"
76 architecture may not work on all Pentium based boards.
78 People using multiprocessor machines who say Y here should also say
79 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
80 Management" code will be disabled if you say Y here.
82 See also the <file:Documentation/smp.txt>,
83 <file:Documentation/i386/IO-APIC.txt>,
84 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
85 <http://www.tldp.org/docs.html#howto>.
87 If you don't know what to do here, say N.
90 prompt "Subarchitecture Type"
96 Choose this option if your computer is a standard PC or compatible.
101 Select this for an AMD Elan processor.
103 Do not use this option for K6/Athlon/Opteron processors!
105 If unsure, choose "PC-compatible" instead.
110 Voyager is an MCA-based 32-way capable SMP architecture proprietary
111 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
115 If you do not specifically know you have a Voyager based machine,
116 say N here, otherwise the kernel you build will not be bootable.
119 bool "NUMAQ (IBM/Sequent)"
123 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
124 multiquad box. This changes the way that processors are bootstrapped,
125 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
126 You will need a new lynxer.elf file to flash your firmware with - send
127 email to <Martin.Bligh@us.ibm.com>.
130 bool "Summit/EXA (IBM x440)"
133 This option is needed for IBM systems that use the Summit/EXA chipset.
134 In particular, it is needed for the x440.
136 If you don't have one of these computers, you should say N here.
139 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
142 This option is needed for the systems that have more than 8 CPUs
143 and if the system is not of any sub-arch type above.
145 If you don't have such a system, you should say N here.
148 bool "SGI 320/540 (Visual Workstation)"
150 The SGI Visual Workstation series is an IA32-based workstation
151 based on SGI systems chips with some legacy PC hardware attached.
153 Say Y here to create a kernel to run on the SGI 320 or 540.
155 A kernel compiled for the Visual Workstation will not run on PCs
156 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
158 config X86_GENERICARCH
159 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
162 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
163 It is intended for a generic binary kernel.
166 bool "Support for Unisys ES7000 IA32 series"
169 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
170 supposed to run on an IA32-based Unisys ES7000 system.
171 Only choose this option if you have such a system, otherwise you
179 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
182 config HAVE_ARCH_PARSE_SRAT
187 config X86_SUMMIT_NUMA
190 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
192 config X86_CYCLONE_TIMER
195 depends on X86_SUMMIT || X86_GENERICARCH
197 config ES7000_CLUSTERED_APIC
200 depends on SMP && X86_ES7000 && MPENTIUMIII
202 source "arch/i386/Kconfig.cpu"
205 bool "HPET Timer Support"
207 This enables the use of the HPET for the kernel's internal timer.
208 HPET is the next generation timer replacing legacy 8254s.
209 You can safely choose Y here. However, HPET will only be
210 activated if the platform and the BIOS support this feature.
211 Otherwise the 8254 will be used for timing services.
213 Choose N to continue using the legacy 8254 timer.
215 config HPET_EMULATE_RTC
217 depends on HPET_TIMER && RTC=y
221 int "Maximum number of CPUs (2-255)"
224 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
227 This allows you to specify the maximum number of CPUs which this
228 kernel will support. The maximum supported value is 255 and the
229 minimum value which makes sense is 2.
231 This is purely to save memory - each supported CPU adds
232 approximately eight kilobytes to the kernel image.
235 bool "SMT (Hyperthreading) scheduler support"
238 SMT scheduler support improves the CPU scheduler's decision making
239 when dealing with Intel Pentium 4 chips with HyperThreading at a
240 cost of slightly increased overhead in some places. If unsure say
244 bool "Multi-core scheduler support"
248 Multi-core scheduler support improves the CPU scheduler's decision
249 making when dealing with multi-core CPU chips at a cost of slightly
250 increased overhead in some places. If unsure say N here.
252 source "kernel/Kconfig.preempt"
255 bool "Local APIC support on uniprocessors"
256 depends on !SMP && !(X86_VISWS || X86_VOYAGER)
258 A local APIC (Advanced Programmable Interrupt Controller) is an
259 integrated interrupt controller in the CPU. If you have a single-CPU
260 system which has a processor with a local APIC, you can say Y here to
261 enable and use it. If you say Y here even though your machine doesn't
262 have a local APIC, then the kernel will still run with no slowdown at
263 all. The local APIC supports CPU-generated self-interrupts (timer,
264 performance counters), and the NMI watchdog which detects hard
268 bool "IO-APIC support on uniprocessors"
269 depends on X86_UP_APIC
271 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
272 SMP-capable replacement for PC-style interrupt controllers. Most
273 SMP systems and many recent uniprocessor systems have one.
275 If you have a single-CPU system with an IO-APIC, you can say Y here
276 to use it. If you say Y here even though your machine doesn't have
277 an IO-APIC, then the kernel will still run with no slowdown at all.
279 config X86_LOCAL_APIC
281 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER)
286 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER))
289 config X86_VISWS_APIC
295 bool "Machine Check Exception"
296 depends on !X86_VOYAGER
298 Machine Check Exception support allows the processor to notify the
299 kernel if it detects a problem (e.g. overheating, component failure).
300 The action the kernel takes depends on the severity of the problem,
301 ranging from a warning message on the console, to halting the machine.
302 Your processor must be a Pentium or newer to support this - check the
303 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
304 have a design flaw which leads to false MCE events - hence MCE is
305 disabled on all P5 processors, unless explicitly enabled with "mce"
306 as a boot argument. Similarly, if MCE is built in and creates a
307 problem on some new non-standard machine, you can boot with "nomce"
308 to disable it. MCE support simply ignores non-MCE processors like
309 the 386 and 486, so nearly everyone can say Y here.
311 config X86_MCE_NONFATAL
312 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
315 Enabling this feature starts a timer that triggers every 5 seconds which
316 will look at the machine check registers to see if anything happened.
317 Non-fatal problems automatically get corrected (but still logged).
318 Disable this if you don't want to see these messages.
319 Seeing the messages this option prints out may be indicative of dying hardware,
320 or out-of-spec (ie, overclocked) hardware.
321 This option only does something on certain CPUs.
322 (AMD Athlon/Duron and Intel Pentium 4)
324 config X86_MCE_P4THERMAL
325 bool "check for P4 thermal throttling interrupt."
326 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
328 Enabling this feature will cause a message to be printed when the P4
329 enters thermal throttling.
333 bool "Enable VM86 support" if EMBEDDED
335 This option is required by programs like DOSEMU to run 16-bit legacy
336 code on X86 processors. It also may be needed by software like
337 XFree86 to initialize some video cards via BIOS. Disabling this
338 option saves about 6k.
341 tristate "Toshiba Laptop support"
343 This adds a driver to safely access the System Management Mode of
344 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
345 not work on models with a Phoenix BIOS. The System Management Mode
346 is used to set the BIOS and power saving options on Toshiba portables.
348 For information on utilities to make use of this driver see the
349 Toshiba Linux utilities web site at:
350 <http://www.buzzard.org.uk/toshiba/>.
352 Say Y if you intend to run this kernel on a Toshiba portable.
356 tristate "Dell laptop support"
358 This adds a driver to safely access the System Management Mode
359 of the CPU on the Dell Inspiron 8000. The System Management Mode
360 is used to read cpu temperature and cooling fan status and to
361 control the fans on the I8K portables.
363 This driver has been tested only on the Inspiron 8000 but it may
364 also work with other Dell laptops. You can force loading on other
365 models by passing the parameter `force=1' to the module. Use at
368 For information on utilities to make use of this driver see the
369 I8K Linux utilities web site at:
370 <http://people.debian.org/~dz/i8k/>
372 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
375 config X86_REBOOTFIXUPS
376 bool "Enable X86 board specific fixups for reboot"
380 This enables chipset and/or board specific fixups to be done
381 in order to get reboot to work correctly. This is only needed on
382 some combinations of hardware and BIOS. The symptom, for which
383 this config is intended, is when reboot ends with a stalled/hung
386 Currently, the only fixup is for the Geode GX1/CS5530A/TROM2.1.
389 Say Y if you want to enable the fixup. Currently, it's safe to
390 enable this option even if you don't need it.
394 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
396 If you say Y here and also to "/dev file system support" in the
397 'File systems' section, you will be able to update the microcode on
398 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
399 Pentium III, Pentium 4, Xeon etc. You will obviously need the
400 actual microcode binary data itself which is not shipped with the
403 For latest news and information on obtaining all the required
404 ingredients for this driver, check:
405 <http://www.urbanmyth.org/microcode/>.
407 To compile this driver as a module, choose M here: the
408 module will be called microcode.
411 tristate "/dev/cpu/*/msr - Model-specific register support"
413 This device gives privileged processes access to the x86
414 Model-Specific Registers (MSRs). It is a character device with
415 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
416 MSR accesses are directed to a specific CPU on multi-processor
420 tristate "/dev/cpu/*/cpuid - CPU information support"
422 This device gives processes access to the x86 CPUID instruction to
423 be executed on a specific processor. It is a character device
424 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
427 source "drivers/firmware/Kconfig"
430 prompt "High Memory Support"
435 depends on !X86_NUMAQ
437 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
438 However, the address space of 32-bit x86 processors is only 4
439 Gigabytes large. That means that, if you have a large amount of
440 physical memory, not all of it can be "permanently mapped" by the
441 kernel. The physical memory that's not permanently mapped is called
444 If you are compiling a kernel which will never run on a machine with
445 more than 1 Gigabyte total physical RAM, answer "off" here (default
446 choice and suitable for most users). This will result in a "3GB/1GB"
447 split: 3GB are mapped so that each process sees a 3GB virtual memory
448 space and the remaining part of the 4GB virtual memory space is used
449 by the kernel to permanently map as much physical memory as
452 If the machine has between 1 and 4 Gigabytes physical RAM, then
455 If more than 4 Gigabytes is used then answer "64GB" here. This
456 selection turns Intel PAE (Physical Address Extension) mode on.
457 PAE implements 3-level paging on IA32 processors. PAE is fully
458 supported by Linux, PAE mode is implemented on all recent Intel
459 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
460 then the kernel will not boot on CPUs that don't support PAE!
462 The actual amount of total physical memory will either be
463 auto detected or can be forced by using a kernel command line option
464 such as "mem=256M". (Try "man bootparam" or see the documentation of
465 your boot loader (lilo or loadlin) about how to pass options to the
466 kernel at boot time.)
468 If unsure, say "off".
472 depends on !X86_NUMAQ
474 Select this if you have a 32-bit processor and between 1 and 4
475 gigabytes of physical RAM.
479 depends on X86_CMPXCHG64
481 Select this if you have a 32-bit processor and more than 4
482 gigabytes of physical RAM.
487 depends on EXPERIMENTAL && !X86_PAE
488 prompt "Memory split" if EMBEDDED
491 Select the desired split between kernel and user memory.
493 If the address range available to the kernel is less than the
494 physical memory installed, the remaining memory will be available
495 as "high memory". Accessing high memory is a little more costly
496 than low memory, as it needs to be mapped into the kernel first.
497 Note that increasing the kernel address space limits the range
498 available to user programs, making the address space there
499 tighter. Selecting anything other than the default 3G/1G split
500 will also likely make your kernel incompatible with binary-only
503 If you are not absolutely sure what you are doing, leave this
507 bool "3G/1G user/kernel split"
508 config VMSPLIT_3G_OPT
509 bool "3G/1G user/kernel split (for full 1G low memory)"
511 bool "2G/2G user/kernel split"
513 bool "1G/3G user/kernel split"
518 default 0xB0000000 if VMSPLIT_3G_OPT
519 default 0x78000000 if VMSPLIT_2G
520 default 0x40000000 if VMSPLIT_1G
525 depends on HIGHMEM64G || HIGHMEM4G
530 depends on HIGHMEM64G
532 select RESOURCES_64BIT
534 # Common NUMA Features
536 bool "Numa Memory Allocation and Scheduler Support"
537 depends on SMP && HIGHMEM64G && (X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI))
539 default y if (X86_NUMAQ || X86_SUMMIT)
541 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
542 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
546 default "4" if X86_NUMAQ
548 depends on NEED_MULTIPLE_NODES
550 config HAVE_ARCH_BOOTMEM_NODE
555 config ARCH_HAVE_MEMORY_PRESENT
557 depends on DISCONTIGMEM
560 config NEED_NODE_MEMMAP_SIZE
562 depends on DISCONTIGMEM || SPARSEMEM
565 config HAVE_ARCH_ALLOC_REMAP
570 config ARCH_FLATMEM_ENABLE
572 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
574 config ARCH_DISCONTIGMEM_ENABLE
578 config ARCH_DISCONTIGMEM_DEFAULT
582 config ARCH_SPARSEMEM_ENABLE
584 depends on (NUMA || (X86_PC && EXPERIMENTAL))
585 select SPARSEMEM_STATIC
587 config ARCH_SELECT_MEMORY_MODEL
589 depends on ARCH_SPARSEMEM_ENABLE
593 config HAVE_ARCH_EARLY_PFN_TO_NID
599 bool "Allocate 3rd-level pagetables from highmem"
600 depends on HIGHMEM4G || HIGHMEM64G
602 The VM uses one page table entry for each page of physical memory.
603 For systems with a lot of RAM, this can be wasteful of precious
604 low memory. Setting this option will put user-space page table
605 entries in high memory.
607 config MATH_EMULATION
608 bool "Math emulation"
610 Linux can emulate a math coprocessor (used for floating point
611 operations) if you don't have one. 486DX and Pentium processors have
612 a math coprocessor built in, 486SX and 386 do not, unless you added
613 a 487DX or 387, respectively. (The messages during boot time can
614 give you some hints here ["man dmesg"].) Everyone needs either a
615 coprocessor or this emulation.
617 If you don't have a math coprocessor, you need to say Y here; if you
618 say Y here even though you have a coprocessor, the coprocessor will
619 be used nevertheless. (This behavior can be changed with the kernel
620 command line option "no387", which comes handy if your coprocessor
621 is broken. Try "man bootparam" or see the documentation of your boot
622 loader (lilo or loadlin) about how to pass options to the kernel at
623 boot time.) This means that it is a good idea to say Y here if you
624 intend to use this kernel on different machines.
626 More information about the internals of the Linux math coprocessor
627 emulation can be found in <file:arch/i386/math-emu/README>.
629 If you are not sure, say Y; apart from resulting in a 66 KB bigger
630 kernel, it won't hurt.
633 bool "MTRR (Memory Type Range Register) support"
635 On Intel P6 family processors (Pentium Pro, Pentium II and later)
636 the Memory Type Range Registers (MTRRs) may be used to control
637 processor access to memory ranges. This is most useful if you have
638 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
639 allows bus write transfers to be combined into a larger transfer
640 before bursting over the PCI/AGP bus. This can increase performance
641 of image write operations 2.5 times or more. Saying Y here creates a
642 /proc/mtrr file which may be used to manipulate your processor's
643 MTRRs. Typically the X server should use this.
645 This code has a reasonably generic interface so that similar
646 control registers on other processors can be easily supported
649 The Cyrix 6x86, 6x86MX and M II processors have Address Range
650 Registers (ARRs) which provide a similar functionality to MTRRs. For
651 these, the ARRs are used to emulate the MTRRs.
652 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
653 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
654 write-combining. All of these processors are supported by this code
655 and it makes sense to say Y here if you have one of them.
657 Saying Y here also fixes a problem with buggy SMP BIOSes which only
658 set the MTRRs for the boot CPU and not for the secondary CPUs. This
659 can lead to all sorts of problems, so it's good to say Y here.
661 You can safely say Y even if your machine doesn't have MTRRs, you'll
662 just add about 9 KB to your kernel.
664 See <file:Documentation/mtrr.txt> for more information.
667 bool "Boot from EFI support (EXPERIMENTAL)"
671 This enables the the kernel to boot on EFI platforms using
672 system configuration information passed to it from the firmware.
673 This also enables the kernel to use any EFI runtime services that are
674 available (such as the EFI variable services).
676 This option is only useful on systems that have EFI firmware
677 and will result in a kernel image that is ~8k larger. In addition,
678 you must use the latest ELILO loader available at
679 <http://elilo.sourceforge.net> in order to take advantage of
680 kernel initialization using EFI information (neither GRUB nor LILO know
681 anything about EFI). However, even with this option, the resultant
682 kernel should continue to boot on existing non-EFI platforms.
685 bool "Enable kernel irq balancing"
686 depends on SMP && X86_IO_APIC
689 The default yes will allow the kernel to do irq load balancing.
690 Saying no will keep the kernel from doing irq load balancing.
692 # turning this on wastes a bunch of space.
693 # Summit needs it only when NUMA is on
696 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
700 bool "Use register arguments"
703 Compile the kernel with -mregparm=3. This instructs gcc to use
704 a more efficient function call ABI which passes the first three
705 arguments of a function call via registers, which results in denser
708 If this option is disabled, then the default ABI of passing
709 arguments via the stack is used.
714 bool "Enable seccomp to safely compute untrusted bytecode"
718 This kernel feature is useful for number crunching applications
719 that may need to compute untrusted bytecode during their
720 execution. By using pipes or other transports made available to
721 the process as file descriptors supporting the read/write
722 syscalls, it's possible to isolate those applications in
723 their own address space using seccomp. Once seccomp is
724 enabled via /proc/<pid>/seccomp, it cannot be disabled
725 and the task is only allowed to execute a few safe syscalls
726 defined by each seccomp mode.
728 If unsure, say Y. Only embedded should say N here.
730 source kernel/Kconfig.hz
733 bool "kexec system call (EXPERIMENTAL)"
734 depends on EXPERIMENTAL
736 kexec is a system call that implements the ability to shutdown your
737 current kernel, and to start another kernel. It is like a reboot
738 but it is independent of the system firmware. And like a reboot
739 you can start any kernel with it, not just Linux.
741 The name comes from the similiarity to the exec system call.
743 It is an ongoing process to be certain the hardware in a machine
744 is properly shutdown, so do not be surprised if this code does not
745 initially work for you. It may help to enable device hotplugging
746 support. As of this writing the exact hardware interface is
747 strongly in flux, so no good recommendation can be made.
750 bool "kernel crash dumps (EXPERIMENTAL)"
751 depends on EXPERIMENTAL
754 Generate crash dump after being started by kexec.
756 config PHYSICAL_START
757 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
759 default "0x1000000" if CRASH_DUMP
762 This gives the physical address where the kernel is loaded. Normally
763 for regular kernels this value is 0x100000 (1MB). But in the case
764 of kexec on panic the fail safe kernel needs to run at a different
765 address than the panic-ed kernel. This option is used to set the load
766 address for kernels used to capture crash dump on being kexec'ed
767 after panic. The default value for crash dump kernels is
768 0x1000000 (16MB). This can also be set based on the "X" value as
769 specified in the "crashkernel=YM@XM" command line boot parameter
770 passed to the panic-ed kernel. Typically this parameter is set as
771 crashkernel=64M@16M. Please take a look at
772 Documentation/kdump/kdump.txt for more details about crash dumps.
774 Don't change this unless you know what you are doing.
777 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
778 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
780 Say Y here to experiment with turning CPUs off and on, and to
781 enable suspend on SMP systems. CPUs can be controlled through
782 /sys/devices/system/cpu.
788 menu "Power management options (ACPI, APM)"
789 depends on !X86_VOYAGER
791 source kernel/power/Kconfig
793 source "drivers/acpi/Kconfig"
795 menu "APM (Advanced Power Management) BIOS Support"
796 depends on PM && !X86_VISWS
799 tristate "APM (Advanced Power Management) BIOS support"
802 APM is a BIOS specification for saving power using several different
803 techniques. This is mostly useful for battery powered laptops with
804 APM compliant BIOSes. If you say Y here, the system time will be
805 reset after a RESUME operation, the /proc/apm device will provide
806 battery status information, and user-space programs will receive
807 notification of APM "events" (e.g. battery status change).
809 If you select "Y" here, you can disable actual use of the APM
810 BIOS by passing the "apm=off" option to the kernel at boot time.
812 Note that the APM support is almost completely disabled for
813 machines with more than one CPU.
815 In order to use APM, you will need supporting software. For location
816 and more information, read <file:Documentation/pm.txt> and the
817 Battery Powered Linux mini-HOWTO, available from
818 <http://www.tldp.org/docs.html#howto>.
820 This driver does not spin down disk drives (see the hdparm(8)
821 manpage ("man 8 hdparm") for that), and it doesn't turn off
822 VESA-compliant "green" monitors.
824 This driver does not support the TI 4000M TravelMate and the ACER
825 486/DX4/75 because they don't have compliant BIOSes. Many "green"
826 desktop machines also don't have compliant BIOSes, and this driver
827 may cause those machines to panic during the boot phase.
829 Generally, if you don't have a battery in your machine, there isn't
830 much point in using this driver and you should say N. If you get
831 random kernel OOPSes or reboots that don't seem to be related to
832 anything, try disabling/enabling this option (or disabling/enabling
835 Some other things you should try when experiencing seemingly random,
838 1) make sure that you have enough swap space and that it is
840 2) pass the "no-hlt" option to the kernel
841 3) switch on floating point emulation in the kernel and pass
842 the "no387" option to the kernel
843 4) pass the "floppy=nodma" option to the kernel
844 5) pass the "mem=4M" option to the kernel (thereby disabling
845 all but the first 4 MB of RAM)
846 6) make sure that the CPU is not over clocked.
847 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
848 8) disable the cache from your BIOS settings
849 9) install a fan for the video card or exchange video RAM
850 10) install a better fan for the CPU
851 11) exchange RAM chips
852 12) exchange the motherboard.
854 To compile this driver as a module, choose M here: the
855 module will be called apm.
857 config APM_IGNORE_USER_SUSPEND
858 bool "Ignore USER SUSPEND"
861 This option will ignore USER SUSPEND requests. On machines with a
862 compliant APM BIOS, you want to say N. However, on the NEC Versa M
863 series notebooks, it is necessary to say Y because of a BIOS bug.
866 bool "Enable PM at boot time"
869 Enable APM features at boot time. From page 36 of the APM BIOS
870 specification: "When disabled, the APM BIOS does not automatically
871 power manage devices, enter the Standby State, enter the Suspend
872 State, or take power saving steps in response to CPU Idle calls."
873 This driver will make CPU Idle calls when Linux is idle (unless this
874 feature is turned off -- see "Do CPU IDLE calls", below). This
875 should always save battery power, but more complicated APM features
876 will be dependent on your BIOS implementation. You may need to turn
877 this option off if your computer hangs at boot time when using APM
878 support, or if it beeps continuously instead of suspending. Turn
879 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
880 T400CDT. This is off by default since most machines do fine without
884 bool "Make CPU Idle calls when idle"
887 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
888 On some machines, this can activate improved power savings, such as
889 a slowed CPU clock rate, when the machine is idle. These idle calls
890 are made after the idle loop has run for some length of time (e.g.,
891 333 mS). On some machines, this will cause a hang at boot time or
892 whenever the CPU becomes idle. (On machines with more than one CPU,
893 this option does nothing.)
895 config APM_DISPLAY_BLANK
896 bool "Enable console blanking using APM"
899 Enable console blanking using the APM. Some laptops can use this to
900 turn off the LCD backlight when the screen blanker of the Linux
901 virtual console blanks the screen. Note that this is only used by
902 the virtual console screen blanker, and won't turn off the backlight
903 when using the X Window system. This also doesn't have anything to
904 do with your VESA-compliant power-saving monitor. Further, this
905 option doesn't work for all laptops -- it might not turn off your
906 backlight at all, or it might print a lot of errors to the console,
907 especially if you are using gpm.
909 config APM_RTC_IS_GMT
910 bool "RTC stores time in GMT"
913 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
914 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
917 It is in fact recommended to store GMT in your RTC, because then you
918 don't have to worry about daylight savings time changes. The only
919 reason not to use GMT in your RTC is if you also run a broken OS
920 that doesn't understand GMT.
922 config APM_ALLOW_INTS
923 bool "Allow interrupts during APM BIOS calls"
926 Normally we disable external interrupts while we are making calls to
927 the APM BIOS as a measure to lessen the effects of a badly behaving
928 BIOS implementation. The BIOS should reenable interrupts if it
929 needs to. Unfortunately, some BIOSes do not -- especially those in
930 many of the newer IBM Thinkpads. If you experience hangs when you
931 suspend, try setting this to Y. Otherwise, say N.
933 config APM_REAL_MODE_POWER_OFF
934 bool "Use real mode APM BIOS call to power off"
937 Use real mode APM BIOS calls to switch off the computer. This is
938 a work-around for a number of buggy BIOSes. Switch this option on if
939 your computer crashes instead of powering off properly.
943 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
947 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
950 bool "PCI support" if !X86_VISWS
951 depends on !X86_VOYAGER
952 default y if X86_VISWS
954 Find out whether you have a PCI motherboard. PCI is the name of a
955 bus system, i.e. the way the CPU talks to the other stuff inside
956 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
957 VESA. If you have PCI, say Y, otherwise N.
959 The PCI-HOWTO, available from
960 <http://www.tldp.org/docs.html#howto>, contains valuable
961 information about which PCI hardware does work under Linux and which
965 prompt "PCI access mode"
966 depends on PCI && !X86_VISWS
969 On PCI systems, the BIOS can be used to detect the PCI devices and
970 determine their configuration. However, some old PCI motherboards
971 have BIOS bugs and may crash if this is done. Also, some embedded
972 PCI-based systems don't have any BIOS at all. Linux can also try to
973 detect the PCI hardware directly without using the BIOS.
975 With this option, you can specify how Linux should detect the
976 PCI devices. If you choose "BIOS", the BIOS will be used,
977 if you choose "Direct", the BIOS won't be used, and if you
978 choose "MMConfig", then PCI Express MMCONFIG will be used.
979 If you choose "Any", the kernel will try MMCONFIG, then the
980 direct access method and falls back to the BIOS if that doesn't
981 work. If unsure, go with the default, which is "Any".
986 config PCI_GOMMCONFIG
999 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1004 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1009 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1012 source "drivers/pci/pcie/Kconfig"
1014 source "drivers/pci/Kconfig"
1022 depends on !(X86_VOYAGER || X86_VISWS)
1024 Find out whether you have ISA slots on your motherboard. ISA is the
1025 name of a bus system, i.e. the way the CPU talks to the other stuff
1026 inside your box. Other bus systems are PCI, EISA, MicroChannel
1027 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1028 newer boards don't support it. If you have ISA, say Y, otherwise N.
1034 The Extended Industry Standard Architecture (EISA) bus was
1035 developed as an open alternative to the IBM MicroChannel bus.
1037 The EISA bus provided some of the features of the IBM MicroChannel
1038 bus while maintaining backward compatibility with cards made for
1039 the older ISA bus. The EISA bus saw limited use between 1988 and
1040 1995 when it was made obsolete by the PCI bus.
1042 Say Y here if you are building a kernel for an EISA-based machine.
1046 source "drivers/eisa/Kconfig"
1049 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1050 default y if X86_VOYAGER
1052 MicroChannel Architecture is found in some IBM PS/2 machines and
1053 laptops. It is a bus system similar to PCI or ISA. See
1054 <file:Documentation/mca.txt> (and especially the web page given
1055 there) before attempting to build an MCA bus kernel.
1057 source "drivers/mca/Kconfig"
1060 tristate "NatSemi SCx200 support"
1061 depends on !X86_VOYAGER
1063 This provides basic support for National Semiconductor's
1064 (now AMD's) Geode processors. The driver probes for the
1065 PCI-IDs of several on-chip devices, so its a good dependency
1066 for other scx200_* drivers.
1068 If compiled as a module, the driver is named scx200.
1070 config SCx200HR_TIMER
1071 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1072 depends on SCx200 && GENERIC_TIME
1075 This driver provides a clocksource built upon the on-chip
1076 27MHz high-resolution timer. Its also a workaround for
1077 NSC Geode SC-1100's buggy TSC, which loses time when the
1078 processor goes idle (as is done by the scheduler). The
1079 other workaround is idle=poll boot option.
1083 depends on AGP_AMD64
1085 source "drivers/pcmcia/Kconfig"
1087 source "drivers/pci/hotplug/Kconfig"
1091 menu "Executable file formats"
1093 source "fs/Kconfig.binfmt"
1097 source "net/Kconfig"
1099 source "drivers/Kconfig"
1103 menu "Instrumentation Support"
1104 depends on EXPERIMENTAL
1106 source "arch/i386/oprofile/Kconfig"
1109 bool "Kprobes (EXPERIMENTAL)"
1110 depends on EXPERIMENTAL && MODULES
1112 Kprobes allows you to trap at almost any kernel address and
1113 execute a callback function. register_kprobe() establishes
1114 a probepoint and specifies the callback. Kprobes is useful
1115 for kernel debugging, non-intrusive instrumentation and testing.
1116 If in doubt, say "N".
1119 source "arch/i386/Kconfig.debug"
1121 source "security/Kconfig"
1123 source "crypto/Kconfig"
1125 source "lib/Kconfig"
1128 # Use the generic interrupt handling code in kernel/irq/:
1130 config GENERIC_HARDIRQS
1134 config GENERIC_IRQ_PROBE
1138 config GENERIC_PENDING_IRQ
1140 depends on GENERIC_HARDIRQS && SMP
1145 depends on SMP && !X86_VOYAGER
1150 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1153 config X86_BIOS_REBOOT
1155 depends on !(X86_VISWS || X86_VOYAGER)
1158 config X86_TRAMPOLINE
1160 depends on X86_SMP || (X86_VOYAGER && SMP)
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