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.
28 config GENERIC_ISA_DMA
35 menu "Processor type and features"
38 prompt "Subarchitecture Type"
44 Choose this option if your computer is a standard PC or compatible.
49 Voyager is a MCA based 32 way capable SMP architecture proprietary
50 to NCR Corp. Machine classes 345x/35xx/4100/51xx are voyager based.
54 If you do not specifically know you have a Voyager based machine,
55 say N here otherwise the kernel you build will not be bootable.
58 bool "NUMAQ (IBM/Sequent)"
60 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
61 multiquad box. This changes the way that processors are bootstrapped,
62 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
63 You will need a new lynxer.elf file to flash your firmware with - send
64 email to Martin.Bligh@us.ibm.com
67 bool "Summit/EXA (IBM x440)"
70 This option is needed for IBM systems that use the Summit/EXA chipset.
71 In particular, it is needed for the x440.
73 If you don't have one of these computers, you should say N here.
76 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
79 This option is needed for the systems that have more than 8 CPUs
80 and if the system is not of any sub-arch type above.
82 If you don't have such a system, you should say N here.
85 bool "SGI 320/540 (Visual Workstation)"
87 The SGI Visual Workstation series is an IA32-based workstation
88 based on SGI systems chips with some legacy PC hardware attached.
90 Say Y here to create a kernel to run on the SGI 320 or 540.
92 A kernel compiled for the Visual Workstation will not run on PCs
93 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
95 config X86_GENERICARCH
96 bool "Generic architecture (Summit, bigsmp, default)"
99 This option compiles in the Summit, bigsmp, default subarchitectures.
100 It is intended for a generic binary kernel.
103 bool "Support for Unisys ES7000 IA32 series"
106 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
107 supposed to run on an IA32-based Unisys ES7000 system.
108 Only choose this option if you have such a system, otherwise you
116 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
118 config X86_CYCLONE_TIMER
121 depends on X86_SUMMIT || X86_GENERICARCH
123 config ES7000_CLUSTERED_APIC
126 depends on SMP && X86_ES7000 && MPENTIUMIII
129 prompt "Processor family"
135 This is the processor type of your CPU. This information is used for
136 optimizing purposes. In order to compile a kernel that can run on
137 all x86 CPU types (albeit not optimally fast), you can specify
140 The kernel will not necessarily run on earlier architectures than
141 the one you have chosen, e.g. a Pentium optimized kernel will run on
142 a PPro, but not necessarily on a i486.
144 Here are the settings recommended for greatest speed:
145 - "386" for the AMD/Cyrix/Intel 386DX/DXL/SL/SLC/SX, Cyrix/TI
146 486DLC/DLC2, UMC 486SX-S and NexGen Nx586. Only "386" kernels
147 will run on a 386 class machine.
148 - "486" for the AMD/Cyrix/IBM/Intel 486DX/DX2/DX4 or
149 SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5D or U5S.
150 - "586" for generic Pentium CPUs lacking the TSC
151 (time stamp counter) register.
152 - "Pentium-Classic" for the Intel Pentium.
153 - "Pentium-MMX" for the Intel Pentium MMX.
154 - "Pentium-Pro" for the Intel Pentium Pro.
155 - "Pentium-II" for the Intel Pentium II or pre-Coppermine Celeron.
156 - "Pentium-III" for the Intel Pentium III or Coppermine Celeron.
157 - "Pentium-4" for the Intel Pentium 4 or P4-based Celeron.
158 - "K6" for the AMD K6, K6-II and K6-III (aka K6-3D).
159 - "Athlon" for the AMD K7 family (Athlon/Duron/Thunderbird).
160 - "Crusoe" for the Transmeta Crusoe series.
161 - "Winchip-C6" for original IDT Winchip.
162 - "Winchip-2" for IDT Winchip 2.
163 - "Winchip-2A" for IDT Winchips with 3dNow! capabilities.
164 - "CyrixIII/VIA C3" for VIA Cyrix III or VIA C3.
165 - "VIA C3-2 for VIA C3-2 "Nehemiah" (model 9 and above).
167 If you don't know what to do, choose "386".
172 Select this for a 486 series processor, either Intel or one of the
173 compatible processors from AMD, Cyrix, IBM, or Intel. Includes DX,
174 DX2, and DX4 variants; also SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5D or
178 bool "586/K5/5x86/6x86/6x86MX"
180 Select this for an 586 or 686 series processor such as the AMD K5,
181 the Intel 5x86 or 6x86, or the Intel 6x86MX. This choice does not
182 assume the RDTSC (Read Time Stamp Counter) instruction.
185 bool "Pentium-Classic"
187 Select this for a Pentium Classic processor with the RDTSC (Read
188 Time Stamp Counter) instruction for benchmarking.
193 Select this for a Pentium with the MMX graphics/multimedia
194 extended instructions.
199 Select this for Intel Pentium Pro chips. This enables the use of
200 Pentium Pro extended instructions, and disables the init-time guard
201 against the f00f bug found in earlier Pentiums.
204 bool "Pentium-II/Celeron(pre-Coppermine)"
206 Select this for Intel chips based on the Pentium-II and
207 pre-Coppermine Celeron core. This option enables an unaligned
208 copy optimization, compiles the kernel with optimization flags
209 tailored for the chip, and applies any applicable Pentium Pro
213 bool "Pentium-III/Celeron(Coppermine)/Pentium-III Xeon"
215 Select this for Intel chips based on the Pentium-III and
216 Celeron-Coppermine core. This option enables use of some
217 extended prefetch instructions in addition to the Pentium II
221 bool "Pentium-4/Celeron(P4-based)/Xeon"
223 Select this for Intel Pentium 4 chips. This includes both
224 the Pentium 4 and P4-based Celeron chips. This option
225 enables compile flags optimized for the chip, uses the
226 correct cache shift, and applies any applicable Pentium III
230 bool "K6/K6-II/K6-III"
232 Select this for an AMD K6-family processor. Enables use of
233 some extended instructions, and passes appropriate optimization
237 bool "Athlon/Duron/K7"
239 Select this for an AMD Athlon K7-family processor. Enables use of
240 some extended instructions, and passes appropriate optimization
244 bool "Opteron/Athlon64/Hammer/K8"
246 Select this for an AMD Opteron or Athlon64 Hammer-family processor. Enables
247 use of some extended instructions, and passes appropriate optimization
256 Select this for a Transmeta Crusoe processor. Treats the processor
257 like a 586 with TSC, and sets some GCC optimization flags (like a
258 Pentium Pro with no alignment requirements).
263 Select this for an IDT Winchip C6 chip. Linux and GCC
264 treat this chip as a 586TSC with some extended instructions
265 and alignment requirements.
270 Select this for an IDT Winchip-2. Linux and GCC
271 treat this chip as a 586TSC with some extended instructions
272 and alignment requirements.
275 bool "Winchip-2A/Winchip-3"
277 Select this for an IDT Winchip-2A or 3. Linux and GCC
278 treat this chip as a 586TSC with some extended instructions
279 and alignment reqirements. Also enable out of order memory
280 stores for this CPU, which can increase performance of some
284 bool "CyrixIII/VIA-C3"
286 Select this for a Cyrix III or C3 chip. Presently Linux and GCC
287 treat this chip as a generic 586. Whilst the CPU is 686 class,
288 it lacks the cmov extension which gcc assumes is present when
290 Note that Nehemiah (Model 9) and above will not boot with this
291 kernel due to them lacking the 3DNow! instructions used in earlier
292 incarnations of the CPU.
295 bool "VIA C3-2 (Nehemiah)"
297 Select this for a VIA C3 "Nehemiah". Selecting this enables usage
298 of SSE and tells gcc to treat the CPU as a 686.
299 Note, this kernel will not boot on older (pre model 9) C3s.
304 bool "Generic x86 support"
306 Including some tuning for non selected x86 CPUs too.
307 when it has moderate overhead. This is intended for generic
308 distributions kernels.
311 # Define implied options from the CPU selection here
323 config X86_L1_CACHE_SHIFT
325 default "7" if MPENTIUM4 || X86_GENERIC
326 default "4" if MELAN || M486 || M386
327 default "5" if MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCRUSOE || MCYRIXIII || MK6 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || M586 || MVIAC3_2
328 default "6" if MK7 || MK8
330 config RWSEM_GENERIC_SPINLOCK
335 config RWSEM_XCHGADD_ALGORITHM
340 config X86_PPRO_FENCE
342 depends on M686 || M586MMX || M586TSC || M586 || M486 || M386
347 depends on M586MMX || M586TSC || M586 || M486 || M386
350 config X86_WP_WORKS_OK
370 config X86_ALIGNMENT_16
372 depends on MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCYRIXIII || MELAN || MK6 || M586MMX || M586TSC || M586 || M486 || MVIAC3_2
377 depends on MK7 || MPENTIUM4 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || MK8
380 config X86_INTEL_USERCOPY
382 depends on MPENTIUM4 || MPENTIUMIII || MPENTIUMII || M586MMX || X86_GENERIC || MK8 || MK7
385 config X86_USE_PPRO_CHECKSUM
387 depends on MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMIII || MPENTIUMII || M686 || MK8 || MVIAC3_2
392 depends on MCYRIXIII || MK7
397 depends on MWINCHIP3D || MWINCHIP2 || MWINCHIPC6
401 bool "HPET Timer Support"
403 This enables the use of the HPET for the kernel's internal timer.
404 HPET is the next generation timer replacing legacy 8254s.
405 You can safely choose Y here. However, HPET will only be
406 activated if the platform and the BIOS support this feature.
407 Otherwise the 8254 will be used for timing services.
409 Choose N to continue using the legacy 8254 timer.
411 config HPET_EMULATE_RTC
412 def_bool HPET_TIMER && RTC=y
415 bool "Symmetric multi-processing support"
417 This enables support for systems with more than one CPU. If you have
418 a system with only one CPU, like most personal computers, say N. If
419 you have a system with more than one CPU, say Y.
421 If you say N here, the kernel will run on single and multiprocessor
422 machines, but will use only one CPU of a multiprocessor machine. If
423 you say Y here, the kernel will run on many, but not all,
424 singleprocessor machines. On a singleprocessor machine, the kernel
425 will run faster if you say N here.
427 Note that if you say Y here and choose architecture "586" or
428 "Pentium" under "Processor family", the kernel will not work on 486
429 architectures. Similarly, multiprocessor kernels for the "PPro"
430 architecture may not work on all Pentium based boards.
432 People using multiprocessor machines who say Y here should also say
433 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
434 Management" code will be disabled if you say Y here.
436 See also the <file:Documentation/smp.tex>,
437 <file:Documentation/smp.txt>, <file:Documentation/i386/IO-APIC.txt>,
438 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
439 <http://www.tldp.org/docs.html#howto>.
441 If you don't know what to do here, say N.
444 int "Maximum number of CPUs (2-255)"
446 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
449 This allows you to specify the maximum number of CPUs which this
450 kernel will support. The maximum supported value is 32 and the
451 minimum value which makes sense is 2.
453 This is purely to save memory - each supported CPU adds
454 approximately eight kilobytes to the kernel image.
457 bool "Preemptible Kernel"
459 This option reduces the latency of the kernel when reacting to
460 real-time or interactive events by allowing a low priority process to
461 be preempted even if it is in kernel mode executing a system call.
462 This allows applications to run more reliably even when the system is
465 Say Y here if you are building a kernel for a desktop, embedded
466 or real-time system. Say N if you are unsure.
469 bool "Local APIC support on uniprocessors" if !SMP
470 depends on !(X86_VISWS || X86_VOYAGER)
472 A local APIC (Advanced Programmable Interrupt Controller) is an
473 integrated interrupt controller in the CPU. If you have a single-CPU
474 system which has a processor with a local APIC, you can say Y here to
475 enable and use it. If you say Y here even though your machine doesn't
476 have a local APIC, then the kernel will still run with no slowdown at
477 all. The local APIC supports CPU-generated self-interrupts (timer,
478 performance counters), and the NMI watchdog which detects hard
481 If you have a system with several CPUs, you do not need to say Y
482 here: the local APIC will be used automatically.
485 bool "IO-APIC support on uniprocessors"
486 depends on !SMP && X86_UP_APIC
488 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
489 SMP-capable replacement for PC-style interrupt controllers. Most
490 SMP systems and a small number of uniprocessor systems have one.
491 If you have a single-CPU system with an IO-APIC, you can say Y here
492 to use it. If you say Y here even though your machine doesn't have
493 an IO-APIC, then the kernel will still run with no slowdown at all.
495 If you have a system with several CPUs, you do not need to say Y
496 here: the IO-APIC will be used automatically.
498 config X86_LOCAL_APIC
500 depends on !SMP && X86_UP_APIC
505 depends on !SMP && X86_UP_IOAPIC
510 depends on (MWINCHIP3D || MWINCHIP2 || MCRUSOE || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || MK8 || MVIAC3_2) && !X86_NUMAQ
514 bool "Machine Check Exception"
516 Machine Check Exception support allows the processor to notify the
517 kernel if it detects a problem (e.g. overheating, component failure).
518 The action the kernel takes depends on the severity of the problem,
519 ranging from a warning message on the console, to halting the machine.
520 Your processor must be a Pentium or newer to support this - check the
521 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
522 have a design flaw which leads to false MCE events - hence MCE is
523 disabled on all P5 processors, unless explicitly enabled with "mce"
524 as a boot argument. Similarly, if MCE is built in and creates a
525 problem on some new non-standard machine, you can boot with "nomce"
526 to disable it. MCE support simply ignores non-MCE processors like
527 the 386 and 486, so nearly everyone can say Y here.
529 config X86_MCE_NONFATAL
530 bool "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
533 Enabling this feature starts a timer that triggers every 5 seconds which
534 will look at the machine check registers to see if anything happened.
535 Non-fatal problems automatically get corrected (but still logged).
536 Disable this if you don't want to see these messages.
537 Seeing the messages this option prints out may be indicative of dying hardware,
538 or out-of-spec (ie, overclocked) hardware.
539 This option only does something on certain CPUs.
540 (AMD Athlon/Duron and Intel Pentium 4)
542 config X86_MCE_P4THERMAL
543 bool "check for P4 thermal throttling interrupt."
544 depends on X86_MCE && (X86_UP_APIC || SMP)
546 Enabling this feature will cause a message to be printed when the P4
547 enters thermal throttling.
550 tristate "Toshiba Laptop support"
552 This adds a driver to safely access the System Management Mode of
553 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
554 not work on models with a Phoenix BIOS. The System Management Mode
555 is used to set the BIOS and power saving options on Toshiba portables.
557 For information on utilities to make use of this driver see the
558 Toshiba Linux utilities web site at:
559 <http://www.buzzard.org.uk/toshiba/>.
561 Say Y if you intend to run this kernel on a Toshiba portable.
565 tristate "Dell laptop support"
567 This adds a driver to safely access the System Management Mode
568 of the CPU on the Dell Inspiron 8000. The System Management Mode
569 is used to read cpu temperature and cooling fan status and to
570 control the fans on the I8K portables.
572 This driver has been tested only on the Inspiron 8000 but it may
573 also work with other Dell laptops. You can force loading on other
574 models by passing the parameter `force=1' to the module. Use at
577 For information on utilities to make use of this driver see the
578 I8K Linux utilities web site at:
579 <http://www.debian.org/~dz/i8k/>
581 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
585 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
587 If you say Y here and also to "/dev file system support" in the
588 'File systems' section, you will be able to update the microcode on
589 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
590 Pentium III, Pentium 4, Xeon etc. You will obviously need the
591 actual microcode binary data itself which is not shipped with the
594 For latest news and information on obtaining all the required
595 ingredients for this driver, check:
596 <http://www.urbanmyth.org/microcode/>.
598 To compile this driver as a module, choose M here: the
599 module will be called microcode.
600 If you use modprobe or kmod you may also want to add the line
601 'alias char-major-10-184 microcode' to your /etc/modules.conf file.
604 tristate "/dev/cpu/*/msr - Model-specific register support"
606 This device gives privileged processes access to the x86
607 Model-Specific Registers (MSRs). It is a character device with
608 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
609 MSR accesses are directed to a specific CPU on multi-processor
613 tristate "/dev/cpu/*/cpuid - CPU information support"
615 This device gives processes access to the x86 CPUID instruction to
616 be executed on a specific processor. It is a character device
617 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
621 tristate "BIOS Enhanced Disk Drive calls determine boot disk (EXPERIMENTAL)"
622 depends on EXPERIMENTAL
624 Say Y or M here if you want to enable BIOS Enhanced Disk Drive
625 Services real mode BIOS calls to determine which disk
626 BIOS tries boot from. This information is then exported via driverfs.
628 This option is experimental, but believed to be safe,
629 and most disk controller BIOS vendors do not yet implement this feature.
632 prompt "High Memory Support"
638 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
639 However, the address space of 32-bit x86 processors is only 4
640 Gigabytes large. That means that, if you have a large amount of
641 physical memory, not all of it can be "permanently mapped" by the
642 kernel. The physical memory that's not permanently mapped is called
645 If you are compiling a kernel which will never run on a machine with
646 more than 1 Gigabyte total physical RAM, answer "off" here (default
647 choice and suitable for most users). This will result in a "3GB/1GB"
648 split: 3GB are mapped so that each process sees a 3GB virtual memory
649 space and the remaining part of the 4GB virtual memory space is used
650 by the kernel to permanently map as much physical memory as
653 If the machine has between 1 and 4 Gigabytes physical RAM, then
656 If more than 4 Gigabytes is used then answer "64GB" here. This
657 selection turns Intel PAE (Physical Address Extension) mode on.
658 PAE implements 3-level paging on IA32 processors. PAE is fully
659 supported by Linux, PAE mode is implemented on all recent Intel
660 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
661 then the kernel will not boot on CPUs that don't support PAE!
663 The actual amount of total physical memory will either be
664 auto detected or can be forced by using a kernel command line option
665 such as "mem=256M". (Try "man bootparam" or see the documentation of
666 your boot loader (lilo or loadlin) about how to pass options to the
667 kernel at boot time.)
669 If unsure, say "off".
674 Select this if you have a 32-bit processor and between 1 and 4
675 gigabytes of physical RAM.
680 Select this if you have a 32-bit processor and more than 4
681 gigabytes of physical RAM.
687 depends on HIGHMEM64G || HIGHMEM4G
692 depends on HIGHMEM64G
695 # Common NUMA Features
697 bool "Numa Memory Allocation Support"
698 depends on SMP && HIGHMEM64G && (X86_PC || X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI && !ACPI_HT_ONLY))
700 default y if (X86_NUMAQ || X86_SUMMIT)
702 # Need comments to help the hapless user trying to turn on NUMA support
703 comment "NUMA (NUMA-Q) requires SMP, 64GB highmem support"
704 depends on X86_NUMAQ && (!HIGHMEM64G || !SMP)
706 comment "NUMA (Summit) requires SMP, 64GB highmem support, full ACPI"
707 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI || ACPI_HT_ONLY)
714 config HAVE_ARCH_BOOTMEM_NODE
720 bool "Allocate 3rd-level pagetables from highmem"
721 depends on HIGHMEM4G || HIGHMEM64G
723 The VM uses one page table entry for each page of physical memory.
724 For systems with a lot of RAM, this can be wasteful of precious
725 low memory. Setting this option will put user-space page table
726 entries in high memory.
728 config MATH_EMULATION
729 bool "Math emulation"
731 Linux can emulate a math coprocessor (used for floating point
732 operations) if you don't have one. 486DX and Pentium processors have
733 a math coprocessor built in, 486SX and 386 do not, unless you added
734 a 487DX or 387, respectively. (The messages during boot time can
735 give you some hints here ["man dmesg"].) Everyone needs either a
736 coprocessor or this emulation.
738 If you don't have a math coprocessor, you need to say Y here; if you
739 say Y here even though you have a coprocessor, the coprocessor will
740 be used nevertheless. (This behavior can be changed with the kernel
741 command line option "no387", which comes handy if your coprocessor
742 is broken. Try "man bootparam" or see the documentation of your boot
743 loader (lilo or loadlin) about how to pass options to the kernel at
744 boot time.) This means that it is a good idea to say Y here if you
745 intend to use this kernel on different machines.
747 More information about the internals of the Linux math coprocessor
748 emulation can be found in <file:arch/i386/math-emu/README>.
750 If you are not sure, say Y; apart from resulting in a 66 KB bigger
751 kernel, it won't hurt.
754 bool "MTRR (Memory Type Range Register) support"
756 On Intel P6 family processors (Pentium Pro, Pentium II and later)
757 the Memory Type Range Registers (MTRRs) may be used to control
758 processor access to memory ranges. This is most useful if you have
759 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
760 allows bus write transfers to be combined into a larger transfer
761 before bursting over the PCI/AGP bus. This can increase performance
762 of image write operations 2.5 times or more. Saying Y here creates a
763 /proc/mtrr file which may be used to manipulate your processor's
764 MTRRs. Typically the X server should use this.
766 This code has a reasonably generic interface so that similar
767 control registers on other processors can be easily supported
770 The Cyrix 6x86, 6x86MX and M II processors have Address Range
771 Registers (ARRs) which provide a similar functionality to MTRRs. For
772 these, the ARRs are used to emulate the MTRRs.
773 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
774 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
775 write-combining. All of these processors are supported by this code
776 and it makes sense to say Y here if you have one of them.
778 Saying Y here also fixes a problem with buggy SMP BIOSes which only
779 set the MTRRs for the boot CPU and not for the secondary CPUs. This
780 can lead to all sorts of problems, so it's good to say Y here.
782 You can safely say Y even if your machine doesn't have MTRRs, you'll
783 just add about 9 KB to your kernel.
785 See <file:Documentation/mtrr.txt> for more information.
789 depends on (SMP || PREEMPT) && X86_CMPXCHG
792 # turning this on wastes a bunch of space.
793 # Summit needs it only when NUMA is on
796 depends on ((X86_SUMMIT || X86_GENERICARCH) && NUMA)
802 menu "Power management options (ACPI, APM)"
803 depends on !X86_VOYAGER
805 source kernel/power/Kconfig
807 source "drivers/acpi/Kconfig"
809 menu "APM (Advanced Power Management) BIOS Support"
813 tristate "APM (Advanced Power Management) BIOS support"
816 APM is a BIOS specification for saving power using several different
817 techniques. This is mostly useful for battery powered laptops with
818 APM compliant BIOSes. If you say Y here, the system time will be
819 reset after a RESUME operation, the /proc/apm device will provide
820 battery status information, and user-space programs will receive
821 notification of APM "events" (e.g. battery status change).
823 If you select "Y" here, you can disable actual use of the APM
824 BIOS by passing the "apm=off" option to the kernel at boot time.
826 Note that the APM support is almost completely disabled for
827 machines with more than one CPU.
829 In order to use APM, you will need supporting software. For location
830 and more information, read <file:Documentation/pm.txt> and the
831 Battery Powered Linux mini-HOWTO, available from
832 <http://www.tldp.org/docs.html#howto>.
834 This driver does not spin down disk drives (see the hdparm(8)
835 manpage ("man 8 hdparm") for that), and it doesn't turn off
836 VESA-compliant "green" monitors.
838 This driver does not support the TI 4000M TravelMate and the ACER
839 486/DX4/75 because they don't have compliant BIOSes. Many "green"
840 desktop machines also don't have compliant BIOSes, and this driver
841 may cause those machines to panic during the boot phase.
843 Generally, if you don't have a battery in your machine, there isn't
844 much point in using this driver and you should say N. If you get
845 random kernel OOPSes or reboots that don't seem to be related to
846 anything, try disabling/enabling this option (or disabling/enabling
849 Some other things you should try when experiencing seemingly random,
852 1) make sure that you have enough swap space and that it is
854 2) pass the "no-hlt" option to the kernel
855 3) switch on floating point emulation in the kernel and pass
856 the "no387" option to the kernel
857 4) pass the "floppy=nodma" option to the kernel
858 5) pass the "mem=4M" option to the kernel (thereby disabling
859 all but the first 4 MB of RAM)
860 6) make sure that the CPU is not over clocked.
861 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
862 8) disable the cache from your BIOS settings
863 9) install a fan for the video card or exchange video RAM
864 10) install a better fan for the CPU
865 11) exchange RAM chips
866 12) exchange the motherboard.
868 To compile this driver as a module, choose M here: the
869 module will be called apm.
871 config APM_IGNORE_USER_SUSPEND
872 bool "Ignore USER SUSPEND"
875 This option will ignore USER SUSPEND requests. On machines with a
876 compliant APM BIOS, you want to say N. However, on the NEC Versa M
877 series notebooks, it is necessary to say Y because of a BIOS bug.
880 bool "Enable PM at boot time"
883 Enable APM features at boot time. From page 36 of the APM BIOS
884 specification: "When disabled, the APM BIOS does not automatically
885 power manage devices, enter the Standby State, enter the Suspend
886 State, or take power saving steps in response to CPU Idle calls."
887 This driver will make CPU Idle calls when Linux is idle (unless this
888 feature is turned off -- see "Do CPU IDLE calls", below). This
889 should always save battery power, but more complicated APM features
890 will be dependent on your BIOS implementation. You may need to turn
891 this option off if your computer hangs at boot time when using APM
892 support, or if it beeps continuously instead of suspending. Turn
893 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
894 T400CDT. This is off by default since most machines do fine without
898 bool "Make CPU Idle calls when idle"
901 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
902 On some machines, this can activate improved power savings, such as
903 a slowed CPU clock rate, when the machine is idle. These idle calls
904 are made after the idle loop has run for some length of time (e.g.,
905 333 mS). On some machines, this will cause a hang at boot time or
906 whenever the CPU becomes idle. (On machines with more than one CPU,
907 this option does nothing.)
909 config APM_DISPLAY_BLANK
910 bool "Enable console blanking using APM"
913 Enable console blanking using the APM. Some laptops can use this to
914 turn off the LCD backlight when the screen blanker of the Linux
915 virtual console blanks the screen. Note that this is only used by
916 the virtual console screen blanker, and won't turn off the backlight
917 when using the X Window system. This also doesn't have anything to
918 do with your VESA-compliant power-saving monitor. Further, this
919 option doesn't work for all laptops -- it might not turn off your
920 backlight at all, or it might print a lot of errors to the console,
921 especially if you are using gpm.
923 config APM_RTC_IS_GMT
924 bool "RTC stores time in GMT"
927 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
928 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
931 It is in fact recommended to store GMT in your RTC, because then you
932 don't have to worry about daylight savings time changes. The only
933 reason not to use GMT in your RTC is if you also run a broken OS
934 that doesn't understand GMT.
936 config APM_ALLOW_INTS
937 bool "Allow interrupts during APM BIOS calls"
940 Normally we disable external interrupts while we are making calls to
941 the APM BIOS as a measure to lessen the effects of a badly behaving
942 BIOS implementation. The BIOS should reenable interrupts if it
943 needs to. Unfortunately, some BIOSes do not -- especially those in
944 many of the newer IBM Thinkpads. If you experience hangs when you
945 suspend, try setting this to Y. Otherwise, say N.
947 config APM_REAL_MODE_POWER_OFF
948 bool "Use real mode APM BIOS call to power off"
951 Use real mode APM BIOS calls to switch off the computer. This is
952 a work-around for a number of buggy BIOSes. Switch this option on if
953 your computer crashes instead of powering off properly.
957 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
962 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
964 config X86_VISWS_APIC
969 config X86_LOCAL_APIC
971 depends on (X86_VISWS || SMP) && !X86_VOYAGER
976 depends on SMP && !(X86_VISWS || X86_VOYAGER)
980 bool "PCI support" if !X86_VISWS
981 depends on !X86_VOYAGER
982 default y if X86_VISWS
984 Find out whether you have a PCI motherboard. PCI is the name of a
985 bus system, i.e. the way the CPU talks to the other stuff inside
986 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
987 VESA. If you have PCI, say Y, otherwise N.
989 The PCI-HOWTO, available from
990 <http://www.tldp.org/docs.html#howto>, contains valuable
991 information about which PCI hardware does work under Linux and which
995 prompt "PCI access mode"
996 depends on PCI && !X86_VISWS
1002 On PCI systems, the BIOS can be used to detect the PCI devices and
1003 determine their configuration. However, some old PCI motherboards
1004 have BIOS bugs and may crash if this is done. Also, some embedded
1005 PCI-based systems don't have any BIOS at all. Linux can also try to
1006 detect the PCI hardware directly without using the BIOS.
1008 With this option, you can specify how Linux should detect the PCI
1009 devices. If you choose "BIOS", the BIOS will be used, if you choose
1010 "Direct", the BIOS won't be used, and if you choose "Any", the
1011 kernel will try the direct access method and falls back to the BIOS
1012 if that doesn't work. If unsure, go with the default, which is
1025 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1030 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1033 source "drivers/pci/Kconfig"
1037 depends on !(X86_VOYAGER || X86_VISWS)
1039 Find out whether you have ISA slots on your motherboard. ISA is the
1040 name of a bus system, i.e. the way the CPU talks to the other stuff
1041 inside your box. Other bus systems are PCI, EISA, MicroChannel
1042 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1043 newer boards don't support it. If you have ISA, say Y, otherwise N.
1049 The Extended Industry Standard Architecture (EISA) bus was
1050 developed as an open alternative to the IBM MicroChannel bus.
1052 The EISA bus provided some of the features of the IBM MicroChannel
1053 bus while maintaining backward compatibility with cards made for
1054 the older ISA bus. The EISA bus saw limited use between 1988 and
1055 1995 when it was made obsolete by the PCI bus.
1057 Say Y here if you are building a kernel for an EISA-based machine.
1061 source "drivers/eisa/Kconfig"
1065 depends on !(X86_VISWS || X86_VOYAGER)
1067 MicroChannel Architecture is found in some IBM PS/2 machines and
1068 laptops. It is a bus system similar to PCI or ISA. See
1069 <file:Documentation/mca.txt> (and especially the web page given
1070 there) before attempting to build an MCA bus kernel.
1073 depends on X86_VOYAGER
1074 default y if X86_VOYAGER
1076 source "drivers/mca/Kconfig"
1079 tristate "NatSemi SCx200 support"
1080 depends on !X86_VOYAGER
1082 This provides basic support for the National Semiconductor SCx200
1083 processor. Right now this is just a driver for the GPIO pins.
1085 If you don't know what to do here, say N.
1087 This support is also available as a module. If compiled as a
1088 module, it will be called scx200.
1091 bool "Support for hot-pluggable devices"
1093 Say Y here if you want to plug devices into your computer while
1094 the system is running, and be able to use them quickly. In many
1095 cases, the devices can likewise be unplugged at any time too.
1097 One well known example of this is PCMCIA- or PC-cards, credit-card
1098 size devices such as network cards, modems or hard drives which are
1099 plugged into slots found on all modern laptop computers. Another
1100 example, used on modern desktops as well as laptops, is USB.
1102 Enable HOTPLUG and KMOD, and build a modular kernel. Get agent
1103 software (at <http://linux-hotplug.sourceforge.net/>) and install it.
1104 Then your kernel will automatically call out to a user mode "policy
1105 agent" (/sbin/hotplug) to load modules and set up software needed
1106 to use devices as you hotplug them.
1108 source "drivers/pcmcia/Kconfig"
1110 source "drivers/pci/hotplug/Kconfig"
1115 menu "Executable file formats"
1117 source "fs/Kconfig.binfmt"
1121 source "drivers/base/Kconfig"
1123 source "drivers/mtd/Kconfig"
1125 source "drivers/parport/Kconfig"
1127 source "drivers/pnp/Kconfig"
1129 source "drivers/block/Kconfig"
1131 source "drivers/ide/Kconfig"
1133 source "drivers/scsi/Kconfig"
1135 source "drivers/cdrom/Kconfig"
1137 source "drivers/md/Kconfig"
1139 source "drivers/message/fusion/Kconfig"
1141 source "drivers/ieee1394/Kconfig"
1143 source "drivers/message/i2o/Kconfig"
1145 source "net/Kconfig"
1147 source "drivers/isdn/Kconfig"
1149 source "drivers/telephony/Kconfig"
1152 # input before char - char/joystick depends on it. As does USB.
1154 source "drivers/input/Kconfig"
1156 source "drivers/char/Kconfig"
1158 #source drivers/misc/Config.in
1159 source "drivers/media/Kconfig"
1163 source "drivers/video/Kconfig"
1165 source "sound/Kconfig"
1167 source "drivers/usb/Kconfig"
1169 source "arch/i386/oprofile/Kconfig"
1172 menu "Kernel hacking"
1175 bool "Kernel debugging"
1177 Say Y here if you are developing drivers or trying to debug and
1178 identify kernel problems.
1180 config DEBUG_STACKOVERFLOW
1181 bool "Check for stack overflows"
1182 depends on DEBUG_KERNEL
1185 bool "Debug memory allocations"
1186 depends on DEBUG_KERNEL
1188 Say Y here to have the kernel do limited verification on memory
1189 allocation as well as poisoning memory on free to catch use of freed
1193 bool "Memory mapped I/O debugging"
1194 depends on DEBUG_KERNEL
1196 Say Y here to get warned whenever an attempt is made to do I/O on
1197 obviously invalid addresses such as those generated when ioremap()
1198 calls are forgotten. Memory mapped I/O will go through an extra
1199 check to catch access to unmapped ISA addresses, an access method
1200 that can still be used by old drivers that are being ported from
1204 bool "Magic SysRq key"
1205 depends on DEBUG_KERNEL
1207 If you say Y here, you will have some control over the system even
1208 if the system crashes for example during kernel debugging (e.g., you
1209 will be able to flush the buffer cache to disk, reboot the system
1210 immediately or dump some status information). This is accomplished
1211 by pressing various keys while holding SysRq (Alt+PrintScreen). It
1212 also works on a serial console (on PC hardware at least), if you
1213 send a BREAK and then within 5 seconds a command keypress. The
1214 keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
1215 unless you really know what this hack does.
1217 config DEBUG_SPINLOCK
1218 bool "Spinlock debugging"
1219 depends on DEBUG_KERNEL
1221 Say Y here and build SMP to catch missing spinlock initialization
1222 and certain other kinds of spinlock errors commonly made. This is
1223 best used in conjunction with the NMI watchdog so that spinlock
1224 deadlocks are also debuggable.
1226 config DEBUG_PAGEALLOC
1227 bool "Page alloc debugging"
1228 depends on DEBUG_KERNEL
1230 Unmap pages from the kernel linear mapping after free_pages().
1231 This results in a large slowdown, but helps to find certain types
1232 of memory corruptions.
1234 config DEBUG_HIGHMEM
1235 bool "Highmem debugging"
1236 depends on DEBUG_KERNEL && HIGHMEM
1238 This options enables addition error checking for high memory systems.
1239 Disable for production systems.
1242 bool "Compile the kernel with debug info"
1243 depends on DEBUG_KERNEL
1245 If you say Y here the resulting kernel image will include
1246 debugging info resulting in a larger kernel image.
1247 Say Y here only if you plan to use gdb to debug the kernel.
1248 If you don't debug the kernel, you can say N.
1250 config DEBUG_SPINLOCK_SLEEP
1251 bool "Sleep-inside-spinlock checking"
1253 If you say Y here, various routines which may sleep will become very
1254 noisy if they are called with a spinlock held.
1256 config FRAME_POINTER
1257 bool "Compile the kernel with frame pointers"
1259 If you say Y here the resulting kernel image will be slightly larger
1260 and slower, but it will give very useful debugging information.
1261 If you don't debug the kernel, you can say N, but we may not be able
1262 to solve problems without frame pointers.
1264 config X86_EXTRA_IRQS
1266 depends on X86_LOCAL_APIC || X86_VOYAGER
1269 config X86_FIND_SMP_CONFIG
1271 depends on X86_LOCAL_APIC || X86_VOYAGER
1276 depends on X86_LOCAL_APIC && !X86_VISWS
1281 source "security/Kconfig"
1283 source "crypto/Kconfig"
1285 source "lib/Kconfig"
1289 depends on SMP && !X86_VOYAGER
1294 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1297 config X86_BIOS_REBOOT
1299 depends on !(X86_VISWS || X86_VOYAGER)
1302 config X86_TRAMPOLINE
1304 depends on SMP || X86_VISWS
1309 depends on X86 && !EMBEDDED