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.
17 config SEMAPHORE_SLEEPERS
32 config GENERIC_ISA_DMA
40 config ARCH_MAY_HAVE_PC_FDC
52 bool "Enable doublefault exception handler" if EMBEDDED
54 This option allows trapping of rare doublefault exceptions that
55 would otherwise cause a system to silently reboot. Disabling this
56 option saves about 4k and might cause you much additional grey
59 menu "Processor type and features"
62 prompt "Subarchitecture Type"
68 Choose this option if your computer is a standard PC or compatible.
73 Select this for an AMD Elan processor.
75 Do not use this option for K6/Athlon/Opteron processors!
77 If unsure, choose "PC-compatible" instead.
82 Voyager is an MCA-based 32-way capable SMP architecture proprietary
83 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
87 If you do not specifically know you have a Voyager based machine,
88 say N here, otherwise the kernel you build will not be bootable.
91 bool "NUMAQ (IBM/Sequent)"
94 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
95 multiquad box. This changes the way that processors are bootstrapped,
96 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
97 You will need a new lynxer.elf file to flash your firmware with - send
98 email to <Martin.Bligh@us.ibm.com>.
101 bool "Summit/EXA (IBM x440)"
104 This option is needed for IBM systems that use the Summit/EXA chipset.
105 In particular, it is needed for the x440.
107 If you don't have one of these computers, you should say N here.
110 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
113 This option is needed for the systems that have more than 8 CPUs
114 and if the system is not of any sub-arch type above.
116 If you don't have such a system, you should say N here.
119 bool "SGI 320/540 (Visual Workstation)"
121 The SGI Visual Workstation series is an IA32-based workstation
122 based on SGI systems chips with some legacy PC hardware attached.
124 Say Y here to create a kernel to run on the SGI 320 or 540.
126 A kernel compiled for the Visual Workstation will not run on PCs
127 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
129 config X86_GENERICARCH
130 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
133 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
134 It is intended for a generic binary kernel.
137 bool "Support for Unisys ES7000 IA32 series"
140 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
141 supposed to run on an IA32-based Unisys ES7000 system.
142 Only choose this option if you have such a system, otherwise you
150 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
152 config X86_SUMMIT_NUMA
155 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
157 config X86_CYCLONE_TIMER
160 depends on X86_SUMMIT || X86_GENERICARCH
162 config ES7000_CLUSTERED_APIC
165 depends on SMP && X86_ES7000 && MPENTIUMIII
167 source "arch/i386/Kconfig.cpu"
170 bool "HPET Timer Support"
172 This enables the use of the HPET for the kernel's internal timer.
173 HPET is the next generation timer replacing legacy 8254s.
174 You can safely choose Y here. However, HPET will only be
175 activated if the platform and the BIOS support this feature.
176 Otherwise the 8254 will be used for timing services.
178 Choose N to continue using the legacy 8254 timer.
180 config HPET_EMULATE_RTC
182 depends on HPET_TIMER && RTC=y
186 bool "Symmetric multi-processing support"
188 This enables support for systems with more than one CPU. If you have
189 a system with only one CPU, like most personal computers, say N. If
190 you have a system with more than one CPU, say Y.
192 If you say N here, the kernel will run on single and multiprocessor
193 machines, but will use only one CPU of a multiprocessor machine. If
194 you say Y here, the kernel will run on many, but not all,
195 singleprocessor machines. On a singleprocessor machine, the kernel
196 will run faster if you say N here.
198 Note that if you say Y here and choose architecture "586" or
199 "Pentium" under "Processor family", the kernel will not work on 486
200 architectures. Similarly, multiprocessor kernels for the "PPro"
201 architecture may not work on all Pentium based boards.
203 People using multiprocessor machines who say Y here should also say
204 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
205 Management" code will be disabled if you say Y here.
207 See also the <file:Documentation/smp.txt>,
208 <file:Documentation/i386/IO-APIC.txt>,
209 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
210 <http://www.tldp.org/docs.html#howto>.
212 If you don't know what to do here, say N.
215 int "Maximum number of CPUs (2-255)"
218 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
221 This allows you to specify the maximum number of CPUs which this
222 kernel will support. The maximum supported value is 255 and the
223 minimum value which makes sense is 2.
225 This is purely to save memory - each supported CPU adds
226 approximately eight kilobytes to the kernel image.
229 bool "SMT (Hyperthreading) scheduler support"
233 SMT scheduler support improves the CPU scheduler's decision making
234 when dealing with Intel Pentium 4 chips with HyperThreading at a
235 cost of slightly increased overhead in some places. If unsure say
238 source "kernel/Kconfig.preempt"
241 bool "Local APIC support on uniprocessors"
242 depends on !SMP && !(X86_VISWS || X86_VOYAGER)
244 A local APIC (Advanced Programmable Interrupt Controller) is an
245 integrated interrupt controller in the CPU. If you have a single-CPU
246 system which has a processor with a local APIC, you can say Y here to
247 enable and use it. If you say Y here even though your machine doesn't
248 have a local APIC, then the kernel will still run with no slowdown at
249 all. The local APIC supports CPU-generated self-interrupts (timer,
250 performance counters), and the NMI watchdog which detects hard
254 bool "IO-APIC support on uniprocessors"
255 depends on X86_UP_APIC
257 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
258 SMP-capable replacement for PC-style interrupt controllers. Most
259 SMP systems and many recent uniprocessor systems have one.
261 If you have a single-CPU system with an IO-APIC, you can say Y here
262 to use it. If you say Y here even though your machine doesn't have
263 an IO-APIC, then the kernel will still run with no slowdown at all.
265 config X86_LOCAL_APIC
267 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER)
272 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER))
275 config X86_VISWS_APIC
281 bool "Machine Check Exception"
282 depends on !X86_VOYAGER
284 Machine Check Exception support allows the processor to notify the
285 kernel if it detects a problem (e.g. overheating, component failure).
286 The action the kernel takes depends on the severity of the problem,
287 ranging from a warning message on the console, to halting the machine.
288 Your processor must be a Pentium or newer to support this - check the
289 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
290 have a design flaw which leads to false MCE events - hence MCE is
291 disabled on all P5 processors, unless explicitly enabled with "mce"
292 as a boot argument. Similarly, if MCE is built in and creates a
293 problem on some new non-standard machine, you can boot with "nomce"
294 to disable it. MCE support simply ignores non-MCE processors like
295 the 386 and 486, so nearly everyone can say Y here.
297 config X86_MCE_NONFATAL
298 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
301 Enabling this feature starts a timer that triggers every 5 seconds which
302 will look at the machine check registers to see if anything happened.
303 Non-fatal problems automatically get corrected (but still logged).
304 Disable this if you don't want to see these messages.
305 Seeing the messages this option prints out may be indicative of dying hardware,
306 or out-of-spec (ie, overclocked) hardware.
307 This option only does something on certain CPUs.
308 (AMD Athlon/Duron and Intel Pentium 4)
310 config X86_MCE_P4THERMAL
311 bool "check for P4 thermal throttling interrupt."
312 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
314 Enabling this feature will cause a message to be printed when the P4
315 enters thermal throttling.
318 tristate "Toshiba Laptop support"
320 This adds a driver to safely access the System Management Mode of
321 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
322 not work on models with a Phoenix BIOS. The System Management Mode
323 is used to set the BIOS and power saving options on Toshiba portables.
325 For information on utilities to make use of this driver see the
326 Toshiba Linux utilities web site at:
327 <http://www.buzzard.org.uk/toshiba/>.
329 Say Y if you intend to run this kernel on a Toshiba portable.
333 tristate "Dell laptop support"
335 This adds a driver to safely access the System Management Mode
336 of the CPU on the Dell Inspiron 8000. The System Management Mode
337 is used to read cpu temperature and cooling fan status and to
338 control the fans on the I8K portables.
340 This driver has been tested only on the Inspiron 8000 but it may
341 also work with other Dell laptops. You can force loading on other
342 models by passing the parameter `force=1' to the module. Use at
345 For information on utilities to make use of this driver see the
346 I8K Linux utilities web site at:
347 <http://people.debian.org/~dz/i8k/>
349 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
352 config X86_REBOOTFIXUPS
353 bool "Enable X86 board specific fixups for reboot"
357 This enables chipset and/or board specific fixups to be done
358 in order to get reboot to work correctly. This is only needed on
359 some combinations of hardware and BIOS. The symptom, for which
360 this config is intended, is when reboot ends with a stalled/hung
363 Currently, the only fixup is for the Geode GX1/CS5530A/TROM2.1.
366 Say Y if you want to enable the fixup. Currently, it's safe to
367 enable this option even if you don't need it.
371 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
373 If you say Y here and also to "/dev file system support" in the
374 'File systems' section, you will be able to update the microcode on
375 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
376 Pentium III, Pentium 4, Xeon etc. You will obviously need the
377 actual microcode binary data itself which is not shipped with the
380 For latest news and information on obtaining all the required
381 ingredients for this driver, check:
382 <http://www.urbanmyth.org/microcode/>.
384 To compile this driver as a module, choose M here: the
385 module will be called microcode.
388 tristate "/dev/cpu/*/msr - Model-specific register support"
390 This device gives privileged processes access to the x86
391 Model-Specific Registers (MSRs). It is a character device with
392 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
393 MSR accesses are directed to a specific CPU on multi-processor
397 tristate "/dev/cpu/*/cpuid - CPU information support"
399 This device gives processes access to the x86 CPUID instruction to
400 be executed on a specific processor. It is a character device
401 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
404 source "drivers/firmware/Kconfig"
407 prompt "High Memory Support"
413 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
414 However, the address space of 32-bit x86 processors is only 4
415 Gigabytes large. That means that, if you have a large amount of
416 physical memory, not all of it can be "permanently mapped" by the
417 kernel. The physical memory that's not permanently mapped is called
420 If you are compiling a kernel which will never run on a machine with
421 more than 1 Gigabyte total physical RAM, answer "off" here (default
422 choice and suitable for most users). This will result in a "3GB/1GB"
423 split: 3GB are mapped so that each process sees a 3GB virtual memory
424 space and the remaining part of the 4GB virtual memory space is used
425 by the kernel to permanently map as much physical memory as
428 If the machine has between 1 and 4 Gigabytes physical RAM, then
431 If more than 4 Gigabytes is used then answer "64GB" here. This
432 selection turns Intel PAE (Physical Address Extension) mode on.
433 PAE implements 3-level paging on IA32 processors. PAE is fully
434 supported by Linux, PAE mode is implemented on all recent Intel
435 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
436 then the kernel will not boot on CPUs that don't support PAE!
438 The actual amount of total physical memory will either be
439 auto detected or can be forced by using a kernel command line option
440 such as "mem=256M". (Try "man bootparam" or see the documentation of
441 your boot loader (lilo or loadlin) about how to pass options to the
442 kernel at boot time.)
444 If unsure, say "off".
449 Select this if you have a 32-bit processor and between 1 and 4
450 gigabytes of physical RAM.
455 Select this if you have a 32-bit processor and more than 4
456 gigabytes of physical RAM.
462 depends on HIGHMEM64G || HIGHMEM4G
467 depends on HIGHMEM64G
470 # Common NUMA Features
472 bool "Numa Memory Allocation and Scheduler Support"
473 depends on SMP && HIGHMEM64G && (X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI))
475 default y if (X86_NUMAQ || X86_SUMMIT)
477 # Need comments to help the hapless user trying to turn on NUMA support
478 comment "NUMA (NUMA-Q) requires SMP, 64GB highmem support"
479 depends on X86_NUMAQ && (!HIGHMEM64G || !SMP)
481 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
482 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
484 config HAVE_ARCH_BOOTMEM_NODE
489 config ARCH_HAVE_MEMORY_PRESENT
491 depends on DISCONTIGMEM
494 config NEED_NODE_MEMMAP_SIZE
496 depends on DISCONTIGMEM || SPARSEMEM
499 config HAVE_ARCH_ALLOC_REMAP
504 config ARCH_FLATMEM_ENABLE
506 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
508 config ARCH_DISCONTIGMEM_ENABLE
512 config ARCH_DISCONTIGMEM_DEFAULT
516 config ARCH_SPARSEMEM_ENABLE
518 depends on (NUMA || (X86_PC && EXPERIMENTAL))
519 select SPARSEMEM_STATIC
521 config ARCH_SELECT_MEMORY_MODEL
523 depends on ARCH_SPARSEMEM_ENABLE
527 config HAVE_ARCH_EARLY_PFN_TO_NID
533 bool "Allocate 3rd-level pagetables from highmem"
534 depends on HIGHMEM4G || HIGHMEM64G
536 The VM uses one page table entry for each page of physical memory.
537 For systems with a lot of RAM, this can be wasteful of precious
538 low memory. Setting this option will put user-space page table
539 entries in high memory.
541 config MATH_EMULATION
542 bool "Math emulation"
544 Linux can emulate a math coprocessor (used for floating point
545 operations) if you don't have one. 486DX and Pentium processors have
546 a math coprocessor built in, 486SX and 386 do not, unless you added
547 a 487DX or 387, respectively. (The messages during boot time can
548 give you some hints here ["man dmesg"].) Everyone needs either a
549 coprocessor or this emulation.
551 If you don't have a math coprocessor, you need to say Y here; if you
552 say Y here even though you have a coprocessor, the coprocessor will
553 be used nevertheless. (This behavior can be changed with the kernel
554 command line option "no387", which comes handy if your coprocessor
555 is broken. Try "man bootparam" or see the documentation of your boot
556 loader (lilo or loadlin) about how to pass options to the kernel at
557 boot time.) This means that it is a good idea to say Y here if you
558 intend to use this kernel on different machines.
560 More information about the internals of the Linux math coprocessor
561 emulation can be found in <file:arch/i386/math-emu/README>.
563 If you are not sure, say Y; apart from resulting in a 66 KB bigger
564 kernel, it won't hurt.
567 bool "MTRR (Memory Type Range Register) support"
569 On Intel P6 family processors (Pentium Pro, Pentium II and later)
570 the Memory Type Range Registers (MTRRs) may be used to control
571 processor access to memory ranges. This is most useful if you have
572 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
573 allows bus write transfers to be combined into a larger transfer
574 before bursting over the PCI/AGP bus. This can increase performance
575 of image write operations 2.5 times or more. Saying Y here creates a
576 /proc/mtrr file which may be used to manipulate your processor's
577 MTRRs. Typically the X server should use this.
579 This code has a reasonably generic interface so that similar
580 control registers on other processors can be easily supported
583 The Cyrix 6x86, 6x86MX and M II processors have Address Range
584 Registers (ARRs) which provide a similar functionality to MTRRs. For
585 these, the ARRs are used to emulate the MTRRs.
586 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
587 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
588 write-combining. All of these processors are supported by this code
589 and it makes sense to say Y here if you have one of them.
591 Saying Y here also fixes a problem with buggy SMP BIOSes which only
592 set the MTRRs for the boot CPU and not for the secondary CPUs. This
593 can lead to all sorts of problems, so it's good to say Y here.
595 You can safely say Y even if your machine doesn't have MTRRs, you'll
596 just add about 9 KB to your kernel.
598 See <file:Documentation/mtrr.txt> for more information.
601 bool "Boot from EFI support (EXPERIMENTAL)"
605 This enables the the kernel to boot on EFI platforms using
606 system configuration information passed to it from the firmware.
607 This also enables the kernel to use any EFI runtime services that are
608 available (such as the EFI variable services).
610 This option is only useful on systems that have EFI firmware
611 and will result in a kernel image that is ~8k larger. In addition,
612 you must use the latest ELILO loader available at
613 <http://elilo.sourceforge.net> in order to take advantage of
614 kernel initialization using EFI information (neither GRUB nor LILO know
615 anything about EFI). However, even with this option, the resultant
616 kernel should continue to boot on existing non-EFI platforms.
619 bool "Enable kernel irq balancing"
620 depends on SMP && X86_IO_APIC
623 The default yes will allow the kernel to do irq load balancing.
624 Saying no will keep the kernel from doing irq load balancing.
626 # turning this on wastes a bunch of space.
627 # Summit needs it only when NUMA is on
630 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
634 bool "Use register arguments (EXPERIMENTAL)"
635 depends on EXPERIMENTAL
638 Compile the kernel with -mregparm=3. This uses a different ABI
639 and passes the first three arguments of a function call in registers.
640 This will probably break binary only modules.
643 bool "Enable seccomp to safely compute untrusted bytecode"
647 This kernel feature is useful for number crunching applications
648 that may need to compute untrusted bytecode during their
649 execution. By using pipes or other transports made available to
650 the process as file descriptors supporting the read/write
651 syscalls, it's possible to isolate those applications in
652 their own address space using seccomp. Once seccomp is
653 enabled via /proc/<pid>/seccomp, it cannot be disabled
654 and the task is only allowed to execute a few safe syscalls
655 defined by each seccomp mode.
657 If unsure, say Y. Only embedded should say N here.
659 source kernel/Kconfig.hz
662 bool "kexec system call (EXPERIMENTAL)"
663 depends on EXPERIMENTAL
665 kexec is a system call that implements the ability to shutdown your
666 current kernel, and to start another kernel. It is like a reboot
667 but it is indepedent of the system firmware. And like a reboot
668 you can start any kernel with it, not just Linux.
670 The name comes from the similiarity to the exec system call.
672 It is an ongoing process to be certain the hardware in a machine
673 is properly shutdown, so do not be surprised if this code does not
674 initially work for you. It may help to enable device hotplugging
675 support. As of this writing the exact hardware interface is
676 strongly in flux, so no good recommendation can be made.
679 bool "kernel crash dumps (EXPERIMENTAL)"
680 depends on EXPERIMENTAL
683 Generate crash dump after being started by kexec.
685 config PHYSICAL_START
686 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
688 default "0x1000000" if CRASH_DUMP
691 This gives the physical address where the kernel is loaded. Normally
692 for regular kernels this value is 0x100000 (1MB). But in the case
693 of kexec on panic the fail safe kernel needs to run at a different
694 address than the panic-ed kernel. This option is used to set the load
695 address for kernels used to capture crash dump on being kexec'ed
696 after panic. The default value for crash dump kernels is
697 0x1000000 (16MB). This can also be set based on the "X" value as
698 specified in the "crashkernel=YM@XM" command line boot parameter
699 passed to the panic-ed kernel. Typically this parameter is set as
700 crashkernel=64M@16M. Please take a look at
701 Documentation/kdump/kdump.txt for more details about crash dumps.
703 Don't change this unless you know what you are doing.
706 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
707 depends on SMP && HOTPLUG && EXPERIMENTAL
709 Say Y here to experiment with turning CPUs off and on. CPUs
710 can be controlled through /sys/devices/system/cpu.
717 menu "Power management options (ACPI, APM)"
718 depends on !X86_VOYAGER
720 source kernel/power/Kconfig
722 source "drivers/acpi/Kconfig"
724 menu "APM (Advanced Power Management) BIOS Support"
725 depends on PM && !X86_VISWS
728 tristate "APM (Advanced Power Management) BIOS support"
731 APM is a BIOS specification for saving power using several different
732 techniques. This is mostly useful for battery powered laptops with
733 APM compliant BIOSes. If you say Y here, the system time will be
734 reset after a RESUME operation, the /proc/apm device will provide
735 battery status information, and user-space programs will receive
736 notification of APM "events" (e.g. battery status change).
738 If you select "Y" here, you can disable actual use of the APM
739 BIOS by passing the "apm=off" option to the kernel at boot time.
741 Note that the APM support is almost completely disabled for
742 machines with more than one CPU.
744 In order to use APM, you will need supporting software. For location
745 and more information, read <file:Documentation/pm.txt> and the
746 Battery Powered Linux mini-HOWTO, available from
747 <http://www.tldp.org/docs.html#howto>.
749 This driver does not spin down disk drives (see the hdparm(8)
750 manpage ("man 8 hdparm") for that), and it doesn't turn off
751 VESA-compliant "green" monitors.
753 This driver does not support the TI 4000M TravelMate and the ACER
754 486/DX4/75 because they don't have compliant BIOSes. Many "green"
755 desktop machines also don't have compliant BIOSes, and this driver
756 may cause those machines to panic during the boot phase.
758 Generally, if you don't have a battery in your machine, there isn't
759 much point in using this driver and you should say N. If you get
760 random kernel OOPSes or reboots that don't seem to be related to
761 anything, try disabling/enabling this option (or disabling/enabling
764 Some other things you should try when experiencing seemingly random,
767 1) make sure that you have enough swap space and that it is
769 2) pass the "no-hlt" option to the kernel
770 3) switch on floating point emulation in the kernel and pass
771 the "no387" option to the kernel
772 4) pass the "floppy=nodma" option to the kernel
773 5) pass the "mem=4M" option to the kernel (thereby disabling
774 all but the first 4 MB of RAM)
775 6) make sure that the CPU is not over clocked.
776 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
777 8) disable the cache from your BIOS settings
778 9) install a fan for the video card or exchange video RAM
779 10) install a better fan for the CPU
780 11) exchange RAM chips
781 12) exchange the motherboard.
783 To compile this driver as a module, choose M here: the
784 module will be called apm.
786 config APM_IGNORE_USER_SUSPEND
787 bool "Ignore USER SUSPEND"
790 This option will ignore USER SUSPEND requests. On machines with a
791 compliant APM BIOS, you want to say N. However, on the NEC Versa M
792 series notebooks, it is necessary to say Y because of a BIOS bug.
795 bool "Enable PM at boot time"
798 Enable APM features at boot time. From page 36 of the APM BIOS
799 specification: "When disabled, the APM BIOS does not automatically
800 power manage devices, enter the Standby State, enter the Suspend
801 State, or take power saving steps in response to CPU Idle calls."
802 This driver will make CPU Idle calls when Linux is idle (unless this
803 feature is turned off -- see "Do CPU IDLE calls", below). This
804 should always save battery power, but more complicated APM features
805 will be dependent on your BIOS implementation. You may need to turn
806 this option off if your computer hangs at boot time when using APM
807 support, or if it beeps continuously instead of suspending. Turn
808 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
809 T400CDT. This is off by default since most machines do fine without
813 bool "Make CPU Idle calls when idle"
816 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
817 On some machines, this can activate improved power savings, such as
818 a slowed CPU clock rate, when the machine is idle. These idle calls
819 are made after the idle loop has run for some length of time (e.g.,
820 333 mS). On some machines, this will cause a hang at boot time or
821 whenever the CPU becomes idle. (On machines with more than one CPU,
822 this option does nothing.)
824 config APM_DISPLAY_BLANK
825 bool "Enable console blanking using APM"
828 Enable console blanking using the APM. Some laptops can use this to
829 turn off the LCD backlight when the screen blanker of the Linux
830 virtual console blanks the screen. Note that this is only used by
831 the virtual console screen blanker, and won't turn off the backlight
832 when using the X Window system. This also doesn't have anything to
833 do with your VESA-compliant power-saving monitor. Further, this
834 option doesn't work for all laptops -- it might not turn off your
835 backlight at all, or it might print a lot of errors to the console,
836 especially if you are using gpm.
838 config APM_RTC_IS_GMT
839 bool "RTC stores time in GMT"
842 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
843 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
846 It is in fact recommended to store GMT in your RTC, because then you
847 don't have to worry about daylight savings time changes. The only
848 reason not to use GMT in your RTC is if you also run a broken OS
849 that doesn't understand GMT.
851 config APM_ALLOW_INTS
852 bool "Allow interrupts during APM BIOS calls"
855 Normally we disable external interrupts while we are making calls to
856 the APM BIOS as a measure to lessen the effects of a badly behaving
857 BIOS implementation. The BIOS should reenable interrupts if it
858 needs to. Unfortunately, some BIOSes do not -- especially those in
859 many of the newer IBM Thinkpads. If you experience hangs when you
860 suspend, try setting this to Y. Otherwise, say N.
862 config APM_REAL_MODE_POWER_OFF
863 bool "Use real mode APM BIOS call to power off"
866 Use real mode APM BIOS calls to switch off the computer. This is
867 a work-around for a number of buggy BIOSes. Switch this option on if
868 your computer crashes instead of powering off properly.
872 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
876 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
879 bool "PCI support" if !X86_VISWS
880 depends on !X86_VOYAGER
881 default y if X86_VISWS
883 Find out whether you have a PCI motherboard. PCI is the name of a
884 bus system, i.e. the way the CPU talks to the other stuff inside
885 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
886 VESA. If you have PCI, say Y, otherwise N.
888 The PCI-HOWTO, available from
889 <http://www.tldp.org/docs.html#howto>, contains valuable
890 information about which PCI hardware does work under Linux and which
894 prompt "PCI access mode"
895 depends on PCI && !X86_VISWS
898 On PCI systems, the BIOS can be used to detect the PCI devices and
899 determine their configuration. However, some old PCI motherboards
900 have BIOS bugs and may crash if this is done. Also, some embedded
901 PCI-based systems don't have any BIOS at all. Linux can also try to
902 detect the PCI hardware directly without using the BIOS.
904 With this option, you can specify how Linux should detect the
905 PCI devices. If you choose "BIOS", the BIOS will be used,
906 if you choose "Direct", the BIOS won't be used, and if you
907 choose "MMConfig", then PCI Express MMCONFIG will be used.
908 If you choose "Any", the kernel will try MMCONFIG, then the
909 direct access method and falls back to the BIOS if that doesn't
910 work. If unsure, go with the default, which is "Any".
915 config PCI_GOMMCONFIG
928 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
933 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
938 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
941 source "drivers/pci/pcie/Kconfig"
943 source "drivers/pci/Kconfig"
951 depends on !(X86_VOYAGER || X86_VISWS)
953 Find out whether you have ISA slots on your motherboard. ISA is the
954 name of a bus system, i.e. the way the CPU talks to the other stuff
955 inside your box. Other bus systems are PCI, EISA, MicroChannel
956 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
957 newer boards don't support it. If you have ISA, say Y, otherwise N.
963 The Extended Industry Standard Architecture (EISA) bus was
964 developed as an open alternative to the IBM MicroChannel bus.
966 The EISA bus provided some of the features of the IBM MicroChannel
967 bus while maintaining backward compatibility with cards made for
968 the older ISA bus. The EISA bus saw limited use between 1988 and
969 1995 when it was made obsolete by the PCI bus.
971 Say Y here if you are building a kernel for an EISA-based machine.
975 source "drivers/eisa/Kconfig"
978 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
979 default y if X86_VOYAGER
981 MicroChannel Architecture is found in some IBM PS/2 machines and
982 laptops. It is a bus system similar to PCI or ISA. See
983 <file:Documentation/mca.txt> (and especially the web page given
984 there) before attempting to build an MCA bus kernel.
986 source "drivers/mca/Kconfig"
989 tristate "NatSemi SCx200 support"
990 depends on !X86_VOYAGER
992 This provides basic support for the National Semiconductor SCx200
993 processor. Right now this is just a driver for the GPIO pins.
995 If you don't know what to do here, say N.
997 This support is also available as a module. If compiled as a
998 module, it will be called scx200.
1000 source "drivers/pcmcia/Kconfig"
1002 source "drivers/pci/hotplug/Kconfig"
1006 menu "Executable file formats"
1008 source "fs/Kconfig.binfmt"
1012 source "net/Kconfig"
1014 source "drivers/Kconfig"
1018 menu "Instrumentation Support"
1019 depends on EXPERIMENTAL
1021 source "arch/i386/oprofile/Kconfig"
1024 bool "Kprobes (EXPERIMENTAL)"
1026 Kprobes allows you to trap at almost any kernel address and
1027 execute a callback function. register_kprobe() establishes
1028 a probepoint and specifies the callback. Kprobes is useful
1029 for kernel debugging, non-intrusive instrumentation and testing.
1030 If in doubt, say "N".
1033 source "arch/i386/Kconfig.debug"
1035 source "security/Kconfig"
1037 source "crypto/Kconfig"
1039 source "lib/Kconfig"
1042 # Use the generic interrupt handling code in kernel/irq/:
1044 config GENERIC_HARDIRQS
1048 config GENERIC_IRQ_PROBE
1052 config GENERIC_PENDING_IRQ
1054 depends on GENERIC_HARDIRQS && SMP
1059 depends on SMP && !X86_VOYAGER
1064 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1067 config X86_BIOS_REBOOT
1069 depends on !(X86_VISWS || X86_VOYAGER)
1072 config X86_TRAMPOLINE
1074 depends on X86_SMP || (X86_VOYAGER && SMP)
Code Review / linux-2.6.git / blob