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 GENERIC_CMOS_UPDATE
25 config CLOCKSOURCE_WATCHDOG
29 config GENERIC_CLOCKEVENTS
33 config GENERIC_CLOCKEVENTS_BROADCAST
36 depends on X86_LOCAL_APIC
38 config LOCKDEP_SUPPORT
42 config STACKTRACE_SUPPORT
46 config SEMAPHORE_SLEEPERS
69 config GENERIC_ISA_DMA
82 config GENERIC_HWEIGHT
86 config ARCH_MAY_HAVE_PC_FDC
96 menu "Processor type and features"
98 source "kernel/time/Kconfig"
101 bool "Symmetric multi-processing support"
103 This enables support for systems with more than one CPU. If you have
104 a system with only one CPU, like most personal computers, say N. If
105 you have a system with more than one CPU, say Y.
107 If you say N here, the kernel will run on single and multiprocessor
108 machines, but will use only one CPU of a multiprocessor machine. If
109 you say Y here, the kernel will run on many, but not all,
110 singleprocessor machines. On a singleprocessor machine, the kernel
111 will run faster if you say N here.
113 Note that if you say Y here and choose architecture "586" or
114 "Pentium" under "Processor family", the kernel will not work on 486
115 architectures. Similarly, multiprocessor kernels for the "PPro"
116 architecture may not work on all Pentium based boards.
118 People using multiprocessor machines who say Y here should also say
119 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
120 Management" code will be disabled if you say Y here.
122 See also the <file:Documentation/smp.txt>,
123 <file:Documentation/i386/IO-APIC.txt>,
124 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
125 <http://www.tldp.org/docs.html#howto>.
127 If you don't know what to do here, say N.
130 prompt "Subarchitecture Type"
136 Choose this option if your computer is a standard PC or compatible.
141 Select this for an AMD Elan processor.
143 Do not use this option for K6/Athlon/Opteron processors!
145 If unsure, choose "PC-compatible" instead.
149 select SMP if !BROKEN
151 Voyager is an MCA-based 32-way capable SMP architecture proprietary
152 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
156 If you do not specifically know you have a Voyager based machine,
157 say N here, otherwise the kernel you build will not be bootable.
160 bool "NUMAQ (IBM/Sequent)"
164 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
165 multiquad box. This changes the way that processors are bootstrapped,
166 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
167 You will need a new lynxer.elf file to flash your firmware with - send
168 email to <Martin.Bligh@us.ibm.com>.
171 bool "Summit/EXA (IBM x440)"
174 This option is needed for IBM systems that use the Summit/EXA chipset.
175 In particular, it is needed for the x440.
177 If you don't have one of these computers, you should say N here.
178 If you want to build a NUMA kernel, you must select ACPI.
181 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
184 This option is needed for the systems that have more than 8 CPUs
185 and if the system is not of any sub-arch type above.
187 If you don't have such a system, you should say N here.
190 bool "SGI 320/540 (Visual Workstation)"
192 The SGI Visual Workstation series is an IA32-based workstation
193 based on SGI systems chips with some legacy PC hardware attached.
195 Say Y here to create a kernel to run on the SGI 320 or 540.
197 A kernel compiled for the Visual Workstation will not run on PCs
198 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
200 config X86_GENERICARCH
201 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
203 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
204 It is intended for a generic binary kernel.
205 If you want a NUMA kernel, select ACPI. We need SRAT for NUMA.
208 bool "Support for Unisys ES7000 IA32 series"
211 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
212 supposed to run on an IA32-based Unisys ES7000 system.
213 Only choose this option if you have such a system, otherwise you
218 config SCHED_NO_NO_OMIT_FRAME_POINTER
219 bool "Single-depth WCHAN output"
222 Calculate simpler /proc/<PID>/wchan values. If this option
223 is disabled then wchan values will recurse back to the
224 caller function. This provides more accurate wchan values,
225 at the expense of slightly more scheduling overhead.
227 If in doubt, say "Y".
231 depends on !(X86_VISWS || X86_VOYAGER)
233 This changes the kernel so it can modify itself when it is run
234 under a hypervisor, potentially improving performance significantly
235 over full virtualization. However, when run without a hypervisor
236 the kernel is theoretically slower and slightly larger.
238 menuconfig PARAVIRT_GUEST
239 bool "Paravirtualized guest support"
241 Say Y here to get to see options related to running Linux under
242 various hypervisors. This option alone does not add any kernel code.
244 If you say N, all options in this submenu will be skipped and disabled.
248 source "arch/x86/xen/Kconfig"
251 bool "VMI Guest support"
253 depends on !(X86_VISWS || X86_VOYAGER)
255 VMI provides a paravirtualized interface to the VMware ESX server
256 (it could be used by other hypervisors in theory too, but is not
257 at the moment), by linking the kernel to a GPL-ed ROM module
258 provided by the hypervisor.
261 bool "Lguest guest support"
265 Lguest is a tiny in-kernel hypervisor. Selecting this will
266 allow your kernel to boot under lguest. This option will increase
267 your kernel size by about 6k. If in doubt, say N.
273 depends on ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH)
276 config HAVE_ARCH_PARSE_SRAT
281 config X86_SUMMIT_NUMA
284 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
286 config X86_CYCLONE_TIMER
289 depends on X86_SUMMIT || X86_GENERICARCH
291 config ES7000_CLUSTERED_APIC
294 depends on SMP && X86_ES7000 && MPENTIUMIII
296 source "arch/i386/Kconfig.cpu"
299 bool "HPET Timer Support"
301 This enables the use of the HPET for the kernel's internal timer.
302 HPET is the next generation timer replacing legacy 8254s.
303 You can safely choose Y here. However, HPET will only be
304 activated if the platform and the BIOS support this feature.
305 Otherwise the 8254 will be used for timing services.
307 Choose N to continue using the legacy 8254 timer.
309 config HPET_EMULATE_RTC
311 depends on HPET_TIMER && RTC=y
315 int "Maximum number of CPUs (2-255)"
318 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
321 This allows you to specify the maximum number of CPUs which this
322 kernel will support. The maximum supported value is 255 and the
323 minimum value which makes sense is 2.
325 This is purely to save memory - each supported CPU adds
326 approximately eight kilobytes to the kernel image.
329 bool "SMT (Hyperthreading) scheduler support"
332 SMT scheduler support improves the CPU scheduler's decision making
333 when dealing with Intel Pentium 4 chips with HyperThreading at a
334 cost of slightly increased overhead in some places. If unsure say
338 bool "Multi-core scheduler support"
342 Multi-core scheduler support improves the CPU scheduler's decision
343 making when dealing with multi-core CPU chips at a cost of slightly
344 increased overhead in some places. If unsure say N here.
346 source "kernel/Kconfig.preempt"
349 bool "Local APIC support on uniprocessors"
350 depends on !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH)
352 A local APIC (Advanced Programmable Interrupt Controller) is an
353 integrated interrupt controller in the CPU. If you have a single-CPU
354 system which has a processor with a local APIC, you can say Y here to
355 enable and use it. If you say Y here even though your machine doesn't
356 have a local APIC, then the kernel will still run with no slowdown at
357 all. The local APIC supports CPU-generated self-interrupts (timer,
358 performance counters), and the NMI watchdog which detects hard
362 bool "IO-APIC support on uniprocessors"
363 depends on X86_UP_APIC
365 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
366 SMP-capable replacement for PC-style interrupt controllers. Most
367 SMP systems and many recent uniprocessor systems have one.
369 If you have a single-CPU system with an IO-APIC, you can say Y here
370 to use it. If you say Y here even though your machine doesn't have
371 an IO-APIC, then the kernel will still run with no slowdown at all.
373 config X86_LOCAL_APIC
375 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH
380 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH
383 config X86_VISWS_APIC
389 bool "Machine Check Exception"
390 depends on !X86_VOYAGER
392 Machine Check Exception support allows the processor to notify the
393 kernel if it detects a problem (e.g. overheating, component failure).
394 The action the kernel takes depends on the severity of the problem,
395 ranging from a warning message on the console, to halting the machine.
396 Your processor must be a Pentium or newer to support this - check the
397 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
398 have a design flaw which leads to false MCE events - hence MCE is
399 disabled on all P5 processors, unless explicitly enabled with "mce"
400 as a boot argument. Similarly, if MCE is built in and creates a
401 problem on some new non-standard machine, you can boot with "nomce"
402 to disable it. MCE support simply ignores non-MCE processors like
403 the 386 and 486, so nearly everyone can say Y here.
405 config X86_MCE_NONFATAL
406 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
409 Enabling this feature starts a timer that triggers every 5 seconds which
410 will look at the machine check registers to see if anything happened.
411 Non-fatal problems automatically get corrected (but still logged).
412 Disable this if you don't want to see these messages.
413 Seeing the messages this option prints out may be indicative of dying
414 or out-of-spec (ie, overclocked) hardware.
415 This option only does something on certain CPUs.
416 (AMD Athlon/Duron and Intel Pentium 4)
418 config X86_MCE_P4THERMAL
419 bool "check for P4 thermal throttling interrupt."
420 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
422 Enabling this feature will cause a message to be printed when the P4
423 enters thermal throttling.
427 bool "Enable VM86 support" if EMBEDDED
429 This option is required by programs like DOSEMU to run 16-bit legacy
430 code on X86 processors. It also may be needed by software like
431 XFree86 to initialize some video cards via BIOS. Disabling this
432 option saves about 6k.
435 tristate "Toshiba Laptop support"
437 This adds a driver to safely access the System Management Mode of
438 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
439 not work on models with a Phoenix BIOS. The System Management Mode
440 is used to set the BIOS and power saving options on Toshiba portables.
442 For information on utilities to make use of this driver see the
443 Toshiba Linux utilities web site at:
444 <http://www.buzzard.org.uk/toshiba/>.
446 Say Y if you intend to run this kernel on a Toshiba portable.
450 tristate "Dell laptop support"
452 This adds a driver to safely access the System Management Mode
453 of the CPU on the Dell Inspiron 8000. The System Management Mode
454 is used to read cpu temperature and cooling fan status and to
455 control the fans on the I8K portables.
457 This driver has been tested only on the Inspiron 8000 but it may
458 also work with other Dell laptops. You can force loading on other
459 models by passing the parameter `force=1' to the module. Use at
462 For information on utilities to make use of this driver see the
463 I8K Linux utilities web site at:
464 <http://people.debian.org/~dz/i8k/>
466 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
469 config X86_REBOOTFIXUPS
470 bool "Enable X86 board specific fixups for reboot"
474 This enables chipset and/or board specific fixups to be done
475 in order to get reboot to work correctly. This is only needed on
476 some combinations of hardware and BIOS. The symptom, for which
477 this config is intended, is when reboot ends with a stalled/hung
480 Currently, the only fixup is for the Geode machines using
481 CS5530A and CS5536 chipsets.
483 Say Y if you want to enable the fixup. Currently, it's safe to
484 enable this option even if you don't need it.
488 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
491 If you say Y here, you will be able to update the microcode on
492 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
493 Pentium III, Pentium 4, Xeon etc. You will obviously need the
494 actual microcode binary data itself which is not shipped with the
497 For latest news and information on obtaining all the required
498 ingredients for this driver, check:
499 <http://www.urbanmyth.org/microcode/>.
501 To compile this driver as a module, choose M here: the
502 module will be called microcode.
504 config MICROCODE_OLD_INTERFACE
510 tristate "/dev/cpu/*/msr - Model-specific register support"
512 This device gives privileged processes access to the x86
513 Model-Specific Registers (MSRs). It is a character device with
514 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
515 MSR accesses are directed to a specific CPU on multi-processor
519 tristate "/dev/cpu/*/cpuid - CPU information support"
521 This device gives processes access to the x86 CPUID instruction to
522 be executed on a specific processor. It is a character device
523 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
526 source "drivers/firmware/Kconfig"
529 prompt "High Memory Support"
530 default HIGHMEM4G if !X86_NUMAQ
531 default HIGHMEM64G if X86_NUMAQ
535 depends on !X86_NUMAQ
537 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
538 However, the address space of 32-bit x86 processors is only 4
539 Gigabytes large. That means that, if you have a large amount of
540 physical memory, not all of it can be "permanently mapped" by the
541 kernel. The physical memory that's not permanently mapped is called
544 If you are compiling a kernel which will never run on a machine with
545 more than 1 Gigabyte total physical RAM, answer "off" here (default
546 choice and suitable for most users). This will result in a "3GB/1GB"
547 split: 3GB are mapped so that each process sees a 3GB virtual memory
548 space and the remaining part of the 4GB virtual memory space is used
549 by the kernel to permanently map as much physical memory as
552 If the machine has between 1 and 4 Gigabytes physical RAM, then
555 If more than 4 Gigabytes is used then answer "64GB" here. This
556 selection turns Intel PAE (Physical Address Extension) mode on.
557 PAE implements 3-level paging on IA32 processors. PAE is fully
558 supported by Linux, PAE mode is implemented on all recent Intel
559 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
560 then the kernel will not boot on CPUs that don't support PAE!
562 The actual amount of total physical memory will either be
563 auto detected or can be forced by using a kernel command line option
564 such as "mem=256M". (Try "man bootparam" or see the documentation of
565 your boot loader (lilo or loadlin) about how to pass options to the
566 kernel at boot time.)
568 If unsure, say "off".
572 depends on !X86_NUMAQ
574 Select this if you have a 32-bit processor and between 1 and 4
575 gigabytes of physical RAM.
579 depends on !M386 && !M486
582 Select this if you have a 32-bit processor and more than 4
583 gigabytes of physical RAM.
588 depends on EXPERIMENTAL
589 prompt "Memory split" if EMBEDDED
592 Select the desired split between kernel and user memory.
594 If the address range available to the kernel is less than the
595 physical memory installed, the remaining memory will be available
596 as "high memory". Accessing high memory is a little more costly
597 than low memory, as it needs to be mapped into the kernel first.
598 Note that increasing the kernel address space limits the range
599 available to user programs, making the address space there
600 tighter. Selecting anything other than the default 3G/1G split
601 will also likely make your kernel incompatible with binary-only
604 If you are not absolutely sure what you are doing, leave this
608 bool "3G/1G user/kernel split"
609 config VMSPLIT_3G_OPT
611 bool "3G/1G user/kernel split (for full 1G low memory)"
613 bool "2G/2G user/kernel split"
614 config VMSPLIT_2G_OPT
616 bool "2G/2G user/kernel split (for full 2G low memory)"
618 bool "1G/3G user/kernel split"
623 default 0xB0000000 if VMSPLIT_3G_OPT
624 default 0x80000000 if VMSPLIT_2G
625 default 0x78000000 if VMSPLIT_2G_OPT
626 default 0x40000000 if VMSPLIT_1G
631 depends on HIGHMEM64G || HIGHMEM4G
635 bool "PAE (Physical Address Extension) Support"
637 depends on !HIGHMEM4G
638 select RESOURCES_64BIT
640 PAE is required for NX support, and furthermore enables
641 larger swapspace support for non-overcommit purposes. It
642 has the cost of more pagetable lookup overhead, and also
643 consumes more pagetable space per process.
645 # Common NUMA Features
647 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
648 depends on SMP && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI) && EXPERIMENTAL
650 default y if (X86_NUMAQ || X86_SUMMIT)
652 NUMA support for i386. This is currently highly experimental
653 and should be only used for kernel development. It might also
656 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
657 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
661 default "4" if X86_NUMAQ
663 depends on NEED_MULTIPLE_NODES
665 config HAVE_ARCH_BOOTMEM_NODE
670 config ARCH_HAVE_MEMORY_PRESENT
672 depends on DISCONTIGMEM
675 config NEED_NODE_MEMMAP_SIZE
677 depends on DISCONTIGMEM || SPARSEMEM
680 config HAVE_ARCH_ALLOC_REMAP
685 config ARCH_FLATMEM_ENABLE
687 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
689 config ARCH_DISCONTIGMEM_ENABLE
693 config ARCH_DISCONTIGMEM_DEFAULT
697 config ARCH_SPARSEMEM_ENABLE
699 depends on (NUMA || (X86_PC && EXPERIMENTAL))
700 select SPARSEMEM_STATIC
702 config ARCH_SELECT_MEMORY_MODEL
704 depends on ARCH_SPARSEMEM_ENABLE
706 config ARCH_POPULATES_NODE_MAP
712 bool "Allocate 3rd-level pagetables from highmem"
713 depends on HIGHMEM4G || HIGHMEM64G
715 The VM uses one page table entry for each page of physical memory.
716 For systems with a lot of RAM, this can be wasteful of precious
717 low memory. Setting this option will put user-space page table
718 entries in high memory.
720 config MATH_EMULATION
721 bool "Math emulation"
723 Linux can emulate a math coprocessor (used for floating point
724 operations) if you don't have one. 486DX and Pentium processors have
725 a math coprocessor built in, 486SX and 386 do not, unless you added
726 a 487DX or 387, respectively. (The messages during boot time can
727 give you some hints here ["man dmesg"].) Everyone needs either a
728 coprocessor or this emulation.
730 If you don't have a math coprocessor, you need to say Y here; if you
731 say Y here even though you have a coprocessor, the coprocessor will
732 be used nevertheless. (This behavior can be changed with the kernel
733 command line option "no387", which comes handy if your coprocessor
734 is broken. Try "man bootparam" or see the documentation of your boot
735 loader (lilo or loadlin) about how to pass options to the kernel at
736 boot time.) This means that it is a good idea to say Y here if you
737 intend to use this kernel on different machines.
739 More information about the internals of the Linux math coprocessor
740 emulation can be found in <file:arch/x86/math-emu/README>.
742 If you are not sure, say Y; apart from resulting in a 66 KB bigger
743 kernel, it won't hurt.
746 bool "MTRR (Memory Type Range Register) support"
748 On Intel P6 family processors (Pentium Pro, Pentium II and later)
749 the Memory Type Range Registers (MTRRs) may be used to control
750 processor access to memory ranges. This is most useful if you have
751 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
752 allows bus write transfers to be combined into a larger transfer
753 before bursting over the PCI/AGP bus. This can increase performance
754 of image write operations 2.5 times or more. Saying Y here creates a
755 /proc/mtrr file which may be used to manipulate your processor's
756 MTRRs. Typically the X server should use this.
758 This code has a reasonably generic interface so that similar
759 control registers on other processors can be easily supported
762 The Cyrix 6x86, 6x86MX and M II processors have Address Range
763 Registers (ARRs) which provide a similar functionality to MTRRs. For
764 these, the ARRs are used to emulate the MTRRs.
765 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
766 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
767 write-combining. All of these processors are supported by this code
768 and it makes sense to say Y here if you have one of them.
770 Saying Y here also fixes a problem with buggy SMP BIOSes which only
771 set the MTRRs for the boot CPU and not for the secondary CPUs. This
772 can lead to all sorts of problems, so it's good to say Y here.
774 You can safely say Y even if your machine doesn't have MTRRs, you'll
775 just add about 9 KB to your kernel.
777 See <file:Documentation/mtrr.txt> for more information.
780 bool "Boot from EFI support"
784 This enables the kernel to boot on EFI platforms using
785 system configuration information passed to it from the firmware.
786 This also enables the kernel to use any EFI runtime services that are
787 available (such as the EFI variable services).
789 This option is only useful on systems that have EFI firmware
790 and will result in a kernel image that is ~8k larger. In addition,
791 you must use the latest ELILO loader available at
792 <http://elilo.sourceforge.net> in order to take advantage of
793 kernel initialization using EFI information (neither GRUB nor LILO know
794 anything about EFI). However, even with this option, the resultant
795 kernel should continue to boot on existing non-EFI platforms.
798 bool "Enable kernel irq balancing"
799 depends on SMP && X86_IO_APIC
802 The default yes will allow the kernel to do irq load balancing.
803 Saying no will keep the kernel from doing irq load balancing.
805 # turning this on wastes a bunch of space.
806 # Summit needs it only when NUMA is on
809 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
813 bool "Enable seccomp to safely compute untrusted bytecode"
817 This kernel feature is useful for number crunching applications
818 that may need to compute untrusted bytecode during their
819 execution. By using pipes or other transports made available to
820 the process as file descriptors supporting the read/write
821 syscalls, it's possible to isolate those applications in
822 their own address space using seccomp. Once seccomp is
823 enabled via /proc/<pid>/seccomp, it cannot be disabled
824 and the task is only allowed to execute a few safe syscalls
825 defined by each seccomp mode.
827 If unsure, say Y. Only embedded should say N here.
829 source kernel/Kconfig.hz
832 bool "kexec system call"
834 kexec is a system call that implements the ability to shutdown your
835 current kernel, and to start another kernel. It is like a reboot
836 but it is independent of the system firmware. And like a reboot
837 you can start any kernel with it, not just Linux.
839 The name comes from the similarity to the exec system call.
841 It is an ongoing process to be certain the hardware in a machine
842 is properly shutdown, so do not be surprised if this code does not
843 initially work for you. It may help to enable device hotplugging
844 support. As of this writing the exact hardware interface is
845 strongly in flux, so no good recommendation can be made.
848 bool "kernel crash dumps (EXPERIMENTAL)"
849 depends on EXPERIMENTAL
852 Generate crash dump after being started by kexec.
853 This should be normally only set in special crash dump kernels
854 which are loaded in the main kernel with kexec-tools into
855 a specially reserved region and then later executed after
856 a crash by kdump/kexec. The crash dump kernel must be compiled
857 to a memory address not used by the main kernel or BIOS using
858 PHYSICAL_START, or it must be built as a relocatable image
859 (CONFIG_RELOCATABLE=y).
860 For more details see Documentation/kdump/kdump.txt
862 config PHYSICAL_START
863 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
864 default "0x1000000" if X86_NUMAQ
867 This gives the physical address where the kernel is loaded.
869 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
870 bzImage will decompress itself to above physical address and
871 run from there. Otherwise, bzImage will run from the address where
872 it has been loaded by the boot loader and will ignore above physical
875 In normal kdump cases one does not have to set/change this option
876 as now bzImage can be compiled as a completely relocatable image
877 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
878 address. This option is mainly useful for the folks who don't want
879 to use a bzImage for capturing the crash dump and want to use a
880 vmlinux instead. vmlinux is not relocatable hence a kernel needs
881 to be specifically compiled to run from a specific memory area
882 (normally a reserved region) and this option comes handy.
884 So if you are using bzImage for capturing the crash dump, leave
885 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
886 Otherwise if you plan to use vmlinux for capturing the crash dump
887 change this value to start of the reserved region (Typically 16MB
888 0x1000000). In other words, it can be set based on the "X" value as
889 specified in the "crashkernel=YM@XM" command line boot parameter
890 passed to the panic-ed kernel. Typically this parameter is set as
891 crashkernel=64M@16M. Please take a look at
892 Documentation/kdump/kdump.txt for more details about crash dumps.
894 Usage of bzImage for capturing the crash dump is recommended as
895 one does not have to build two kernels. Same kernel can be used
896 as production kernel and capture kernel. Above option should have
897 gone away after relocatable bzImage support is introduced. But it
898 is present because there are users out there who continue to use
899 vmlinux for dump capture. This option should go away down the
902 Don't change this unless you know what you are doing.
905 bool "Build a relocatable kernel (EXPERIMENTAL)"
906 depends on EXPERIMENTAL
908 This builds a kernel image that retains relocation information
909 so it can be loaded someplace besides the default 1MB.
910 The relocations tend to make the kernel binary about 10% larger,
911 but are discarded at runtime.
913 One use is for the kexec on panic case where the recovery kernel
914 must live at a different physical address than the primary
917 config PHYSICAL_ALIGN
918 hex "Alignment value to which kernel should be aligned"
920 range 0x2000 0x400000
922 This value puts the alignment restrictions on physical address
923 where kernel is loaded and run from. Kernel is compiled for an
924 address which meets above alignment restriction.
926 If bootloader loads the kernel at a non-aligned address and
927 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
928 address aligned to above value and run from there.
930 If bootloader loads the kernel at a non-aligned address and
931 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
932 load address and decompress itself to the address it has been
933 compiled for and run from there. The address for which kernel is
934 compiled already meets above alignment restrictions. Hence the
935 end result is that kernel runs from a physical address meeting
936 above alignment restrictions.
938 Don't change this unless you know what you are doing.
941 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
942 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
944 Say Y here to experiment with turning CPUs off and on, and to
945 enable suspend on SMP systems. CPUs can be controlled through
946 /sys/devices/system/cpu.
949 bool "Compat VDSO support"
952 Map the VDSO to the predictable old-style address too.
954 Say N here if you are running a sufficiently recent glibc
955 version (2.3.3 or later), to remove the high-mapped
956 VDSO mapping and to exclusively use the randomized VDSO.
962 config ARCH_ENABLE_MEMORY_HOTPLUG
966 menu "Power management options (ACPI, APM)"
967 depends on !X86_VOYAGER
969 source kernel/power/Kconfig
971 source "drivers/acpi/Kconfig"
974 tristate "APM (Advanced Power Management) BIOS support"
975 depends on PM_SLEEP && !X86_VISWS
977 APM is a BIOS specification for saving power using several different
978 techniques. This is mostly useful for battery powered laptops with
979 APM compliant BIOSes. If you say Y here, the system time will be
980 reset after a RESUME operation, the /proc/apm device will provide
981 battery status information, and user-space programs will receive
982 notification of APM "events" (e.g. battery status change).
984 If you select "Y" here, you can disable actual use of the APM
985 BIOS by passing the "apm=off" option to the kernel at boot time.
987 Note that the APM support is almost completely disabled for
988 machines with more than one CPU.
990 In order to use APM, you will need supporting software. For location
991 and more information, read <file:Documentation/pm.txt> and the
992 Battery Powered Linux mini-HOWTO, available from
993 <http://www.tldp.org/docs.html#howto>.
995 This driver does not spin down disk drives (see the hdparm(8)
996 manpage ("man 8 hdparm") for that), and it doesn't turn off
997 VESA-compliant "green" monitors.
999 This driver does not support the TI 4000M TravelMate and the ACER
1000 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1001 desktop machines also don't have compliant BIOSes, and this driver
1002 may cause those machines to panic during the boot phase.
1004 Generally, if you don't have a battery in your machine, there isn't
1005 much point in using this driver and you should say N. If you get
1006 random kernel OOPSes or reboots that don't seem to be related to
1007 anything, try disabling/enabling this option (or disabling/enabling
1010 Some other things you should try when experiencing seemingly random,
1013 1) make sure that you have enough swap space and that it is
1015 2) pass the "no-hlt" option to the kernel
1016 3) switch on floating point emulation in the kernel and pass
1017 the "no387" option to the kernel
1018 4) pass the "floppy=nodma" option to the kernel
1019 5) pass the "mem=4M" option to the kernel (thereby disabling
1020 all but the first 4 MB of RAM)
1021 6) make sure that the CPU is not over clocked.
1022 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1023 8) disable the cache from your BIOS settings
1024 9) install a fan for the video card or exchange video RAM
1025 10) install a better fan for the CPU
1026 11) exchange RAM chips
1027 12) exchange the motherboard.
1029 To compile this driver as a module, choose M here: the
1030 module will be called apm.
1034 config APM_IGNORE_USER_SUSPEND
1035 bool "Ignore USER SUSPEND"
1037 This option will ignore USER SUSPEND requests. On machines with a
1038 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1039 series notebooks, it is necessary to say Y because of a BIOS bug.
1041 config APM_DO_ENABLE
1042 bool "Enable PM at boot time"
1044 Enable APM features at boot time. From page 36 of the APM BIOS
1045 specification: "When disabled, the APM BIOS does not automatically
1046 power manage devices, enter the Standby State, enter the Suspend
1047 State, or take power saving steps in response to CPU Idle calls."
1048 This driver will make CPU Idle calls when Linux is idle (unless this
1049 feature is turned off -- see "Do CPU IDLE calls", below). This
1050 should always save battery power, but more complicated APM features
1051 will be dependent on your BIOS implementation. You may need to turn
1052 this option off if your computer hangs at boot time when using APM
1053 support, or if it beeps continuously instead of suspending. Turn
1054 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1055 T400CDT. This is off by default since most machines do fine without
1059 bool "Make CPU Idle calls when idle"
1061 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1062 On some machines, this can activate improved power savings, such as
1063 a slowed CPU clock rate, when the machine is idle. These idle calls
1064 are made after the idle loop has run for some length of time (e.g.,
1065 333 mS). On some machines, this will cause a hang at boot time or
1066 whenever the CPU becomes idle. (On machines with more than one CPU,
1067 this option does nothing.)
1069 config APM_DISPLAY_BLANK
1070 bool "Enable console blanking using APM"
1072 Enable console blanking using the APM. Some laptops can use this to
1073 turn off the LCD backlight when the screen blanker of the Linux
1074 virtual console blanks the screen. Note that this is only used by
1075 the virtual console screen blanker, and won't turn off the backlight
1076 when using the X Window system. This also doesn't have anything to
1077 do with your VESA-compliant power-saving monitor. Further, this
1078 option doesn't work for all laptops -- it might not turn off your
1079 backlight at all, or it might print a lot of errors to the console,
1080 especially if you are using gpm.
1082 config APM_ALLOW_INTS
1083 bool "Allow interrupts during APM BIOS calls"
1085 Normally we disable external interrupts while we are making calls to
1086 the APM BIOS as a measure to lessen the effects of a badly behaving
1087 BIOS implementation. The BIOS should reenable interrupts if it
1088 needs to. Unfortunately, some BIOSes do not -- especially those in
1089 many of the newer IBM Thinkpads. If you experience hangs when you
1090 suspend, try setting this to Y. Otherwise, say N.
1092 config APM_REAL_MODE_POWER_OFF
1093 bool "Use real mode APM BIOS call to power off"
1095 Use real mode APM BIOS calls to switch off the computer. This is
1096 a work-around for a number of buggy BIOSes. Switch this option on if
1097 your computer crashes instead of powering off properly.
1101 source "arch/x86/kernel/cpu/cpufreq/Kconfig_32"
1103 source "drivers/cpuidle/Kconfig"
1107 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
1110 bool "PCI support" if !X86_VISWS
1111 depends on !X86_VOYAGER
1112 default y if X86_VISWS
1113 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1115 Find out whether you have a PCI motherboard. PCI is the name of a
1116 bus system, i.e. the way the CPU talks to the other stuff inside
1117 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1118 VESA. If you have PCI, say Y, otherwise N.
1120 The PCI-HOWTO, available from
1121 <http://www.tldp.org/docs.html#howto>, contains valuable
1122 information about which PCI hardware does work under Linux and which
1126 prompt "PCI access mode"
1127 depends on PCI && !X86_VISWS
1130 On PCI systems, the BIOS can be used to detect the PCI devices and
1131 determine their configuration. However, some old PCI motherboards
1132 have BIOS bugs and may crash if this is done. Also, some embedded
1133 PCI-based systems don't have any BIOS at all. Linux can also try to
1134 detect the PCI hardware directly without using the BIOS.
1136 With this option, you can specify how Linux should detect the
1137 PCI devices. If you choose "BIOS", the BIOS will be used,
1138 if you choose "Direct", the BIOS won't be used, and if you
1139 choose "MMConfig", then PCI Express MMCONFIG will be used.
1140 If you choose "Any", the kernel will try MMCONFIG, then the
1141 direct access method and falls back to the BIOS if that doesn't
1142 work. If unsure, go with the default, which is "Any".
1147 config PCI_GOMMCONFIG
1160 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1165 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1170 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1178 source "drivers/pci/pcie/Kconfig"
1180 source "drivers/pci/Kconfig"
1188 depends on !(X86_VOYAGER || X86_VISWS)
1190 Find out whether you have ISA slots on your motherboard. ISA is the
1191 name of a bus system, i.e. the way the CPU talks to the other stuff
1192 inside your box. Other bus systems are PCI, EISA, MicroChannel
1193 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1194 newer boards don't support it. If you have ISA, say Y, otherwise N.
1200 The Extended Industry Standard Architecture (EISA) bus was
1201 developed as an open alternative to the IBM MicroChannel bus.
1203 The EISA bus provided some of the features of the IBM MicroChannel
1204 bus while maintaining backward compatibility with cards made for
1205 the older ISA bus. The EISA bus saw limited use between 1988 and
1206 1995 when it was made obsolete by the PCI bus.
1208 Say Y here if you are building a kernel for an EISA-based machine.
1212 source "drivers/eisa/Kconfig"
1215 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1216 default y if X86_VOYAGER
1218 MicroChannel Architecture is found in some IBM PS/2 machines and
1219 laptops. It is a bus system similar to PCI or ISA. See
1220 <file:Documentation/mca.txt> (and especially the web page given
1221 there) before attempting to build an MCA bus kernel.
1223 source "drivers/mca/Kconfig"
1226 tristate "NatSemi SCx200 support"
1227 depends on !X86_VOYAGER
1229 This provides basic support for National Semiconductor's
1230 (now AMD's) Geode processors. The driver probes for the
1231 PCI-IDs of several on-chip devices, so its a good dependency
1232 for other scx200_* drivers.
1234 If compiled as a module, the driver is named scx200.
1236 config SCx200HR_TIMER
1237 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1238 depends on SCx200 && GENERIC_TIME
1241 This driver provides a clocksource built upon the on-chip
1242 27MHz high-resolution timer. Its also a workaround for
1243 NSC Geode SC-1100's buggy TSC, which loses time when the
1244 processor goes idle (as is done by the scheduler). The
1245 other workaround is idle=poll boot option.
1247 config GEODE_MFGPT_TIMER
1248 bool "Geode Multi-Function General Purpose Timer (MFGPT) events"
1249 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1252 This driver provides a clock event source based on the MFGPT
1253 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1254 MFGPTs have a better resolution and max interval than the
1255 generic PIT, and are suitable for use as high-res timers.
1259 depends on AGP_AMD64
1261 source "drivers/pcmcia/Kconfig"
1263 source "drivers/pci/hotplug/Kconfig"
1267 menu "Executable file formats"
1269 source "fs/Kconfig.binfmt"
1273 source "net/Kconfig"
1275 source "drivers/Kconfig"
1279 source "arch/i386/Kconfig.debug"
1281 source "security/Kconfig"
1283 source "crypto/Kconfig"
1285 source "lib/Kconfig"
1288 # Use the generic interrupt handling code in kernel/irq/:
1290 config GENERIC_HARDIRQS
1294 config GENERIC_IRQ_PROBE
1298 config GENERIC_PENDING_IRQ
1300 depends on GENERIC_HARDIRQS && SMP
1305 depends on SMP && !X86_VOYAGER
1310 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1313 config X86_BIOS_REBOOT
1315 depends on !(X86_VISWS || X86_VOYAGER)
1318 config X86_TRAMPOLINE
1320 depends on X86_SMP || (X86_VOYAGER && SMP)