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.
150 Voyager is an MCA-based 32-way capable SMP architecture proprietary
151 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
155 If you do not specifically know you have a Voyager based machine,
156 say N here, otherwise the kernel you build will not be bootable.
159 bool "NUMAQ (IBM/Sequent)"
163 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
164 multiquad box. This changes the way that processors are bootstrapped,
165 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
166 You will need a new lynxer.elf file to flash your firmware with - send
167 email to <Martin.Bligh@us.ibm.com>.
170 bool "Summit/EXA (IBM x440)"
173 This option is needed for IBM systems that use the Summit/EXA chipset.
174 In particular, it is needed for the x440.
176 If you don't have one of these computers, you should say N here.
177 If you want to build a NUMA kernel, you must select ACPI.
180 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
183 This option is needed for the systems that have more than 8 CPUs
184 and if the system is not of any sub-arch type above.
186 If you don't have such a system, you should say N here.
189 bool "SGI 320/540 (Visual Workstation)"
191 The SGI Visual Workstation series is an IA32-based workstation
192 based on SGI systems chips with some legacy PC hardware attached.
194 Say Y here to create a kernel to run on the SGI 320 or 540.
196 A kernel compiled for the Visual Workstation will not run on PCs
197 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
199 config X86_GENERICARCH
200 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
202 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
203 It is intended for a generic binary kernel.
204 If you want a NUMA kernel, select ACPI. We need SRAT for NUMA.
207 bool "Support for Unisys ES7000 IA32 series"
210 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
211 supposed to run on an IA32-based Unisys ES7000 system.
212 Only choose this option if you have such a system, otherwise you
218 bool "Paravirtualization support (EXPERIMENTAL)"
219 depends on EXPERIMENTAL
220 depends on !(X86_VISWS || X86_VOYAGER)
222 Paravirtualization is a way of running multiple instances of
223 Linux on the same machine, under a hypervisor. This option
224 changes the kernel so it can modify itself when it is run
225 under a hypervisor, improving performance significantly.
226 However, when run without a hypervisor the kernel is
227 theoretically slower. If in doubt, say N.
229 source "arch/i386/xen/Kconfig"
232 bool "VMI Paravirt-ops support"
235 VMI provides a paravirtualized interface to the VMware ESX server
236 (it could be used by other hypervisors in theory too, but is not
237 at the moment), by linking the kernel to a GPL-ed ROM module
238 provided by the hypervisor.
243 depends on ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH)
246 config HAVE_ARCH_PARSE_SRAT
251 config X86_SUMMIT_NUMA
254 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
256 config X86_CYCLONE_TIMER
259 depends on X86_SUMMIT || X86_GENERICARCH
261 config ES7000_CLUSTERED_APIC
264 depends on SMP && X86_ES7000 && MPENTIUMIII
266 source "arch/i386/Kconfig.cpu"
269 bool "HPET Timer Support"
271 This enables the use of the HPET for the kernel's internal timer.
272 HPET is the next generation timer replacing legacy 8254s.
273 You can safely choose Y here. However, HPET will only be
274 activated if the platform and the BIOS support this feature.
275 Otherwise the 8254 will be used for timing services.
277 Choose N to continue using the legacy 8254 timer.
279 config HPET_EMULATE_RTC
281 depends on HPET_TIMER && RTC=y
285 int "Maximum number of CPUs (2-255)"
288 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
291 This allows you to specify the maximum number of CPUs which this
292 kernel will support. The maximum supported value is 255 and the
293 minimum value which makes sense is 2.
295 This is purely to save memory - each supported CPU adds
296 approximately eight kilobytes to the kernel image.
299 bool "SMT (Hyperthreading) scheduler support"
302 SMT scheduler support improves the CPU scheduler's decision making
303 when dealing with Intel Pentium 4 chips with HyperThreading at a
304 cost of slightly increased overhead in some places. If unsure say
308 bool "Multi-core scheduler support"
312 Multi-core scheduler support improves the CPU scheduler's decision
313 making when dealing with multi-core CPU chips at a cost of slightly
314 increased overhead in some places. If unsure say N here.
316 source "kernel/Kconfig.preempt"
319 bool "Local APIC support on uniprocessors"
320 depends on !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH)
322 A local APIC (Advanced Programmable Interrupt Controller) is an
323 integrated interrupt controller in the CPU. If you have a single-CPU
324 system which has a processor with a local APIC, you can say Y here to
325 enable and use it. If you say Y here even though your machine doesn't
326 have a local APIC, then the kernel will still run with no slowdown at
327 all. The local APIC supports CPU-generated self-interrupts (timer,
328 performance counters), and the NMI watchdog which detects hard
332 bool "IO-APIC support on uniprocessors"
333 depends on X86_UP_APIC
335 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
336 SMP-capable replacement for PC-style interrupt controllers. Most
337 SMP systems and many recent uniprocessor systems have one.
339 If you have a single-CPU system with an IO-APIC, you can say Y here
340 to use it. If you say Y here even though your machine doesn't have
341 an IO-APIC, then the kernel will still run with no slowdown at all.
343 config X86_LOCAL_APIC
345 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH
350 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH
353 config X86_VISWS_APIC
359 bool "Machine Check Exception"
360 depends on !X86_VOYAGER
362 Machine Check Exception support allows the processor to notify the
363 kernel if it detects a problem (e.g. overheating, component failure).
364 The action the kernel takes depends on the severity of the problem,
365 ranging from a warning message on the console, to halting the machine.
366 Your processor must be a Pentium or newer to support this - check the
367 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
368 have a design flaw which leads to false MCE events - hence MCE is
369 disabled on all P5 processors, unless explicitly enabled with "mce"
370 as a boot argument. Similarly, if MCE is built in and creates a
371 problem on some new non-standard machine, you can boot with "nomce"
372 to disable it. MCE support simply ignores non-MCE processors like
373 the 386 and 486, so nearly everyone can say Y here.
375 config X86_MCE_NONFATAL
376 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
379 Enabling this feature starts a timer that triggers every 5 seconds which
380 will look at the machine check registers to see if anything happened.
381 Non-fatal problems automatically get corrected (but still logged).
382 Disable this if you don't want to see these messages.
383 Seeing the messages this option prints out may be indicative of dying hardware,
384 or out-of-spec (ie, overclocked) hardware.
385 This option only does something on certain CPUs.
386 (AMD Athlon/Duron and Intel Pentium 4)
388 config X86_MCE_P4THERMAL
389 bool "check for P4 thermal throttling interrupt."
390 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
392 Enabling this feature will cause a message to be printed when the P4
393 enters thermal throttling.
397 bool "Enable VM86 support" if EMBEDDED
399 This option is required by programs like DOSEMU to run 16-bit legacy
400 code on X86 processors. It also may be needed by software like
401 XFree86 to initialize some video cards via BIOS. Disabling this
402 option saves about 6k.
405 tristate "Toshiba Laptop support"
407 This adds a driver to safely access the System Management Mode of
408 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
409 not work on models with a Phoenix BIOS. The System Management Mode
410 is used to set the BIOS and power saving options on Toshiba portables.
412 For information on utilities to make use of this driver see the
413 Toshiba Linux utilities web site at:
414 <http://www.buzzard.org.uk/toshiba/>.
416 Say Y if you intend to run this kernel on a Toshiba portable.
420 tristate "Dell laptop support"
422 This adds a driver to safely access the System Management Mode
423 of the CPU on the Dell Inspiron 8000. The System Management Mode
424 is used to read cpu temperature and cooling fan status and to
425 control the fans on the I8K portables.
427 This driver has been tested only on the Inspiron 8000 but it may
428 also work with other Dell laptops. You can force loading on other
429 models by passing the parameter `force=1' to the module. Use at
432 For information on utilities to make use of this driver see the
433 I8K Linux utilities web site at:
434 <http://people.debian.org/~dz/i8k/>
436 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
439 config X86_REBOOTFIXUPS
440 bool "Enable X86 board specific fixups for reboot"
444 This enables chipset and/or board specific fixups to be done
445 in order to get reboot to work correctly. This is only needed on
446 some combinations of hardware and BIOS. The symptom, for which
447 this config is intended, is when reboot ends with a stalled/hung
450 Currently, the only fixup is for the Geode machines using
451 CS5530A and CS5536 chipsets.
453 Say Y if you want to enable the fixup. Currently, it's safe to
454 enable this option even if you don't need it.
458 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
461 If you say Y here, you will be able to update the microcode on
462 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
463 Pentium III, Pentium 4, Xeon etc. You will obviously need the
464 actual microcode binary data itself which is not shipped with the
467 For latest news and information on obtaining all the required
468 ingredients for this driver, check:
469 <http://www.urbanmyth.org/microcode/>.
471 To compile this driver as a module, choose M here: the
472 module will be called microcode.
474 config MICROCODE_OLD_INTERFACE
480 tristate "/dev/cpu/*/msr - Model-specific register support"
482 This device gives privileged processes access to the x86
483 Model-Specific Registers (MSRs). It is a character device with
484 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
485 MSR accesses are directed to a specific CPU on multi-processor
489 tristate "/dev/cpu/*/cpuid - CPU information support"
491 This device gives processes access to the x86 CPUID instruction to
492 be executed on a specific processor. It is a character device
493 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
496 source "drivers/firmware/Kconfig"
499 prompt "High Memory Support"
500 default HIGHMEM4G if !X86_NUMAQ
501 default HIGHMEM64G if X86_NUMAQ
505 depends on !X86_NUMAQ
507 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
508 However, the address space of 32-bit x86 processors is only 4
509 Gigabytes large. That means that, if you have a large amount of
510 physical memory, not all of it can be "permanently mapped" by the
511 kernel. The physical memory that's not permanently mapped is called
514 If you are compiling a kernel which will never run on a machine with
515 more than 1 Gigabyte total physical RAM, answer "off" here (default
516 choice and suitable for most users). This will result in a "3GB/1GB"
517 split: 3GB are mapped so that each process sees a 3GB virtual memory
518 space and the remaining part of the 4GB virtual memory space is used
519 by the kernel to permanently map as much physical memory as
522 If the machine has between 1 and 4 Gigabytes physical RAM, then
525 If more than 4 Gigabytes is used then answer "64GB" here. This
526 selection turns Intel PAE (Physical Address Extension) mode on.
527 PAE implements 3-level paging on IA32 processors. PAE is fully
528 supported by Linux, PAE mode is implemented on all recent Intel
529 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
530 then the kernel will not boot on CPUs that don't support PAE!
532 The actual amount of total physical memory will either be
533 auto detected or can be forced by using a kernel command line option
534 such as "mem=256M". (Try "man bootparam" or see the documentation of
535 your boot loader (lilo or loadlin) about how to pass options to the
536 kernel at boot time.)
538 If unsure, say "off".
542 depends on !X86_NUMAQ
544 Select this if you have a 32-bit processor and between 1 and 4
545 gigabytes of physical RAM.
549 depends on !M386 && !M486
552 Select this if you have a 32-bit processor and more than 4
553 gigabytes of physical RAM.
558 depends on EXPERIMENTAL
559 prompt "Memory split" if EMBEDDED
562 Select the desired split between kernel and user memory.
564 If the address range available to the kernel is less than the
565 physical memory installed, the remaining memory will be available
566 as "high memory". Accessing high memory is a little more costly
567 than low memory, as it needs to be mapped into the kernel first.
568 Note that increasing the kernel address space limits the range
569 available to user programs, making the address space there
570 tighter. Selecting anything other than the default 3G/1G split
571 will also likely make your kernel incompatible with binary-only
574 If you are not absolutely sure what you are doing, leave this
578 bool "3G/1G user/kernel split"
579 config VMSPLIT_3G_OPT
581 bool "3G/1G user/kernel split (for full 1G low memory)"
583 bool "2G/2G user/kernel split"
584 config VMSPLIT_2G_OPT
586 bool "2G/2G user/kernel split (for full 2G low memory)"
588 bool "1G/3G user/kernel split"
593 default 0xB0000000 if VMSPLIT_3G_OPT
594 default 0x80000000 if VMSPLIT_2G
595 default 0x78000000 if VMSPLIT_2G_OPT
596 default 0x40000000 if VMSPLIT_1G
601 depends on HIGHMEM64G || HIGHMEM4G
605 bool "PAE (Physical Address Extension) Support"
607 depends on !HIGHMEM4G
608 select RESOURCES_64BIT
610 PAE is required for NX support, and furthermore enables
611 larger swapspace support for non-overcommit purposes. It
612 has the cost of more pagetable lookup overhead, and also
613 consumes more pagetable space per process.
615 # Common NUMA Features
617 bool "Numa Memory Allocation and Scheduler Support"
618 depends on SMP && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI)
620 default y if (X86_NUMAQ || X86_SUMMIT)
622 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
623 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
627 default "4" if X86_NUMAQ
629 depends on NEED_MULTIPLE_NODES
631 config HAVE_ARCH_BOOTMEM_NODE
636 config ARCH_HAVE_MEMORY_PRESENT
638 depends on DISCONTIGMEM
641 config NEED_NODE_MEMMAP_SIZE
643 depends on DISCONTIGMEM || SPARSEMEM
646 config HAVE_ARCH_ALLOC_REMAP
651 config ARCH_FLATMEM_ENABLE
653 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
655 config ARCH_DISCONTIGMEM_ENABLE
659 config ARCH_DISCONTIGMEM_DEFAULT
663 config ARCH_SPARSEMEM_ENABLE
665 depends on (NUMA || (X86_PC && EXPERIMENTAL))
666 select SPARSEMEM_STATIC
668 config ARCH_SELECT_MEMORY_MODEL
670 depends on ARCH_SPARSEMEM_ENABLE
672 config ARCH_POPULATES_NODE_MAP
678 bool "Allocate 3rd-level pagetables from highmem"
679 depends on HIGHMEM4G || HIGHMEM64G
681 The VM uses one page table entry for each page of physical memory.
682 For systems with a lot of RAM, this can be wasteful of precious
683 low memory. Setting this option will put user-space page table
684 entries in high memory.
686 config MATH_EMULATION
687 bool "Math emulation"
689 Linux can emulate a math coprocessor (used for floating point
690 operations) if you don't have one. 486DX and Pentium processors have
691 a math coprocessor built in, 486SX and 386 do not, unless you added
692 a 487DX or 387, respectively. (The messages during boot time can
693 give you some hints here ["man dmesg"].) Everyone needs either a
694 coprocessor or this emulation.
696 If you don't have a math coprocessor, you need to say Y here; if you
697 say Y here even though you have a coprocessor, the coprocessor will
698 be used nevertheless. (This behavior can be changed with the kernel
699 command line option "no387", which comes handy if your coprocessor
700 is broken. Try "man bootparam" or see the documentation of your boot
701 loader (lilo or loadlin) about how to pass options to the kernel at
702 boot time.) This means that it is a good idea to say Y here if you
703 intend to use this kernel on different machines.
705 More information about the internals of the Linux math coprocessor
706 emulation can be found in <file:arch/i386/math-emu/README>.
708 If you are not sure, say Y; apart from resulting in a 66 KB bigger
709 kernel, it won't hurt.
712 bool "MTRR (Memory Type Range Register) support"
714 On Intel P6 family processors (Pentium Pro, Pentium II and later)
715 the Memory Type Range Registers (MTRRs) may be used to control
716 processor access to memory ranges. This is most useful if you have
717 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
718 allows bus write transfers to be combined into a larger transfer
719 before bursting over the PCI/AGP bus. This can increase performance
720 of image write operations 2.5 times or more. Saying Y here creates a
721 /proc/mtrr file which may be used to manipulate your processor's
722 MTRRs. Typically the X server should use this.
724 This code has a reasonably generic interface so that similar
725 control registers on other processors can be easily supported
728 The Cyrix 6x86, 6x86MX and M II processors have Address Range
729 Registers (ARRs) which provide a similar functionality to MTRRs. For
730 these, the ARRs are used to emulate the MTRRs.
731 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
732 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
733 write-combining. All of these processors are supported by this code
734 and it makes sense to say Y here if you have one of them.
736 Saying Y here also fixes a problem with buggy SMP BIOSes which only
737 set the MTRRs for the boot CPU and not for the secondary CPUs. This
738 can lead to all sorts of problems, so it's good to say Y here.
740 You can safely say Y even if your machine doesn't have MTRRs, you'll
741 just add about 9 KB to your kernel.
743 See <file:Documentation/mtrr.txt> for more information.
746 bool "Boot from EFI support"
750 This enables the kernel to boot on EFI platforms using
751 system configuration information passed to it from the firmware.
752 This also enables the kernel to use any EFI runtime services that are
753 available (such as the EFI variable services).
755 This option is only useful on systems that have EFI firmware
756 and will result in a kernel image that is ~8k larger. In addition,
757 you must use the latest ELILO loader available at
758 <http://elilo.sourceforge.net> in order to take advantage of
759 kernel initialization using EFI information (neither GRUB nor LILO know
760 anything about EFI). However, even with this option, the resultant
761 kernel should continue to boot on existing non-EFI platforms.
764 bool "Enable kernel irq balancing"
765 depends on SMP && X86_IO_APIC
768 The default yes will allow the kernel to do irq load balancing.
769 Saying no will keep the kernel from doing irq load balancing.
771 # turning this on wastes a bunch of space.
772 # Summit needs it only when NUMA is on
775 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
779 bool "Enable seccomp to safely compute untrusted bytecode"
783 This kernel feature is useful for number crunching applications
784 that may need to compute untrusted bytecode during their
785 execution. By using pipes or other transports made available to
786 the process as file descriptors supporting the read/write
787 syscalls, it's possible to isolate those applications in
788 their own address space using seccomp. Once seccomp is
789 enabled via /proc/<pid>/seccomp, it cannot be disabled
790 and the task is only allowed to execute a few safe syscalls
791 defined by each seccomp mode.
793 If unsure, say Y. Only embedded should say N here.
795 source kernel/Kconfig.hz
798 bool "kexec system call"
800 kexec is a system call that implements the ability to shutdown your
801 current kernel, and to start another kernel. It is like a reboot
802 but it is independent of the system firmware. And like a reboot
803 you can start any kernel with it, not just Linux.
805 The name comes from the similarity to the exec system call.
807 It is an ongoing process to be certain the hardware in a machine
808 is properly shutdown, so do not be surprised if this code does not
809 initially work for you. It may help to enable device hotplugging
810 support. As of this writing the exact hardware interface is
811 strongly in flux, so no good recommendation can be made.
814 bool "kernel crash dumps (EXPERIMENTAL)"
815 depends on EXPERIMENTAL
818 Generate crash dump after being started by kexec.
819 This should be normally only set in special crash dump kernels
820 which are loaded in the main kernel with kexec-tools into
821 a specially reserved region and then later executed after
822 a crash by kdump/kexec. The crash dump kernel must be compiled
823 to a memory address not used by the main kernel or BIOS using
825 For more details see Documentation/kdump/kdump.txt
827 config PHYSICAL_START
828 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
829 default "0x1000000" if X86_NUMAQ
832 This gives the physical address where the kernel is loaded.
834 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
835 bzImage will decompress itself to above physical address and
836 run from there. Otherwise, bzImage will run from the address where
837 it has been loaded by the boot loader and will ignore above physical
840 In normal kdump cases one does not have to set/change this option
841 as now bzImage can be compiled as a completely relocatable image
842 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
843 address. This option is mainly useful for the folks who don't want
844 to use a bzImage for capturing the crash dump and want to use a
845 vmlinux instead. vmlinux is not relocatable hence a kernel needs
846 to be specifically compiled to run from a specific memory area
847 (normally a reserved region) and this option comes handy.
849 So if you are using bzImage for capturing the crash dump, leave
850 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
851 Otherwise if you plan to use vmlinux for capturing the crash dump
852 change this value to start of the reserved region (Typically 16MB
853 0x1000000). In other words, it can be set based on the "X" value as
854 specified in the "crashkernel=YM@XM" command line boot parameter
855 passed to the panic-ed kernel. Typically this parameter is set as
856 crashkernel=64M@16M. Please take a look at
857 Documentation/kdump/kdump.txt for more details about crash dumps.
859 Usage of bzImage for capturing the crash dump is recommended as
860 one does not have to build two kernels. Same kernel can be used
861 as production kernel and capture kernel. Above option should have
862 gone away after relocatable bzImage support is introduced. But it
863 is present because there are users out there who continue to use
864 vmlinux for dump capture. This option should go away down the
867 Don't change this unless you know what you are doing.
870 bool "Build a relocatable kernel(EXPERIMENTAL)"
871 depends on EXPERIMENTAL
873 This builds a kernel image that retains relocation information
874 so it can be loaded someplace besides the default 1MB.
875 The relocations tend to make the kernel binary about 10% larger,
876 but are discarded at runtime.
878 One use is for the kexec on panic case where the recovery kernel
879 must live at a different physical address than the primary
882 config PHYSICAL_ALIGN
883 hex "Alignment value to which kernel should be aligned"
885 range 0x2000 0x400000
887 This value puts the alignment restrictions on physical address
888 where kernel is loaded and run from. Kernel is compiled for an
889 address which meets above alignment restriction.
891 If bootloader loads the kernel at a non-aligned address and
892 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
893 address aligned to above value and run from there.
895 If bootloader loads the kernel at a non-aligned address and
896 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
897 load address and decompress itself to the address it has been
898 compiled for and run from there. The address for which kernel is
899 compiled already meets above alignment restrictions. Hence the
900 end result is that kernel runs from a physical address meeting
901 above alignment restrictions.
903 Don't change this unless you know what you are doing.
906 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
907 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
909 Say Y here to experiment with turning CPUs off and on, and to
910 enable suspend on SMP systems. CPUs can be controlled through
911 /sys/devices/system/cpu.
914 bool "Compat VDSO support"
917 Map the VDSO to the predictable old-style address too.
919 Say N here if you are running a sufficiently recent glibc
920 version (2.3.3 or later), to remove the high-mapped
921 VDSO mapping and to exclusively use the randomized VDSO.
927 config ARCH_ENABLE_MEMORY_HOTPLUG
931 menu "Power management options (ACPI, APM)"
932 depends on !X86_VOYAGER
934 source kernel/power/Kconfig
936 source "drivers/acpi/Kconfig"
939 tristate "APM (Advanced Power Management) BIOS support"
940 depends on PM_SLEEP && !X86_VISWS
942 APM is a BIOS specification for saving power using several different
943 techniques. This is mostly useful for battery powered laptops with
944 APM compliant BIOSes. If you say Y here, the system time will be
945 reset after a RESUME operation, the /proc/apm device will provide
946 battery status information, and user-space programs will receive
947 notification of APM "events" (e.g. battery status change).
949 If you select "Y" here, you can disable actual use of the APM
950 BIOS by passing the "apm=off" option to the kernel at boot time.
952 Note that the APM support is almost completely disabled for
953 machines with more than one CPU.
955 In order to use APM, you will need supporting software. For location
956 and more information, read <file:Documentation/pm.txt> and the
957 Battery Powered Linux mini-HOWTO, available from
958 <http://www.tldp.org/docs.html#howto>.
960 This driver does not spin down disk drives (see the hdparm(8)
961 manpage ("man 8 hdparm") for that), and it doesn't turn off
962 VESA-compliant "green" monitors.
964 This driver does not support the TI 4000M TravelMate and the ACER
965 486/DX4/75 because they don't have compliant BIOSes. Many "green"
966 desktop machines also don't have compliant BIOSes, and this driver
967 may cause those machines to panic during the boot phase.
969 Generally, if you don't have a battery in your machine, there isn't
970 much point in using this driver and you should say N. If you get
971 random kernel OOPSes or reboots that don't seem to be related to
972 anything, try disabling/enabling this option (or disabling/enabling
975 Some other things you should try when experiencing seemingly random,
978 1) make sure that you have enough swap space and that it is
980 2) pass the "no-hlt" option to the kernel
981 3) switch on floating point emulation in the kernel and pass
982 the "no387" option to the kernel
983 4) pass the "floppy=nodma" option to the kernel
984 5) pass the "mem=4M" option to the kernel (thereby disabling
985 all but the first 4 MB of RAM)
986 6) make sure that the CPU is not over clocked.
987 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
988 8) disable the cache from your BIOS settings
989 9) install a fan for the video card or exchange video RAM
990 10) install a better fan for the CPU
991 11) exchange RAM chips
992 12) exchange the motherboard.
994 To compile this driver as a module, choose M here: the
995 module will be called apm.
999 config APM_IGNORE_USER_SUSPEND
1000 bool "Ignore USER SUSPEND"
1002 This option will ignore USER SUSPEND requests. On machines with a
1003 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1004 series notebooks, it is necessary to say Y because of a BIOS bug.
1006 config APM_DO_ENABLE
1007 bool "Enable PM at boot time"
1009 Enable APM features at boot time. From page 36 of the APM BIOS
1010 specification: "When disabled, the APM BIOS does not automatically
1011 power manage devices, enter the Standby State, enter the Suspend
1012 State, or take power saving steps in response to CPU Idle calls."
1013 This driver will make CPU Idle calls when Linux is idle (unless this
1014 feature is turned off -- see "Do CPU IDLE calls", below). This
1015 should always save battery power, but more complicated APM features
1016 will be dependent on your BIOS implementation. You may need to turn
1017 this option off if your computer hangs at boot time when using APM
1018 support, or if it beeps continuously instead of suspending. Turn
1019 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1020 T400CDT. This is off by default since most machines do fine without
1024 bool "Make CPU Idle calls when idle"
1026 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1027 On some machines, this can activate improved power savings, such as
1028 a slowed CPU clock rate, when the machine is idle. These idle calls
1029 are made after the idle loop has run for some length of time (e.g.,
1030 333 mS). On some machines, this will cause a hang at boot time or
1031 whenever the CPU becomes idle. (On machines with more than one CPU,
1032 this option does nothing.)
1034 config APM_DISPLAY_BLANK
1035 bool "Enable console blanking using APM"
1037 Enable console blanking using the APM. Some laptops can use this to
1038 turn off the LCD backlight when the screen blanker of the Linux
1039 virtual console blanks the screen. Note that this is only used by
1040 the virtual console screen blanker, and won't turn off the backlight
1041 when using the X Window system. This also doesn't have anything to
1042 do with your VESA-compliant power-saving monitor. Further, this
1043 option doesn't work for all laptops -- it might not turn off your
1044 backlight at all, or it might print a lot of errors to the console,
1045 especially if you are using gpm.
1047 config APM_ALLOW_INTS
1048 bool "Allow interrupts during APM BIOS calls"
1050 Normally we disable external interrupts while we are making calls to
1051 the APM BIOS as a measure to lessen the effects of a badly behaving
1052 BIOS implementation. The BIOS should reenable interrupts if it
1053 needs to. Unfortunately, some BIOSes do not -- especially those in
1054 many of the newer IBM Thinkpads. If you experience hangs when you
1055 suspend, try setting this to Y. Otherwise, say N.
1057 config APM_REAL_MODE_POWER_OFF
1058 bool "Use real mode APM BIOS call to power off"
1060 Use real mode APM BIOS calls to switch off the computer. This is
1061 a work-around for a number of buggy BIOSes. Switch this option on if
1062 your computer crashes instead of powering off properly.
1066 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
1070 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
1073 bool "PCI support" if !X86_VISWS
1074 depends on !X86_VOYAGER
1075 default y if X86_VISWS
1076 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1078 Find out whether you have a PCI motherboard. PCI is the name of a
1079 bus system, i.e. the way the CPU talks to the other stuff inside
1080 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1081 VESA. If you have PCI, say Y, otherwise N.
1083 The PCI-HOWTO, available from
1084 <http://www.tldp.org/docs.html#howto>, contains valuable
1085 information about which PCI hardware does work under Linux and which
1089 prompt "PCI access mode"
1090 depends on PCI && !X86_VISWS
1093 On PCI systems, the BIOS can be used to detect the PCI devices and
1094 determine their configuration. However, some old PCI motherboards
1095 have BIOS bugs and may crash if this is done. Also, some embedded
1096 PCI-based systems don't have any BIOS at all. Linux can also try to
1097 detect the PCI hardware directly without using the BIOS.
1099 With this option, you can specify how Linux should detect the
1100 PCI devices. If you choose "BIOS", the BIOS will be used,
1101 if you choose "Direct", the BIOS won't be used, and if you
1102 choose "MMConfig", then PCI Express MMCONFIG will be used.
1103 If you choose "Any", the kernel will try MMCONFIG, then the
1104 direct access method and falls back to the BIOS if that doesn't
1105 work. If unsure, go with the default, which is "Any".
1110 config PCI_GOMMCONFIG
1123 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1128 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1133 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1136 source "drivers/pci/pcie/Kconfig"
1138 source "drivers/pci/Kconfig"
1146 depends on !(X86_VOYAGER || X86_VISWS)
1148 Find out whether you have ISA slots on your motherboard. ISA is the
1149 name of a bus system, i.e. the way the CPU talks to the other stuff
1150 inside your box. Other bus systems are PCI, EISA, MicroChannel
1151 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1152 newer boards don't support it. If you have ISA, say Y, otherwise N.
1158 The Extended Industry Standard Architecture (EISA) bus was
1159 developed as an open alternative to the IBM MicroChannel bus.
1161 The EISA bus provided some of the features of the IBM MicroChannel
1162 bus while maintaining backward compatibility with cards made for
1163 the older ISA bus. The EISA bus saw limited use between 1988 and
1164 1995 when it was made obsolete by the PCI bus.
1166 Say Y here if you are building a kernel for an EISA-based machine.
1170 source "drivers/eisa/Kconfig"
1173 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1174 default y if X86_VOYAGER
1176 MicroChannel Architecture is found in some IBM PS/2 machines and
1177 laptops. It is a bus system similar to PCI or ISA. See
1178 <file:Documentation/mca.txt> (and especially the web page given
1179 there) before attempting to build an MCA bus kernel.
1181 source "drivers/mca/Kconfig"
1184 tristate "NatSemi SCx200 support"
1185 depends on !X86_VOYAGER
1187 This provides basic support for National Semiconductor's
1188 (now AMD's) Geode processors. The driver probes for the
1189 PCI-IDs of several on-chip devices, so its a good dependency
1190 for other scx200_* drivers.
1192 If compiled as a module, the driver is named scx200.
1194 config SCx200HR_TIMER
1195 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1196 depends on SCx200 && GENERIC_TIME
1199 This driver provides a clocksource built upon the on-chip
1200 27MHz high-resolution timer. Its also a workaround for
1201 NSC Geode SC-1100's buggy TSC, which loses time when the
1202 processor goes idle (as is done by the scheduler). The
1203 other workaround is idle=poll boot option.
1207 depends on AGP_AMD64
1209 source "drivers/pcmcia/Kconfig"
1211 source "drivers/pci/hotplug/Kconfig"
1215 menu "Executable file formats"
1217 source "fs/Kconfig.binfmt"
1221 source "net/Kconfig"
1223 source "drivers/Kconfig"
1227 menuconfig INSTRUMENTATION
1228 bool "Instrumentation Support"
1229 depends on EXPERIMENTAL
1234 source "arch/i386/oprofile/Kconfig"
1238 depends on KALLSYMS && MODULES
1240 Kprobes allows you to trap at almost any kernel address and
1241 execute a callback function. register_kprobe() establishes
1242 a probepoint and specifies the callback. Kprobes is useful
1243 for kernel debugging, non-intrusive instrumentation and testing.
1244 If in doubt, say "N".
1246 endif # INSTRUMENTATION
1248 source "arch/i386/Kconfig.debug"
1250 source "security/Kconfig"
1252 source "crypto/Kconfig"
1254 source "lib/Kconfig"
1257 # Use the generic interrupt handling code in kernel/irq/:
1259 config GENERIC_HARDIRQS
1263 config GENERIC_IRQ_PROBE
1267 config GENERIC_PENDING_IRQ
1269 depends on GENERIC_HARDIRQS && SMP
1274 depends on SMP && !X86_VOYAGER
1279 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1282 config X86_BIOS_REBOOT
1284 depends on !(X86_VISWS || X86_VOYAGER)
1287 config X86_TRAMPOLINE
1289 depends on X86_SMP || (X86_VOYAGER && SMP)
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