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 LOCKDEP_SUPPORT
25 config STACKTRACE_SUPPORT
29 config SEMAPHORE_SLEEPERS
48 config GENERIC_ISA_DMA
61 config GENERIC_HWEIGHT
65 config ARCH_MAY_HAVE_PC_FDC
75 menu "Processor type and features"
78 bool "Symmetric multi-processing support"
80 This enables support for systems with more than one CPU. If you have
81 a system with only one CPU, like most personal computers, say N. If
82 you have a system with more than one CPU, say Y.
84 If you say N here, the kernel will run on single and multiprocessor
85 machines, but will use only one CPU of a multiprocessor machine. If
86 you say Y here, the kernel will run on many, but not all,
87 singleprocessor machines. On a singleprocessor machine, the kernel
88 will run faster if you say N here.
90 Note that if you say Y here and choose architecture "586" or
91 "Pentium" under "Processor family", the kernel will not work on 486
92 architectures. Similarly, multiprocessor kernels for the "PPro"
93 architecture may not work on all Pentium based boards.
95 People using multiprocessor machines who say Y here should also say
96 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
97 Management" code will be disabled if you say Y here.
99 See also the <file:Documentation/smp.txt>,
100 <file:Documentation/i386/IO-APIC.txt>,
101 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
102 <http://www.tldp.org/docs.html#howto>.
104 If you don't know what to do here, say N.
107 prompt "Subarchitecture Type"
113 Choose this option if your computer is a standard PC or compatible.
118 Select this for an AMD Elan processor.
120 Do not use this option for K6/Athlon/Opteron processors!
122 If unsure, choose "PC-compatible" instead.
127 Voyager is an MCA-based 32-way capable SMP architecture proprietary
128 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
132 If you do not specifically know you have a Voyager based machine,
133 say N here, otherwise the kernel you build will not be bootable.
136 bool "NUMAQ (IBM/Sequent)"
140 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
141 multiquad box. This changes the way that processors are bootstrapped,
142 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
143 You will need a new lynxer.elf file to flash your firmware with - send
144 email to <Martin.Bligh@us.ibm.com>.
147 bool "Summit/EXA (IBM x440)"
150 This option is needed for IBM systems that use the Summit/EXA chipset.
151 In particular, it is needed for the x440.
153 If you don't have one of these computers, you should say N here.
154 If you want to build a NUMA kernel, you must select ACPI.
157 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
160 This option is needed for the systems that have more than 8 CPUs
161 and if the system is not of any sub-arch type above.
163 If you don't have such a system, you should say N here.
166 bool "SGI 320/540 (Visual Workstation)"
168 The SGI Visual Workstation series is an IA32-based workstation
169 based on SGI systems chips with some legacy PC hardware attached.
171 Say Y here to create a kernel to run on the SGI 320 or 540.
173 A kernel compiled for the Visual Workstation will not run on PCs
174 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
176 config X86_GENERICARCH
177 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
179 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
180 It is intended for a generic binary kernel.
181 If you want a NUMA kernel, select ACPI. We need SRAT for NUMA.
184 bool "Support for Unisys ES7000 IA32 series"
187 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
188 supposed to run on an IA32-based Unisys ES7000 system.
189 Only choose this option if you have such a system, otherwise you
195 bool "Paravirtualization support (EXPERIMENTAL)"
196 depends on EXPERIMENTAL
197 depends on !(X86_VISWS || X86_VOYAGER)
199 Paravirtualization is a way of running multiple instances of
200 Linux on the same machine, under a hypervisor. This option
201 changes the kernel so it can modify itself when it is run
202 under a hypervisor, improving performance significantly.
203 However, when run without a hypervisor the kernel is
204 theoretically slower. If in doubt, say N.
207 bool "VMI Paravirt-ops support"
211 VMI provides a paravirtualized interface to multiple hypervisors
212 include VMware ESX server and Xen by connecting to a ROM module
213 provided by the hypervisor.
218 depends on ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH)
221 config HAVE_ARCH_PARSE_SRAT
226 config X86_SUMMIT_NUMA
229 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
231 config X86_CYCLONE_TIMER
234 depends on X86_SUMMIT || X86_GENERICARCH
236 config ES7000_CLUSTERED_APIC
239 depends on SMP && X86_ES7000 && MPENTIUMIII
241 source "arch/i386/Kconfig.cpu"
244 bool "HPET Timer Support"
246 This enables the use of the HPET for the kernel's internal timer.
247 HPET is the next generation timer replacing legacy 8254s.
248 You can safely choose Y here. However, HPET will only be
249 activated if the platform and the BIOS support this feature.
250 Otherwise the 8254 will be used for timing services.
252 Choose N to continue using the legacy 8254 timer.
254 config HPET_EMULATE_RTC
256 depends on HPET_TIMER && RTC=y
260 int "Maximum number of CPUs (2-255)"
263 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
266 This allows you to specify the maximum number of CPUs which this
267 kernel will support. The maximum supported value is 255 and the
268 minimum value which makes sense is 2.
270 This is purely to save memory - each supported CPU adds
271 approximately eight kilobytes to the kernel image.
274 bool "SMT (Hyperthreading) scheduler support"
277 SMT scheduler support improves the CPU scheduler's decision making
278 when dealing with Intel Pentium 4 chips with HyperThreading at a
279 cost of slightly increased overhead in some places. If unsure say
283 bool "Multi-core scheduler support"
287 Multi-core scheduler support improves the CPU scheduler's decision
288 making when dealing with multi-core CPU chips at a cost of slightly
289 increased overhead in some places. If unsure say N here.
291 source "kernel/Kconfig.preempt"
294 bool "Local APIC support on uniprocessors"
295 depends on !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH)
297 A local APIC (Advanced Programmable Interrupt Controller) is an
298 integrated interrupt controller in the CPU. If you have a single-CPU
299 system which has a processor with a local APIC, you can say Y here to
300 enable and use it. If you say Y here even though your machine doesn't
301 have a local APIC, then the kernel will still run with no slowdown at
302 all. The local APIC supports CPU-generated self-interrupts (timer,
303 performance counters), and the NMI watchdog which detects hard
307 bool "IO-APIC support on uniprocessors"
308 depends on X86_UP_APIC
310 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
311 SMP-capable replacement for PC-style interrupt controllers. Most
312 SMP systems and many recent uniprocessor systems have one.
314 If you have a single-CPU system with an IO-APIC, you can say Y here
315 to use it. If you say Y here even though your machine doesn't have
316 an IO-APIC, then the kernel will still run with no slowdown at all.
318 config X86_LOCAL_APIC
320 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH
325 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH
328 config X86_VISWS_APIC
334 bool "Machine Check Exception"
335 depends on !X86_VOYAGER
337 Machine Check Exception support allows the processor to notify the
338 kernel if it detects a problem (e.g. overheating, component failure).
339 The action the kernel takes depends on the severity of the problem,
340 ranging from a warning message on the console, to halting the machine.
341 Your processor must be a Pentium or newer to support this - check the
342 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
343 have a design flaw which leads to false MCE events - hence MCE is
344 disabled on all P5 processors, unless explicitly enabled with "mce"
345 as a boot argument. Similarly, if MCE is built in and creates a
346 problem on some new non-standard machine, you can boot with "nomce"
347 to disable it. MCE support simply ignores non-MCE processors like
348 the 386 and 486, so nearly everyone can say Y here.
350 config X86_MCE_NONFATAL
351 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
354 Enabling this feature starts a timer that triggers every 5 seconds which
355 will look at the machine check registers to see if anything happened.
356 Non-fatal problems automatically get corrected (but still logged).
357 Disable this if you don't want to see these messages.
358 Seeing the messages this option prints out may be indicative of dying hardware,
359 or out-of-spec (ie, overclocked) hardware.
360 This option only does something on certain CPUs.
361 (AMD Athlon/Duron and Intel Pentium 4)
363 config X86_MCE_P4THERMAL
364 bool "check for P4 thermal throttling interrupt."
365 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
367 Enabling this feature will cause a message to be printed when the P4
368 enters thermal throttling.
372 bool "Enable VM86 support" if EMBEDDED
374 This option is required by programs like DOSEMU to run 16-bit legacy
375 code on X86 processors. It also may be needed by software like
376 XFree86 to initialize some video cards via BIOS. Disabling this
377 option saves about 6k.
380 tristate "Toshiba Laptop support"
382 This adds a driver to safely access the System Management Mode of
383 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
384 not work on models with a Phoenix BIOS. The System Management Mode
385 is used to set the BIOS and power saving options on Toshiba portables.
387 For information on utilities to make use of this driver see the
388 Toshiba Linux utilities web site at:
389 <http://www.buzzard.org.uk/toshiba/>.
391 Say Y if you intend to run this kernel on a Toshiba portable.
395 tristate "Dell laptop support"
397 This adds a driver to safely access the System Management Mode
398 of the CPU on the Dell Inspiron 8000. The System Management Mode
399 is used to read cpu temperature and cooling fan status and to
400 control the fans on the I8K portables.
402 This driver has been tested only on the Inspiron 8000 but it may
403 also work with other Dell laptops. You can force loading on other
404 models by passing the parameter `force=1' to the module. Use at
407 For information on utilities to make use of this driver see the
408 I8K Linux utilities web site at:
409 <http://people.debian.org/~dz/i8k/>
411 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
414 config X86_REBOOTFIXUPS
415 bool "Enable X86 board specific fixups for reboot"
419 This enables chipset and/or board specific fixups to be done
420 in order to get reboot to work correctly. This is only needed on
421 some combinations of hardware and BIOS. The symptom, for which
422 this config is intended, is when reboot ends with a stalled/hung
425 Currently, the only fixup is for the Geode GX1/CS5530A/TROM2.1.
428 Say Y if you want to enable the fixup. Currently, it's safe to
429 enable this option even if you don't need it.
433 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
436 If you say Y here and also to "/dev file system support" in the
437 'File systems' section, you will be able to update the microcode on
438 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
439 Pentium III, Pentium 4, Xeon etc. You will obviously need the
440 actual microcode binary data itself which is not shipped with the
443 For latest news and information on obtaining all the required
444 ingredients for this driver, check:
445 <http://www.urbanmyth.org/microcode/>.
447 To compile this driver as a module, choose M here: the
448 module will be called microcode.
450 config MICROCODE_OLD_INTERFACE
456 tristate "/dev/cpu/*/msr - Model-specific register support"
458 This device gives privileged processes access to the x86
459 Model-Specific Registers (MSRs). It is a character device with
460 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
461 MSR accesses are directed to a specific CPU on multi-processor
465 tristate "/dev/cpu/*/cpuid - CPU information support"
467 This device gives processes access to the x86 CPUID instruction to
468 be executed on a specific processor. It is a character device
469 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
472 source "drivers/firmware/Kconfig"
475 prompt "High Memory Support"
476 default HIGHMEM4G if !X86_NUMAQ
477 default HIGHMEM64G if X86_NUMAQ
481 depends on !X86_NUMAQ
483 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
484 However, the address space of 32-bit x86 processors is only 4
485 Gigabytes large. That means that, if you have a large amount of
486 physical memory, not all of it can be "permanently mapped" by the
487 kernel. The physical memory that's not permanently mapped is called
490 If you are compiling a kernel which will never run on a machine with
491 more than 1 Gigabyte total physical RAM, answer "off" here (default
492 choice and suitable for most users). This will result in a "3GB/1GB"
493 split: 3GB are mapped so that each process sees a 3GB virtual memory
494 space and the remaining part of the 4GB virtual memory space is used
495 by the kernel to permanently map as much physical memory as
498 If the machine has between 1 and 4 Gigabytes physical RAM, then
501 If more than 4 Gigabytes is used then answer "64GB" here. This
502 selection turns Intel PAE (Physical Address Extension) mode on.
503 PAE implements 3-level paging on IA32 processors. PAE is fully
504 supported by Linux, PAE mode is implemented on all recent Intel
505 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
506 then the kernel will not boot on CPUs that don't support PAE!
508 The actual amount of total physical memory will either be
509 auto detected or can be forced by using a kernel command line option
510 such as "mem=256M". (Try "man bootparam" or see the documentation of
511 your boot loader (lilo or loadlin) about how to pass options to the
512 kernel at boot time.)
514 If unsure, say "off".
518 depends on !X86_NUMAQ
520 Select this if you have a 32-bit processor and between 1 and 4
521 gigabytes of physical RAM.
525 depends on X86_CMPXCHG64
527 Select this if you have a 32-bit processor and more than 4
528 gigabytes of physical RAM.
533 depends on EXPERIMENTAL
534 prompt "Memory split" if EMBEDDED
537 Select the desired split between kernel and user memory.
539 If the address range available to the kernel is less than the
540 physical memory installed, the remaining memory will be available
541 as "high memory". Accessing high memory is a little more costly
542 than low memory, as it needs to be mapped into the kernel first.
543 Note that increasing the kernel address space limits the range
544 available to user programs, making the address space there
545 tighter. Selecting anything other than the default 3G/1G split
546 will also likely make your kernel incompatible with binary-only
549 If you are not absolutely sure what you are doing, leave this
553 bool "3G/1G user/kernel split"
554 config VMSPLIT_3G_OPT
556 bool "3G/1G user/kernel split (for full 1G low memory)"
558 bool "2G/2G user/kernel split"
560 bool "1G/3G user/kernel split"
565 default 0xB0000000 if VMSPLIT_3G_OPT
566 default 0x78000000 if VMSPLIT_2G
567 default 0x40000000 if VMSPLIT_1G
572 depends on HIGHMEM64G || HIGHMEM4G
577 depends on HIGHMEM64G
579 select RESOURCES_64BIT
581 # Common NUMA Features
583 bool "Numa Memory Allocation and Scheduler Support"
584 depends on SMP && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI)
586 default y if (X86_NUMAQ || X86_SUMMIT)
588 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
589 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
593 default "4" if X86_NUMAQ
595 depends on NEED_MULTIPLE_NODES
597 config HAVE_ARCH_BOOTMEM_NODE
602 config ARCH_HAVE_MEMORY_PRESENT
604 depends on DISCONTIGMEM
607 config NEED_NODE_MEMMAP_SIZE
609 depends on DISCONTIGMEM || SPARSEMEM
612 config HAVE_ARCH_ALLOC_REMAP
617 config ARCH_FLATMEM_ENABLE
619 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
621 config ARCH_DISCONTIGMEM_ENABLE
625 config ARCH_DISCONTIGMEM_DEFAULT
629 config ARCH_SPARSEMEM_ENABLE
631 depends on (NUMA || (X86_PC && EXPERIMENTAL))
632 select SPARSEMEM_STATIC
634 config ARCH_SELECT_MEMORY_MODEL
636 depends on ARCH_SPARSEMEM_ENABLE
638 config ARCH_POPULATES_NODE_MAP
644 bool "Allocate 3rd-level pagetables from highmem"
645 depends on HIGHMEM4G || HIGHMEM64G
647 The VM uses one page table entry for each page of physical memory.
648 For systems with a lot of RAM, this can be wasteful of precious
649 low memory. Setting this option will put user-space page table
650 entries in high memory.
652 config MATH_EMULATION
653 bool "Math emulation"
655 Linux can emulate a math coprocessor (used for floating point
656 operations) if you don't have one. 486DX and Pentium processors have
657 a math coprocessor built in, 486SX and 386 do not, unless you added
658 a 487DX or 387, respectively. (The messages during boot time can
659 give you some hints here ["man dmesg"].) Everyone needs either a
660 coprocessor or this emulation.
662 If you don't have a math coprocessor, you need to say Y here; if you
663 say Y here even though you have a coprocessor, the coprocessor will
664 be used nevertheless. (This behavior can be changed with the kernel
665 command line option "no387", which comes handy if your coprocessor
666 is broken. Try "man bootparam" or see the documentation of your boot
667 loader (lilo or loadlin) about how to pass options to the kernel at
668 boot time.) This means that it is a good idea to say Y here if you
669 intend to use this kernel on different machines.
671 More information about the internals of the Linux math coprocessor
672 emulation can be found in <file:arch/i386/math-emu/README>.
674 If you are not sure, say Y; apart from resulting in a 66 KB bigger
675 kernel, it won't hurt.
678 bool "MTRR (Memory Type Range Register) support"
680 On Intel P6 family processors (Pentium Pro, Pentium II and later)
681 the Memory Type Range Registers (MTRRs) may be used to control
682 processor access to memory ranges. This is most useful if you have
683 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
684 allows bus write transfers to be combined into a larger transfer
685 before bursting over the PCI/AGP bus. This can increase performance
686 of image write operations 2.5 times or more. Saying Y here creates a
687 /proc/mtrr file which may be used to manipulate your processor's
688 MTRRs. Typically the X server should use this.
690 This code has a reasonably generic interface so that similar
691 control registers on other processors can be easily supported
694 The Cyrix 6x86, 6x86MX and M II processors have Address Range
695 Registers (ARRs) which provide a similar functionality to MTRRs. For
696 these, the ARRs are used to emulate the MTRRs.
697 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
698 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
699 write-combining. All of these processors are supported by this code
700 and it makes sense to say Y here if you have one of them.
702 Saying Y here also fixes a problem with buggy SMP BIOSes which only
703 set the MTRRs for the boot CPU and not for the secondary CPUs. This
704 can lead to all sorts of problems, so it's good to say Y here.
706 You can safely say Y even if your machine doesn't have MTRRs, you'll
707 just add about 9 KB to your kernel.
709 See <file:Documentation/mtrr.txt> for more information.
712 bool "Boot from EFI support"
716 This enables the kernel to boot on EFI platforms using
717 system configuration information passed to it from the firmware.
718 This also enables the kernel to use any EFI runtime services that are
719 available (such as the EFI variable services).
721 This option is only useful on systems that have EFI firmware
722 and will result in a kernel image that is ~8k larger. In addition,
723 you must use the latest ELILO loader available at
724 <http://elilo.sourceforge.net> in order to take advantage of
725 kernel initialization using EFI information (neither GRUB nor LILO know
726 anything about EFI). However, even with this option, the resultant
727 kernel should continue to boot on existing non-EFI platforms.
730 bool "Enable kernel irq balancing"
731 depends on SMP && X86_IO_APIC
734 The default yes will allow the kernel to do irq load balancing.
735 Saying no will keep the kernel from doing irq load balancing.
737 # turning this on wastes a bunch of space.
738 # Summit needs it only when NUMA is on
741 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
745 bool "Enable seccomp to safely compute untrusted bytecode"
749 This kernel feature is useful for number crunching applications
750 that may need to compute untrusted bytecode during their
751 execution. By using pipes or other transports made available to
752 the process as file descriptors supporting the read/write
753 syscalls, it's possible to isolate those applications in
754 their own address space using seccomp. Once seccomp is
755 enabled via /proc/<pid>/seccomp, it cannot be disabled
756 and the task is only allowed to execute a few safe syscalls
757 defined by each seccomp mode.
759 If unsure, say Y. Only embedded should say N here.
761 source kernel/Kconfig.hz
764 bool "kexec system call"
766 kexec is a system call that implements the ability to shutdown your
767 current kernel, and to start another kernel. It is like a reboot
768 but it is independent of the system firmware. And like a reboot
769 you can start any kernel with it, not just Linux.
771 The name comes from the similarity to the exec system call.
773 It is an ongoing process to be certain the hardware in a machine
774 is properly shutdown, so do not be surprised if this code does not
775 initially work for you. It may help to enable device hotplugging
776 support. As of this writing the exact hardware interface is
777 strongly in flux, so no good recommendation can be made.
780 bool "kernel crash dumps (EXPERIMENTAL)"
781 depends on EXPERIMENTAL
784 Generate crash dump after being started by kexec.
785 This should be normally only set in special crash dump kernels
786 which are loaded in the main kernel with kexec-tools into
787 a specially reserved region and then later executed after
788 a crash by kdump/kexec. The crash dump kernel must be compiled
789 to a memory address not used by the main kernel or BIOS using
791 For more details see Documentation/kdump/kdump.txt
793 config PHYSICAL_START
794 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
797 This gives the physical address where the kernel is loaded.
799 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
800 bzImage will decompress itself to above physical address and
801 run from there. Otherwise, bzImage will run from the address where
802 it has been loaded by the boot loader and will ignore above physical
805 In normal kdump cases one does not have to set/change this option
806 as now bzImage can be compiled as a completely relocatable image
807 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
808 address. This option is mainly useful for the folks who don't want
809 to use a bzImage for capturing the crash dump and want to use a
810 vmlinux instead. vmlinux is not relocatable hence a kernel needs
811 to be specifically compiled to run from a specific memory area
812 (normally a reserved region) and this option comes handy.
814 So if you are using bzImage for capturing the crash dump, leave
815 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
816 Otherwise if you plan to use vmlinux for capturing the crash dump
817 change this value to start of the reserved region (Typically 16MB
818 0x1000000). In other words, it can be set based on the "X" value as
819 specified in the "crashkernel=YM@XM" command line boot parameter
820 passed to the panic-ed kernel. Typically this parameter is set as
821 crashkernel=64M@16M. Please take a look at
822 Documentation/kdump/kdump.txt for more details about crash dumps.
824 Usage of bzImage for capturing the crash dump is recommended as
825 one does not have to build two kernels. Same kernel can be used
826 as production kernel and capture kernel. Above option should have
827 gone away after relocatable bzImage support is introduced. But it
828 is present because there are users out there who continue to use
829 vmlinux for dump capture. This option should go away down the
832 Don't change this unless you know what you are doing.
835 bool "Build a relocatable kernel(EXPERIMENTAL)"
836 depends on EXPERIMENTAL
838 This build a kernel image that retains relocation information
839 so it can be loaded someplace besides the default 1MB.
840 The relocations tend to the kernel binary about 10% larger,
841 but are discarded at runtime.
843 One use is for the kexec on panic case where the recovery kernel
844 must live at a different physical address than the primary
847 config PHYSICAL_ALIGN
848 hex "Alignment value to which kernel should be aligned"
850 range 0x2000 0x400000
852 This value puts the alignment restrictions on physical address
853 where kernel is loaded and run from. Kernel is compiled for an
854 address which meets above alignment restriction.
856 If bootloader loads the kernel at a non-aligned address and
857 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
858 address aligned to above value and run from there.
860 If bootloader loads the kernel at a non-aligned address and
861 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
862 load address and decompress itself to the address it has been
863 compiled for and run from there. The address for which kernel is
864 compiled already meets above alignment restrictions. Hence the
865 end result is that kernel runs from a physical address meeting
866 above alignment restrictions.
868 Don't change this unless you know what you are doing.
871 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
872 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
874 Say Y here to experiment with turning CPUs off and on, and to
875 enable suspend on SMP systems. CPUs can be controlled through
876 /sys/devices/system/cpu.
879 bool "Compat VDSO support"
883 Map the VDSO to the predictable old-style address too.
885 Say N here if you are running a sufficiently recent glibc
886 version (2.3.3 or later), to remove the high-mapped
887 VDSO mapping and to exclusively use the randomized VDSO.
893 config ARCH_ENABLE_MEMORY_HOTPLUG
897 menu "Power management options (ACPI, APM)"
898 depends on !X86_VOYAGER
900 source kernel/power/Kconfig
902 source "drivers/acpi/Kconfig"
904 menu "APM (Advanced Power Management) BIOS Support"
905 depends on PM && !X86_VISWS
908 tristate "APM (Advanced Power Management) BIOS support"
911 APM is a BIOS specification for saving power using several different
912 techniques. This is mostly useful for battery powered laptops with
913 APM compliant BIOSes. If you say Y here, the system time will be
914 reset after a RESUME operation, the /proc/apm device will provide
915 battery status information, and user-space programs will receive
916 notification of APM "events" (e.g. battery status change).
918 If you select "Y" here, you can disable actual use of the APM
919 BIOS by passing the "apm=off" option to the kernel at boot time.
921 Note that the APM support is almost completely disabled for
922 machines with more than one CPU.
924 In order to use APM, you will need supporting software. For location
925 and more information, read <file:Documentation/pm.txt> and the
926 Battery Powered Linux mini-HOWTO, available from
927 <http://www.tldp.org/docs.html#howto>.
929 This driver does not spin down disk drives (see the hdparm(8)
930 manpage ("man 8 hdparm") for that), and it doesn't turn off
931 VESA-compliant "green" monitors.
933 This driver does not support the TI 4000M TravelMate and the ACER
934 486/DX4/75 because they don't have compliant BIOSes. Many "green"
935 desktop machines also don't have compliant BIOSes, and this driver
936 may cause those machines to panic during the boot phase.
938 Generally, if you don't have a battery in your machine, there isn't
939 much point in using this driver and you should say N. If you get
940 random kernel OOPSes or reboots that don't seem to be related to
941 anything, try disabling/enabling this option (or disabling/enabling
944 Some other things you should try when experiencing seemingly random,
947 1) make sure that you have enough swap space and that it is
949 2) pass the "no-hlt" option to the kernel
950 3) switch on floating point emulation in the kernel and pass
951 the "no387" option to the kernel
952 4) pass the "floppy=nodma" option to the kernel
953 5) pass the "mem=4M" option to the kernel (thereby disabling
954 all but the first 4 MB of RAM)
955 6) make sure that the CPU is not over clocked.
956 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
957 8) disable the cache from your BIOS settings
958 9) install a fan for the video card or exchange video RAM
959 10) install a better fan for the CPU
960 11) exchange RAM chips
961 12) exchange the motherboard.
963 To compile this driver as a module, choose M here: the
964 module will be called apm.
966 config APM_IGNORE_USER_SUSPEND
967 bool "Ignore USER SUSPEND"
970 This option will ignore USER SUSPEND requests. On machines with a
971 compliant APM BIOS, you want to say N. However, on the NEC Versa M
972 series notebooks, it is necessary to say Y because of a BIOS bug.
975 bool "Enable PM at boot time"
978 Enable APM features at boot time. From page 36 of the APM BIOS
979 specification: "When disabled, the APM BIOS does not automatically
980 power manage devices, enter the Standby State, enter the Suspend
981 State, or take power saving steps in response to CPU Idle calls."
982 This driver will make CPU Idle calls when Linux is idle (unless this
983 feature is turned off -- see "Do CPU IDLE calls", below). This
984 should always save battery power, but more complicated APM features
985 will be dependent on your BIOS implementation. You may need to turn
986 this option off if your computer hangs at boot time when using APM
987 support, or if it beeps continuously instead of suspending. Turn
988 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
989 T400CDT. This is off by default since most machines do fine without
993 bool "Make CPU Idle calls when idle"
996 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
997 On some machines, this can activate improved power savings, such as
998 a slowed CPU clock rate, when the machine is idle. These idle calls
999 are made after the idle loop has run for some length of time (e.g.,
1000 333 mS). On some machines, this will cause a hang at boot time or
1001 whenever the CPU becomes idle. (On machines with more than one CPU,
1002 this option does nothing.)
1004 config APM_DISPLAY_BLANK
1005 bool "Enable console blanking using APM"
1008 Enable console blanking using the APM. Some laptops can use this to
1009 turn off the LCD backlight when the screen blanker of the Linux
1010 virtual console blanks the screen. Note that this is only used by
1011 the virtual console screen blanker, and won't turn off the backlight
1012 when using the X Window system. This also doesn't have anything to
1013 do with your VESA-compliant power-saving monitor. Further, this
1014 option doesn't work for all laptops -- it might not turn off your
1015 backlight at all, or it might print a lot of errors to the console,
1016 especially if you are using gpm.
1018 config APM_RTC_IS_GMT
1019 bool "RTC stores time in GMT"
1022 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
1023 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
1026 It is in fact recommended to store GMT in your RTC, because then you
1027 don't have to worry about daylight savings time changes. The only
1028 reason not to use GMT in your RTC is if you also run a broken OS
1029 that doesn't understand GMT.
1031 config APM_ALLOW_INTS
1032 bool "Allow interrupts during APM BIOS calls"
1035 Normally we disable external interrupts while we are making calls to
1036 the APM BIOS as a measure to lessen the effects of a badly behaving
1037 BIOS implementation. The BIOS should reenable interrupts if it
1038 needs to. Unfortunately, some BIOSes do not -- especially those in
1039 many of the newer IBM Thinkpads. If you experience hangs when you
1040 suspend, try setting this to Y. Otherwise, say N.
1042 config APM_REAL_MODE_POWER_OFF
1043 bool "Use real mode APM BIOS call to power off"
1046 Use real mode APM BIOS calls to switch off the computer. This is
1047 a work-around for a number of buggy BIOSes. Switch this option on if
1048 your computer crashes instead of powering off properly.
1052 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
1056 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
1059 bool "PCI support" if !X86_VISWS
1060 depends on !X86_VOYAGER
1061 default y if X86_VISWS
1063 Find out whether you have a PCI motherboard. PCI is the name of a
1064 bus system, i.e. the way the CPU talks to the other stuff inside
1065 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1066 VESA. If you have PCI, say Y, otherwise N.
1068 The PCI-HOWTO, available from
1069 <http://www.tldp.org/docs.html#howto>, contains valuable
1070 information about which PCI hardware does work under Linux and which
1074 prompt "PCI access mode"
1075 depends on PCI && !X86_VISWS
1078 On PCI systems, the BIOS can be used to detect the PCI devices and
1079 determine their configuration. However, some old PCI motherboards
1080 have BIOS bugs and may crash if this is done. Also, some embedded
1081 PCI-based systems don't have any BIOS at all. Linux can also try to
1082 detect the PCI hardware directly without using the BIOS.
1084 With this option, you can specify how Linux should detect the
1085 PCI devices. If you choose "BIOS", the BIOS will be used,
1086 if you choose "Direct", the BIOS won't be used, and if you
1087 choose "MMConfig", then PCI Express MMCONFIG will be used.
1088 If you choose "Any", the kernel will try MMCONFIG, then the
1089 direct access method and falls back to the BIOS if that doesn't
1090 work. If unsure, go with the default, which is "Any".
1095 config PCI_GOMMCONFIG
1108 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1113 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1118 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1121 source "drivers/pci/pcie/Kconfig"
1123 source "drivers/pci/Kconfig"
1131 depends on !(X86_VOYAGER || X86_VISWS)
1133 Find out whether you have ISA slots on your motherboard. ISA is the
1134 name of a bus system, i.e. the way the CPU talks to the other stuff
1135 inside your box. Other bus systems are PCI, EISA, MicroChannel
1136 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1137 newer boards don't support it. If you have ISA, say Y, otherwise N.
1143 The Extended Industry Standard Architecture (EISA) bus was
1144 developed as an open alternative to the IBM MicroChannel bus.
1146 The EISA bus provided some of the features of the IBM MicroChannel
1147 bus while maintaining backward compatibility with cards made for
1148 the older ISA bus. The EISA bus saw limited use between 1988 and
1149 1995 when it was made obsolete by the PCI bus.
1151 Say Y here if you are building a kernel for an EISA-based machine.
1155 source "drivers/eisa/Kconfig"
1158 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1159 default y if X86_VOYAGER
1161 MicroChannel Architecture is found in some IBM PS/2 machines and
1162 laptops. It is a bus system similar to PCI or ISA. See
1163 <file:Documentation/mca.txt> (and especially the web page given
1164 there) before attempting to build an MCA bus kernel.
1166 source "drivers/mca/Kconfig"
1169 tristate "NatSemi SCx200 support"
1170 depends on !X86_VOYAGER
1172 This provides basic support for National Semiconductor's
1173 (now AMD's) Geode processors. The driver probes for the
1174 PCI-IDs of several on-chip devices, so its a good dependency
1175 for other scx200_* drivers.
1177 If compiled as a module, the driver is named scx200.
1179 config SCx200HR_TIMER
1180 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1181 depends on SCx200 && GENERIC_TIME
1184 This driver provides a clocksource built upon the on-chip
1185 27MHz high-resolution timer. Its also a workaround for
1186 NSC Geode SC-1100's buggy TSC, which loses time when the
1187 processor goes idle (as is done by the scheduler). The
1188 other workaround is idle=poll boot option.
1192 depends on AGP_AMD64
1194 source "drivers/pcmcia/Kconfig"
1196 source "drivers/pci/hotplug/Kconfig"
1200 menu "Executable file formats"
1202 source "fs/Kconfig.binfmt"
1206 source "net/Kconfig"
1208 source "drivers/Kconfig"
1212 menu "Instrumentation Support"
1213 depends on EXPERIMENTAL
1215 source "arch/i386/oprofile/Kconfig"
1218 bool "Kprobes (EXPERIMENTAL)"
1219 depends on KALLSYMS && EXPERIMENTAL && MODULES
1221 Kprobes allows you to trap at almost any kernel address and
1222 execute a callback function. register_kprobe() establishes
1223 a probepoint and specifies the callback. Kprobes is useful
1224 for kernel debugging, non-intrusive instrumentation and testing.
1225 If in doubt, say "N".
1228 source "arch/i386/Kconfig.debug"
1230 source "security/Kconfig"
1232 source "crypto/Kconfig"
1234 source "lib/Kconfig"
1237 # Use the generic interrupt handling code in kernel/irq/:
1239 config GENERIC_HARDIRQS
1243 config GENERIC_IRQ_PROBE
1247 config GENERIC_PENDING_IRQ
1249 depends on GENERIC_HARDIRQS && SMP
1254 depends on SMP && !X86_VOYAGER
1259 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1262 config X86_BIOS_REBOOT
1264 depends on !(X86_VISWS || X86_VOYAGER)
1267 config X86_TRAMPOLINE
1269 depends on X86_SMP || (X86_VOYAGER && SMP)
1281 Switches the regular HZ timer off when the system is going idle.
1282 This helps a hypervisor detect that the Linux system is idle,
1283 reducing the overhead of idle systems.
git.openpandora.org / pandora-kernel.git / blob