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 SEMAPHORE_SLEEPERS
36 config GENERIC_ISA_DMA
44 config GENERIC_HWEIGHT
48 config ARCH_MAY_HAVE_PC_FDC
58 menu "Processor type and features"
61 bool "Symmetric multi-processing support"
63 This enables support for systems with more than one CPU. If you have
64 a system with only one CPU, like most personal computers, say N. If
65 you have a system with more than one CPU, say Y.
67 If you say N here, the kernel will run on single and multiprocessor
68 machines, but will use only one CPU of a multiprocessor machine. If
69 you say Y here, the kernel will run on many, but not all,
70 singleprocessor machines. On a singleprocessor machine, the kernel
71 will run faster if you say N here.
73 Note that if you say Y here and choose architecture "586" or
74 "Pentium" under "Processor family", the kernel will not work on 486
75 architectures. Similarly, multiprocessor kernels for the "PPro"
76 architecture may not work on all Pentium based boards.
78 People using multiprocessor machines who say Y here should also say
79 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
80 Management" code will be disabled if you say Y here.
82 See also the <file:Documentation/smp.txt>,
83 <file:Documentation/i386/IO-APIC.txt>,
84 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
85 <http://www.tldp.org/docs.html#howto>.
87 If you don't know what to do here, say N.
90 prompt "Subarchitecture Type"
96 Choose this option if your computer is a standard PC or compatible.
101 Select this for an AMD Elan processor.
103 Do not use this option for K6/Athlon/Opteron processors!
105 If unsure, choose "PC-compatible" instead.
110 Voyager is an MCA-based 32-way capable SMP architecture proprietary
111 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
115 If you do not specifically know you have a Voyager based machine,
116 say N here, otherwise the kernel you build will not be bootable.
119 bool "NUMAQ (IBM/Sequent)"
123 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
124 multiquad box. This changes the way that processors are bootstrapped,
125 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
126 You will need a new lynxer.elf file to flash your firmware with - send
127 email to <Martin.Bligh@us.ibm.com>.
130 bool "Summit/EXA (IBM x440)"
133 This option is needed for IBM systems that use the Summit/EXA chipset.
134 In particular, it is needed for the x440.
136 If you don't have one of these computers, you should say N here.
139 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
142 This option is needed for the systems that have more than 8 CPUs
143 and if the system is not of any sub-arch type above.
145 If you don't have such a system, you should say N here.
148 bool "SGI 320/540 (Visual Workstation)"
150 The SGI Visual Workstation series is an IA32-based workstation
151 based on SGI systems chips with some legacy PC hardware attached.
153 Say Y here to create a kernel to run on the SGI 320 or 540.
155 A kernel compiled for the Visual Workstation will not run on PCs
156 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
158 config X86_GENERICARCH
159 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
162 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
163 It is intended for a generic binary kernel.
166 bool "Support for Unisys ES7000 IA32 series"
169 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
170 supposed to run on an IA32-based Unisys ES7000 system.
171 Only choose this option if you have such a system, otherwise you
179 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
182 config HAVE_ARCH_PARSE_SRAT
187 config X86_SUMMIT_NUMA
190 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
192 config X86_CYCLONE_TIMER
195 depends on X86_SUMMIT || X86_GENERICARCH
197 config ES7000_CLUSTERED_APIC
200 depends on SMP && X86_ES7000 && MPENTIUMIII
202 source "arch/i386/Kconfig.cpu"
205 bool "HPET Timer Support"
207 This enables the use of the HPET for the kernel's internal timer.
208 HPET is the next generation timer replacing legacy 8254s.
209 You can safely choose Y here. However, HPET will only be
210 activated if the platform and the BIOS support this feature.
211 Otherwise the 8254 will be used for timing services.
213 Choose N to continue using the legacy 8254 timer.
215 config HPET_EMULATE_RTC
217 depends on HPET_TIMER && RTC=y
221 int "Maximum number of CPUs (2-255)"
224 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
227 This allows you to specify the maximum number of CPUs which this
228 kernel will support. The maximum supported value is 255 and the
229 minimum value which makes sense is 2.
231 This is purely to save memory - each supported CPU adds
232 approximately eight kilobytes to the kernel image.
235 bool "SMT (Hyperthreading) scheduler support"
238 SMT scheduler support improves the CPU scheduler's decision making
239 when dealing with Intel Pentium 4 chips with HyperThreading at a
240 cost of slightly increased overhead in some places. If unsure say
244 bool "Multi-core scheduler support"
248 Multi-core scheduler support improves the CPU scheduler's decision
249 making when dealing with multi-core CPU chips at a cost of slightly
250 increased overhead in some places. If unsure say N here.
252 source "kernel/Kconfig.preempt"
255 bool "Local APIC support on uniprocessors"
256 depends on !SMP && !(X86_VISWS || X86_VOYAGER)
258 A local APIC (Advanced Programmable Interrupt Controller) is an
259 integrated interrupt controller in the CPU. If you have a single-CPU
260 system which has a processor with a local APIC, you can say Y here to
261 enable and use it. If you say Y here even though your machine doesn't
262 have a local APIC, then the kernel will still run with no slowdown at
263 all. The local APIC supports CPU-generated self-interrupts (timer,
264 performance counters), and the NMI watchdog which detects hard
268 bool "IO-APIC support on uniprocessors"
269 depends on X86_UP_APIC
271 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
272 SMP-capable replacement for PC-style interrupt controllers. Most
273 SMP systems and many recent uniprocessor systems have one.
275 If you have a single-CPU system with an IO-APIC, you can say Y here
276 to use it. If you say Y here even though your machine doesn't have
277 an IO-APIC, then the kernel will still run with no slowdown at all.
279 config X86_LOCAL_APIC
281 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER)
286 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER))
289 config X86_VISWS_APIC
295 bool "Machine Check Exception"
296 depends on !X86_VOYAGER
298 Machine Check Exception support allows the processor to notify the
299 kernel if it detects a problem (e.g. overheating, component failure).
300 The action the kernel takes depends on the severity of the problem,
301 ranging from a warning message on the console, to halting the machine.
302 Your processor must be a Pentium or newer to support this - check the
303 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
304 have a design flaw which leads to false MCE events - hence MCE is
305 disabled on all P5 processors, unless explicitly enabled with "mce"
306 as a boot argument. Similarly, if MCE is built in and creates a
307 problem on some new non-standard machine, you can boot with "nomce"
308 to disable it. MCE support simply ignores non-MCE processors like
309 the 386 and 486, so nearly everyone can say Y here.
311 config X86_MCE_NONFATAL
312 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
315 Enabling this feature starts a timer that triggers every 5 seconds which
316 will look at the machine check registers to see if anything happened.
317 Non-fatal problems automatically get corrected (but still logged).
318 Disable this if you don't want to see these messages.
319 Seeing the messages this option prints out may be indicative of dying hardware,
320 or out-of-spec (ie, overclocked) hardware.
321 This option only does something on certain CPUs.
322 (AMD Athlon/Duron and Intel Pentium 4)
324 config X86_MCE_P4THERMAL
325 bool "check for P4 thermal throttling interrupt."
326 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
328 Enabling this feature will cause a message to be printed when the P4
329 enters thermal throttling.
332 tristate "Toshiba Laptop support"
334 This adds a driver to safely access the System Management Mode of
335 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
336 not work on models with a Phoenix BIOS. The System Management Mode
337 is used to set the BIOS and power saving options on Toshiba portables.
339 For information on utilities to make use of this driver see the
340 Toshiba Linux utilities web site at:
341 <http://www.buzzard.org.uk/toshiba/>.
343 Say Y if you intend to run this kernel on a Toshiba portable.
347 tristate "Dell laptop support"
349 This adds a driver to safely access the System Management Mode
350 of the CPU on the Dell Inspiron 8000. The System Management Mode
351 is used to read cpu temperature and cooling fan status and to
352 control the fans on the I8K portables.
354 This driver has been tested only on the Inspiron 8000 but it may
355 also work with other Dell laptops. You can force loading on other
356 models by passing the parameter `force=1' to the module. Use at
359 For information on utilities to make use of this driver see the
360 I8K Linux utilities web site at:
361 <http://people.debian.org/~dz/i8k/>
363 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
366 config X86_REBOOTFIXUPS
367 bool "Enable X86 board specific fixups for reboot"
371 This enables chipset and/or board specific fixups to be done
372 in order to get reboot to work correctly. This is only needed on
373 some combinations of hardware and BIOS. The symptom, for which
374 this config is intended, is when reboot ends with a stalled/hung
377 Currently, the only fixup is for the Geode GX1/CS5530A/TROM2.1.
380 Say Y if you want to enable the fixup. Currently, it's safe to
381 enable this option even if you don't need it.
385 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
387 If you say Y here and also to "/dev file system support" in the
388 'File systems' section, you will be able to update the microcode on
389 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
390 Pentium III, Pentium 4, Xeon etc. You will obviously need the
391 actual microcode binary data itself which is not shipped with the
394 For latest news and information on obtaining all the required
395 ingredients for this driver, check:
396 <http://www.urbanmyth.org/microcode/>.
398 To compile this driver as a module, choose M here: the
399 module will be called microcode.
402 tristate "/dev/cpu/*/msr - Model-specific register support"
404 This device gives privileged processes access to the x86
405 Model-Specific Registers (MSRs). It is a character device with
406 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
407 MSR accesses are directed to a specific CPU on multi-processor
411 tristate "/dev/cpu/*/cpuid - CPU information support"
413 This device gives processes access to the x86 CPUID instruction to
414 be executed on a specific processor. It is a character device
415 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
418 source "drivers/firmware/Kconfig"
421 prompt "High Memory Support"
426 depends on !X86_NUMAQ
428 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
429 However, the address space of 32-bit x86 processors is only 4
430 Gigabytes large. That means that, if you have a large amount of
431 physical memory, not all of it can be "permanently mapped" by the
432 kernel. The physical memory that's not permanently mapped is called
435 If you are compiling a kernel which will never run on a machine with
436 more than 1 Gigabyte total physical RAM, answer "off" here (default
437 choice and suitable for most users). This will result in a "3GB/1GB"
438 split: 3GB are mapped so that each process sees a 3GB virtual memory
439 space and the remaining part of the 4GB virtual memory space is used
440 by the kernel to permanently map as much physical memory as
443 If the machine has between 1 and 4 Gigabytes physical RAM, then
446 If more than 4 Gigabytes is used then answer "64GB" here. This
447 selection turns Intel PAE (Physical Address Extension) mode on.
448 PAE implements 3-level paging on IA32 processors. PAE is fully
449 supported by Linux, PAE mode is implemented on all recent Intel
450 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
451 then the kernel will not boot on CPUs that don't support PAE!
453 The actual amount of total physical memory will either be
454 auto detected or can be forced by using a kernel command line option
455 such as "mem=256M". (Try "man bootparam" or see the documentation of
456 your boot loader (lilo or loadlin) about how to pass options to the
457 kernel at boot time.)
459 If unsure, say "off".
463 depends on !X86_NUMAQ
465 Select this if you have a 32-bit processor and between 1 and 4
466 gigabytes of physical RAM.
470 depends on X86_CMPXCHG64
472 Select this if you have a 32-bit processor and more than 4
473 gigabytes of physical RAM.
478 depends on EXPERIMENTAL && !X86_PAE
479 prompt "Memory split" if EMBEDDED
482 Select the desired split between kernel and user memory.
484 If the address range available to the kernel is less than the
485 physical memory installed, the remaining memory will be available
486 as "high memory". Accessing high memory is a little more costly
487 than low memory, as it needs to be mapped into the kernel first.
488 Note that increasing the kernel address space limits the range
489 available to user programs, making the address space there
490 tighter. Selecting anything other than the default 3G/1G split
491 will also likely make your kernel incompatible with binary-only
494 If you are not absolutely sure what you are doing, leave this
498 bool "3G/1G user/kernel split"
499 config VMSPLIT_3G_OPT
500 bool "3G/1G user/kernel split (for full 1G low memory)"
502 bool "2G/2G user/kernel split"
504 bool "1G/3G user/kernel split"
509 default 0xB0000000 if VMSPLIT_3G_OPT
510 default 0x78000000 if VMSPLIT_2G
511 default 0x40000000 if VMSPLIT_1G
516 depends on HIGHMEM64G || HIGHMEM4G
521 depends on HIGHMEM64G
524 # Common NUMA Features
526 bool "Numa Memory Allocation and Scheduler Support"
527 depends on SMP && HIGHMEM64G && (X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI))
529 default y if (X86_NUMAQ || X86_SUMMIT)
531 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
532 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
536 default "4" if X86_NUMAQ
538 depends on NEED_MULTIPLE_NODES
540 config HAVE_ARCH_BOOTMEM_NODE
545 config ARCH_HAVE_MEMORY_PRESENT
547 depends on DISCONTIGMEM
550 config NEED_NODE_MEMMAP_SIZE
552 depends on DISCONTIGMEM || SPARSEMEM
555 config HAVE_ARCH_ALLOC_REMAP
560 config ARCH_FLATMEM_ENABLE
562 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
564 config ARCH_DISCONTIGMEM_ENABLE
568 config ARCH_DISCONTIGMEM_DEFAULT
572 config ARCH_SPARSEMEM_ENABLE
574 depends on (NUMA || (X86_PC && EXPERIMENTAL))
575 select SPARSEMEM_STATIC
577 config ARCH_SELECT_MEMORY_MODEL
579 depends on ARCH_SPARSEMEM_ENABLE
583 config HAVE_ARCH_EARLY_PFN_TO_NID
589 bool "Allocate 3rd-level pagetables from highmem"
590 depends on HIGHMEM4G || HIGHMEM64G
592 The VM uses one page table entry for each page of physical memory.
593 For systems with a lot of RAM, this can be wasteful of precious
594 low memory. Setting this option will put user-space page table
595 entries in high memory.
597 config MATH_EMULATION
598 bool "Math emulation"
600 Linux can emulate a math coprocessor (used for floating point
601 operations) if you don't have one. 486DX and Pentium processors have
602 a math coprocessor built in, 486SX and 386 do not, unless you added
603 a 487DX or 387, respectively. (The messages during boot time can
604 give you some hints here ["man dmesg"].) Everyone needs either a
605 coprocessor or this emulation.
607 If you don't have a math coprocessor, you need to say Y here; if you
608 say Y here even though you have a coprocessor, the coprocessor will
609 be used nevertheless. (This behavior can be changed with the kernel
610 command line option "no387", which comes handy if your coprocessor
611 is broken. Try "man bootparam" or see the documentation of your boot
612 loader (lilo or loadlin) about how to pass options to the kernel at
613 boot time.) This means that it is a good idea to say Y here if you
614 intend to use this kernel on different machines.
616 More information about the internals of the Linux math coprocessor
617 emulation can be found in <file:arch/i386/math-emu/README>.
619 If you are not sure, say Y; apart from resulting in a 66 KB bigger
620 kernel, it won't hurt.
623 bool "MTRR (Memory Type Range Register) support"
625 On Intel P6 family processors (Pentium Pro, Pentium II and later)
626 the Memory Type Range Registers (MTRRs) may be used to control
627 processor access to memory ranges. This is most useful if you have
628 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
629 allows bus write transfers to be combined into a larger transfer
630 before bursting over the PCI/AGP bus. This can increase performance
631 of image write operations 2.5 times or more. Saying Y here creates a
632 /proc/mtrr file which may be used to manipulate your processor's
633 MTRRs. Typically the X server should use this.
635 This code has a reasonably generic interface so that similar
636 control registers on other processors can be easily supported
639 The Cyrix 6x86, 6x86MX and M II processors have Address Range
640 Registers (ARRs) which provide a similar functionality to MTRRs. For
641 these, the ARRs are used to emulate the MTRRs.
642 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
643 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
644 write-combining. All of these processors are supported by this code
645 and it makes sense to say Y here if you have one of them.
647 Saying Y here also fixes a problem with buggy SMP BIOSes which only
648 set the MTRRs for the boot CPU and not for the secondary CPUs. This
649 can lead to all sorts of problems, so it's good to say Y here.
651 You can safely say Y even if your machine doesn't have MTRRs, you'll
652 just add about 9 KB to your kernel.
654 See <file:Documentation/mtrr.txt> for more information.
657 bool "Boot from EFI support (EXPERIMENTAL)"
661 This enables the the kernel to boot on EFI platforms using
662 system configuration information passed to it from the firmware.
663 This also enables the kernel to use any EFI runtime services that are
664 available (such as the EFI variable services).
666 This option is only useful on systems that have EFI firmware
667 and will result in a kernel image that is ~8k larger. In addition,
668 you must use the latest ELILO loader available at
669 <http://elilo.sourceforge.net> in order to take advantage of
670 kernel initialization using EFI information (neither GRUB nor LILO know
671 anything about EFI). However, even with this option, the resultant
672 kernel should continue to boot on existing non-EFI platforms.
675 bool "Enable kernel irq balancing"
676 depends on SMP && X86_IO_APIC
679 The default yes will allow the kernel to do irq load balancing.
680 Saying no will keep the kernel from doing irq load balancing.
682 # turning this on wastes a bunch of space.
683 # Summit needs it only when NUMA is on
686 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
690 bool "Use register arguments"
693 Compile the kernel with -mregparm=3. This instructs gcc to use
694 a more efficient function call ABI which passes the first three
695 arguments of a function call via registers, which results in denser
698 If this option is disabled, then the default ABI of passing
699 arguments via the stack is used.
704 bool "Enable seccomp to safely compute untrusted bytecode"
708 This kernel feature is useful for number crunching applications
709 that may need to compute untrusted bytecode during their
710 execution. By using pipes or other transports made available to
711 the process as file descriptors supporting the read/write
712 syscalls, it's possible to isolate those applications in
713 their own address space using seccomp. Once seccomp is
714 enabled via /proc/<pid>/seccomp, it cannot be disabled
715 and the task is only allowed to execute a few safe syscalls
716 defined by each seccomp mode.
718 If unsure, say Y. Only embedded should say N here.
720 source kernel/Kconfig.hz
723 bool "kexec system call (EXPERIMENTAL)"
724 depends on EXPERIMENTAL
726 kexec is a system call that implements the ability to shutdown your
727 current kernel, and to start another kernel. It is like a reboot
728 but it is indepedent of the system firmware. And like a reboot
729 you can start any kernel with it, not just Linux.
731 The name comes from the similiarity to the exec system call.
733 It is an ongoing process to be certain the hardware in a machine
734 is properly shutdown, so do not be surprised if this code does not
735 initially work for you. It may help to enable device hotplugging
736 support. As of this writing the exact hardware interface is
737 strongly in flux, so no good recommendation can be made.
740 bool "kernel crash dumps (EXPERIMENTAL)"
741 depends on EXPERIMENTAL
744 Generate crash dump after being started by kexec.
746 config PHYSICAL_START
747 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
749 default "0x1000000" if CRASH_DUMP
752 This gives the physical address where the kernel is loaded. Normally
753 for regular kernels this value is 0x100000 (1MB). But in the case
754 of kexec on panic the fail safe kernel needs to run at a different
755 address than the panic-ed kernel. This option is used to set the load
756 address for kernels used to capture crash dump on being kexec'ed
757 after panic. The default value for crash dump kernels is
758 0x1000000 (16MB). This can also be set based on the "X" value as
759 specified in the "crashkernel=YM@XM" command line boot parameter
760 passed to the panic-ed kernel. Typically this parameter is set as
761 crashkernel=64M@16M. Please take a look at
762 Documentation/kdump/kdump.txt for more details about crash dumps.
764 Don't change this unless you know what you are doing.
767 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
768 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
770 Say Y here to experiment with turning CPUs off and on, and to
771 enable suspend on SMP systems. CPUs can be controlled through
772 /sys/devices/system/cpu.
778 menu "Power management options (ACPI, APM)"
779 depends on !X86_VOYAGER
781 source kernel/power/Kconfig
783 source "drivers/acpi/Kconfig"
785 menu "APM (Advanced Power Management) BIOS Support"
786 depends on PM && !X86_VISWS
789 tristate "APM (Advanced Power Management) BIOS support"
792 APM is a BIOS specification for saving power using several different
793 techniques. This is mostly useful for battery powered laptops with
794 APM compliant BIOSes. If you say Y here, the system time will be
795 reset after a RESUME operation, the /proc/apm device will provide
796 battery status information, and user-space programs will receive
797 notification of APM "events" (e.g. battery status change).
799 If you select "Y" here, you can disable actual use of the APM
800 BIOS by passing the "apm=off" option to the kernel at boot time.
802 Note that the APM support is almost completely disabled for
803 machines with more than one CPU.
805 In order to use APM, you will need supporting software. For location
806 and more information, read <file:Documentation/pm.txt> and the
807 Battery Powered Linux mini-HOWTO, available from
808 <http://www.tldp.org/docs.html#howto>.
810 This driver does not spin down disk drives (see the hdparm(8)
811 manpage ("man 8 hdparm") for that), and it doesn't turn off
812 VESA-compliant "green" monitors.
814 This driver does not support the TI 4000M TravelMate and the ACER
815 486/DX4/75 because they don't have compliant BIOSes. Many "green"
816 desktop machines also don't have compliant BIOSes, and this driver
817 may cause those machines to panic during the boot phase.
819 Generally, if you don't have a battery in your machine, there isn't
820 much point in using this driver and you should say N. If you get
821 random kernel OOPSes or reboots that don't seem to be related to
822 anything, try disabling/enabling this option (or disabling/enabling
825 Some other things you should try when experiencing seemingly random,
828 1) make sure that you have enough swap space and that it is
830 2) pass the "no-hlt" option to the kernel
831 3) switch on floating point emulation in the kernel and pass
832 the "no387" option to the kernel
833 4) pass the "floppy=nodma" option to the kernel
834 5) pass the "mem=4M" option to the kernel (thereby disabling
835 all but the first 4 MB of RAM)
836 6) make sure that the CPU is not over clocked.
837 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
838 8) disable the cache from your BIOS settings
839 9) install a fan for the video card or exchange video RAM
840 10) install a better fan for the CPU
841 11) exchange RAM chips
842 12) exchange the motherboard.
844 To compile this driver as a module, choose M here: the
845 module will be called apm.
847 config APM_IGNORE_USER_SUSPEND
848 bool "Ignore USER SUSPEND"
851 This option will ignore USER SUSPEND requests. On machines with a
852 compliant APM BIOS, you want to say N. However, on the NEC Versa M
853 series notebooks, it is necessary to say Y because of a BIOS bug.
856 bool "Enable PM at boot time"
859 Enable APM features at boot time. From page 36 of the APM BIOS
860 specification: "When disabled, the APM BIOS does not automatically
861 power manage devices, enter the Standby State, enter the Suspend
862 State, or take power saving steps in response to CPU Idle calls."
863 This driver will make CPU Idle calls when Linux is idle (unless this
864 feature is turned off -- see "Do CPU IDLE calls", below). This
865 should always save battery power, but more complicated APM features
866 will be dependent on your BIOS implementation. You may need to turn
867 this option off if your computer hangs at boot time when using APM
868 support, or if it beeps continuously instead of suspending. Turn
869 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
870 T400CDT. This is off by default since most machines do fine without
874 bool "Make CPU Idle calls when idle"
877 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
878 On some machines, this can activate improved power savings, such as
879 a slowed CPU clock rate, when the machine is idle. These idle calls
880 are made after the idle loop has run for some length of time (e.g.,
881 333 mS). On some machines, this will cause a hang at boot time or
882 whenever the CPU becomes idle. (On machines with more than one CPU,
883 this option does nothing.)
885 config APM_DISPLAY_BLANK
886 bool "Enable console blanking using APM"
889 Enable console blanking using the APM. Some laptops can use this to
890 turn off the LCD backlight when the screen blanker of the Linux
891 virtual console blanks the screen. Note that this is only used by
892 the virtual console screen blanker, and won't turn off the backlight
893 when using the X Window system. This also doesn't have anything to
894 do with your VESA-compliant power-saving monitor. Further, this
895 option doesn't work for all laptops -- it might not turn off your
896 backlight at all, or it might print a lot of errors to the console,
897 especially if you are using gpm.
899 config APM_RTC_IS_GMT
900 bool "RTC stores time in GMT"
903 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
904 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
907 It is in fact recommended to store GMT in your RTC, because then you
908 don't have to worry about daylight savings time changes. The only
909 reason not to use GMT in your RTC is if you also run a broken OS
910 that doesn't understand GMT.
912 config APM_ALLOW_INTS
913 bool "Allow interrupts during APM BIOS calls"
916 Normally we disable external interrupts while we are making calls to
917 the APM BIOS as a measure to lessen the effects of a badly behaving
918 BIOS implementation. The BIOS should reenable interrupts if it
919 needs to. Unfortunately, some BIOSes do not -- especially those in
920 many of the newer IBM Thinkpads. If you experience hangs when you
921 suspend, try setting this to Y. Otherwise, say N.
923 config APM_REAL_MODE_POWER_OFF
924 bool "Use real mode APM BIOS call to power off"
927 Use real mode APM BIOS calls to switch off the computer. This is
928 a work-around for a number of buggy BIOSes. Switch this option on if
929 your computer crashes instead of powering off properly.
933 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
937 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
940 bool "PCI support" if !X86_VISWS
941 depends on !X86_VOYAGER
942 default y if X86_VISWS
944 Find out whether you have a PCI motherboard. PCI is the name of a
945 bus system, i.e. the way the CPU talks to the other stuff inside
946 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
947 VESA. If you have PCI, say Y, otherwise N.
949 The PCI-HOWTO, available from
950 <http://www.tldp.org/docs.html#howto>, contains valuable
951 information about which PCI hardware does work under Linux and which
955 prompt "PCI access mode"
956 depends on PCI && !X86_VISWS
959 On PCI systems, the BIOS can be used to detect the PCI devices and
960 determine their configuration. However, some old PCI motherboards
961 have BIOS bugs and may crash if this is done. Also, some embedded
962 PCI-based systems don't have any BIOS at all. Linux can also try to
963 detect the PCI hardware directly without using the BIOS.
965 With this option, you can specify how Linux should detect the
966 PCI devices. If you choose "BIOS", the BIOS will be used,
967 if you choose "Direct", the BIOS won't be used, and if you
968 choose "MMConfig", then PCI Express MMCONFIG will be used.
969 If you choose "Any", the kernel will try MMCONFIG, then the
970 direct access method and falls back to the BIOS if that doesn't
971 work. If unsure, go with the default, which is "Any".
976 config PCI_GOMMCONFIG
989 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
994 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
999 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1002 source "drivers/pci/pcie/Kconfig"
1004 source "drivers/pci/Kconfig"
1012 depends on !(X86_VOYAGER || X86_VISWS)
1014 Find out whether you have ISA slots on your motherboard. ISA is the
1015 name of a bus system, i.e. the way the CPU talks to the other stuff
1016 inside your box. Other bus systems are PCI, EISA, MicroChannel
1017 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1018 newer boards don't support it. If you have ISA, say Y, otherwise N.
1024 The Extended Industry Standard Architecture (EISA) bus was
1025 developed as an open alternative to the IBM MicroChannel bus.
1027 The EISA bus provided some of the features of the IBM MicroChannel
1028 bus while maintaining backward compatibility with cards made for
1029 the older ISA bus. The EISA bus saw limited use between 1988 and
1030 1995 when it was made obsolete by the PCI bus.
1032 Say Y here if you are building a kernel for an EISA-based machine.
1036 source "drivers/eisa/Kconfig"
1039 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1040 default y if X86_VOYAGER
1042 MicroChannel Architecture is found in some IBM PS/2 machines and
1043 laptops. It is a bus system similar to PCI or ISA. See
1044 <file:Documentation/mca.txt> (and especially the web page given
1045 there) before attempting to build an MCA bus kernel.
1047 source "drivers/mca/Kconfig"
1050 tristate "NatSemi SCx200 support"
1051 depends on !X86_VOYAGER
1053 This provides basic support for National Semiconductor's
1054 (now AMD's) Geode processors. The driver probes for the
1055 PCI-IDs of several on-chip devices, so its a good dependency
1056 for other scx200_* drivers.
1058 If compiled as a module, the driver is named scx200.
1060 config SCx200HR_TIMER
1061 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1062 depends on SCx200 && GENERIC_TIME
1065 This driver provides a clocksource built upon the on-chip
1066 27MHz high-resolution timer. Its also a workaround for
1067 NSC Geode SC-1100's buggy TSC, which loses time when the
1068 processor goes idle (as is done by the scheduler). The
1069 other workaround is idle=poll boot option.
1071 source "drivers/pcmcia/Kconfig"
1073 source "drivers/pci/hotplug/Kconfig"
1077 menu "Executable file formats"
1079 source "fs/Kconfig.binfmt"
1083 source "net/Kconfig"
1085 source "drivers/Kconfig"
1089 menu "Instrumentation Support"
1090 depends on EXPERIMENTAL
1092 source "arch/i386/oprofile/Kconfig"
1095 bool "Kprobes (EXPERIMENTAL)"
1096 depends on EXPERIMENTAL && MODULES
1098 Kprobes allows you to trap at almost any kernel address and
1099 execute a callback function. register_kprobe() establishes
1100 a probepoint and specifies the callback. Kprobes is useful
1101 for kernel debugging, non-intrusive instrumentation and testing.
1102 If in doubt, say "N".
1105 source "arch/i386/Kconfig.debug"
1107 source "security/Kconfig"
1109 source "crypto/Kconfig"
1111 source "lib/Kconfig"
1114 # Use the generic interrupt handling code in kernel/irq/:
1116 config GENERIC_HARDIRQS
1120 config GENERIC_IRQ_PROBE
1124 config GENERIC_PENDING_IRQ
1126 depends on GENERIC_HARDIRQS && SMP
1131 depends on SMP && !X86_VOYAGER
1136 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1139 config X86_BIOS_REBOOT
1141 depends on !(X86_VISWS || X86_VOYAGER)
1144 config X86_TRAMPOLINE
1146 depends on X86_SMP || (X86_VOYAGER && SMP)
projects / linux-2.6 / blob