X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=Documentation%2Fkernel-parameters.txt;h=09220a1e22d964b3ad19a235952a77c2bd9d1cef;hb=640b31bf1291d1fb8a3e90abed8f145410122bf8;hp=0d189c93eeaf94b283d22fd39d4dea8274d2d3cc;hpb=e6e5494cb23d1933735ee47cc674ffe1c4afed6f;p=safe%2Fjmp%2Flinux-2.6 diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 0d189c9..09220a1 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -35,7 +35,6 @@ parameter is applicable: APM Advanced Power Management support is enabled. AX25 Appropriate AX.25 support is enabled. CD Appropriate CD support is enabled. - DEVFS devfs support is enabled. DRM Direct Rendering Management support is enabled. EDD BIOS Enhanced Disk Drive Services (EDD) is enabled EFI EFI Partitioning (GPT) is enabled @@ -49,6 +48,7 @@ parameter is applicable: ISAPNP ISA PnP code is enabled. ISDN Appropriate ISDN support is enabled. JOY Appropriate joystick support is enabled. + LIBATA Libata driver is enabled LP Printer support is enabled. LOOP Loopback device support is enabled. M68k M68k architecture is enabled. @@ -64,6 +64,7 @@ parameter is applicable: GENERIC_TIME The generic timeofday code is enabled. NFS Appropriate NFS support is enabled. OSS OSS sound support is enabled. + PV_OPS A paravirtualized kernel PARIDE The ParIDE subsystem is enabled. PARISC The PA-RISC architecture is enabled. PCI PCI bus support is enabled. @@ -79,6 +80,7 @@ parameter is applicable: Documentation/scsi/. SELINUX SELinux support is enabled. SERIAL Serial support is enabled. + SH SuperH architecture is enabled. SMP The kernel is an SMP kernel. SPARC Sparc architecture is enabled. SWSUSP Software suspend is enabled. @@ -105,17 +107,28 @@ loader, and have no meaning to the kernel directly. Do not modify the syntax of boot loader parameters without extreme need or coordination with . +There are also arch-specific kernel-parameters not documented here. +See for example . + Note that ALL kernel parameters listed below are CASE SENSITIVE, and that a trailing = on the name of any parameter states that that parameter will be entered as an environment variable, whereas its absence indicates that it will appear as a kernel argument readable via /proc/cmdline by programs running once the system is up. +The number of kernel parameters is not limited, but the length of the +complete command line (parameters including spaces etc.) is limited to +a fixed number of characters. This limit depends on the architecture +and is between 256 and 4096 characters. It is defined in the file +./include/asm/setup.h as COMMAND_LINE_SIZE. + + 53c7xx= [HW,SCSI] Amiga SCSI controllers See header of drivers/scsi/53c7xx.c. See also Documentation/scsi/ncr53c7xx.txt. - acpi= [HW,ACPI] Advanced Configuration and Power Interface + acpi= [HW,ACPI,X86-64,i386] + Advanced Configuration and Power Interface Format: { force | off | ht | strict | noirq } force -- enable ACPI if default was off off -- disable ACPI if default was on @@ -126,6 +139,12 @@ running once the system is up. See also Documentation/pm.txt, pci=noacpi + acpi_apic_instance= [ACPI, IOAPIC] + Format: + 2: use 2nd APIC table, if available + 1,0: use 1st APIC table + default: 0 + acpi_sleep= [HW,ACPI] Sleep options Format: { s3_bios, s3_mode } See Documentation/power/video.txt @@ -158,20 +177,46 @@ running once the system is up. acpi_skip_timer_override [HW,ACPI] Recognize and ignore IRQ0/pin2 Interrupt Override. For broken nForce2 BIOS resulting in XT-PIC timer. + acpi_use_timer_override [HW,ACPI} + Use timer override. For some broken Nvidia NF5 boards + that require a timer override, but don't have + HPET - acpi_dbg_layer= [HW,ACPI] + acpi.debug_layer= [HW,ACPI] Format: Each bit of the indicates an ACPI debug layer, 1: enable, 0: disable. It is useful for boot time debugging. After system has booted up, it can be set - via /proc/acpi/debug_layer. - - acpi_dbg_level= [HW,ACPI] + via /sys/module/acpi/parameters/debug_layer. + CONFIG_ACPI_DEBUG must be enabled for this to produce any output. + Available bits (add the numbers together) to enable debug output + for specific parts of the ACPI subsystem: + 0x01 utilities 0x02 hardware 0x04 events 0x08 tables + 0x10 namespace 0x20 parser 0x40 dispatcher + 0x80 executer 0x100 resources 0x200 acpica debugger + 0x400 os services 0x800 acpica disassembler. + The number can be in decimal or prefixed with 0x in hex. + Warning: Many of these options can produce a lot of + output and make your system unusable. Be very careful. + + acpi.debug_level= [HW,ACPI] Format: Each bit of the indicates an ACPI debug level, 1: enable, 0: disable. It is useful for boot time debugging. After system has booted up, it can be set - via /proc/acpi/debug_level. + via /sys/module/acpi/parameters/debug_level. + CONFIG_ACPI_DEBUG must be enabled for this to produce any output. + Available bits (add the numbers together) to enable different + debug output levels of the ACPI subsystem: + 0x01 error 0x02 warn 0x04 init 0x08 debug object + 0x10 info 0x20 init names 0x40 parse 0x80 load + 0x100 dispatch 0x200 execute 0x400 names 0x800 operation region + 0x1000 bfield 0x2000 tables 0x4000 values 0x8000 objects + 0x10000 resources 0x20000 user requests 0x40000 package. + The number can be in decimal or prefixed with 0x in hex. + Warning: Many of these options can produce a lot of + output and make your system unusable. Be very careful. + acpi_fake_ecdt [HW,ACPI] Workaround failure due to BIOS lacking ECDT @@ -283,9 +328,6 @@ running once the system is up. autotest [IA64] - awe= [HW,OSS] AWE32/SB32/AWE64 wave table synth - Format: ,, - aztcd= [HW,CD] Aztech CD268 CDROM driver Format: ,0x79 (?) @@ -349,11 +391,16 @@ running once the system is up. clock= [BUGS=IA-32, HW] gettimeofday clocksource override. [Deprecated] - Forces specified clocksource (if avaliable) to be used + Forces specified clocksource (if available) to be used when calculating gettimeofday(). If specified - clocksource is not avalible, it defaults to PIT. + clocksource is not available, it defaults to PIT. Format: { pit | tsc | cyclone | pmtmr } + code_bytes [IA32] How many bytes of object code to print in an + oops report. + Range: 0 - 8192 + Default: 64 + disable_8254_timer enable_8254_timer [IA32/X86_64] Disable/Enable interrupt 0 timer routing @@ -436,12 +483,42 @@ running once the system is up. debug [KNL] Enable kernel debugging (events log level). + debug_locks_verbose= + [KNL] verbose self-tests + Format=<0|1> + Print debugging info while doing the locking API + self-tests. + We default to 0 (no extra messages), setting it to + 1 will print _a lot_ more information - normally + only useful to kernel developers. + decnet= [HW,NET] Format: [,] See also Documentation/networking/decnet.txt. - devfs= [DEVFS] - See Documentation/filesystems/devfs/boot-options. + default_blu= [VT] + Format: ,,,..., + Change the default blue palette of the console. + This is a 16-member array composed of values + ranging from 0-255. + + default_grn= [VT] + Format: ,,,..., + Change the default green palette of the console. + This is a 16-member array composed of values + ranging from 0-255. + + default_red= [VT] + Format: ,,,..., + Change the default red palette of the console. + This is a 16-member array composed of values + ranging from 0-255. + + default_utf8= [VT] + Format=<0|1> + Set system-wide default UTF-8 mode for all tty's. + Default is 0 and by setting to 1, it enables UTF-8 + mode for all newly opened or allocated terminals. dhash_entries= [KNL] Set number of hash buckets for dentry cache. @@ -463,7 +540,7 @@ running once the system is up. dtc3181e= [HW,SCSI] - earlyprintk= [IA-32,X86-64] + earlyprintk= [IA-32,X86-64,SH] earlyprintk=vga earlyprintk=serial[,ttySn[,baudrate]] @@ -524,10 +601,6 @@ running once the system is up. Default value is 0. Value can be changed at runtime via /selinux/enforce. - es1370= [HW,OSS] - Format: [,] - See also header of sound/oss/es1370.c. - es1371= [HW,OSS] Format: ,[,[]] See also header of sound/oss/es1371.c. @@ -539,6 +612,13 @@ running once the system is up. eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog. Format: [,] + failslab= + fail_page_alloc= + fail_make_request=[KNL] + General fault injection mechanism. + Format: ,,, + See also /Documentation/fault-injection/. + fd_mcs= [HW,SCSI] See header of drivers/scsi/fd_mcs.c. @@ -548,9 +628,6 @@ running once the system is up. floppy= [HW] See Documentation/floppy.txt. - ftape= [HW] Floppy Tape subsystem debugging options. - See Documentation/ftape.txt. - gamecon.map[2|3]= [HW,JOY] Multisystem joystick and NES/SNES/PSX pad support via parallel port (up to 5 devices per port) @@ -568,11 +645,6 @@ running once the system is up. gscd= [HW,CD] Format: - gt96100eth= [NET] MIPS GT96100 Advanced Communication Controller - - gus= [HW,OSS] - Format: ,,, - gvp11= [HW,SCSI] hashdist= [KNL,NUMA] Large hashes allocated during boot @@ -593,16 +665,18 @@ running once the system is up. highmem otherwise. This also works to reduce highmem size on bigger boxes. + highres= [KNL] Enable/disable high resolution timer mode. + Valid parameters: "on", "off" + Default: "on" + hisax= [HW,ISDN] See Documentation/isdn/README.HiSax. hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages. - noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing - i8042.direct [HW] Put keyboard port into non-translated mode - i8042.dumbkbd [HW] Pretend that controlled can only read data from - keyboard and can not control its state + i8042.dumbkbd [HW] Pretend that controller can only read data from + keyboard and cannot control its state (Don't attempt to blink the leds) i8042.noaux [HW] Don't check for auxiliary (== mouse) port i8042.nokbd [HW] Don't check/create keyboard port @@ -646,8 +720,19 @@ running once the system is up. idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed See Documentation/ide.txt. - idle= [HW] - Format: idle=poll or idle=halt + idle= [X86] + Format: idle=poll or idle=mwait + Poll forces a polling idle loop that can slightly improves the performance + of waking up a idle CPU, but will use a lot of power and make the system + run hot. Not recommended. + idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose + to not use it because it doesn't save as much power as a normal idle + loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same + as idle=poll. + + ignore_loglevel [KNL] + Ignore loglevel setting - this will print /all/ + kernel messages to the console. Useful for debugging. ihash_entries= [KNL] Set number of hash buckets for inode cache. @@ -669,14 +754,6 @@ running once the system is up. inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver Format: - combined_mode= [HW] control which driver uses IDE ports in combined - mode: legacy IDE driver, libata, or both - (in the libata case, libata.atapi_enabled=1 may be - useful as well). Note that using the ide or libata - options may affect your device naming (e.g. by - changing hdc to sdb). - Format: combined (default), ide, or libata - inttest= [IA64] io7= [HW] IO7 for Marvel based alpha systems @@ -692,6 +769,12 @@ running once the system is up. ips= [HW,SCSI] Adaptec / IBM ServeRAID controller See header of drivers/scsi/ips.c. + ports= [IP_VS_FTP] IPVS ftp helper module + Default is 21. + Up to 8 (IP_VS_APP_MAX_PORTS) ports + may be specified. + Format: ,.... + irqfixup [HW] When an interrupt is not handled search all handlers for it. Intended to get systems with badly broken @@ -707,7 +790,12 @@ running once the system is up. Format: ,,, isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler. - Format: ,..., + Format: + ,..., + or + - (must be a positive range in ascending order) + or a mixture + ,...,- This option can be used to specify one or more CPUs to isolate from the general SMP balancing and scheduling algorithms. The only way to move a process onto or off @@ -738,9 +826,17 @@ running once the system is up. lapic [IA-32,APIC] Enable the local APIC even if BIOS disabled it. + lapic_timer_c2_ok [IA-32,x86-64,APIC] trust the local apic timer in + C2 power state. + lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip Format: addr:,irq: + legacy_serial.force [HW,IA-32,X86-64] + Probe for COM ports at legacy addresses even + if PNPBIOS or ACPI should describe them. This + is for working around firmware defects. + llsc*= [IA64] See function print_params() in arch/ia64/sn/kernel/llsc4.c. @@ -825,18 +921,19 @@ running once the system is up. (machvec) in a generic kernel. Example: machvec=hpzx1_swiotlb - mad16= [HW,OSS] Format: - ,,,,,, - - maui= [HW,OSS] - Format: , - max_loop= [LOOP] Maximum number of loopback devices that can be mounted Format: <1-256> maxcpus= [SMP] Maximum number of processors that an SMP kernel - should make use of + should make use of. + Using "nosmp" or "maxcpus=0" will disable SMP + entirely (the MPS table probe still happens, though). + A command-line option of "maxcpus=", where + is an integer greater than 0, limits the maximum number + of CPUs activated in SMP mode to . + Using "maxcpus=1" on an SMP kernel is the trivial + case of an SMP kernel with only one CPU. max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or equal to this physical address is ignored. @@ -1011,6 +1108,14 @@ running once the system is up. emulation library even if a 387 maths coprocessor is present. + noacpi [LIBATA] Disables use of ACPI in libata suspend/resume + when set. + Format: + + noaliencache [MM, NUMA] Disables the allcoation of alien caches in + the slab allocator. Saves per-node memory, but will + impact performance on real NUMA hardware. + noalign [KNL,ARM] noapic [SMP,APIC] Tells the kernel to not make use of any @@ -1024,6 +1129,8 @@ running once the system is up. nocache [ARM] + nodelayacct [KNL] Disable per-task delay accounting + nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects. noexec [IA-64] @@ -1049,9 +1156,18 @@ running once the system is up. in certain environments such as networked servers or real-time systems. + nohz= [KNL] Boottime enable/disable dynamic ticks + Valid arguments: on, off + Default: on + + noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing + noirqdebug [IA-32] Disables the code which attempts to detect and disable unhandled interrupt sources. + no_timer_check [IA-32,X86_64,APIC] Disables the code which tests for + broken timer IRQ sources. + noisapnp [ISAPNP] Disables ISA PnP code. noinitrd [RAM] Tells the kernel not to load any configured @@ -1061,6 +1177,8 @@ running once the system is up. nolapic [IA-32,APIC] Do not enable or use the local APIC. + nolapic_timer [IA-32,APIC] Do not use the local APIC timer. + noltlbs [PPC] Do not use large page/tlb entries for kernel lowmem mapping on PPC40x. @@ -1068,6 +1186,11 @@ running once the system is up. nomce [IA-32] Machine Check Exception + noreplace-paravirt [IA-32,PV_OPS] Don't patch paravirt_ops + + noreplace-smp [IA-32,SMP] Don't replace SMP instructions + with UP alternatives + noresidual [PPC] Don't use residual data on PReP machines. noresume [SWSUSP] Disables resume and restores original swap @@ -1096,9 +1219,6 @@ running once the system is up. opl3= [HW,OSS] Format: - opl3sa= [HW,OSS] - Format: ,,,,, - opl3sa2= [HW,OSS] Format: ,,,,,,,[,, - step/bucket size as a power of 2 for statistical time based profiling. + Param: "sleep" - profile D-state sleeping (millisecs) processor.max_cstate= [HW,ACPI] Limit processor to maximum C-state @@ -1309,7 +1445,7 @@ running once the system is up. pt. [PARIDE] See Documentation/paride.txt. - quiet= [KNL] Disable log messages + quiet [KNL] Disable most log messages r128= [HW,DRM] @@ -1335,10 +1471,6 @@ running once the system is up. rcu.qlowmark= [KNL,BOOT] Set threshold of queued RCU callbacks below which batch limiting is re-enabled. - rcu.rsinterval= [KNL,BOOT,SMP] Set the number of additional - RCU callbacks to queued before forcing reschedule - on all cpus. - rdinit= [KNL] Format: Run specified binary instead of /init from the ramdisk, @@ -1346,13 +1478,29 @@ running once the system is up. reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode Format: [,[,...]] - See arch/*/kernel/reboot.c. + See arch/*/kernel/reboot.c or arch/*/kernel/process.c reserve= [KNL,BUGS] Force the kernel to ignore some iomem area + reservetop= [IA-32] + Format: nn[KMG] + Reserves a hole at the top of the kernel virtual + address space. + + reset_devices [KNL] Force drivers to reset the underlying device + during initialization. + resume= [SWSUSP] Specify the partition device for software suspend + resume_offset= [SWSUSP] + Specify the offset from the beginning of the partition + given by "resume=" at which the swap header is located, + in units (needed only for swap files). + See Documentation/power/swsusp-and-swap-files.txt + + retain_initrd [RAM] Keep initrd memory after extraction + rhash_entries= [KNL,NET] Set number of hash buckets for route cache @@ -1403,6 +1551,11 @@ running once the system is up. scsi_logging= [SCSI] + scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are + discovered. async scans them in kernel threads, + allowing boot to proceed. none ignores them, expecting + user space to do the scan. + selinux [SELINUX] Disable or enable SELinux at boot time. Format: { "0" | "1" } See security/selinux/Kconfig help text. @@ -1425,9 +1578,6 @@ running once the system is up. sg_def_reserved_size= [SCSI] - sgalaxy= [HW,OSS] - Format: ,,,, - shapers= [NET] Maximal number of shapers. @@ -1446,6 +1596,20 @@ running once the system is up. smart2= [HW] Format: [,[,...,]] + smp-alt-once [IA-32,SMP] On a hotplug CPU system, only + attempt to substitute SMP alternatives once at boot. + + smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices + smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port + smsc-ircc2.ircc_sir= [HW] SIR base I/O port + smsc-ircc2.ircc_fir= [HW] FIR base I/O port + smsc-ircc2.ircc_irq= [HW] IRQ line + smsc-ircc2.ircc_dma= [HW] DMA channel + smsc-ircc2.ircc_transceiver= [HW] Transceiver type: + 0: Toshiba Satellite 1800 (GP data pin select) + 1: Fast pin select (default) + 2: ATC IRMode + snd-ad1816a= [HW,ALSA] snd-ad1848= [HW,ALSA] @@ -1568,9 +1732,6 @@ running once the system is up. snd-ymfpci= [HW,ALSA] - sonicvibes= [HW,OSS] - Format: - sonycd535= [HW,CD] Format: [,] @@ -1607,6 +1768,22 @@ running once the system is up. stifb= [HW] Format: bpp:[:[:...]] + sunrpc.pool_mode= + [NFS] + Control how the NFS server code allocates CPUs to + service thread pools. Depending on how many NICs + you have and where their interrupts are bound, this + option will affect which CPUs will do NFS serving. + Note: this parameter cannot be changed while the + NFS server is running. + + auto the server chooses an appropriate mode + automatically using heuristics + global a single global pool contains all CPUs + percpu one pool for each CPU + pernode one pool for each NUMA node (equivalent + to global on non-NUMA machines) + swiotlb= [IA-64] Number of I/O TLB slabs switches= [HW,M68k] @@ -1614,6 +1791,12 @@ running once the system is up. sym53c416= [HW,SCSI] See header of drivers/scsi/sym53c416.c. + sysrq_always_enabled + [KNL] + Ignore sysrq setting - this boot parameter will + neutralize any effect of /proc/sys/kernel/sysrq. + Useful for debugging. + t128= [HW,SCSI] See header of drivers/scsi/t128.c. @@ -1666,10 +1849,26 @@ running once the system is up. uart6850= [HW,OSS] Format: , + uhci-hcd.ignore_oc= + [USB] Ignore overcurrent events (default N). + Some badly-designed motherboards generate lots of + bogus events, for ports that aren't wired to + anything. Set this parameter to avoid log spamming. + Note that genuine overcurrent events won't be + reported either. + + usbcore.autosuspend= + [USB] The autosuspend time delay (in seconds) used + for newly-detected USB devices (default 2). This + is the time required before an idle device will be + autosuspended. Devices for which the delay is set + to a negative value won't be autosuspended at all. + usbhid.mousepoll= [USBHID] The interval which mice are to be polled at. - vdso= [IA-32] + vdso= [IA-32,SH] + vdso=2: enable compat VDSO (default with COMPAT_VDSO) vdso=1: enable VDSO (default) vdso=0: disable VDSO mapping @@ -1689,9 +1888,14 @@ running once the system is up. decrease the size and leave more room for directly mapped kernel RAM. - vmhalt= [KNL,S390] + vmhalt= [KNL,S390] Perform z/VM CP command after system halt. + Format: + + vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic. + Format: - vmpoff= [KNL,S390] + vmpoff= [KNL,S390] Perform z/VM CP command after power off. + Format: waveartist= [HW,OSS] Format: ,,, @@ -1715,6 +1919,9 @@ running once the system is up. norandmaps Don't use address space randomization Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space + unwind_debug=N N > 0 will enable dwarf2 unwinder debugging + This is useful to get more information why + you got a "dwarf2 unwinder stuck" ______________________________________________________________________