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.
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.
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.
Do not modify the syntax of boot loader parameters without extreme
need or coordination with <Documentation/i386/boot.txt>.
+There are also arch-specific kernel-parameters not documented here.
+See for example <Documentation/x86_64/boot-options.txt>.
+
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
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
See also Documentation/pm.txt, pci=noacpi
+ acpi_apic_instance= [ACPI, IOAPIC]
+ Format: <int>
+ 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
acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
Format: To spoof as Windows 98: ="Microsoft Windows"
- acpi_osi= [HW,ACPI] empty param disables _OSI
+ acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
+ acpi_osi="string1" # add string1 -- only one string
+ acpi_osi="!string2" # remove built-in string2
+ acpi_osi= # disable all strings
acpi_serialize [HW,ACPI] force serialization of AML methods
that require a timer override, but don't have
HPET
- acpi_dbg_layer= [HW,ACPI]
+ acpi.debug_layer= [HW,ACPI]
Format: <int>
Each bit of the <int> 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: <int>
Each bit of the <int> 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
- acpi_generic_hotkey [HW,ACPI]
- Allow consolidated generic hotkey driver to
- override platform specific driver.
- See also Documentation/acpi-hotkey.txt.
+ acpi_fake_ecdt [HW,ACPI] Workaround failure due to BIOS lacking ECDT
acpi_pm_good [IA-32,X86-64]
Override the pmtimer bug detection: force the kernel
clocksource is not available, it defaults to PIT.
Format: { pit | tsc | cyclone | pmtmr }
+ clocksource= [GENERIC_TIME] Override the default clocksource
+ Format: <string>
+ Override the default clocksource and use the clocksource
+ with the name specified.
+ Some clocksource names to choose from, depending on
+ the platform:
+ [all] jiffies (this is the base, fallback clocksource)
+ [ACPI] acpi_pm
+ [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
+ pxa_timer,timer3,32k_counter,timer0_1
+ [AVR32] avr32
+ [IA-32] pit,hpet,tsc,vmi-timer;
+ scx200_hrt on Geode; cyclone on IBM x440
+ [MIPS] MIPS
+ [PARISC] cr16
+ [S390] tod
+ [SH] SuperH
+ [SPARC64] tick
+ [X86-64] hpet,tsc
+
+ 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
Format: <area>[,<node>]
See also Documentation/networking/decnet.txt.
+ default_blu= [VT]
+ Format: <blue0>,<blue1>,<blue2>,...,<blue15>
+ 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: <green0>,<green1>,<green2>,...,<green15>
+ 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: <red0>,<red1>,<red2>,...,<red15>
+ 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.
dtc3181e= [HW,SCSI]
- earlyprintk= [IA-32,X86-64]
+ earlyprintk= [IA-32,X86-64,SH]
earlyprintk=vga
earlyprintk=serial[,ttySn[,baudrate]]
eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
Format: <io>[,<irq>]
+ failslab=
+ fail_page_alloc=
+ fail_make_request=[KNL]
+ General fault injection mechanism.
+ Format: <interval>,<probability>,<space>,<times>
+ See also /Documentation/fault-injection/.
+
fd_mcs= [HW,SCSI]
See header of drivers/scsi/fd_mcs.c.
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.
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.
inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
Format: <irq>
- 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
Format: <RDP>,<reset>,<pci_scan>,<verbosity>
isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
- Format: <cpu number>,...,<cpu number>
+ Format:
+ <cpu number>,...,<cpu number>
+ or
+ <cpu number>-<cpu number> (must be a positive range in ascending order)
+ or a mixture
+ <cpu number>,...,<cpu number>-<cpu number>
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
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:<io>,irq:<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.
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=<NUM>", where <NUM>
+ is an integer greater than 0, limits the maximum number
+ of CPUs activated in SMP mode to <NUM>.
+ 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.
mga= [HW,DRM]
- migration_cost=
- [KNL,SMP] debug: override scheduler migration costs
- Format: <level-1-usecs>,<level-2-usecs>,...
- This debugging option can be used to override the
- default scheduler migration cost matrix. The numbers
- are indexed by 'CPU domain distance'.
- E.g. migration_cost=1000,2000,3000 on an SMT NUMA
- box will set up an intra-core migration cost of
- 1 msec, an inter-core migration cost of 2 msecs,
- and an inter-node migration cost of 3 msecs.
-
- WARNING: using the wrong values here can break
- scheduler performance, so it's only for scheduler
- development purposes, not production environments.
-
- migration_debug=
- [KNL,SMP] migration cost auto-detect verbosity
- Format=<0|1|2>
- If a system's migration matrix reported at bootup
- seems erroneous then this option can be used to
- increase verbosity of the detection process.
- We default to 0 (no extra messages), 1 will print
- some more information, and 2 will be really
- verbose (probably only useful if you also have a
- serial console attached to the system).
-
- migration_factor=
- [KNL,SMP] multiply/divide migration costs by a factor
- Format=<percent>
- This debug option can be used to proportionally
- increase or decrease the auto-detected migration
- costs for all entries of the migration matrix.
- E.g. migration_factor=150 will increase migration
- costs by 50%. (and thus the scheduler will be less
- eager migrating cache-hot tasks)
- migration_factor=80 will decrease migration costs
- by 20%. (thus the scheduler will be more eager to
- migrate tasks)
-
- WARNING: using the wrong values here can break
- scheduler performance, so it's only for scheduler
- development purposes, not production environments.
-
mousedev.tap_time=
[MOUSE] Maximum time between finger touching and
leaving touchpad surface for touch to be considered
emulation library even if a 387 maths coprocessor
is present.
+ noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
+ when set.
+ Format: <int>
+
+ noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
+ caches in the slab allocator. Saves per-node memory,
+ but will impact performance.
+
noalign [KNL,ARM]
noapic [SMP,APIC] Tells the kernel to not make use of any
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
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.
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
This sorting is done to get a device
order compatible with older (<= 2.4) kernels.
nobfsort Don't sort PCI devices into breadth-first order.
+ cbiosize=nn[KMG] The fixed amount of bus space which is
+ reserved for the CardBus bridge's IO window.
+ The default value is 256 bytes.
+ cbmemsize=nn[KMG] The fixed amount of bus space which is
+ reserved for the CardBus bridge's memory
+ window. The default value is 64 megabytes.
pcmv= [HW,PCMCIA] BadgePAD 4
Param: "schedule" - profile schedule points.
Param: <number> - 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
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 <PAGE_SIZE> 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
slram= [HW,MTD]
+ slub_debug [MM, SLUB]
+ Enabling slub_debug allows one to determine the culprit
+ if slab objects become corrupted. Enabling slub_debug
+ creates guard zones around objects and poisons objects
+ when not in use. Also tracks the last alloc / free.
+ For more information see Documentation/vm/slub.txt.
+
+ slub_max_order= [MM, SLUB]
+ Determines the maximum allowed order for slabs. Setting
+ this too high may cause fragmentation.
+ For more information see Documentation/vm/slub.txt.
+
+ slub_min_objects= [MM, SLUB]
+ The minimum objects per slab. SLUB will increase the
+ slab order up to slub_max_order to generate a
+ sufficiently big slab to satisfy the number of objects.
+ The higher the number of objects the smaller the overhead
+ of tracking slabs.
+ For more information see Documentation/vm/slub.txt.
+
+ slub_min_order= [MM, SLUB]
+ Determines the mininum page order for slabs. Must be
+ lower than slub_max_order
+ For more information see Documentation/vm/slub.txt.
+
+ slub_nomerge [MM, SLUB]
+ Disable merging of slabs of similar size. May be
+ necessary if there is some reason to distinguish
+ allocs to different slabs.
+ For more information see Documentation/vm/slub.txt.
+
smart2= [HW]
Format: <io1>[,<io2>[,...,<io8>]]
+ 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]
stifb= [HW]
Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
+ 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]
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.
time Show timing data prefixed to each printk message line
- clocksource= [GENERIC_TIME] Override the default clocksource
- Override the default clocksource and use the clocksource
- with the name specified.
-
tipar.timeout= [HW,PPT]
Set communications timeout in tenths of a second
(default 15).
uart6850= [HW,OSS]
Format: <io>,<irq>
+ 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
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff