parameter is applicable:
ACPI ACPI support is enabled.
+ AGP AGP (Accelerated Graphics Port) is enabled.
ALSA ALSA sound support is enabled.
APIC APIC support is enabled.
APM Advanced Power Management support is enabled.
+ AVR32 AVR32 architecture is enabled.
AX25 Appropriate AX.25 support is enabled.
+ BLACKFIN Blackfin architecture is enabled.
DRM Direct Rendering Management support is enabled.
EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
EFI EFI Partitioning (GPT) is enabled
EIDE EIDE/ATAPI support is enabled.
FB The frame buffer device is enabled.
HW Appropriate hardware is enabled.
- IA-32 IA-32 aka i386 architecture is enabled.
IA-64 IA-64 architecture is enabled.
IOSCHED More than one I/O scheduler is enabled.
IP_PNP IP DHCP, BOOTP, or RARP is enabled.
MDA MDA console support is enabled.
MOUSE Appropriate mouse support is enabled.
MSI Message Signaled Interrupts (PCI).
- MTD MTD support is enabled.
+ MTD MTD (Memory Technology Device) support is enabled.
NET Appropriate network support is enabled.
NUMA NUMA support 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.
+ PV_OPS A paravirtualized kernel is enabled.
+ PARIDE The ParIDE (parallel port IDE) subsystem is enabled.
PARISC The PA-RISC architecture is enabled.
PCI PCI bus support is enabled.
+ PCIE PCI Express support is enabled.
PCMCIA The PCMCIA subsystem is enabled.
PNP Plug & Play support is enabled.
PPC PowerPC architecture is enabled.
PPT Parallel port support is enabled.
PS2 Appropriate PS/2 support is enabled.
RAM RAM disk support is enabled.
+ ROOTPLUG The example Root Plug LSM is enabled.
S390 S390 architecture is enabled.
SCSI Appropriate SCSI support is enabled.
A lot of drivers has their options described inside of
Documentation/scsi/.
+ SECURITY Different security models are enabled.
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.
+ SWSUSP Software suspend (hibernation) is enabled.
+ SUSPEND System suspend states are enabled.
+ FTRACE Function tracing enabled.
TS Appropriate touchscreen support is enabled.
+ UMS USB Mass Storage support is enabled.
USB USB support is enabled.
USBHID USB Human Interface Device support is enabled.
V4L Video For Linux support is enabled.
VT Virtual terminal support is enabled.
WDT Watchdog support is enabled.
XT IBM PC/XT MFM hard disk support is enabled.
+ X86-32 X86-32, aka i386 architecture is enabled.
X86-64 X86-64 architecture is enabled.
More X86-64 boot options can be found in
- Documentation/x86_64/boot-options.txt .
+ Documentation/x86/x86_64/boot-options.txt .
+ X86 Either 32bit or 64bit x86 (same as X86-32+X86-64)
In addition, the following text indicates that the option:
Parameters denoted with BOOT are actually interpreted by the boot
loader, and have no meaning to the kernel directly.
Do not modify the syntax of boot loader parameters without extreme
-need or coordination with <Documentation/i386/boot.txt>.
+need or coordination with <Documentation/x86/i386/boot.txt>.
There are also arch-specific kernel-parameters not documented here.
-See for example <Documentation/x86_64/boot-options.txt>.
+See for example <Documentation/x86/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
./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,X86-64,i386]
Advanced Configuration and Power Interface
- Format: { force | off | ht | strict | noirq }
+ Format: { force | off | ht | strict | noirq | rsdt }
force -- enable ACPI if default was off
off -- disable ACPI if default was on
noirq -- do not use ACPI for IRQ routing
ht -- run only enough ACPI to enable Hyper Threading
strict -- Be less tolerant of platforms that are not
strictly ACPI specification compliant.
+ rsdt -- prefer RSDT over (default) XSDT
- See also Documentation/pm.txt, pci=noacpi
+ See also Documentation/power/pm.txt, pci=noacpi
acpi_apic_instance= [ACPI, IOAPIC]
Format: <int>
default: 0
acpi_sleep= [HW,ACPI] Sleep options
- Format: { s3_bios, s3_mode }
- See Documentation/power/video.txt
+ Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
+ old_ordering, s4_nonvs }
+ See Documentation/power/video.txt for information on
+ s3_bios and s3_mode.
+ s3_beep is for debugging; it makes the PC's speaker beep
+ as soon as the kernel's real-mode entry point is called.
+ s4_nohwsig prevents ACPI hardware signature from being
+ used during resume from hibernation.
+ old_ordering causes the ACPI 1.0 ordering of the _PTS
+ control method, with respect to putting devices into
+ low power states, to be enforced (the ACPI 2.0 ordering
+ of _PTS is used by default).
+ s4_nonvs prevents the kernel from saving/restoring the
+ ACPI NVS memory during hibernation.
acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
Format: { level | edge | high | low }
acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
Format: <irq>,<irq>...
+ acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
+
acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
Format: To spoof as Windows 98: ="Microsoft Windows"
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}
+ 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.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 /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]
+ acpi_backlight= [HW,ACPI]
+ acpi_backlight=vendor
+ acpi_backlight=video
+ If set to vendor, prefer vendor specific driver
+ (e.g. thinkpad_acpi, sony_acpi, etc.) instead
+ of the ACPI video.ko driver.
+
+ acpi_display_output= [HW,ACPI]
+ acpi_display_output=vendor
+ acpi_display_output=video
+ See above.
+
+ acpi.debug_layer= [HW,ACPI,ACPI_DEBUG]
+ acpi.debug_level= [HW,ACPI,ACPI_DEBUG]
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 /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_pm_good [IA-32,X86-64]
+ CONFIG_ACPI_DEBUG must be enabled to produce any ACPI
+ debug output. Bits in debug_layer correspond to a
+ _COMPONENT in an ACPI source file, e.g.,
+ #define _COMPONENT ACPI_PCI_COMPONENT
+ Bits in debug_level correspond to a level in
+ ACPI_DEBUG_PRINT statements, e.g.,
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, ...
+ The debug_level mask defaults to "info". See
+ Documentation/acpi/debug.txt for more information about
+ debug layers and levels.
+
+ Enable processor driver info messages:
+ acpi.debug_layer=0x20000000
+ Enable PCI/PCI interrupt routing info messages:
+ acpi.debug_layer=0x400000
+ Enable AML "Debug" output, i.e., stores to the Debug
+ object while interpreting AML:
+ acpi.debug_layer=0xffffffff acpi.debug_level=0x2
+ Enable all messages related to ACPI hardware:
+ acpi.debug_layer=0x2 acpi.debug_level=0xffffffff
+
+ Some values produce so much output that the system is
+ unusable. The "log_buf_len" parameter may be useful
+ if you need to capture more output.
+
+ acpi.power_nocheck= [HW,ACPI]
+ Format: 1/0 enable/disable the check of power state.
+ On some bogus BIOS the _PSC object/_STA object of
+ power resource can't return the correct device power
+ state. In such case it is unneccessary to check its
+ power state again in power transition.
+ 1 : disable the power state check
+
+ acpi_pm_good [X86-32,X86-64]
Override the pmtimer bug detection: force the kernel
to assume that this machine's pmtimer latches its value
and always returns good values.
+ agp= [AGP]
+ { off | try_unsupported }
+ off: disable AGP support
+ try_unsupported: try to drive unsupported chipsets
+ (may crash computer or cause data corruption)
+
enable_timer_pin_1 [i386,x86-64]
Enable PIN 1 of APIC timer
Can be useful to work around chipset bugs
aic79xx= [HW,SCSI]
See Documentation/scsi/aic79xx.txt.
+ amd_iommu= [HW,X86-84]
+ Pass parameters to the AMD IOMMU driver in the system.
+ Possible values are:
+ isolate - enable device isolation (each device, as far
+ as possible, will get its own protection
+ domain) [default]
+ share - put every device behind one IOMMU into the
+ same protection domain
+ fullflush - enable flushing of IO/TLB entries when
+ they are unmapped. Otherwise they are
+ flushed before they will be reused, which
+ is a lot of faster
+
+ amd_iommu_size= [HW,X86-64]
+ Define the size of the aperture for the AMD IOMMU
+ driver. Possible values are:
+ '32M', '64M' (default), '128M', '256M', '512M', '1G'
+
amijoy.map= [HW,JOY] Amiga joystick support
Map of devices attached to JOY0DAT and JOY1DAT
Format: <a>,<b>
not play well with APC CPU idle - disable it if you have
APC and your system crashes randomly.
- apic= [APIC,i386] Change the output verbosity whilst booting
+ apic= [APIC,i386] Advanced Programmable Interrupt Controller
+ Change the output verbosity whilst booting
Format: { quiet (default) | verbose | debug }
Change the amount of debugging information output
when initialising the APIC and IO-APIC components.
apm= [APM] Advanced Power Management
- See header of arch/i386/kernel/apm.c.
-
- applicom= [HW]
- Format: <mem>,<irq>
+ See header of arch/x86/kernel/apm_32.c.
arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
Format: <io>,<irq>,<nodeID>
Format: <io>,<irq>,<mode>
See header of drivers/net/hamradio/baycom_ser_hdx.c.
- blkmtd_device= [HW,MTD]
- blkmtd_erasesz=
- blkmtd_ro=
- blkmtd_bs=
- blkmtd_count=
+ boot_delay= Milliseconds to delay each printk during boot.
+ Values larger than 10 seconds (10000) are changed to
+ no delay (0).
+ Format: integer
+
+ bootmem_debug [KNL] Enable bootmem allocator debug messages.
bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
bttv.radio= Most important insmod options are available as
c101= [NET] Moxa C101 synchronous serial card
- cachesize= [BUGS=IA-32] Override level 2 CPU cache size detection.
+ cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
Sometimes CPU hardware bugs make them report the cache
size incorrectly. The kernel will attempt work arounds
to fix known problems, but for some CPUs it is not
possible to determine what the correct size should be.
This option provides an override for these situations.
- chandev= [HW,NET] Generic channel device initialisation
+ security= [SECURITY] Choose a security module to enable at boot.
+ If this boot parameter is not specified, only the first
+ security module asking for security registration will be
+ loaded. An invalid security module name will be treated
+ as if no module has been chosen.
+
+ capability.disable=
+ [SECURITY] Disable capabilities. This would normally
+ be used only if an alternative security model is to be
+ configured. Potentially dangerous and should only be
+ used if you are entirely sure of the consequences.
+
+ ccw_timeout_log [S390]
+ See Documentation/s390/CommonIO for details.
+
+ cgroup_disable= [KNL] Disable a particular controller
+ Format: {name of the controller(s) to disable}
+ {Currently supported controllers - "memory"}
checkreqprot [SELINUX] Set initial checkreqprot flag value.
Format: { "0" | "1" }
Value can be changed at runtime via
/selinux/checkreqprot.
- clock= [BUGS=IA-32, HW] gettimeofday clocksource override.
+ cio_ignore= [S390]
+ See Documentation/s390/CommonIO for details.
+
+ clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
[Deprecated]
Forces specified clocksource (if available) to be used
when calculating gettimeofday(). If specified
[ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
pxa_timer,timer3,32k_counter,timer0_1
[AVR32] avr32
- [IA-32] pit,hpet,tsc,vmi-timer;
+ [X86-32] pit,hpet,tsc,vmi-timer;
scx200_hrt on Geode; cyclone on IBM x440
[MIPS] MIPS
[PARISC] cr16
[SPARC64] tick
[X86-64] hpet,tsc
- code_bytes [IA32] How many bytes of object code to print in an
- oops report.
+ clearcpuid=BITNUM [X86]
+ Disable CPUID feature X for the kernel. See
+ arch/x86/include/asm/cpufeature.h for the valid bit
+ numbers. Note the Linux specific bits are not necessarily
+ stable over kernel options, but the vendor specific
+ ones should be.
+ Also note that user programs calling CPUID directly
+ or using the feature without checking anything
+ will still see it. This just prevents it from
+ being used by the kernel or shown in /proc/cpuinfo.
+ Also note the kernel might malfunction if you disable
+ some critical bits.
+
+ code_bytes [IA32/X86_64] 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
- over the 8254 in addition to over the IO-APIC. The
- kernel tries to set a sensible default.
-
- hpet= [IA-32,HPET] option to disable HPET and use PIT.
- Format: disable
+ hpet= [X86-32,HPET] option to control HPET usage
+ Format: { enable (default) | disable | force }
+ disable: disable HPET and use PIT instead
+ force: allow force enabled of undocumented chips (ICH4,
+ VIA, nVidia)
com20020= [HW,NET] ARCnet - COM20020 chipset
Format:
switching to the matching ttyS device later. The
options are the same as for ttyS, above.
+ If the device connected to the port is not a TTY but a braille
+ device, prepend "brl," before the device type, for instance
+ console=brl,ttyS0
+ For now, only VisioBraille is supported.
+
earlycon= [KNL] Output early console device and options.
uart[8250],io,<addr>[,options]
uart[8250],mmio,<addr>[,options]
UART at the specified I/O port or MMIO address.
The options are the same as for ttyS, above.
+ no_console_suspend
+ [HW] Never suspend the console
+ Disable suspending of consoles during suspend and
+ hibernate operations. Once disabled, debugging
+ messages can reach various consoles while the rest
+ of the system is being put to sleep (ie, while
+ debugging driver suspend/resume hooks). This may
+ not work reliably with all consoles, but is known
+ to work with serial and VGA consoles.
+
+ coredump_filter=
+ [KNL] Change the default value for
+ /proc/<pid>/coredump_filter.
+ See also Documentation/filesystems/proc.txt.
+
cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
Format:
<first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
- cpia_pp= [HW,PPT]
- Format: { parport<nr> | auto | none }
-
crashkernel=nn[KMG]@ss[KMG]
[KNL] Reserve a chunk of physical memory to
hold a kernel to switch to with kexec on panic.
- cs4232= [HW,OSS]
- Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
+ crashkernel=range1:size1[,range2:size2,...][@offset]
+ [KNL] Same as above, but depends on the memory
+ in the running system. The syntax of range is
+ start-[end] where start and end are both
+ a memory unit (amount[KMG]). See also
+ Documentation/kdump/kdump.txt for a example.
cs89x0_dma= [HW,NET]
Format: <dma>
cs89x0_media= [HW,NET]
Format: { rj45 | aui | bnc }
- cyclades= [HW,SERIAL] Cyclades multi-serial port adapter.
-
dasd= [HW,NET]
See header of drivers/s390/block/dasd_devmap.c.
1 will print _a lot_ more information - normally
only useful to kernel developers.
- decnet= [HW,NET]
+ debug_objects [KNL] Enable object debugging
+
+ debugpat [X86] Enable PAT debugging
+
+ decnet.addr= [HW,NET]
Format: <area>[,<node>]
See also Documentation/networking/decnet.txt.
- default_blu= [VT]
+ vt.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]
+ vt.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]
+ vt.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]
+ vt.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.
+ Default is 1, i.e. UTF-8 mode is enabled for all
+ newly opened terminals.
dhash_entries= [KNL]
Set number of hash buckets for dentry cache.
digiepca= [HW,SERIAL]
See drivers/char/README.epca and
- Documentation/digiepca.txt.
+ Documentation/serial/digiepca.txt.
+
+ disable_mtrr_cleanup [X86]
+ enable_mtrr_cleanup [X86]
+ The kernel tries to adjust MTRR layout from continuous
+ to discrete, to make X server driver able to add WB
+ entry later. This parameter enables/disables that.
+
+ mtrr_chunk_size=nn[KMG] [X86]
+ used for mtrr cleanup. It is largest continous chunk
+ that could hold holes aka. UC entries.
- dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
- support available.
- Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
+ mtrr_gran_size=nn[KMG] [X86]
+ Used for mtrr cleanup. It is granularity of mtrr block.
+ Default is 1.
+ Large value could prevent small alignment from
+ using up MTRRs.
+
+ mtrr_spare_reg_nr=n [X86]
+ Format: <integer>
+ Range: 0,7 : spare reg number
+ Default : 1
+ Used for mtrr cleanup. It is spare mtrr entries number.
+ Set to 2 or more if your graphical card needs more.
+
+ disable_mtrr_trim [X86, Intel and AMD only]
+ By default the kernel will trim any uncacheable
+ memory out of your available memory pool based on
+ MTRR settings. This parameter disables that behavior,
+ possibly causing your machine to run very slowly.
dmasound= [HW,OSS] Sound subsystem buffers
dtc3181e= [HW,SCSI]
- earlyprintk= [IA-32,X86-64,SH]
+ earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
earlyprintk=vga
earlyprintk=serial[,ttySn[,baudrate]]
+ earlyprintk=dbgp
Append ",keep" to not disable it when the real console
takes over.
- Only vga or serial at a time, not both.
+ Only vga or serial or usb debug port at a time.
Currently only ttyS0 and ttyS1 are supported.
eata= [HW,SCSI]
- ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode
- Format: <int>
- 0: polling mode
- non-0: interrupt mode (default)
-
- eda= [HW,PS2]
-
- edb= [HW,PS2]
-
edd= [EDD]
- Format: {"of[f]" | "sk[ipmbr]"}
- See comment in arch/i386/boot/edd.S
-
- eicon= [HW,ISDN]
- Format: <id>,<membase>,<irq>
+ Format: {"off" | "on" | "skip[mbr]"}
eisa_irq_edge= [PARISC,HW]
See header of drivers/parisc/eisa.c.
- elanfreq= [IA-32]
+ elanfreq= [X86-32]
See comment before function elanfreq_setup() in
- arch/i386/kernel/cpu/cpufreq/elanfreq.c.
+ arch/x86/kernel/cpu/cpufreq/elanfreq.c.
elevator= [IOSCHED]
Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
See Documentation/block/as-iosched.txt and
Documentation/block/deadline-iosched.txt for details.
- elfcorehdr= [IA-32, X86_64]
+ elfcorehdr= [IA64,PPC,SH,X86-32,X86_64]
Specifies physical address of start of kernel core
image elf header. Generally kexec loader will
pass this option to capture kernel.
Default value is 0.
Value can be changed at runtime via /selinux/enforce.
- es1371= [HW,OSS]
- Format: <spdif>,[<nomix>,[<amplifier>]]
- See also header of sound/oss/es1371.c.
-
ether= [HW,NET] Ethernet cards parameters
This option is obsoleted by the "netdev=" option, which
has equivalent usage. See its documentation for details.
See header of drivers/scsi/fdomain.c.
floppy= [HW]
- See Documentation/floppy.txt.
+ See Documentation/blockdev/floppy.txt.
+
+ force_pal_cache_flush
+ [IA-64] Avoid check_sal_cache_flush which may hang on
+ buggy SAL_CACHE_FLUSH implementations. Using this
+ parameter will force ia64_sal_cache_flush to call
+ ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
+
+ ftrace=[tracer]
+ [ftrace] will set and start the specified tracer
+ as early as possible in order to facilitate early
+ boot debugging.
+
+ ftrace_dump_on_oops
+ [ftrace] will dump the trace buffers on oops.
gamecon.map[2|3]=
[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
gamma= [HW,DRM]
+ gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
+ Format: off | on
+ default: on
+
gdth= [HW,SCSI]
See header of drivers/scsi/gdth.c.
hd= [EIDE] (E)IDE hard drive subsystem geometry
Format: <cyl>,<head>,<sect>
- hd?= [HW] (E)IDE subsystem
- hd?lun= See Documentation/ide.txt.
-
highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
size of <nn>. This works even on boxes that have no
highmem otherwise. This also works to reduce highmem
hisax= [HW,ISDN]
See Documentation/isdn/README.HiSax.
- hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
-
+ hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot.
+ hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages.
+ On x86-64 and powerpc, this option can be specified
+ multiple times interleaved with hugepages= to reserve
+ huge pages of different sizes. Valid pages sizes on
+ x86-64 are 2M (when the CPU supports "pse") and 1G
+ (when the CPU supports the "pdpe1gb" cpuinfo flag)
+ Note that 1GB pages can only be allocated at boot time
+ using hugepages= and not freed afterwards.
+ default_hugepagesz=
+ [same as hugepagesz=] The size of the default
+ HugeTLB page size. This is the size represented by
+ the legacy /proc/ hugepages APIs, used for SHM, and
+ default size when mounting hugetlbfs filesystems.
+ Defaults to the default architecture's huge page size
+ if not specified.
+
+ hlt [BUGS=ARM,SH]
+
+ hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC)
+ terminal devices. Valid values: 0..8
+
+ i8042.debug [HW] Toggle i8042 debug mode
i8042.direct [HW] Put keyboard port into non-translated mode
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
+ i8042.noloop [HW] Disable the AUX Loopback command while probing
+ for the AUX port
i8042.nomux [HW] Don't check presence of an active multiplexing
controller
i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
icn= [HW,ISDN]
Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
- ide= [HW] (E)IDE subsystem
- Format: ide=nodma or ide=doubler or ide=reverse
- See Documentation/ide.txt.
-
- ide?= [HW] (E)IDE subsystem
- Format: ide?=noprobe or chipset specific parameters.
- See Documentation/ide.txt.
+ ide-core.nodma= [HW] (E)IDE subsystem
+ Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc
+ .vlb_clock .pci_clock .noflush .noprobe .nowerr .cdrom
+ .chs .ignore_cable are additional options
+ See Documentation/ide/ide.txt.
idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
- See Documentation/ide.txt.
+ See Documentation/ide/ide.txt.
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.
+ Format: idle=poll, idle=mwait, idle=halt, idle=nomwait
+ Poll forces a polling idle loop that can slightly
+ improve 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.
+ idle=halt: Halt is forced to be used for CPU idle.
+ In such case C2/C3 won't be used again.
+ idle=nomwait: Disable mwait for CPU C-states
+
+ ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
+ Claim all unknown PCI IDE storage controllers.
ignore_loglevel [KNL]
Ignore loglevel setting - this will print /all/
inttest= [IA64]
+ iomem= Disable strict checking of access to MMIO memory
+ strict regions from userspace.
+ relaxed
+
+ iommu= [x86]
+ off
+ force
+ noforce
+ biomerge
+ panic
+ nopanic
+ merge
+ nomerge
+ forcesac
+ soft
+
+
+ intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
+ on
+ Enable intel iommu driver.
+ off
+ Disable intel iommu driver.
+ igfx_off [Default Off]
+ By default, gfx is mapped as normal device. If a gfx
+ device has a dedicated DMAR unit, the DMAR unit is
+ bypassed by not enabling DMAR with this option. In
+ this case, gfx device will use physical address for
+ DMA.
+ forcedac [x86_64]
+ With this option iommu will not optimize to look
+ for io virtual address below 32 bit forcing dual
+ address cycle on pci bus for cards supporting greater
+ than 32 bit addressing. The default is to look
+ for translation below 32 bit and if not available
+ then look in the higher range.
+ strict [Default Off]
+ With this option on every unmap_single operation will
+ result in a hardware IOTLB flush operation as opposed
+ to batching them for performance.
+
+ io_delay= [X86-32,X86-64] I/O delay method
+ 0x80
+ Standard port 0x80 based delay
+ 0xed
+ Alternate port 0xed based delay (needed on some systems)
+ udelay
+ Simple two microseconds delay
+ none
+ No delay
+
io7= [HW] IO7 for Marvel based alpha systems
See comment before marvel_specify_io7 in
arch/alpha/kernel/core_marvel.c.
ip= [IP_PNP]
- See Documentation/nfsroot.txt.
+ See Documentation/filesystems/nfsroot.txt.
ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
- See comment before ip2_setup() in drivers/char/ip2.c.
+ See comment before ip2_setup() in
+ drivers/char/ip2/ip2base.c.
ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
See header of drivers/scsi/ips.c.
Format:
<cpu number>,...,<cpu number>
or
- <cpu number>-<cpu number> (must be a positive range in ascending order)
+ <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
- an "isolated" CPU is via the CPU affinity syscalls.
+ algorithms. You can move a process onto or off an
+ "isolated" CPU via the CPU affinity syscalls or cpuset.
<cpu number> begins at 0 and the maximum value is
"number of CPUs in system - 1".
js= [HW,JOY] Analog joystick
See Documentation/input/joystick.txt.
- kernelcore=nn[KMG] [KNL,IA-32,IA-64,PPC,X86-64] This parameter
+ kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
specifies the amount of memory usable by the kernel
for non-movable allocations. The requested amount is
spread evenly throughout all nodes in the system. The
use the HighMem zone if it exists, and the Normal
zone if it does not.
- movablecore=nn[KMG] [KNL,IA-32,IA-64,PPC,X86-64] This parameter
+ movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
is similar to kernelcore except it specifies the
amount of memory used for migratable allocations.
If both kernelcore and movablecore is specified,
keepinitrd [HW,ARM]
- kstack=N [IA-32,X86-64] Print N words from the kernel stack
+ kstack=N [X86-32,X86-64] Print N words from the kernel stack
in oops dumps.
+ kgdboc= [HW] kgdb over consoles.
+ Requires a tty driver that supports console polling.
+ (only serial suported for now)
+ Format: <serial_device>[,baud]
+
+ kmac= [MIPS] korina ethernet MAC address.
+ Configure the RouterBoard 532 series on-chip
+ Ethernet adapter MAC address.
+
l2cr= [PPC]
- lapic [IA-32,APIC] Enable the local APIC even if BIOS
+ l3cr= [PPC]
+
+ lapic [X86-32,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.
+ lapic_timer_c2_ok [X86-32,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>
+ libata.dma= [LIBATA] DMA control
+ libata.dma=0 Disable all PATA and SATA DMA
+ libata.dma=1 PATA and SATA Disk DMA only
+ libata.dma=2 ATAPI (CDROM) DMA only
+ libata.dma=4 Compact Flash DMA only
+ Combinations also work, so libata.dma=3 enables DMA
+ for disks and CDROMs, but not CFs.
- 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.
+ libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
+ when set.
+ Format: <int>
+
+ libata.force= [LIBATA] Force configurations. The format is comma
+ separated list of "[ID:]VAL" where ID is
+ PORT[:DEVICE]. PORT and DEVICE are decimal numbers
+ matching port, link or device. Basically, it matches
+ the ATA ID string printed on console by libata. If
+ the whole ID part is omitted, the last PORT and DEVICE
+ values are used. If ID hasn't been specified yet, the
+ configuration applies to all ports, links and devices.
+
+ If only DEVICE is omitted, the parameter applies to
+ the port and all links and devices behind it. DEVICE
+ number of 0 either selects the first device or the
+ first fan-out link behind PMP device. It does not
+ select the host link. DEVICE number of 15 selects the
+ host link and device attached to it.
+
+ The VAL specifies the configuration to force. As long
+ as there's no ambiguity shortcut notation is allowed.
+ For example, both 1.5 and 1.5G would work for 1.5Gbps.
+ The following configurations can be forced.
+
+ * Cable type: 40c, 80c, short40c, unk, ign or sata.
+ Any ID with matching PORT is used.
+
+ * SATA link speed limit: 1.5Gbps or 3.0Gbps.
+
+ * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
+ udma[/][16,25,33,44,66,100,133] notation is also
+ allowed.
- llsc*= [IA64] See function print_params() in
- arch/ia64/sn/kernel/llsc4.c.
+ * [no]ncq: Turn on or off NCQ.
+
+ * nohrst, nosrst, norst: suppress hard, soft
+ and both resets.
+
+ If there are multiple matching configurations changing
+ the same attribute, the last one is used.
+
+ lmb=debug [KNL] Enable lmb debug messages.
load_ramdisk= [RAM] List of ramdisks to load from floppy
- See Documentation/ramdisk.txt.
+ See Documentation/blockdev/ramdisk.txt.
lockd.nlm_grace_period=P [NFS] Assign grace period.
Format: <integer>
n must be a power of two. The default size
is set in the kernel config file.
+ logo.nologo [FB] Disables display of the built-in Linux logo.
+ This may be used to provide more screen space for
+ kernel log messages and is useful when debugging
+ kernel boot problems.
+
lp=0 [LP] Specify parallel ports to use, e.g,
lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
lp=reset first parallel port). 'lp=0' disables the
mac5380= [HW,SCSI] Format:
<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
- mac53c9x= [HW,SCSI] Format:
- <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
-
machvec= [IA64] Force the use of a particular machine-vector
(machvec) in a generic kernel.
Example: machvec=hpzx1_swiotlb
Format: <1-256>
maxcpus= [SMP] Maximum number of processors that an SMP kernel
- 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.
+ should make use of. maxcpus=n : n >= 0 limits the
+ kernel to using 'n' processors. n=0 is a special case,
+ it is equivalent to "nosmp", which also disables
+ the IO APIC.
+
+ max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater than
+ or equal to this physical address is ignored.
max_luns= [SCSI] Maximum number of LUNs to probe.
Should be between 1 and 2^32-1.
[SCSI] Maximum number of LUNs received.
Should be between 1 and 16384.
- mca-pentium [BUGS=IA-32]
-
mcatest= [IA-64]
- mce [IA-32] Machine Check Exception
+ mce [X86-32] Machine Check Exception
+
+ mce=option [X86-64] See Documentation/x86/x86_64/boot-options.txt
md= [HW] RAID subsystems devices and level
See Documentation/md.txt.
mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
Amount of memory to be used when the kernel is not able
to see the whole system memory or for test.
- [IA-32] Use together with memmap= to avoid physical
+ [X86-32] Use together with memmap= to avoid physical
address space collisions. Without memmap= PCI devices
could be placed at addresses belonging to unused RAM.
- mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
+ mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
memory.
- memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact
+ memchunk=nn[KMG]
+ [KNL,SH] Allow user to override the default size for
+ per-device physically contiguous DMA buffers.
+
+ memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
E820 memory map, as specified by the user.
Such memmap=exactmap lines can be constructed based on
BIOS output or other requirements. See the memmap=nn@ss
memmap=nn[KMG]$ss[KMG]
[KNL,ACPI] Mark specific memory as reserved.
Region of memory to be used, from ss to ss+nn.
+ Example: Exclude memory from 0x18690000-0x1869ffff
+ memmap=64K$0x18690000
+ or
+ memmap=0x10000$0x18690000
+
+ memory_corruption_check=0/1 [X86]
+ Some BIOSes seem to corrupt the first 64k of
+ memory when doing things like suspend/resume.
+ Setting this option will scan the memory
+ looking for corruption. Enabling this will
+ both detect corruption and prevent the kernel
+ from using the memory being corrupted.
+ However, its intended as a diagnostic tool; if
+ repeatable BIOS-originated corruption always
+ affects the same memory, you can use memmap=
+ to prevent the kernel from using that memory.
+
+ memory_corruption_check_size=size [X86]
+ By default it checks for corruption in the low
+ 64k, making this memory unavailable for normal
+ use. Use this parameter to scan for
+ corruption in more or less memory.
+
+ memory_corruption_check_period=seconds [X86]
+ By default it checks for corruption every 60
+ seconds. Use this parameter to check at some
+ other rate. 0 disables periodic checking.
+
+ memtest= [KNL,X86] Enable memtest
+ Format: <integer>
+ range: 0,4 : pattern number
+ default : 0 <disable>
meye.*= [HW] Set MotionEye Camera parameters
See Documentation/video4linux/meye.txt.
+ mfgpt_irq= [IA-32] Specify the IRQ to use for the
+ Multi-Function General Purpose Timers on AMD Geode
+ platforms.
+
+ mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
+ the BIOS has incorrectly applied a workaround. TinyBIOS
+ version 0.98 is known to be affected, 0.99 fixes the
+ problem by letting the user disable the workaround.
+
mga= [HW,DRM]
+ min_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory below this
+ physical address is ignored.
+
+ mminit_loglevel=
+ [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
+ parameter allows control of the logging verbosity for
+ the additional memory initialisation checks. A value
+ of 0 disables mminit logging and a level of 4 will
+ log everything. Information is printed at KERN_DEBUG
+ so loglevel=8 may also need to be specified.
+
mousedev.tap_time=
[MOUSE] Maximum time between finger touching and
leaving touchpad surface for touch to be considered
<name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
mtdparts= [MTD]
- See drivers/mtd/cmdline.c.
+ See drivers/mtd/cmdlinepart.c.
+
+ mtdset= [ARM]
+ ARM/S3C2412 JIVE boot control
+
+ See arch/arm/mach-s3c2412/mach-jive.c
mtouchusb.raw_coordinates=
[HW] Make the MicroTouch USB driver use raw coordinates
This usage is only documented in each driver source
file if at all.
+ nf_conntrack.acct=
+ [NETFILTER] Enable connection tracking flow accounting
+ 0 to disable accounting
+ 1 to enable accounting
+ Default value depends on CONFIG_NF_CT_ACCT that is
+ going to be removed in 2.6.29.
+
nfsaddrs= [NFS]
- See Documentation/nfsroot.txt.
+ See Documentation/filesystems/nfsroot.txt.
nfsroot= [NFS] nfs root filesystem for disk-less boxes.
- See Documentation/nfsroot.txt.
+ See Documentation/filesystems/nfsroot.txt.
nfs.callback_tcpport=
[NFS] set the TCP port on which the NFSv4 callback
[NFS] set the maximum lifetime for idmapper cache
entries.
- nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels
-
- no387 [BUGS=IA-32] Tells the kernel to use the 387 maths
+ nfs.enable_ino64=
+ [NFS] enable 64-bit inode numbers.
+ If zero, the NFS client will fake up a 32-bit inode
+ number for the readdir() and stat() syscalls instead
+ of returning the full 64-bit number.
+ The default is to return 64-bit inode numbers.
+
+ nmi_debug= [KNL,AVR32] Specify one or more actions to take
+ when a NMI is triggered.
+ Format: [state][,regs][,debounce][,die]
+
+ nmi_watchdog= [KNL,BUGS=X86-32,X86-64] Debugging features for SMP kernels
+ Format: [panic,][num]
+ Valid num: 0,1,2
+ 0 - turn nmi_watchdog off
+ 1 - use the IO-APIC timer for the NMI watchdog
+ 2 - use the local APIC for the NMI watchdog using
+ a performance counter. Note: This will use one performance
+ counter and the local APIC's performance vector.
+ When panic is specified panic when an NMI watchdog timeout occurs.
+ This is useful when you use a panic=... timeout and need the box
+ quickly up again.
+ Instead of 1 and 2 it is possible to use the following
+ symbolic names: lapic and ioapic
+ Example: nmi_watchdog=2 or nmi_watchdog=panic,lapic
+
+ no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
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.
noapic [SMP,APIC] Tells the kernel to not make use of any
IOAPICs that may be present in the system.
- noasync [HW,M68K] Disables async and sync negotiation for
- all devices.
-
nobats [PPC] Do not use BATs for mapping kernel lowmem
on "Classic" PPC cores.
nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
+ nodsp [SH] Disable hardware DSP at boot time.
+
+ noefi [X86-32,X86-64] Disable EFI runtime services support.
+
noexec [IA-64]
- noexec [IA-32,X86-64]
+ noexec [X86-32,X86-64]
+ On X86-32 available only on PAE configured kernels.
noexec=on: enable non-executable mappings (default)
- noexec=off: disable nn-executable mappings
+ noexec=off: disable non-executable mappings
+
+ noexec32 [X86-64]
+ This affects only 32-bit executables.
+ noexec32=on: enable non-executable mappings (default)
+ read doesn't imply executable mappings
+ noexec32=off: disable non-executable mappings
+ read implies executable mappings
+
+ nofpu [SH] Disable hardware FPU at boot time.
- nofxsr [BUGS=IA-32] Disables x86 floating point extended
+ nofxsr [BUGS=X86-32] Disables x86 floating point extended
register save and restore. The kernel will only save
legacy floating-point registers on task switch.
- nohlt [BUGS=ARM]
+ noclflush [BUGS=X86] Don't use the CLFLUSH instruction
- no-hlt [BUGS=IA-32] Tells the kernel that the hlt
+ nohlt [BUGS=ARM,SH]
+
+ no-hlt [BUGS=X86-32] Tells the kernel that the hlt
instruction doesn't work correctly and not to
use it.
+ no_file_caps Tells the kernel not to honor file capabilities. The
+ only way then for a file to be executed with privilege
+ is to be setuid root or executed by root.
+
nohalt [IA-64] Tells the kernel not to use the power saving
function PAL_HALT_LIGHT when idle. This increases
power-consumption. On the positive side, it reduces
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
+ noirqdebug [X86-32] 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
+ no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for
broken timer IRQ sources.
noisapnp [ISAPNP] Disables ISA PnP code.
nojitter [IA64] Disables jitter checking for ITC timers.
- nolapic [IA-32,APIC] Do not enable or use the local APIC.
+ nolapic [X86-32,APIC] Do not enable or use the local APIC.
- nolapic_timer [IA-32,APIC] Do not use the local APIC timer.
+ nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
+
+ nox2apic [X86-64,APIC] Do not enable x2APIC mode.
+
+ x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
+ default x2apic cluster mode on platforms
+ supporting x2apic.
noltlbs [PPC] Do not use large page/tlb entries for kernel
lowmem mapping on PPC40x.
nomca [IA-64] Disable machine check abort handling
- nomce [IA-32] Machine Check Exception
+ nomce [X86-32] Machine Check Exception
- noreplace-paravirt [IA-32,PV_OPS] Don't patch paravirt_ops
+ nomfgpt [X86-32] Disable Multi-Function General Purpose
+ Timer usage (for AMD Geode machines).
- noreplace-smp [IA-32,SMP] Don't replace SMP instructions
+ noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
+
+ noreplace-smp [X86-32,SMP] Don't replace SMP instructions
with UP alternatives
noresidual [PPC] Don't use residual data on PReP machines.
nosbagart [IA-64]
- nosep [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
+ nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
- nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
+ nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
+ and disable the IO APIC. legacy for "maxcpus=0".
nosoftlockup [KNL] Disable the soft-lockup detector.
+ noswapaccount [KNL] Disable accounting of swap in memory resource
+ controller. (See Documentation/controllers/memory.txt)
+
nosync [HW,M68K] Disables sync negotiation for all devices.
- notsc [BUGS=IA-32] Disable Time Stamp Counter
+ notsc [BUGS=X86-32] Disable Time Stamp Counter
nousb [USB] Disable the USB subsystem
nowb [ARM]
+ nptcg= [IA64] Override max number of concurrent global TLB
+ purges which is reported from either PAL_VM_SUMMARY or
+ SAL PALO.
+
numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
one of ['zone', 'node', 'default'] can be specified
This can be set from sysctl after boot.
nr_uarts= [SERIAL] maximum number of UARTs to be registered.
+ ohci1394_dma=early [HW] enable debugging via the ohci1394 driver.
+ See Documentation/debugging-via-ohci1394.txt for more
+ info.
+
+ olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
+ Rather than timing out after 20 ms if an EC
+ command is not properly ACKed, override the length
+ of the timeout. We have interrupts disabled while
+ waiting for the ACK, so if this is set too high
+ interrupts *may* be lost!
+
opl3= [HW,OSS]
Format: <io>
pcd. [PARIDE]
See header of drivers/block/paride/pcd.c.
- See also Documentation/paride.txt.
+ See also Documentation/blockdev/paride.txt.
pci=option[,option...] [PCI] various PCI subsystem options:
- off [IA-32] don't probe for the PCI bus
- bios [IA-32] force use of PCI BIOS, don't access
+ off [X86] don't probe for the PCI bus
+ bios [X86-32] force use of PCI BIOS, don't access
the hardware directly. Use this if your machine
has a non-standard PCI host bridge.
- nobios [IA-32] disallow use of PCI BIOS, only direct
+ nobios [X86-32] disallow use of PCI BIOS, only direct
hardware access methods are allowed. Use this
if you experience crashes upon bootup and you
suspect they are caused by the BIOS.
- conf1 [IA-32] Force use of PCI Configuration
+ conf1 [X86] Force use of PCI Configuration
Mechanism 1.
- conf2 [IA-32] Force use of PCI Configuration
+ conf2 [X86] Force use of PCI Configuration
Mechanism 2.
- nommconf [IA-32,X86_64] Disable use of MMCONFIG for PCI
+ noaer [PCIE] If the PCIEAER kernel config parameter is
+ enabled, this kernel boot option can be used to
+ disable the use of PCIE advanced error reporting.
+ nodomains [PCI] Disable support for multiple PCI
+ root domains (aka PCI segments, in ACPI-speak).
+ nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
Configuration
nomsi [MSI] If the PCI_MSI kernel config parameter is
enabled, this kernel boot option can be used to
disable the use of MSI interrupts system-wide.
- nosort [IA-32] Don't sort PCI devices according to
- order given by the PCI BIOS. This sorting is
- done to get a device order compatible with
- older kernels.
- biosirq [IA-32] Use PCI BIOS calls to get the interrupt
+ noioapicquirk [APIC] Disable all boot interrupt quirks.
+ Safety option to keep boot IRQs enabled. This
+ should never be necessary.
+ ioapicreroute [APIC] Enable rerouting of boot IRQs to the
+ primary IO-APIC for bridges that cannot disable
+ boot IRQs. This fixes a source of spurious IRQs
+ when the system masks IRQs.
+ noioapicreroute [APIC] Disable workaround that uses the
+ boot IRQ equivalent of an IRQ that connects to
+ a chipset where boot IRQs cannot be disabled.
+ The opposite of ioapicreroute.
+ biosirq [X86-32] Use PCI BIOS calls to get the interrupt
routing table. These calls are known to be buggy
on several machines and they hang the machine
when used, but on other computers it's the only
this option if the kernel is unable to allocate
IRQs or discover secondary PCI buses on your
motherboard.
- rom [IA-32] Assign address space to expansion ROMs.
+ rom [X86] Assign address space to expansion ROMs.
Use with caution as certain devices share
address decoders between ROMs and other
resources.
- irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be
+ norom [X86] Do not assign address space to
+ expansion ROMs that do not already have
+ BIOS assigned address ranges.
+ irqmask=0xMMMM [X86] Set a bit mask of IRQs allowed to be
assigned automatically to PCI devices. You can
make the kernel exclude IRQs of your ISA cards
this way.
- pirqaddr=0xAAAAA [IA-32] Specify the physical address
+ pirqaddr=0xAAAAA [X86] Specify the physical address
of the PIRQ table (normally generated
by the BIOS) if it is outside the
F0000h-100000h range.
- lastbus=N [IA-32] Scan all buses thru bus #N. Can be
+ lastbus=N [X86] Scan all buses thru bus #N. Can be
useful if the kernel is unable to find your
secondary buses and you want to tell it
explicitly which ones they are.
- assign-busses [IA-32] Always assign all PCI bus
+ assign-busses [X86] Always assign all PCI bus
numbers ourselves, overriding
whatever the firmware may have done.
- usepirqmask [IA-32] Honor the possible IRQ mask stored
+ usepirqmask [X86] Honor the possible IRQ mask stored
in the BIOS $PIR table. This is needed on
some systems with broken BIOSes, notably
some HP Pavilion N5400 and Omnibook XE3
notebooks. This will have no effect if ACPI
IRQ routing is enabled.
- noacpi [IA-32] Do not use ACPI for IRQ routing
+ noacpi [X86] Do not use ACPI for IRQ routing
or for PCI scanning.
+ use_crs [X86] Use _CRS for PCI resource
+ allocation.
routeirq Do IRQ routing for all PCI devices.
This is normally done in pci_enable_device(),
so this option is a temporary workaround
for broken drivers that don't call it.
+ skip_isa_align [X86] do not align io start addr, so can
+ handle more pci cards
firmware [ARM] Do not re-enumerate the bus but instead
just use the configuration from the
bootloader. This is currently used on
reserved for the CardBus bridge's memory
window. The default value is 64 megabytes.
+ pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
+ Management.
+ off Disable ASPM.
+ force Enable ASPM even on devices that claim not to support it.
+ WARNING: Forcing ASPM on may cause system lockups.
+
pcmv= [HW,PCMCIA] BadgePAD 4
pd. [PARIDE]
- See Documentation/paride.txt.
+ See Documentation/blockdev/paride.txt.
pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
boot time.
See arch/parisc/kernel/pdc_chassis.c
pf. [PARIDE]
- See Documentation/paride.txt.
+ See Documentation/blockdev/paride.txt.
pg. [PARIDE]
- See Documentation/paride.txt.
+ See Documentation/blockdev/paride.txt.
pirq= [SMP,APIC] Manual mp-table setup
- See Documentation/i386/IO-APIC.txt.
+ See Documentation/x86/i386/IO-APIC.txt.
plip= [PPT,NET] Parallel port network link
Format: { parport<nr> | timid | 0 }
See also Documentation/parport.txt.
+ pmtmr= [X86] Manual setup of pmtmr I/O Port.
+ Override pmtimer IOPort with a hex value.
+ e.g. pmtmr=0x508
+
+ pnp.debug [PNP]
+ Enable PNP debug messages. This depends on the
+ CONFIG_PNP_DEBUG_MESSAGES option.
+
pnpacpi= [ACPI]
{ off }
autoconfiguration.
Ranges are in pairs (memory base and size).
+ dynamic_printk Enables pr_debug()/dev_dbg() calls if
+ CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled.
+ These can also be switched on/off via
+ <debugfs>/dynamic_printk/modules
+
print-fatal-signals=
[KNL] debug: print fatal signals
print-fatal-signals=1: print segfault info to
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)
+ Param: "sleep" - profile D-state sleeping (millisecs).
+ Requires CONFIG_SCHEDSTATS
+ Param: "kvm" - profile VM exits.
processor.max_cstate= [HW,ACPI]
Limit processor to maximum C-state
prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
before loading.
- See Documentation/ramdisk.txt.
+ See Documentation/blockdev/ramdisk.txt.
psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
probe for; one of (bare|imps|exps|lifebook|any).
<io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
pt. [PARIDE]
- See Documentation/paride.txt.
+ See Documentation/blockdev/paride.txt.
+
+ pty.legacy_count=
+ [KNL] Number of legacy pty's. Overwrites compiled-in
+ default number.
quiet [KNL] Disable most log messages
raid= [HW,RAID]
See Documentation/md.txt.
- ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]
- See Documentation/ramdisk.txt.
-
ramdisk_blocksize= [RAM]
- See Documentation/ramdisk.txt.
+ See Documentation/blockdev/ramdisk.txt.
ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
- New name for the ramdisk parameter.
- See Documentation/ramdisk.txt.
+ See Documentation/blockdev/ramdisk.txt.
- rcu.blimit= [KNL,BOOT] Set maximum number of finished
- RCU callbacks to process in one batch.
+ rcupdate.blimit= [KNL,BOOT]
+ Set maximum number of finished RCU callbacks to process
+ in one batch.
- rcu.qhimark= [KNL,BOOT] Set threshold of queued
+ rcupdate.qhimark= [KNL,BOOT]
+ Set threshold of queued
RCU callbacks over which batch limiting is disabled.
- rcu.qlowmark= [KNL,BOOT] Set threshold of queued
- RCU callbacks below which batch limiting is re-enabled.
+ rcupdate.qlowmark= [KNL,BOOT]
+ Set threshold of queued RCU callbacks below which
+ batch limiting is re-enabled.
rdinit= [KNL]
Format: <full_path>
Run specified binary instead of /init from the ramdisk,
used for early userspace startup. See initrd.
- reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
+ reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
Format: <reboot_mode>[,<reboot_mode2>[,...]]
- See arch/*/kernel/reboot.c or arch/*/kernel/process.c
+ See arch/*/kernel/reboot.c or arch/*/kernel/process.c
+
+ relax_domain_level=
+ [KNL, SMP] Set scheduler's default relax_domain_level.
+ See Documentation/cpusets.txt.
reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
- reservetop= [IA-32]
+ reservetop= [X86-32]
Format: nn[KMG]
Reserves a hole at the top of the kernel virtual
address space.
Useful for devices that are detected asynchronously
(e.g. USB and MMC devices).
+ root_plug.vendor_id=
+ [ROOTPLUG] Override the default vendor ID
+
+ root_plug.product_id=
+ [ROOTPLUG] Override the default product ID
+
+ root_plug.debug=
+ [ROOTPLUG] Enable debugging output
+
rw [KNL] Mount root device read-write on boot
S [KNL] Run init in single mode
sa1100ir [NET]
See drivers/net/irda/sa1100_ir.c.
- sb= [HW,OSS]
- Format: <io>,<irq>,<dma>,<dma2>
-
sbni= [NET] Granch SBNI12 leased line adapter
sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
Format: <vendor>:<model>:<flags>
(flags are integer value)
- scsi_logging= [SCSI]
+ scsi_logging_level= [SCSI] a bit mask of logging levels
+ See drivers/scsi/scsi_logging.h for bits. Also
+ settable via sysctl at dev.scsi.logging_level
+ (/proc/sys/dev/scsi/logging_level).
+ There is also a nice 'scsi_logging_level' script in the
+ S390-tools package, available for download at
+ http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html
scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
discovered. async scans them in kernel threads,
Value can be changed at runtime via
/selinux/compat_net.
- serialnumber [BUGS=IA-32]
-
- sg_def_reserved_size= [SCSI]
+ serialnumber [BUGS=X86-32]
shapers= [NET]
Maximal number of shapers.
+ show_msr= [x86] show boot-time MSR settings
+ Format: { <integer> }
+ Show boot-time (BIOS-initialized) MSR settings.
+ The parameter means the number of CPUs to show,
+ for example 1 means boot CPU only.
+
sim710= [SCSI,HW]
See header of drivers/scsi/sim710.c.
smart2= [HW]
Format: <io1>[,<io2>[,...,<io8>]]
- smp-alt-once [IA-32,SMP] On a hotplug CPU system, only
+ smp-alt-once [X86-32,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
snd-ymfpci= [HW,ALSA]
+ softlockup_panic=
+ [KNL] Should the soft-lockup detector generate panics.
+
sonypi.*= [HW] Sony Programmable I/O Control Device driver
See Documentation/sonypi.txt
specialix= [HW,SERIAL] Specialix multi-serial port adapter
- See Documentation/specialix.txt.
+ See Documentation/serial/specialix.txt.
spia_io_base= [HW,MTD]
spia_fio_base=
st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
See Documentation/scsi/st.txt.
- st0x= [HW,SCSI]
- See header of drivers/scsi/seagate.c.
+ stacktrace [FTRACE]
+ Enabled the stack tracer on boot up.
sti= [PARISC,HW]
Format: <num>
tdfx= [HW,DRM]
+ test_suspend= [SUSPEND]
+ Specify "mem" (for Suspend-to-RAM) or "standby" (for
+ standby suspend) as the system sleep state to briefly
+ enter during system startup. The system is woken from
+ this state using a wakeup-capable RTC alarm.
+
thash_entries= [KNL,NET]
Set number of hash buckets for TCP connection
- time Show timing data prefixed to each printk message line
- [deprecated, see 'printk.time']
+ thermal.act= [HW,ACPI]
+ -1: disable all active trip points in all thermal zones
+ <degrees C>: override all lowest active trip points
+
+ thermal.crt= [HW,ACPI]
+ -1: disable all critical trip points in all thermal zones
+ <degrees C>: override all critical trip points
+
+ thermal.nocrt= [HW,ACPI]
+ Set to disable actions on ACPI thermal zone
+ critical and hot trip points.
- tipar.timeout= [HW,PPT]
- Set communications timeout in tenths of a second
- (default 15).
+ thermal.off= [HW,ACPI]
+ 1: disable ACPI thermal control
- tipar.delay= [HW,PPT]
- Set inter-bit delay in microseconds (default 10).
+ thermal.psv= [HW,ACPI]
+ -1: disable all passive trip points
+ <degrees C>: override all passive trip points to this
+ value
- tmc8xx= [HW,SCSI]
- See header of drivers/scsi/seagate.c.
+ thermal.tzp= [HW,ACPI]
+ Specify global default ACPI thermal zone polling rate
+ <deci-seconds>: poll all this frequency
+ 0: no polling (default)
tmscsim= [HW,SCSI]
See comment before function dc390_setup() in
drivers/scsi/tmscsim.c.
+ topology= [S390]
+ Format: {off | on}
+ Specify if the kernel should make use of the cpu
+ topology informations if the hardware supports these.
+ The scheduler will make use of these informations and
+ e.g. base its process migration decisions on it.
+ Default is off.
+
tp720= [HW,PS2]
trix= [HW,OSS] MediaTrix AudioTrix Pro
Format:
<io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
- tsdev.xres= [TS] Horizontal screen resolution.
- tsdev.yres= [TS] Vertical screen resolution.
+ tsc= Disable clocksource-must-verify flag for TSC.
+ Format: <string>
+ [x86] reliable: mark tsc clocksource as reliable, this
+ disables clocksource verification at runtime.
+ Used to enable high-resolution timer mode on older
+ hardware, and in virtualized environment.
turbografx.map[2|3]= [HW,JOY]
TurboGraFX parallel port interface
Note that genuine overcurrent events won't be
reported either.
+ unknown_nmi_panic
+ [X86-32,X86-64]
+ Set unknown_nmi_panic=1 early on boot.
+
usbcore.autosuspend=
[USB] The autosuspend time delay (in seconds) used
for newly-detected USB devices (default 2). This
autosuspended. Devices for which the delay is set
to a negative value won't be autosuspended at all.
+ usbcore.usbfs_snoop=
+ [USB] Set to log all usbfs traffic (default 0 = off).
+
+ usbcore.blinkenlights=
+ [USB] Set to cycle leds on hubs (default 0 = off).
+
+ usbcore.old_scheme_first=
+ [USB] Start with the old device initialization
+ scheme (default 0 = off).
+
+ usbcore.use_both_schemes=
+ [USB] Try the other device initialization scheme
+ if the first one fails (default 1 = enabled).
+
+ usbcore.initial_descriptor_timeout=
+ [USB] Specifies timeout for the initial 64-byte
+ USB_REQ_GET_DESCRIPTOR request in milliseconds
+ (default 5000 = 5.0 seconds).
+
usbhid.mousepoll=
[USBHID] The interval which mice are to be polled at.
- vdso= [IA-32,SH,x86-64]
+ usb-storage.delay_use=
+ [UMS] The delay in seconds before a new device is
+ scanned for Logical Units (default 5).
+
+ usb-storage.quirks=
+ [UMS] A list of quirks entries to supplement or
+ override the built-in unusual_devs list. List
+ entries are separated by commas. Each entry has
+ the form VID:PID:Flags where VID and PID are Vendor
+ and Product ID values (4-digit hex numbers) and
+ Flags is a set of characters, each corresponding
+ to a common usb-storage quirk flag as follows:
+ a = SANE_SENSE (collect more than 18 bytes
+ of sense data);
+ c = FIX_CAPACITY (decrease the reported
+ device capacity by one sector);
+ h = CAPACITY_HEURISTICS (decrease the
+ reported device capacity by one
+ sector if the number is odd);
+ i = IGNORE_DEVICE (don't bind to this
+ device);
+ l = NOT_LOCKABLE (don't try to lock and
+ unlock ejectable media);
+ m = MAX_SECTORS_64 (don't transfer more
+ than 64 sectors = 32 KB at a time);
+ o = CAPACITY_OK (accept the capacity
+ reported by the device);
+ r = IGNORE_RESIDUE (the device reports
+ bogus residue values);
+ s = SINGLE_LUN (the device has only one
+ Logical Unit);
+ w = NO_WP_DETECT (don't test whether the
+ medium is write-protected).
+ Example: quirks=0419:aaf5:rl,0421:0433:rc
+
+ add_efi_memmap [EFI; x86-32,X86-64] Include EFI memory map in
+ kernel's map of available physical RAM.
+
+ vdso= [X86-32,SH,x86-64]
vdso=2: enable compat VDSO (default with COMPAT_VDSO)
vdso=1: enable VDSO (default)
vdso=0: disable VDSO mapping
+ vdso32= [X86-32,X86-64]
+ vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
+ vdso32=1: enable 32-bit VDSO (default)
+ vdso32=0: disable 32-bit VDSO mapping
+
vector= [IA-64,SMP]
vector=percpu: enable percpu vector domain
video= [FB] Frame buffer configuration
See Documentation/fb/modedb.txt.
- vga= [BOOT,IA-32] Select a particular video mode
- See Documentation/i386/boot.txt and
+ vga= [BOOT,X86-32] Select a particular video mode
+ See Documentation/x86/i386/boot.txt and
Documentation/svga.txt.
Use vga=ask for menu.
This is actually a boot loader parameter; the value is
See header of drivers/scsi/wd7000.c.
wdt= [WDT] Watchdog
- See Documentation/watchdog/watchdog.txt.
+ See Documentation/watchdog/wdt.txt.
xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
xd_geo= See header of drivers/block/xd.c.
Format:
<irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
- 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"
+ norandmaps Don't use address space randomization. Equivalent to
+ echo 0 > /proc/sys/kernel/randomize_va_space
______________________________________________________________________
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff