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.
AX25 Appropriate AX.25 support is enabled.
- CD Appropriate CD 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.
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 .
./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 }
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_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
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_pm_good [IA-32,X86-64]
+ 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
Disable PIN 1 of APIC timer
Can be useful to work around chipset bugs.
- ad1816= [HW,OSS]
- Format: <io>,<irq>,<dma>,<dma2>
- See also Documentation/sound/oss/AD1816.
-
ad1848= [HW,OSS]
Format: <io>,<irq>,<dma>,<dma2>,<type>
- adlib= [HW,OSS]
- Format: <io>
-
advansys= [HW,SCSI]
See header of drivers/scsi/advansys.c.
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>
-
arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
Format: <io>,<irq>,<nodeID>
autotest [IA64]
- aztcd= [HW,CD] Aztech CD268 CDROM driver
- Format: <io>,0x79 (?)
-
baycom_epp= [HW,AX25]
Format: <io>,<mode>
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
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.
- cdu31a= [HW,CD]
- Format: <io>,<irq>[,PAS]
- See header of drivers/cdrom/cdu31a.c.
+ 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.
chandev= [HW,NET] Generic channel device initialisation
Value can be changed at runtime via
/selinux/checkreqprot.
- clock= [BUGS=IA-32, HW] gettimeofday clocksource override.
+ 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
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
-
- cm206= [HW,CD]
- Format: { auto | [<io>,][<irq>] }
+ 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:
Documentation/networking/netconsole.txt for an
alternative.
- uart,io,<addr>[,options]
- uart,mmio,<addr>[,options]
+ uart[8250],io,<addr>[,options]
+ uart[8250],mmio,<addr>[,options]
Start an early, polled-mode console on the 8250/16550
UART at the specified I/O port or MMIO address,
switching to the matching ttyS device later. The
options are the same as for ttyS, above.
+ earlycon= [KNL] Output early console device and options.
+ uart[8250],io,<addr>[,options]
+ uart[8250],mmio,<addr>[,options]
+ Start an early, polled-mode console on the 8250/16550
+ 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.
+
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.
+ 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.
+
cs4232= [HW,OSS]
Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
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.
See drivers/char/README.epca and
Documentation/digiepca.txt.
- dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
- support available.
- Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
-
dmasound= [HW,OSS] Sound subsystem buffers
dscc4.setup= [NET]
dtc3181e= [HW,SCSI]
- earlyprintk= [IA-32,X86-64,SH]
+ earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
earlyprintk=vga
earlyprintk=serial[,ttySn[,baudrate]]
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>
-
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.
See Documentation/block/as-iosched.txt and
Documentation/block/deadline-iosched.txt for details.
- elfcorehdr= [IA-32, X86_64]
+ elfcorehdr= [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.
gpt [EFI] Forces disk with valid GPT signature but
invalid Protective MBR to be treated as GPT.
- gscd= [HW,CD]
- Format: <io>
-
gvp11= [HW,SCSI]
hashdist= [KNL,NUMA] Large hashes allocated during boot
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] Maximal number of HugeTLB pages.
i8042.direct [HW] Put keyboard port into non-translated mode
i8042.dumbkbd [HW] Pretend that controller can only read data from
inttest= [IA64]
+ intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
+ 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.
+
io7= [HW] IO7 for Marvel based alpha systems
See comment before marvel_specify_io7 in
arch/alpha/kernel/core_marvel.c.
See Documentation/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.
tasks in the system -- can cause problems and
suboptimal load balancer performance.
- isp16= [HW,CD]
- Format: <io>,<irq>,<dma>,<setup>
-
iucv= [HW,NET]
js= [HW,JOY] Analog joystick
See Documentation/input/joystick.txt.
+ 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
+ remaining memory in each node is used for Movable
+ pages. In the event, a node is too small to have both
+ kernelcore and Movable pages, kernelcore pages will
+ take priority and other nodes will have a larger number
+ of kernelcore pages. The Movable zone is used for the
+ allocation of pages that may be reclaimed or moved
+ by the page migration subsystem. This means that
+ HugeTLB pages may not be allocated from this zone.
+ Note that allocations like PTEs-from-HighMem still
+ use the HighMem zone if it exists, and the Normal
+ zone if it does not.
+
+ 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,
+ then kernelcore will be at *least* the specified
+ value but may be more. If movablecore on its own
+ is specified, the administrator must be careful
+ that the amount of memory usable for all allocations
+ is not too small.
+
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.
l2cr= [PPC]
- lapic [IA-32,APIC] Enable the local APIC even if BIOS
+ 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
+ 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>
-
- 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.
+ libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
+ when set.
+ Format: <int>
load_ramdisk= [RAM] List of ramdisks to load from floppy
See Documentation/ramdisk.txt.
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
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.
+ 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=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
equal to this physical address is ignored.
[SCSI] Maximum number of LUNs received.
Should be between 1 and 16384.
- mca-pentium [BUGS=IA-32]
+ mca-pentium [BUGS=X86-32]
mcatest= [IA-64]
- mcd= [HW,CD]
- Format: <port>,<irq>,<mitsumi_bug_93_wait>
-
- mcdx= [HW,CD]
+ mce [X86-32] Machine Check Exception
- mce [IA-32] Machine Check Exception
+ mce=option [X86-64] See Documentation/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
+ 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
meye.*= [HW] Set MotionEye Camera parameters
See Documentation/video4linux/meye.txt.
- mga= [HW,DRM]
+ mfgpt_irq= [IA-32] Specify the IRQ to use for the
+ Multi-Function General Purpose Timers on AMD Geode
+ platforms.
- 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.
+ mga= [HW,DRM]
mousedev.tap_time=
[MOUSE] Maximum time between finger touching and
<name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
mtdparts= [MTD]
- See drivers/mtd/cmdline.c.
+ See drivers/mtd/cmdlinepart.c.
mtouchusb.raw_coordinates=
[HW] Make the MicroTouch USB driver use raw coordinates
[NFS] set the maximum lifetime for idmapper cache
entries.
- nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels
+ 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.
- no387 [BUGS=IA-32] Tells the kernel to use the 387 maths
+ nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels
+
+ 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.
noexec [IA-64]
- noexec [IA-32,X86-64]
+ noexec [X86-32,X86-64]
noexec=on: enable non-executable mappings (default)
noexec=off: disable nn-executable mappings
- 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]
- no-hlt [BUGS=IA-32] Tells the kernel that the hlt
+ no-hlt [BUGS=X86-32] Tells the kernel that the hlt
instruction doesn't work correctly and not to
use it.
Valid arguments: on, off
Default: on
- noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing
+ noirqbalance [X86-32,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.
nointroute [IA-64]
- nolapic [IA-32,APIC] Do not enable or use the local APIC.
+ nojitter [IA64] Disables jitter checking for ITC timers.
- nolapic_timer [IA-32,APIC] Do not use the local APIC timer.
+ nolapic [X86-32,APIC] Do not enable or use the local APIC.
+
+ nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
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
+
+ nomfgpt [X86-32] Disable Multi-Function General Purpose
+ Timer usage (for AMD Geode machines).
- noreplace-paravirt [IA-32,PV_OPS] Don't patch paravirt_ops
+ noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
- noreplace-smp [IA-32,SMP] Don't replace SMP instructions
+ 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.
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]
+ 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.
+ See Documentation/sysctl/vm.txt for details.
+
nr_uarts= [SERIAL] maximum number of UARTs to be registered.
opl3= [HW,OSS]
Format: <io>
- opl3sa2= [HW,OSS] Format:
- <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
-
oprofile.timer= [HW]
Use timer interrupt instead of performance counters
- optcd= [HW,CD]
- Format: <io>
-
osst= [HW,SCSI] SCSI Tape Driver
Format: <buffer_size>,<write_threshold>
See also Documentation/scsi/st.txt.
See also Documentation/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 [X86-32] 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 [X86-32] Force use of PCI Configuration
Mechanism 1.
- conf2 [IA-32] Force use of PCI Configuration
+ conf2 [X86-32] 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
+ nosort [X86-32] 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
+ 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 [X86-32] 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
+ irqmask=0xMMMM [X86-32] 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 [X86-32] 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 [X86-32] 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 [X86-32] Always assign all PCI bus
numbers ourselves, overriding
whatever the firmware may have done.
- usepirqmask [IA-32] Honor the possible IRQ mask stored
+ usepirqmask [X86-32] 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 [X86-32] Do not use ACPI for IRQ routing
or for PCI scanning.
+ use_crs [X86-32] 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
autoconfiguration.
Ranges are in pairs (memory base and size).
+ print-fatal-signals=
+ [KNL] debug: print fatal signals
+ print-fatal-signals=1: print segfault info to
+ the kernel console.
+ default: off.
+
+ printk.time= Show timing data prefixed to each printk message line
+ Format: <bool> (1/Y/y=enable, 0/N/n=disable)
+
profile= [KNL] Enable kernel profiling via /proc/profile
Format: [schedule,]<number>
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
pt. [PARIDE]
See Documentation/paride.txt.
+ pty.legacy_count=
+ [KNL] Number of legacy pty's. Overwrites compiled-in
+ default number.
+
quiet [KNL] Disable most log messages
r128= [HW,DRM]
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.
ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
- New name for the ramdisk parameter.
See Documentation/ramdisk.txt.
rcu.blimit= [KNL,BOOT] Set maximum number of finished
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
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.
rootfstype= [KNL] Set root filesystem type
+ rootwait [KNL] Wait (indefinitely) for root device to show up.
+ 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
- sbpcd= [HW,CD] Soundblaster CD adapter
- Format: <io>,<type>
- See a comment before function sbpcd_setup() in
- drivers/cdrom/sbpcd.c.
-
sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
Format: <io>[,<timeout>[,<isapnp>]]
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.
simeth= [IA-64]
simscsi=
- sjcd= [HW,CD]
- Format: <io>,<irq>,<dma>
- See header of drivers/cdrom/sjcd.c.
-
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_debug[=options[,slabs]] [MM, SLUB]
+ Enabling slub_debug allows one to determine the
+ culprit if slab objects become corrupted. Enabling
+ slub_debug can create guard zones around objects and
+ may poison 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.
+ Determines the maximum allowed order for slabs.
+ A high setting may cause OOMs due to memory
+ 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.
+ The minimum number of objects per slab. SLUB will
+ increase the slab order up to slub_max_order to
+ generate a sufficiently large slab able to contain
+ the number of objects indicated. The higher the number
+ of objects the smaller the overhead of tracking slabs
+ and the less frequently locks need to be acquired.
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
+ 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
+ Disable merging of slabs with similar size. May be
necessary if there is some reason to distinguish
- allocs to different slabs.
+ allocs to different slabs. Debug options disable
+ merging on their own.
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
+ 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]
- sonycd535= [HW,CD]
- Format: <io>[,<irq>]
-
sonypi.*= [HW] Sony Programmable I/O Control Device driver
See Documentation/sonypi.txt
thash_entries= [KNL,NET]
Set number of hash buckets for TCP connection
+ 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>: lower all critical trip points
+
+ thermal.nocrt= [HW,ACPI]
+ Set to disable actions on ACPI thermal zone
+ critical and hot trip points.
+
+ thermal.off= [HW,ACPI]
+ 1: disable ACPI thermal control
+
+ thermal.psv= [HW,ACPI]
+ -1: disable all passive trip points
+ <degrees C>: override all passive trip points to this value
+
+ thermal.tzp= [HW,ACPI]
+ Specify global default ACPI thermal zone polling rate
+ <deci-seconds>: poll all this frequency
+ 0: no polling (default)
+
time Show timing data prefixed to each printk message line
+ [deprecated, see 'printk.time']
tipar.timeout= [HW,PPT]
Set communications timeout in tenths of a second
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.
-
turbografx.map[2|3]= [HW,JOY]
TurboGraFX parallel port interface
Format:
usbhid.mousepoll=
[USBHID] The interval which mice are to be polled at.
- vdso= [IA-32,SH]
+ 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
+ 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
+ vga= [BOOT,X86-32] Select a particular video mode
See Documentation/i386/boot.txt and
Documentation/svga.txt.
Use vga=ask for menu.
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.
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"
-
______________________________________________________________________
TODO: