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.
DRM Direct Rendering Management support is enabled.
EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
EFI EFI Partitioning (GPT) is enabled
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
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]
Override the pmtimer bug detection: force the kernel
to assume that this machine's pmtimer latches its value
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.
autotest [IA64]
- aztcd= [HW,CD] Aztech CD268 CDROM driver
- Format: <io>,0x79 (?)
-
baycom_epp= [HW,AX25]
Format: <io>,<mode>
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.
-
chandev= [HW,NET] Generic channel device initialisation
checkreqprot [SELINUX] Set initial checkreqprot flag value.
clocksource is not available, it defaults to PIT.
Format: { pit | tsc | cyclone | pmtmr }
+ clocksource= [GENERIC_TIME] Override the default clocksource
+ Format: <string>
+ Override the default clocksource and use the clocksource
+ with the name specified.
+ Some clocksource names to choose from, depending on
+ the platform:
+ [all] jiffies (this is the base, fallback clocksource)
+ [ACPI] acpi_pm
+ [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
+ pxa_timer,timer3,32k_counter,timer0_1
+ [AVR32] avr32
+ [IA-32] pit,hpet,tsc,vmi-timer;
+ scx200_hrt on Geode; cyclone on IBM x440
+ [MIPS] MIPS
+ [PARISC] cr16
+ [S390] tod
+ [SH] SuperH
+ [SPARC64] tick
+ [X86-64] hpet,tsc
+
code_bytes [IA32] How many bytes of object code to print in an
oops report.
Range: 0 - 8192
hpet= [IA-32,HPET] option to disable HPET and use PIT.
Format: disable
- cm206= [HW,CD]
- Format: { auto | [<io>,][<irq>] }
-
com20020= [HW,NET] ARCnet - COM20020 chipset
Format:
<io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
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.
+
cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
Format:
<first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
Format: <area>[,<node>]
See also Documentation/networking/decnet.txt.
+ default_blu= [VT]
+ Format: <blue0>,<blue1>,<blue2>,...,<blue15>
+ Change the default blue palette of the console.
+ This is a 16-member array composed of values
+ ranging from 0-255.
+
+ default_grn= [VT]
+ Format: <green0>,<green1>,<green2>,...,<green15>
+ Change the default green palette of the console.
+ This is a 16-member array composed of values
+ ranging from 0-255.
+
+ default_red= [VT]
+ Format: <red0>,<red1>,<red2>,...,<red15>
+ Change the default red palette of the console.
+ This is a 16-member array composed of values
+ ranging from 0-255.
+
+ default_utf8= [VT]
+ Format=<0|1>
+ Set system-wide default UTF-8 mode for all tty's.
+ Default is 0 and by setting to 1, it enables UTF-8
+ mode for all newly opened or allocated terminals.
+
dhash_entries= [KNL]
Set number of hash buckets for dentry cache.
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
inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
Format: <irq>
- combined_mode= [HW] control which driver uses IDE ports in combined
- mode: legacy IDE driver, libata, or both
- (in the libata case, libata.atapi_enabled=1 may be
- useful as well). Note that using the ide or libata
- options may affect your device naming (e.g. by
- changing hdc to sdb).
- Format: combined (default), ide, or libata
-
inttest= [IA64]
io7= [HW] IO7 for Marvel based alpha systems
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,IA-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,IA-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
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.
mcatest= [IA-64]
- mcd= [HW,CD]
- Format: <port>,<irq>,<mitsumi_bug_93_wait>
-
- mcdx= [HW,CD]
-
mce [IA-32] Machine Check Exception
md= [HW] RAID subsystems devices and level
mga= [HW,DRM]
- migration_cost=
- [KNL,SMP] debug: override scheduler migration costs
- Format: <level-1-usecs>,<level-2-usecs>,...
- This debugging option can be used to override the
- default scheduler migration cost matrix. The numbers
- are indexed by 'CPU domain distance'.
- E.g. migration_cost=1000,2000,3000 on an SMT NUMA
- box will set up an intra-core migration cost of
- 1 msec, an inter-core migration cost of 2 msecs,
- and an inter-node migration cost of 3 msecs.
-
- WARNING: using the wrong values here can break
- scheduler performance, so it's only for scheduler
- development purposes, not production environments.
-
- migration_debug=
- [KNL,SMP] migration cost auto-detect verbosity
- Format=<0|1|2>
- If a system's migration matrix reported at bootup
- seems erroneous then this option can be used to
- increase verbosity of the detection process.
- We default to 0 (no extra messages), 1 will print
- some more information, and 2 will be really
- verbose (probably only useful if you also have a
- serial console attached to the system).
-
- migration_factor=
- [KNL,SMP] multiply/divide migration costs by a factor
- Format=<percent>
- This debug option can be used to proportionally
- increase or decrease the auto-detected migration
- costs for all entries of the migration matrix.
- E.g. migration_factor=150 will increase migration
- costs by 50%. (and thus the scheduler will be less
- eager migrating cache-hot tasks)
- migration_factor=80 will decrease migration costs
- by 20%. (thus the scheduler will be more eager to
- migrate tasks)
-
- WARNING: using the wrong values here can break
- scheduler performance, so it's only for scheduler
- development purposes, not production environments.
-
mousedev.tap_time=
[MOUSE] Maximum time between finger touching and
leaving touchpad surface for touch to be considered
when set.
Format: <int>
- noaliencache [MM, NUMA] Disables the allcoation of alien caches in
- the slab allocator. Saves per-node memory, but will
- impact performance on real NUMA hardware.
+ noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
+ caches in the slab allocator. Saves per-node memory,
+ but will impact performance.
noalign [KNL,ARM]
nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
+ nosoftlockup [KNL] Disable the soft-lockup detector.
+
nosync [HW,M68K] Disables sync negotiation for all devices.
notsc [BUGS=IA-32] Disable Time Stamp Counter
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.
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.
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).
+
rw [KNL] Mount root device read-write on boot
S [KNL] Run init in single mode
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>]]
simeth= [IA-64]
simscsi=
- sjcd= [HW,CD]
- Format: <io>,<irq>,<dma>
- See header of drivers/cdrom/sjcd.c.
-
slram= [HW,MTD]
+ 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.
+ 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 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.
+ For more information see Documentation/vm/slub.txt.
+
+ slub_nomerge [MM, SLUB]
+ Disable merging of slabs with similar size. May be
+ necessary if there is some reason to distinguish
+ 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
attempt to substitute SMP alternatives once at boot.
+ smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
+ smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
+ smsc-ircc2.ircc_sir= [HW] SIR base I/O port
+ smsc-ircc2.ircc_fir= [HW] FIR base I/O port
+ smsc-ircc2.ircc_irq= [HW] IRQ line
+ smsc-ircc2.ircc_dma= [HW] DMA channel
+ smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
+ 0: Toshiba Satellite 1800 (GP data pin select)
+ 1: Fast pin select (default)
+ 2: ATC IRMode
+
snd-ad1816a= [HW,ALSA]
snd-ad1848= [HW,ALSA]
snd-ymfpci= [HW,ALSA]
- sonycd535= [HW,CD]
- Format: <io>[,<irq>]
-
sonypi.*= [HW] Sony Programmable I/O Control Device driver
See Documentation/sonypi.txt
Set number of hash buckets for TCP connection
time Show timing data prefixed to each printk message line
-
- clocksource= [GENERIC_TIME] Override the default clocksource
- Override the default clocksource and use the clocksource
- with the name specified.
+ [deprecated, see 'printk.time']
tipar.timeout= [HW,PPT]
Set communications timeout in tenths of a second