AX25 Appropriate AX.25 support is enabled.
BLACKFIN Blackfin architecture is enabled.
DRM Direct Rendering Management support is enabled.
+ DYNAMIC_DEBUG Build in debug messages and enable them at runtime
EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
EFI EFI Partitioning (GPT) is enabled
EIDE EIDE/ATAPI support is enabled.
IMA Integrity measurement architecture is enabled.
IOSCHED More than one I/O scheduler is enabled.
IP_PNP IP DHCP, BOOTP, or RARP is enabled.
+ IPV6 IPv6 support is enabled.
ISAPNP ISA PnP code is enabled.
ISDN Appropriate ISDN support is enabled.
JOY Appropriate joystick support is enabled.
+ KGDB Kernel debugger support is enabled.
KVM Kernel Virtual Machine support is enabled.
LIBATA Libata driver is enabled
LP Printer 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 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/.
+ A lot of drivers have their options described inside
+ the Documentation/scsi/ sub-directory.
SECURITY Different security models are enabled.
SELINUX SELinux support is enabled.
+ APPARMOR AppArmor support is enabled.
SERIAL Serial support is enabled.
SH SuperH architecture is enabled.
SMP The kernel is an SMP kernel.
SWSUSP Software suspend (hibernation) is enabled.
SUSPEND System suspend states are enabled.
FTRACE Function tracing enabled.
+ TPM TPM drivers are enabled.
TS Appropriate touchscreen support is enabled.
UMS USB Mass Storage support is enabled.
USB USB support is enabled.
More X86-64 boot options can be found in
Documentation/x86/x86_64/boot-options.txt .
X86 Either 32bit or 64bit x86 (same as X86-32+X86-64)
+ XEN Xen support is enabled
In addition, the following text indicates that the option:
and is between 256 and 4096 characters. It is defined in the file
./include/asm/setup.h as COMMAND_LINE_SIZE.
+Finally, the [KMG] suffix is commonly described after a number of kernel
+parameter values. These 'K', 'M', and 'G' letters represent the _binary_
+multipliers 'Kilo', 'Mega', and 'Giga', equalling 2^10, 2^20, and 2^30
+bytes respectively. Such letter suffixes can also be entirely omitted.
+
acpi= [HW,ACPI,X86]
Advanced Configuration and Power Interface
- Format: { force | off | ht | strict | noirq | rsdt }
+ Format: { force | off | 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
+ copy_dsdt -- copy DSDT to memory
See also Documentation/power/pm.txt, pci=noacpi
unusable. The "log_buf_len" parameter may be useful
if you need to capture more output.
- acpi_display_output= [HW,ACPI]
- acpi_display_output=vendor
- acpi_display_output=video
- See above.
-
acpi_irq_balance [HW,ACPI]
ACPI will balance active IRQs
default in APIC mode
acpi_sleep= [HW,ACPI] Sleep options
Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
- old_ordering, s4_nonvs, sci_force_enable }
+ old_ordering, nonvs, sci_force_enable }
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
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.
+ nonvs prevents the kernel from saving/restoring the
+ ACPI NVS memory during suspend/hibernation and resume.
sci_force_enable causes the kernel to set SCI_EN directly
on resume from S1/S3 (which is against the ACPI spec,
but some broken systems don't work without it).
no: ACPI OperationRegions are not marked as reserved,
no further checks are performed.
- ad1848= [HW,OSS]
- Format: <io>,<irq>,<dma>,<dma2>,<type>
-
add_efi_memmap [EFI; X86] Include EFI memory map in
kernel's map of available physical RAM.
- advansys= [HW,SCSI]
- See header of drivers/scsi/advansys.c.
-
- advwdt= [HW,WDT] Advantech WDT
- Format: <iostart>,<iostop>
-
- aedsp16= [HW,OSS] Audio Excel DSP 16
- Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
- See also header of sound/oss/aedsp16.c.
-
agp= [AGP]
{ off | try_unsupported }
off: disable AGP support
try_unsupported: try to drive unsupported chipsets
(may crash computer or cause data corruption)
- aha152x= [HW,SCSI]
- See Documentation/scsi/aha152x.txt.
+ ALSA [HW,ALSA]
+ See Documentation/sound/alsa/alsa-parameters.txt
- aha1542= [HW,SCSI]
- Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
-
- aic7xxx= [HW,SCSI]
- See Documentation/scsi/aic7xxx.txt.
-
- aic79xx= [HW,SCSI]
- See Documentation/scsi/aic79xx.txt.
+ alignment= [KNL,ARM]
+ Allow the default userspace alignment fault handler
+ behaviour to be specified. Bit 0 enables warnings,
+ bit 1 enables fixups, and bit 2 sends a segfault.
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
+ off - do not initialize any AMD IOMMU found in
+ the system
amijoy.map= [HW,JOY] Amiga joystick support
Map of devices attached to JOY0DAT and JOY1DAT
Change the amount of debugging information output
when initialising the APIC and IO-APIC components.
+ autoconf= [IPV6]
+ See Documentation/networking/ipv6.txt.
+
+ show_lapic= [APIC,X86] Advanced Programmable Interrupt Controller
+ Limit apic dumping. The parameter defines the maximal
+ number of local apics being dumped. Also it is possible
+ to set it to "all" by meaning -- no limit here.
+ Format: { 1 (default) | 2 | ... | all }.
+ The parameter valid if only apic=debug or
+ apic=verbose is specified.
+ Example: apic=debug show_lapic=all
+
apm= [APM] Advanced Power Management
See header of arch/x86/kernel/apm_32.c.
atarimouse= [HW,MOUSE] Atari Mouse
- atascsi= [HW,SCSI] Atari SCSI
-
atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
EzKey and similar keyboards
bttv.pll= See Documentation/video4linux/bttv/Insmod-options
bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
- BusLogic= [HW,SCSI]
- See drivers/scsi/BusLogic.c, comment before function
- BusLogic_ParseDriverOptions().
+ bulk_remove=off [PPC] This parameter disables the use of the pSeries
+ firmware feature for flushing multiple hpte entries
+ at a time.
c101= [NET] Moxa C101 synchronous serial card
clocksource is not available, it defaults to PIT.
Format: { pit | tsc | cyclone | pmtmr }
- clocksource= [GENERIC_TIME] Override the default clocksource
+ clocksource= Override the default clocksource
Format: <string>
Override the default clocksource and use the clocksource
with the name specified.
[ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
pxa_timer,timer3,32k_counter,timer0_1
[AVR32] avr32
- [X86-32] pit,hpet,tsc,vmi-timer;
+ [X86-32] pit,hpet,tsc;
scx200_hrt on Geode; cyclone on IBM x440
[MIPS] MIPS
[PARISC] cr16
Format:
<first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
- crashkernel=nn[KMG]@ss[KMG]
- [KNL] Reserve a chunk of physical memory to
- hold a kernel to switch to with kexec on panic.
+ crashkernel=size[KMG][@offset[KMG]]
+ [KNL] Using kexec, Linux can switch to a 'crash kernel'
+ upon panic. This parameter reserves the physical
+ memory region [offset, offset + size] for that kernel
+ image. If '@offset' is omitted, then a suitable offset
+ is selected automatically. Check
+ Documentation/kdump/kdump.txt for further details.
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.
+ Documentation/kdump/kdump.txt for an example.
cs89x0_dma= [HW,NET]
Format: <dma>
Format: <port#>,<type>
See also Documentation/input/joystick-parport.txt
+ ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot
+ time. See Documentation/dynamic-debug-howto.txt for
+ details.
+
debug [KNL] Enable kernel debugging (events log level).
debug_locks_verbose=
See drivers/char/README.epca and
Documentation/serial/digiepca.txt.
+ disable= [IPV6]
+ See Documentation/networking/ipv6.txt.
+
+ disable_ddw [PPC/PSERIES]
+ Disable Dynamic DMA Window support. Use this if
+ to workaround buggy firmware.
+
+ disable_ipv6= [IPV6]
+ See Documentation/networking/ipv6.txt.
+
disable_mtrr_cleanup [X86]
The kernel tries to adjust MTRR layout from continuous
to discrete, to make X server driver able to add WB
Disable PIN 1 of APIC timer
Can be useful to work around chipset bugs.
- dmasound= [HW,OSS] Sound subsystem buffers
-
dma_debug=off If the kernel is compiled with DMA_API_DEBUG support,
this option disables the debugging code at boot.
dscc4.setup= [NET]
- dtc3181e= [HW,SCSI]
-
- 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
-
earlycon= [KNL] Output early console device and options.
uart[8250],io,<addr>[,options]
uart[8250],mmio,<addr>[,options]
+ uart[8250],mmio32,<addr>[,options]
Start an early, polled-mode console on the 8250/16550
UART at the specified I/O port or MMIO address.
+ MMIO inter-register address stride is either 8bit (mmio)
+ or 32bit (mmio32).
The options are the same as for ttyS, above.
earlyprintk= [X86,SH,BLACKFIN]
The VGA output is eventually overwritten by the real
console.
- eata= [HW,SCSI]
+ ekgdboc= [X86,KGDB] Allow early kernel console debugging
+ ekgdboc=kbd
+
+ This is designed to be used in conjunction with
+ the boot argument: earlyprintk=vga
edd= [EDD]
Format: {"off" | "on" | "skip[mbr]"}
arch/x86/kernel/cpu/cpufreq/elanfreq.c.
elevator= [IOSCHED]
- Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
+ Format: {"cfq" | "deadline" | "noop"}
See Documentation/block/as-iosched.txt and
Documentation/block/deadline-iosched.txt for details.
Default value is 0.
Value can be changed at runtime via /selinux/enforce.
+ erst_disable [ACPI]
+ Disable Error Record Serialization Table (ERST)
+ support.
+
ether= [HW,NET] Ethernet cards parameters
This option is obsoleted by the "netdev=" option, which
has equivalent usage. See its documentation for details.
- eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
- Format: <io>[,<irq>]
-
failslab=
fail_page_alloc=
fail_make_request=[KNL]
Format: <interval>,<probability>,<space>,<times>
See also /Documentation/fault-injection/.
- fd_mcs= [HW,SCSI]
- See header of drivers/scsi/fd_mcs.c.
-
- fdomain= [HW,SCSI]
- See header of drivers/scsi/fdomain.c.
-
floppy= [HW]
See Documentation/blockdev/floppy.txt.
as early as possible in order to facilitate early
boot debugging.
- ftrace_dump_on_oops
+ ftrace_dump_on_oops[=orig_cpu]
[FTRACE] will dump the trace buffers on oops.
+ If no parameter is passed, ftrace will dump
+ buffers of all CPUs, but if you pass orig_cpu, it will
+ dump only the buffer of the CPU that triggered the
+ oops.
ftrace_filter=[function-list]
[FTRACE] Limit the functions traced by the function
by the set_ftrace_notrace file in the debugfs
tracing directory.
+ ftrace_graph_filter=[function-list]
+ [FTRACE] Limit the top level callers functions traced
+ by the function graph tracer at boot up.
+ function-list is a comma separated list of functions
+ that can be changed at run time by the
+ set_graph_function file in the debugfs tracing directory.
+
gamecon.map[2|3]=
[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
support via parallel port (up to 5 devices per port)
When zero, profiling data is discarded and associated
debugfs files are removed at module unload time.
- gdth= [HW,SCSI]
- See header of drivers/scsi/gdth.c.
-
gpt [EFI] Forces disk with valid GPT signature but
invalid Protective MBR to be treated as GPT.
- gvp11= [HW,SCSI]
-
hashdist= [KNL,NUMA] Large hashes allocated during boot
are distributed across NUMA nodes. Defaults on
for 64bit NUMA, off otherwise.
hd= [EIDE] (E)IDE hard drive subsystem geometry
Format: <cyl>,<head>,<sect>
+ hest_disable [ACPI]
+ Disable Hardware Error Source Table (HEST) support;
+ corresponding firmware-first mode error processing
+ logic will be disabled.
+
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
If specified, z/VM IUCV HVC accepts connections
from listed z/VM user IDs only.
+ keep_bootcon [KNL]
+ Do not unregister boot console at start. This is only
+ useful for debugging when something happens in the window
+ between unregistering the boot console and initializing
+ the real console.
+
i2c_bus= [HW] Override the default board specific I2C bus speed
or register an additional I2C bus that is not
registered from board initialization code.
controller
i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
controllers
- i8042.panicblink=
- [HW] Frequency with which keyboard LEDs should blink
- when kernel panics (default is 0.5 sec)
i8042.notimeout [HW] Ignore timeout condition signalled by conroller
i8042.reset [HW] Reset the controller during init and cleanup
i8042.unlock [HW] Unlock (ignore) the keylock
i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
capability is set.
- ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
- See Documentation/mca.txt.
-
icn= [HW,ISDN]
Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
programs exec'd, files mmap'd for exec, and all files
opened for read by uid=0.
- in2000= [HW,SCSI]
- See header of drivers/scsi/in2000.c.
-
init= [KNL]
Format: <full_path>
Run specified binary instead of /sbin/init as init
With this option on every unmap_single operation will
result in a hardware IOTLB flush operation as opposed
to batching them for performance.
+ sp_off [Default Off]
+ By default, super page will be supported if Intel IOMMU
+ has the capability. With this option, super page will
+ not be supported.
+ intremap= [X86-64, Intel-IOMMU]
+ Format: { on (default) | off | nosid }
+ on enable Interrupt Remapping (default)
+ off disable Interrupt Remapping
+ nosid disable Source ID checking
inttest= [IA64]
No delay
ip= [IP_PNP]
- See Documentation/filesystems/nfsroot.txt.
+ See Documentation/filesystems/nfs/nfsroot.txt.
ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
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.
-
irqfixup [HW]
When an interrupt is not handled search all handlers
for it. Intended to get systems with badly broken
use the HighMem zone if it exists, and the Normal
zone if it does not.
- kgdboc= [HW] kgdb over consoles.
- Requires a tty driver that supports console polling.
- (only serial supported for now)
- Format: <serial_device>[,baud]
+ kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port.
+ Format: <Controller#>[,poll interval]
+ The controller # is the number of the ehci usb debug
+ port as it is probed via PCI. The poll interval is
+ optional and is the number seconds in between
+ each poll cycle to the debug port in case you need
+ the functionality for interrupting the kernel with
+ gdb or control-c on the dbgp connection. When
+ not using this parameter you use sysrq-g to break into
+ the kernel debugger.
+
+ kgdboc= [KGDB,HW] kgdb over consoles.
+ Requires a tty driver that supports console polling,
+ or a supported polling keyboard driver (non-usb).
+ Serial only format: <serial_device>[,baud]
+ keyboard only format: kbd
+ keyboard and serial format: kbd,<serial_device>[,baud]
+ Optional Kernel mode setting:
+ kms, kbd format: kms,kbd
+ kms, kbd and serial format: kms,kbd,<ser_dev>[,baud]
+
+ kgdbwait [KGDB] Stop kernel execution and enter the
+ kernel debugger at the earliest opportunity.
kmac= [MIPS] korina ethernet MAC address.
Configure the RouterBoard 532 series on-chip
kvm.oos_shadow= [KVM] Disable out-of-sync shadow paging.
Default is 1 (enabled)
- kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM.
+ kvm.mmu_audit= [KVM] This is a R/W parameter which allows audit
+ KVM MMU at runtime.
Default is 0 (off)
+ kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM.
+ Default is 1 (enabled)
+
kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
for all guests.
Default is 1 (enabled) if in 64bit or 32bit-PAE mode
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
+ 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
* nohrst, nosrst, norst: suppress hard, soft
and both resets.
+ * dump_id: dump IDENTIFY data.
+
If there are multiple matching configurations changing
the same attribute, the last one is used.
- lmb=debug [KNL] Enable lmb debug messages.
+ memblock=debug [KNL] Enable memblock debug messages.
load_ramdisk= [RAM] List of ramdisks to load from floppy
See Documentation/blockdev/ramdisk.txt.
6 (KERN_INFO) informational
7 (KERN_DEBUG) debug-level messages
- log_buf_len=n Sets the size of the printk ring buffer, in bytes.
- Format: { n | nk | nM }
- n must be a power of two. The default size
- is set in the kernel config file.
+ log_buf_len=n[KMG] Sets the size of the printk ring buffer,
+ in bytes. 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
ltpc= [NET]
Format: <io>,<irq>,<dma>
- mac5380= [HW,SCSI] Format:
- <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
be mounted
Format: <1-256>
- max_luns= [SCSI] Maximum number of LUNs to probe.
- Should be between 1 and 2^32-1.
-
- max_report_luns=
- [SCSI] Maximum number of LUNs received.
- Should be between 1 and 16384.
-
mcatest= [IA-64]
mce [X86-32] Machine Check Exception
that the amount of memory usable for all allocations
is not too small.
- mpu401= [HW,OSS]
- Format: <io>,<irq>
-
MTD_Partition= [MTD]
Format: <name>,<region-number>,<size>,<offset>
mtdparts= [MTD]
See drivers/mtd/cmdlinepart.c.
+ multitce=off [PPC] This parameter disables the use of the pSeries
+ firmware feature for updating multiple TCE entries
+ at a time.
+
onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
Format: [die0_boundary][,die0_lock][,die1_boundary][,die1_lock]
n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
- NCR_D700= [HW,SCSI]
- See header of drivers/scsi/NCR_D700.c.
-
- ncr5380= [HW,SCSI]
-
- ncr53c400= [HW,SCSI]
-
- ncr53c400a= [HW,SCSI]
-
- ncr53c406a= [HW,SCSI]
-
- ncr53c8xx= [HW,SCSI]
-
netdev= [NET] Network devices parameters
Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
Note that mem_start is often overloaded to mean
[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.
+ Default value is 0.
- nfsaddrs= [NFS]
- See Documentation/filesystems/nfsroot.txt.
+ nfsaddrs= [NFS] Deprecated. Use ip= instead.
+ See Documentation/filesystems/nfs/nfsroot.txt.
nfsroot= [NFS] nfs root filesystem for disk-less boxes.
- See Documentation/filesystems/nfsroot.txt.
+ See Documentation/filesystems/nfs/nfsroot.txt.
+
+ nfsrootdebug [NFS] enable nfsroot debugging messages.
+ See Documentation/filesystems/nfs/nfsroot.txt.
nfs.callback_tcpport=
[NFS] set the TCP port on which the NFSv4 callback
of returning the full 64-bit number.
The default is to return 64-bit inode numbers.
+ nfs.nfs4_disable_idmapping=
+ [NFSv4] When set, this option disables the NFSv4
+ idmapper on the client, but only if the mount
+ is using the 'sec=sys' security flavour. This may
+ make migration from legacy NFSv2/v3 systems easier
+ provided that the server has the appropriate support.
+ The default is to always enable NFSv4 idmapping.
+
nmi_debug= [KNL,AVR32,SH] Specify one or more actions to take
when a NMI is triggered.
Format: [state][,regs][,debounce][,die]
nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels
- Format: [panic,][num]
- Valid num: 0,1,2
+ Format: [panic,][nopanic,][num]
+ Valid num: 0
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.
+ timeout occurs (or 'nopanic' to override the opposite
+ default).
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
netpoll.carrier_timeout=
[NET] Specifies amount of time (in seconds) that
noapic [SMP,APIC] Tells the kernel to not make use of any
IOAPICs that may be present in the system.
+ noautogroup Disable scheduler automatic task group creation.
+
nobats [PPC] Do not use BATs for mapping kernel lowmem
on "Classic" PPC cores.
noexec=on: enable non-executable mappings (default)
noexec=off: disable non-executable mappings
+ nosmep [X86]
+ Disable SMEP (Supervisor Mode Execution Protection)
+ even if it is supported by processor.
+
noexec32 [X86-64]
This affects only 32-bit executables.
noexec32=on: enable non-executable mappings (default)
nointremap [X86-64, Intel-IOMMU] Do not enable interrupt
remapping.
+ [Deprecated - use intremap=off]
nointroute [IA-64]
nojitter [IA64] Disables jitter checking for ITC timers.
+ no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
+
+ no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page
+ fault handling.
+
nolapic [X86-32,APIC] Do not enable or use the local APIC.
nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
nomfgpt [X86-32] Disable Multi-Function General Purpose
Timer usage (for AMD Geode machines).
+ nopat [X86] Disable PAT (page attribute table extension of
+ pagetables) support.
+
norandmaps Don't use address space randomization. Equivalent to
echo 0 > /proc/sys/kernel/randomize_va_space
- noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
+ noreplace-paravirt [X86,IA-64,PV_OPS] Don't patch paravirt_ops
noreplace-smp [X86-32,SMP] Don't replace SMP instructions
with UP alternatives
nosoftlockup [KNL] Disable the soft-lockup detector.
- noswapaccount [KNL] Disable accounting of swap in memory resource
- controller. (See Documentation/cgroups/memory.txt)
-
nosync [HW,M68K] Disables sync negotiation for all devices.
notsc [BUGS=X86-32] Disable Time Stamp Counter
nousb [USB] Disable the USB subsystem
+ nowatchdog [KNL] Disable the lockup detector (NMI watchdog).
+
nowb [ARM]
nox2apic [X86-64,APIC] Do not enable x2APIC mode.
purges which is reported from either PAL_VM_SUMMARY or
SAL PALO.
+ nr_cpus= [SMP] Maximum number of processors that an SMP kernel
+ could support. nr_cpus=n : n >= 1 limits the kernel to
+ supporting 'n' processors. Later in runtime you can not
+ use hotplug cpu feature to put more cpu back to online.
+ just like you compile the kernel NR_CPUS=n
+
nr_uarts= [SERIAL] maximum number of UARTs to be registered.
numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
waiting for the ACK, so if this is set too high
interrupts *may* be lost!
- opl3= [HW,OSS]
- Format: <io>
+ omap_mux= [OMAP] Override bootloader pin multiplexing.
+ Format: <mux_mode0.mode_name=value>...
+ For example, to override I2C bus2:
+ omap_mux=i2c2_scl.i2c2_scl=0x100,i2c2_sda.i2c2_sda=0x100
oprofile.timer= [HW]
Use timer interrupt instead of performance counters
perfmon on Intel CPUs instead of the
CPU specific event set.
- osst= [HW,SCSI] SCSI Tape Driver
- Format: <buffer_size>,<write_threshold>
- See also Documentation/scsi/st.txt.
+ oops=panic Always panic on oopses. Default is to just kill the
+ process, but there is a small probability of
+ deadlocking the machine.
+ This will also cause panics on machine check exceptions.
+ Useful together with panic=30 to trigger a reboot.
- panic= [KNL] Kernel behaviour on panic
+ OSS [HW,OSS]
+ See Documentation/sound/oss/oss-parameters.txt
+
+ panic= [KNL] Kernel behaviour on panic: delay <timeout>
+ seconds before rebooting
Format: <timeout>
parkbd.port= [HW] Parallel port number the keyboard adapter is
Currently this function knows 686a and 8231 chips.
Format: [spp|ps2|epp|ecp|ecpepp]
- pas2= [HW,OSS] Format:
- <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
-
- pas16= [HW,SCSI]
- See header of drivers/scsi/pas16.c.
-
pause_on_oops=
Halt all CPUs after the first oops has been printed for
the specified number of seconds. This is to be used if
norom [X86] Do not assign address space to
expansion ROMs that do not already have
BIOS assigned address ranges.
+ nobar [X86] Do not assign address space to the
+ BARs that weren't assigned by the BIOS.
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
IRQ routing is enabled.
noacpi [X86] Do not use ACPI for IRQ routing
or for PCI scanning.
- use_crs [X86] Use _CRS for PCI resource
- allocation.
+ use_crs [X86] Use PCI host bridge window information
+ from ACPI. On BIOSes from 2008 or later, this
+ is enabled by default. If you need to use this,
+ please report a bug.
+ nocrs [X86] Ignore PCI host bridge windows from ACPI.
+ If you need to use this, please report a bug.
routeirq Do IRQ routing for all PCI devices.
This is normally done in pci_enable_device(),
so this option is a temporary workaround
the default.
off: Turn ECRC off
on: Turn ECRC on.
+ realloc reallocate PCI resources if allocations done by BIOS
+ are erroneous.
pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
Management.
force Enable ASPM even on devices that claim not to support it.
WARNING: Forcing ASPM on may cause system lockups.
+ pcie_ports= [PCIE] PCIe ports handling:
+ auto Ask the BIOS whether or not to use native PCIe services
+ associated with PCIe ports (PME, hot-plug, AER). Use
+ them only if that is allowed by the BIOS.
+ native Use native PCIe services associated with PCIe ports
+ unconditionally.
+ compat Treat PCIe ports as PCI-to-PCI bridges, disable the PCIe
+ ports driver.
+
+ pcie_pme= [PCIE,PM] Native PCIe PME signaling options:
+ nomsi Do not use MSI for native PCIe PME signaling (this makes
+ all PCIe root ports use INTx for all services).
+
pcmv= [HW,PCMCIA] BadgePAD 4
pd. [PARIDE]
print-fatal-signals=
[KNL] debug: print fatal signals
- print-fatal-signals=1: print segfault info to
- the kernel console.
+
+ If enabled, warn about various signal handling
+ related application anomalies: too many signals,
+ too many POSIX.1 timers, fatal signals causing a
+ coredump - etc.
+
+ If you hit the warning due to signal overflow,
+ you might want to try "ulimit -i unlimited".
+
default: off.
printk.time= Show timing data prefixed to each printk message line
[HW,MOUSE] Controls Logitech smartscroll autorepeat.
0 = disabled, 1 = enabled (default).
- pss= [HW,OSS] Personal Sound System (ECHO ESC614)
- Format:
- <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
-
pt. [PARIDE]
See Documentation/blockdev/paride.txt.
Reserves a hole at the top of the kernel virtual
address space.
+ reservelow= [X86]
+ Format: nn[K]
+ Set the amount of memory to reserve for BIOS at
+ the bottom of the address space.
+
reset_devices [KNL] Force drivers to reset the underlying device
during initialization.
in <PAGE_SIZE> units (needed only for swap files).
See Documentation/power/swsusp-and-swap-files.txt
+ hibernate= [HIBERNATION]
+ noresume Don't check if there's a hibernation image
+ present during boot.
+ nocompress Don't compress/decompress hibernation images.
+
retain_initrd [RAM] Keep initrd memory after extraction
rhash_entries= [KNL,NET]
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
sbni= [NET] Granch SBNI12 leased line adapter
- sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
- Format: <io>[,<timeout>[,<isapnp>]]
-
- scsi_debug_*= [SCSI]
- See drivers/scsi/scsi_debug.c.
-
- scsi_default_dev_flags=
- [SCSI] SCSI default device flags
- Format: <integer>
-
- scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
- Format: <vendor>:<model>:<flags>
- (flags are integer value)
-
- 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,
- allowing boot to proceed. none ignores them, expecting
- user space to do the scan.
+ sched_debug [KNL] Enables verbose scheduler debug messages.
security= [SECURITY] Choose a security module to enable at boot.
If this boot parameter is not specified, only the first
If enabled at boot time, /selinux/disable can be used
later to disable prior to initial policy load.
+ apparmor= [APPARMOR] Disable or enable AppArmor at boot time
+ Format: { "0" | "1" }
+ See security/apparmor/Kconfig help text
+ 0 -- disable.
+ 1 -- enable.
+ Default value is set via kernel config option.
+
serialnumber [BUGS=X86-32]
shapers= [NET]
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.
-
simeth= [IA-64]
simscsi=
1: Fast pin select (default)
2: ATC IRMode
- snd-ad1816a= [HW,ALSA]
-
- snd-ad1848= [HW,ALSA]
-
- snd-ali5451= [HW,ALSA]
-
- snd-als100= [HW,ALSA]
-
- snd-als4000= [HW,ALSA]
-
- snd-azt2320= [HW,ALSA]
-
- snd-cmi8330= [HW,ALSA]
-
- snd-cmipci= [HW,ALSA]
-
- snd-cs4231= [HW,ALSA]
-
- snd-cs4232= [HW,ALSA]
-
- snd-cs4236= [HW,ALSA]
-
- snd-cs4281= [HW,ALSA]
-
- snd-cs46xx= [HW,ALSA]
-
- snd-dt019x= [HW,ALSA]
-
- snd-dummy= [HW,ALSA]
-
- snd-emu10k1= [HW,ALSA]
-
- snd-ens1370= [HW,ALSA]
-
- snd-ens1371= [HW,ALSA]
-
- snd-es968= [HW,ALSA]
-
- snd-es1688= [HW,ALSA]
-
- snd-es18xx= [HW,ALSA]
-
- snd-es1938= [HW,ALSA]
-
- snd-es1968= [HW,ALSA]
-
- snd-fm801= [HW,ALSA]
-
- snd-gusclassic= [HW,ALSA]
-
- snd-gusextreme= [HW,ALSA]
-
- snd-gusmax= [HW,ALSA]
-
- snd-hdsp= [HW,ALSA]
-
- snd-ice1712= [HW,ALSA]
-
- snd-intel8x0= [HW,ALSA]
-
- snd-interwave= [HW,ALSA]
-
- snd-interwave-stb=
- [HW,ALSA]
-
- snd-korg1212= [HW,ALSA]
-
- snd-maestro3= [HW,ALSA]
-
- snd-mpu401= [HW,ALSA]
-
- snd-mtpav= [HW,ALSA]
-
- snd-nm256= [HW,ALSA]
-
- snd-opl3sa2= [HW,ALSA]
-
- snd-opti92x-ad1848=
- [HW,ALSA]
-
- snd-opti92x-cs4231=
- [HW,ALSA]
-
- snd-opti93x= [HW,ALSA]
-
- snd-pmac= [HW,ALSA]
-
- snd-rme32= [HW,ALSA]
-
- snd-rme96= [HW,ALSA]
-
- snd-rme9652= [HW,ALSA]
-
- snd-sb8= [HW,ALSA]
-
- snd-sb16= [HW,ALSA]
-
- snd-sbawe= [HW,ALSA]
-
- snd-serial= [HW,ALSA]
-
- snd-sgalaxy= [HW,ALSA]
-
- snd-sonicvibes= [HW,ALSA]
-
- snd-sun-amd7930=
- [HW,ALSA]
-
- snd-sun-cs4231= [HW,ALSA]
-
- snd-trident= [HW,ALSA]
-
- snd-usb-audio= [HW,ALSA,USB]
-
- snd-via82xx= [HW,ALSA]
-
- snd-virmidi= [HW,ALSA]
-
- snd-wavefront= [HW,ALSA]
-
- snd-ymfpci= [HW,ALSA]
-
softlockup_panic=
[KNL] Should the soft-lockup detector generate panics.
+ Format: <integer>
sonypi.*= [HW] Sony Programmable I/O Control Device driver
See Documentation/sonypi.txt
spia_pedr=
spia_peddr=
- sscape= [HW,OSS]
- Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
-
- st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
- See Documentation/scsi/st.txt.
-
stacktrace [FTRACE]
Enabled the stack tracer on boot up.
improve throughput, but will also increase the
amount of memory reserved for use by the client.
+ swapaccount[=0|1]
+ [KNL] Enable accounting of swap in memory resource
+ controller if no parameter or 1 is given or disable
+ it if 0 is given (See Documentation/cgroups/memory.txt)
+
swiotlb= [IA-64] Number of I/O TLB slabs
switches= [HW,M68k]
- sym53c416= [HW,SCSI]
- See header of drivers/scsi/sym53c416.c.
+ sysfs.deprecated=0|1 [KNL]
+ Enable/disable old style sysfs layout for old udev
+ on older distributions. When this option is enabled
+ very new udev will not work anymore. When this option
+ is disabled (or CONFIG_SYSFS_DEPRECATED not compiled)
+ in older udev will not work anymore.
+ Default depends on CONFIG_SYSFS_DEPRECATED_V2 set in
+ the kernel configuration.
sysrq_always_enabled
[KNL]
neutralize any effect of /proc/sys/kernel/sysrq.
Useful for debugging.
- t128= [HW,SCSI]
- See header of drivers/scsi/t128.c.
-
tdfx= [HW,DRM]
test_suspend= [SUSPEND]
<deci-seconds>: poll all this frequency
0: no polling (default)
- tmscsim= [HW,SCSI]
- See comment before function dc390_setup() in
- drivers/scsi/tmscsim.c.
+ threadirqs [KNL]
+ Force threading of all interrupt handlers except those
+ marked explicitely IRQF_NO_THREAD.
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
+ topology information if the hardware supports this.
+ The scheduler will make use of this information and
e.g. base its process migration decisions on it.
- Default is off.
+ Default is on.
tp720= [HW,PS2]
+ tpm_suspend_pcr=[HW,TPM]
+ Format: integer pcr id
+ Specify that at suspend time, the tpm driver
+ should extend the specified pcr with zeros,
+ as a workaround for some chips which fail to
+ flush the last written pcr on TPM_SaveState.
+ This will guarantee that all the other pcrs
+ are saved.
+
trace_buf_size=nn[KMG]
[FTRACE] will set tracing buffer size.
to facilitate early boot debugging.
See also Documentation/trace/events.txt
- trix= [HW,OSS] MediaTrix AudioTrix Pro
- Format:
- <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
-
- tsc= Disable clocksource-must-verify flag for TSC.
+ tsc= Disable clocksource stability checks 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.
+ disables clocksource verification at runtime, as well
+ as the stability checks done at bootup. Used to enable
+ high-resolution timer mode on older hardware, and in
+ virtualized environment.
[x86] noirqtime: Do not use TSC to do irq accounting.
Used to run time disable IRQ_TIME_ACCOUNTING on any
platforms where RDTSC is slow and this accounting
<port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
See also Documentation/input/joystick-parport.txt
- u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
- See header of drivers/scsi/u14-34f.c.
-
- uart401= [HW,OSS]
- Format: <io>,<irq>
-
- uart6850= [HW,OSS]
- Format: <io>,<irq>
+ uhash_entries= [KNL,NET]
+ Set number of hash buckets for UDP/UDP-Lite connections
uhci-hcd.ignore_oc=
[USB] Ignore overcurrent events (default N).
reported either.
unknown_nmi_panic
- [X86]
- Set unknown_nmi_panic=1 early on boot.
+ [X86] Cause panic on unknown NMI.
usbcore.autosuspend=
[USB] The autosuspend time delay (in seconds) used
bytes of sense data);
c = FIX_CAPACITY (decrease the reported
device capacity by one sector);
+ d = NO_READ_DISC_INFO (don't use
+ READ_DISC_INFO command);
+ e = NO_READ_CAPACITY_16 (don't use
+ READ_CAPACITY_16 command);
h = CAPACITY_HEURISTICS (decrease the
reported device capacity by one
sector if the number is odd);
unlock ejectable media);
m = MAX_SECTORS_64 (don't transfer more
than 64 sectors = 32 KB at a time);
+ n = INITIAL_READ10 (force a retry of the
+ initial READ(10) command);
o = CAPACITY_OK (accept the capacity
reported by the device);
r = IGNORE_RESIDUE (the device reports
vmpoff= [KNL,S390] Perform z/VM CP command after power off.
Format: <command>
+ vt.cur_default= [VT] Default cursor shape.
+ Format: 0xCCBBAA, where AA, BB, and CC are the same as
+ the parameters of the <Esc>[?A;B;Cc escape sequence;
+ see VGA-softcursor.txt. Default: 2 = underline.
+
vt.default_blu= [VT]
Format: <blue0>,<blue1>,<blue2>,...,<blue15>
Change the default blue palette of the console.
Default is 1, i.e. UTF-8 mode is enabled for all
newly opened terminals.
- waveartist= [HW,OSS]
- Format: <io>,<irq>,<dma>,<dma2>
-
- wd33c93= [HW,SCSI]
- See header of drivers/scsi/wd33c93.c.
-
- wd7000= [HW,SCSI]
- See header of drivers/scsi/wd7000.c.
-
- wdt= [WDT] Watchdog
- See Documentation/watchdog/wdt.txt.
+ vt.global_cursor_default=
+ [VT]
+ Format=<-1|0|1>
+ Set system-wide default for whether a cursor
+ is shown on new VTs. Default is -1,
+ i.e. cursors will be created by default unless
+ overridden by individual drivers. 0 will hide
+ cursors, 1 will display them.
+
+ watchdog timers [HW,WDT] For information on watchdog timers,
+ see Documentation/watchdog/watchdog-parameters.txt
+ or other driver-specific files in the
+ Documentation/watchdog/ directory.
x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
default x2apic cluster mode on platforms
supporting x2apic.
+ x86_mrst_timer= [X86-32,APBT]
+ Choose timer option for x86 Moorestown MID platform.
+ Two valid options are apbt timer only and lapic timer
+ plus one apbt timer for broadcast timer.
+ x86_mrst_timer=apbt_only | lapic_and_apbt
+
xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
xd_geo= See header of drivers/block/xd.c.
+ xen_emul_unplug= [HW,X86,XEN]
+ Unplug Xen emulated devices
+ Format: [unplug0,][unplug1]
+ ide-disks -- unplug primary master IDE devices
+ aux-ide-disks -- unplug non-primary-master IDE devices
+ nics -- unplug network devices
+ all -- unplug all emulated devices (NICs and IDE disks)
+ unnecessary -- unplugging emulated devices is
+ unnecessary even if the host did not respond to
+ the unplug protocol
+ never -- do not unplug even if version check succeeds
+
xirc2ps_cs= [NET,PCMCIA]
Format:
<irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
TODO:
- Add documentation for ALSA options.
Add more DRM drivers.
projects / firefly-linux-kernel-4.4.55.git / blobdiff