FB The frame buffer device is enabled.
HW Appropriate hardware is enabled.
IA-64 IA-64 architecture 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.
ISAPNP ISA PnP code is enabled.
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/x86/i386/boot.txt>.
+need or coordination with <Documentation/x86/boot.txt>.
There are also arch-specific kernel-parameters not documented here.
See for example <Documentation/x86/x86_64/boot-options.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/power/pm.txt, pci=noacpi
default: 0
acpi_sleep= [HW,ACPI] Sleep options
- Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig, old_ordering }
- See Documentation/power/video.txt for s3_bios and s3_mode.
+ 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, wrt putting devices into low power
- states, to be enforced (the ACPI 2.0 ordering of _PTS is
- used by default).
+ 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_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
Range: 0 - 8192
Default: 64
+ dma_debug=off If the kernel is compiled with DMA_API_DEBUG support
+ this option disables the debugging code at boot.
+
+ dma_debug_entries=<number>
+ This option allows to tune the number of preallocated
+ entries for DMA-API debugging code. One entry is
+ required per DMA-API allocation. Use this if the
+ DMA-API debugging code disables itself because the
+ architectural default is too low.
+
hpet= [X86-32,HPET] option to control HPET usage
- Format: { enable (default) | disable | force }
+ Format: { enable (default) | disable | force |
+ verbose }
disable: disable HPET and use PIT instead
force: allow force enabled of undocumented chips (ICH4,
VIA, nVidia)
+ verbose: show contents of HPET registers during setup
com20020= [HW,NET] ARCnet - COM20020 chipset
Format:
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_dma= [HW,NET]
Format: <dma>
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.
hlt [BUGS=ARM,SH]
- hvc_iucv= [S390] Number of z/VM IUCV Hypervisor console (HVC)
- back-ends. Valid parameters: 0..8
+ hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC)
+ terminal devices. Valid values: 0..8
+ hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
+ If specified, z/VM IUCV HVC accepts connections
+ from listed z/VM user IDs only.
+
+ 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.
+ Format:
+ <bus_id>,<clkrate>
i8042.debug [HW] Toggle i8042 debug mode
i8042.direct [HW] Put keyboard port into non-translated mode
icn= [HW,ISDN]
Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
- ide= [HW] (E)IDE subsystem
- Format: ide=nodma or ide=doubler
+ 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/ide.txt.
idle= [X86]
- Format: idle=poll or idle=mwait, idle=halt, idle=nomwait
- 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.
- idle=halt. Halt is forced to be used for CPU idle.
+ 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
+ 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.
ihash_entries= [KNL]
Set number of hash buckets for inode cache.
+ ima_audit= [IMA]
+ Format: { "0" | "1" }
+ 0 -- integrity auditing messages. (Default)
+ 1 -- enable informational integrity auditing messages.
+
+ ima_hash= [IMA]
+ Formt: { "sha1" | "md5" }
+ default: "sha1"
+
in2000= [HW,SCSI]
See header of drivers/scsi/in2000.c.
inttest= [IA64]
+ iomem= Disable strict checking of access to MMIO memory
+ strict regions from userspace.
+ relaxed
+
iommu= [x86]
off
force
intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
+ on
+ Enable intel iommu driver.
off
Disable intel iommu driver.
igfx_off [Default Off]
lapic [X86-32,APIC] Enable the local APIC even if BIOS
disabled it.
- lapic_timer_c2_ok [X86-32,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.
libata.dma= [LIBATA] DMA control
libata.dma=0 Disable all PATA and SATA DMA
memtest= [KNL,X86] Enable memtest
Format: <integer>
- range: 0,4 : pattern number
default : 0 <disable>
+ Specifies the number of memtest passes to be
+ performed. Each pass selects another test
+ pattern from a given set of patterns. Memtest
+ fills the memory with this pattern, validates
+ memory contents and reserves bad memory
+ regions that are detected.
meye.*= [HW] Set MotionEye Camera parameters
See Documentation/video4linux/meye.txt.
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=X86-32] Disable Time Stamp Counter
See also Documentation/blockdev/paride.txt.
pci=option[,option...] [PCI] various PCI subsystem options:
+ earlydump [X86] dump PCI config space before the kernel
+ changes anything
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
cbmemsize=nn[KMG] The fixed amount of bus space which is
reserved for the CardBus bridge's memory
window. The default value is 64 megabytes.
+ resource_alignment=
+ Format:
+ [<order of align>@][<domain>:]<bus>:<slot>.<func>[; ...]
+ Specifies alignment and device to reassign
+ aligned memory resources.
+ If <order of align> is not specified,
+ PAGE_SIZE is used as alignment.
+ PCI-PCI bridge can be specified, if resource
+ windows need to be expanded.
pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
Management.
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
If enabled at boot time, /selinux/disable can be used
later to disable prior to initial policy load.
- selinux_compat_net =
- [SELINUX] Set initial selinux_compat_net flag value.
- Format: { "0" | "1" }
- 0 -- use new secmark-based packet controls
- 1 -- use legacy packet controls
- Default value is 0 (preferred).
- Value can be changed at runtime via
- /selinux/compat_net.
-
serialnumber [BUGS=X86-32]
shapers= [NET]
thermal.psv= [HW,ACPI]
-1: disable all passive trip points
- <degrees C>: override all passive trip points to this value
+ <degrees C>: override all passive trip points to this
+ value
thermal.tzp= [HW,ACPI]
Specify global default ACPI thermal zone polling rate
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
See Documentation/fb/modedb.txt.
vga= [BOOT,X86-32] Select a particular video mode
- See Documentation/x86/i386/boot.txt and
+ See Documentation/x86/boot.txt and
Documentation/svga.txt.
Use vga=ask for menu.
This is actually a boot loader parameter; the value is