mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
synced 2025-10-31 09:36:25 +00:00
ea3acb199a
Commit c953094 ("early_printk: Allow more than one early console")
introduced a regression in the parsing of the earlyprintk= kernel
arguments.
If you specify "earlyprintk=serial,ttyS0,115200" as a kernel
argument, the "serial,ttyS" should be parsed as a single argument
and not as "serial" and then "ttyS".
Also update the documentation to reflect you can specify the ttyS
directly without the "serial" argument.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <gregkh@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
LKML-Reference: <4ABB7D5E.6000301@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2761 lines
88 KiB
Plaintext
2761 lines
88 KiB
Plaintext
Kernel Parameters
|
|
~~~~~~~~~~~~~~~~~
|
|
|
|
The following is a consolidated list of the kernel parameters as implemented
|
|
(mostly) by the __setup() macro and sorted into English Dictionary order
|
|
(defined as ignoring all punctuation and sorting digits before letters in a
|
|
case insensitive manner), and with descriptions where known.
|
|
|
|
Module parameters for loadable modules are specified only as the
|
|
parameter name with optional '=' and value as appropriate, such as:
|
|
|
|
modprobe usbcore blinkenlights=1
|
|
|
|
Module parameters for modules that are built into the kernel image
|
|
are specified on the kernel command line with the module name plus
|
|
'.' plus parameter name, with '=' and value if appropriate, such as:
|
|
|
|
usbcore.blinkenlights=1
|
|
|
|
Hyphens (dashes) and underscores are equivalent in parameter names, so
|
|
log_buf_len=1M print-fatal-signals=1
|
|
can also be entered as
|
|
log-buf-len=1M print_fatal_signals=1
|
|
|
|
|
|
This document may not be entirely up to date and comprehensive. The command
|
|
"modinfo -p ${modulename}" shows a current list of all parameters of a loadable
|
|
module. Loadable modules, after being loaded into the running kernel, also
|
|
reveal their parameters in /sys/module/${modulename}/parameters/. Some of these
|
|
parameters may be changed at runtime by the command
|
|
"echo -n ${value} > /sys/module/${modulename}/parameters/${parm}".
|
|
|
|
The parameters listed below are only valid if certain kernel build options were
|
|
enabled and if respective hardware is present. The text in square brackets at
|
|
the beginning of each description states the restrictions within which a
|
|
parameter is applicable:
|
|
|
|
ACPI ACPI support is enabled.
|
|
AGP AGP (Accelerated Graphics Port) is enabled.
|
|
ALSA ALSA sound support is enabled.
|
|
APIC APIC support is enabled.
|
|
APM Advanced Power Management support is enabled.
|
|
AVR32 AVR32 architecture is enabled.
|
|
AX25 Appropriate AX.25 support is enabled.
|
|
BLACKFIN Blackfin architecture is enabled.
|
|
DRM Direct Rendering Management support is enabled.
|
|
EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
|
|
EFI EFI Partitioning (GPT) is enabled
|
|
EIDE EIDE/ATAPI support is enabled.
|
|
FB The frame buffer device is enabled.
|
|
GCOV GCOV profiling 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.
|
|
ISDN Appropriate ISDN support is enabled.
|
|
JOY Appropriate joystick support is enabled.
|
|
KVM Kernel Virtual Machine support is enabled.
|
|
LIBATA Libata driver is enabled
|
|
LP Printer support is enabled.
|
|
LOOP Loopback device support is enabled.
|
|
M68k M68k architecture is enabled.
|
|
These options have more detailed description inside of
|
|
Documentation/m68k/kernel-options.txt.
|
|
MCA MCA bus support is enabled.
|
|
MDA MDA console support is enabled.
|
|
MOUSE Appropriate mouse support is enabled.
|
|
MSI Message Signaled Interrupts (PCI).
|
|
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.
|
|
PARIDE The ParIDE (parallel port IDE) subsystem is enabled.
|
|
PARISC The PA-RISC architecture is enabled.
|
|
PCI PCI bus support is enabled.
|
|
PCIE PCI Express support is enabled.
|
|
PCMCIA The PCMCIA subsystem is enabled.
|
|
PNP Plug & Play support is enabled.
|
|
PPC PowerPC architecture is enabled.
|
|
PPT Parallel port support is enabled.
|
|
PS2 Appropriate PS/2 support is enabled.
|
|
RAM RAM disk support is enabled.
|
|
ROOTPLUG The example Root Plug LSM is enabled.
|
|
S390 S390 architecture is enabled.
|
|
SCSI Appropriate SCSI support is enabled.
|
|
A lot of drivers has their options described inside of
|
|
Documentation/scsi/.
|
|
SECURITY Different security models are enabled.
|
|
SELINUX SELinux support is enabled.
|
|
SERIAL Serial support is enabled.
|
|
SH SuperH architecture is enabled.
|
|
SMP The kernel is an SMP kernel.
|
|
SPARC Sparc architecture is enabled.
|
|
SWSUSP Software suspend (hibernation) is enabled.
|
|
SUSPEND System suspend states are enabled.
|
|
FTRACE Function tracing enabled.
|
|
TS Appropriate touchscreen support is enabled.
|
|
UMS USB Mass Storage support is enabled.
|
|
USB USB support is enabled.
|
|
USBHID USB Human Interface Device support is enabled.
|
|
V4L Video For Linux support is enabled.
|
|
VGA The VGA console has been 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/x86_64/boot-options.txt .
|
|
X86 Either 32bit or 64bit x86 (same as X86-32+X86-64)
|
|
|
|
In addition, the following text indicates that the option:
|
|
|
|
BUGS= Relates to possible processor bugs on the said processor.
|
|
KNL Is a kernel start-up parameter.
|
|
BOOT Is a boot loader parameter.
|
|
|
|
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/boot.txt>.
|
|
|
|
There are also arch-specific kernel-parameters not documented here.
|
|
See for example <Documentation/x86/x86_64/boot-options.txt>.
|
|
|
|
Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
|
|
a trailing = on the name of any parameter states that that parameter will
|
|
be entered as an environment variable, whereas its absence indicates that
|
|
it will appear as a kernel argument readable via /proc/cmdline by programs
|
|
running once the system is up.
|
|
|
|
The number of kernel parameters is not limited, but the length of the
|
|
complete command line (parameters including spaces etc.) is limited to
|
|
a fixed number of characters. This limit depends on the architecture
|
|
and is between 256 and 4096 characters. It is defined in the file
|
|
./include/asm/setup.h as COMMAND_LINE_SIZE.
|
|
|
|
|
|
acpi= [HW,ACPI,X86]
|
|
Advanced Configuration and Power Interface
|
|
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
|
|
|
|
acpi_apic_instance= [ACPI, IOAPIC]
|
|
Format: <int>
|
|
2: use 2nd APIC table, if available
|
|
1,0: use 1st APIC table
|
|
default: 0
|
|
|
|
acpi_backlight= [HW,ACPI]
|
|
acpi_backlight=vendor
|
|
acpi_backlight=video
|
|
If set to vendor, prefer vendor specific driver
|
|
(e.g. thinkpad_acpi, sony_acpi, etc.) instead
|
|
of the ACPI video.ko driver.
|
|
|
|
acpi.debug_layer= [HW,ACPI,ACPI_DEBUG]
|
|
acpi.debug_level= [HW,ACPI,ACPI_DEBUG]
|
|
Format: <int>
|
|
CONFIG_ACPI_DEBUG must be enabled to produce any ACPI
|
|
debug output. Bits in debug_layer correspond to a
|
|
_COMPONENT in an ACPI source file, e.g.,
|
|
#define _COMPONENT ACPI_PCI_COMPONENT
|
|
Bits in debug_level correspond to a level in
|
|
ACPI_DEBUG_PRINT statements, e.g.,
|
|
ACPI_DEBUG_PRINT((ACPI_DB_INFO, ...
|
|
The debug_level mask defaults to "info". See
|
|
Documentation/acpi/debug.txt for more information about
|
|
debug layers and levels.
|
|
|
|
Enable processor driver info messages:
|
|
acpi.debug_layer=0x20000000
|
|
Enable PCI/PCI interrupt routing info messages:
|
|
acpi.debug_layer=0x400000
|
|
Enable AML "Debug" output, i.e., stores to the Debug
|
|
object while interpreting AML:
|
|
acpi.debug_layer=0xffffffff acpi.debug_level=0x2
|
|
Enable all messages related to ACPI hardware:
|
|
acpi.debug_layer=0x2 acpi.debug_level=0xffffffff
|
|
|
|
Some values produce so much output that the system is
|
|
unusable. The "log_buf_len" parameter may be useful
|
|
if you need to capture more output.
|
|
|
|
acpi_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_irq_nobalance [HW,ACPI]
|
|
ACPI will not move active IRQs (default)
|
|
default in PIC mode
|
|
|
|
acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
|
|
Format: <irq>,<irq>...
|
|
|
|
acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
|
|
use by PCI
|
|
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] 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_pm_good [X86]
|
|
Override the pmtimer bug detection: force the kernel
|
|
to assume that this machine's pmtimer latches its value
|
|
and always returns good values.
|
|
|
|
acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
|
|
Format: { level | edge | high | low }
|
|
|
|
acpi_serialize [HW,ACPI] force serialization of AML methods
|
|
|
|
acpi_skip_timer_override [HW,ACPI]
|
|
Recognize and ignore IRQ0/pin2 Interrupt Override.
|
|
For broken nForce2 BIOS resulting in XT-PIC timer.
|
|
|
|
acpi_sleep= [HW,ACPI] Sleep options
|
|
Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
|
|
old_ordering, s4_nonvs }
|
|
See Documentation/power/video.txt for information on
|
|
s3_bios and s3_mode.
|
|
s3_beep is for debugging; it makes the PC's speaker beep
|
|
as soon as the kernel's real-mode entry point is called.
|
|
s4_nohwsig prevents ACPI hardware signature from being
|
|
used during resume from hibernation.
|
|
old_ordering causes the ACPI 1.0 ordering of the _PTS
|
|
control method, with respect to putting devices into
|
|
low power states, to be enforced (the ACPI 2.0 ordering
|
|
of _PTS is used by default).
|
|
s4_nonvs prevents the kernel from saving/restoring the
|
|
ACPI NVS memory during hibernation.
|
|
|
|
acpi_use_timer_override [HW,ACPI]
|
|
Use timer override. For some broken Nvidia NF5 boards
|
|
that require a timer override, but don't have HPET
|
|
|
|
acpi_enforce_resources= [ACPI]
|
|
{ strict | lax | no }
|
|
Check for resource conflicts between native drivers
|
|
and ACPI OperationRegions (SystemIO and SystemMemory
|
|
only). IO ports and memory declared in ACPI might be
|
|
used by the ACPI subsystem in arbitrary AML code and
|
|
can interfere with legacy drivers.
|
|
strict (default): access to resources claimed by ACPI
|
|
is denied; legacy drivers trying to access reserved
|
|
resources will fail to bind to device using them.
|
|
lax: access to resources claimed by ACPI is allowed;
|
|
legacy drivers trying to access reserved resources
|
|
will bind successfully but a warning message is logged.
|
|
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.
|
|
|
|
aha1542= [HW,SCSI]
|
|
Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
|
|
|
|
aic7xxx= [HW,SCSI]
|
|
See Documentation/scsi/aic7xxx.txt.
|
|
|
|
aic79xx= [HW,SCSI]
|
|
See Documentation/scsi/aic79xx.txt.
|
|
|
|
amd_iommu= [HW,X86-84]
|
|
Pass parameters to the AMD IOMMU driver in the system.
|
|
Possible values are:
|
|
isolate - enable device isolation (each device, as far
|
|
as possible, will get its own protection
|
|
domain) [default]
|
|
share - put every device behind one IOMMU into the
|
|
same protection domain
|
|
fullflush - enable flushing of IO/TLB entries when
|
|
they are unmapped. Otherwise they are
|
|
flushed before they will be reused, which
|
|
is a lot of faster
|
|
|
|
amijoy.map= [HW,JOY] Amiga joystick support
|
|
Map of devices attached to JOY0DAT and JOY1DAT
|
|
Format: <a>,<b>
|
|
See also Documentation/kernel/input/joystick.txt
|
|
|
|
analog.map= [HW,JOY] Analog joystick and gamepad support
|
|
Specifies type or capabilities of an analog joystick
|
|
connected to one of 16 gameports
|
|
Format: <type1>,<type2>,..<type16>
|
|
|
|
apc= [HW,SPARC]
|
|
Power management functions (SPARCstation-4/5 + deriv.)
|
|
Format: noidle
|
|
Disable APC CPU standby support. SPARCstation-Fox does
|
|
not play well with APC CPU idle - disable it if you have
|
|
APC and your system crashes randomly.
|
|
|
|
apic= [APIC,X86-32] 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/x86/kernel/apm_32.c.
|
|
|
|
arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
|
|
Format: <io>,<irq>,<nodeID>
|
|
|
|
ataflop= [HW,M68k]
|
|
|
|
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
|
|
|
|
atkbd.reset= [HW] Reset keyboard during initialization
|
|
|
|
atkbd.set= [HW] Select keyboard code set
|
|
Format: <int> (2 = AT (default), 3 = PS/2)
|
|
|
|
atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
|
|
keyboards
|
|
|
|
atkbd.softraw= [HW] Choose between synthetic and real raw mode
|
|
Format: <bool> (0 = real, 1 = synthetic (default))
|
|
|
|
atkbd.softrepeat= [HW]
|
|
Use software keyboard repeat
|
|
|
|
autotest [IA64]
|
|
|
|
baycom_epp= [HW,AX25]
|
|
Format: <io>,<mode>
|
|
|
|
baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
|
|
Format: <io>,<mode>
|
|
See header of drivers/net/hamradio/baycom_par.c.
|
|
|
|
baycom_ser_fdx= [HW,AX25]
|
|
BayCom Serial Port AX.25 Modem (Full Duplex Mode)
|
|
Format: <io>,<irq>,<mode>[,<baud>]
|
|
See header of drivers/net/hamradio/baycom_ser_fdx.c.
|
|
|
|
baycom_ser_hdx= [HW,AX25]
|
|
BayCom Serial Port AX.25 Modem (Half Duplex Mode)
|
|
Format: <io>,<irq>,<mode>
|
|
See header of drivers/net/hamradio/baycom_ser_hdx.c.
|
|
|
|
boot_delay= Milliseconds to delay each printk during boot.
|
|
Values larger than 10 seconds (10000) are changed to
|
|
no delay (0).
|
|
Format: integer
|
|
|
|
bootmem_debug [KNL] Enable bootmem allocator debug messages.
|
|
|
|
bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
|
|
bttv.radio= Most important insmod options are available as
|
|
kernel args too.
|
|
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().
|
|
|
|
c101= [NET] Moxa C101 synchronous serial card
|
|
|
|
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.
|
|
|
|
capability.disable=
|
|
[SECURITY] Disable capabilities. This would normally
|
|
be used only if an alternative security model is to be
|
|
configured. Potentially dangerous and should only be
|
|
used if you are entirely sure of the consequences.
|
|
|
|
ccw_timeout_log [S390]
|
|
See Documentation/s390/CommonIO for details.
|
|
|
|
cgroup_disable= [KNL] Disable a particular controller
|
|
Format: {name of the controller(s) to disable}
|
|
{Currently supported controllers - "memory"}
|
|
|
|
checkreqprot [SELINUX] Set initial checkreqprot flag value.
|
|
Format: { "0" | "1" }
|
|
See security/selinux/Kconfig help text.
|
|
0 -- check protection applied by kernel (includes
|
|
any implied execute protection).
|
|
1 -- check protection requested by application.
|
|
Default value is set via a kernel config option.
|
|
Value can be changed at runtime via
|
|
/selinux/checkreqprot.
|
|
|
|
cio_ignore= [S390]
|
|
See Documentation/s390/CommonIO for details.
|
|
|
|
clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
|
|
[Deprecated]
|
|
Forces specified clocksource (if available) to be used
|
|
when calculating gettimeofday(). If specified
|
|
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
|
|
[X86-32] 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
|
|
|
|
clearcpuid=BITNUM [X86]
|
|
Disable CPUID feature X for the kernel. See
|
|
arch/x86/include/asm/cpufeature.h for the valid bit
|
|
numbers. Note the Linux specific bits are not necessarily
|
|
stable over kernel options, but the vendor specific
|
|
ones should be.
|
|
Also note that user programs calling CPUID directly
|
|
or using the feature without checking anything
|
|
will still see it. This just prevents it from
|
|
being used by the kernel or shown in /proc/cpuinfo.
|
|
Also note the kernel might malfunction if you disable
|
|
some critical bits.
|
|
|
|
cmo_free_hint= [PPC] Format: { yes | no }
|
|
Specify whether pages are marked as being inactive
|
|
when they are freed. This is used in CMO environments
|
|
to determine OS memory pressure for page stealing by
|
|
a hypervisor.
|
|
Default: yes
|
|
|
|
code_bytes [X86] How many bytes of object code to print
|
|
in an oops report.
|
|
Range: 0 - 8192
|
|
Default: 64
|
|
|
|
com20020= [HW,NET] ARCnet - COM20020 chipset
|
|
Format:
|
|
<io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
|
|
|
|
com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
|
|
Format: <io>[,<irq>]
|
|
|
|
com90xx= [HW,NET]
|
|
ARCnet - COM90xx chipset (memory-mapped buffers)
|
|
Format: <io>[,<irq>[,<memstart>]]
|
|
|
|
condev= [HW,S390] console device
|
|
conmode=
|
|
|
|
console= [KNL] Output console device and options.
|
|
|
|
tty<n> Use the virtual console device <n>.
|
|
|
|
ttyS<n>[,options]
|
|
ttyUSB0[,options]
|
|
Use the specified serial port. The options are of
|
|
the form "bbbbpnf", where "bbbb" is the baud rate,
|
|
"p" is parity ("n", "o", or "e"), "n" is number of
|
|
bits, and "f" is flow control ("r" for RTS or
|
|
omit it). Default is "9600n8".
|
|
|
|
See Documentation/serial-console.txt for more
|
|
information. See
|
|
Documentation/networking/netconsole.txt for an
|
|
alternative.
|
|
|
|
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.
|
|
|
|
If the device connected to the port is not a TTY but a braille
|
|
device, prepend "brl," before the device type, for instance
|
|
console=brl,ttyS0
|
|
For now, only VisioBraille is supported.
|
|
|
|
consoleblank= [KNL] The console blank (screen saver) timeout in
|
|
seconds. Defaults to 10*60 = 10mins. A value of 0
|
|
disables the blank timer.
|
|
|
|
coredump_filter=
|
|
[KNL] Change the default value for
|
|
/proc/<pid>/coredump_filter.
|
|
See also Documentation/filesystems/proc.txt.
|
|
|
|
cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
|
|
Format:
|
|
<first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
|
|
|
|
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.
|
|
|
|
cs89x0_dma= [HW,NET]
|
|
Format: <dma>
|
|
|
|
cs89x0_media= [HW,NET]
|
|
Format: { rj45 | aui | bnc }
|
|
|
|
dasd= [HW,NET]
|
|
See header of drivers/s390/block/dasd_devmap.c.
|
|
|
|
db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
|
|
(one device per port)
|
|
Format: <port#>,<type>
|
|
See also Documentation/input/joystick-parport.txt
|
|
|
|
debug [KNL] Enable kernel debugging (events log level).
|
|
|
|
debug_locks_verbose=
|
|
[KNL] verbose self-tests
|
|
Format=<0|1>
|
|
Print debugging info while doing the locking API
|
|
self-tests.
|
|
We default to 0 (no extra messages), setting it to
|
|
1 will print _a lot_ more information - normally
|
|
only useful to kernel developers.
|
|
|
|
debug_objects [KNL] Enable object debugging
|
|
|
|
no_debug_objects
|
|
[KNL] Disable object debugging
|
|
|
|
debugpat [X86] Enable PAT debugging
|
|
|
|
decnet.addr= [HW,NET]
|
|
Format: <area>[,<node>]
|
|
See also Documentation/networking/decnet.txt.
|
|
|
|
default_hugepagesz=
|
|
[same as hugepagesz=] The size of the default
|
|
HugeTLB page size. This is the size represented by
|
|
the legacy /proc/ hugepages APIs, used for SHM, and
|
|
default size when mounting hugetlbfs filesystems.
|
|
Defaults to the default architecture's huge page size
|
|
if not specified.
|
|
|
|
dhash_entries= [KNL]
|
|
Set number of hash buckets for dentry cache.
|
|
|
|
digi= [HW,SERIAL]
|
|
IO parameters + enable/disable command.
|
|
|
|
digiepca= [HW,SERIAL]
|
|
See drivers/char/README.epca and
|
|
Documentation/serial/digiepca.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
|
|
entry later. This parameter disables that.
|
|
|
|
disable_mtrr_trim [X86, Intel and AMD only]
|
|
By default the kernel will trim any uncacheable
|
|
memory out of your available memory pool based on
|
|
MTRR settings. This parameter disables that behavior,
|
|
possibly causing your machine to run very slowly.
|
|
|
|
disable_timer_pin_1 [X86]
|
|
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.
|
|
|
|
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.
|
|
|
|
dma_debug_driver=<driver_name>
|
|
With this option the DMA-API debugging driver
|
|
filter feature can be enabled at boot time. Just
|
|
pass the driver to filter for as the parameter.
|
|
The filter can be disabled or changed to another
|
|
driver later using sysfs.
|
|
|
|
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]
|
|
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.
|
|
|
|
earlyprintk= [X86,SH,BLACKFIN]
|
|
earlyprintk=vga
|
|
earlyprintk=serial[,ttySn[,baudrate]]
|
|
earlyprintk=ttySn[,baudrate]
|
|
earlyprintk=dbgp[debugController#]
|
|
|
|
Append ",keep" to not disable it when the real console
|
|
takes over.
|
|
|
|
Only vga or serial or usb debug port at a time.
|
|
|
|
Currently only ttyS0 and ttyS1 are supported.
|
|
|
|
Interaction with the standard serial driver is not
|
|
very good.
|
|
|
|
The VGA output is eventually overwritten by the real
|
|
console.
|
|
|
|
eata= [HW,SCSI]
|
|
|
|
edd= [EDD]
|
|
Format: {"off" | "on" | "skip[mbr]"}
|
|
|
|
eisa_irq_edge= [PARISC,HW]
|
|
See header of drivers/parisc/eisa.c.
|
|
|
|
elanfreq= [X86-32]
|
|
See comment before function elanfreq_setup() in
|
|
arch/x86/kernel/cpu/cpufreq/elanfreq.c.
|
|
|
|
elevator= [IOSCHED]
|
|
Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
|
|
See Documentation/block/as-iosched.txt and
|
|
Documentation/block/deadline-iosched.txt for details.
|
|
|
|
elfcorehdr= [IA64,PPC,SH,X86]
|
|
Specifies physical address of start of kernel core
|
|
image elf header. Generally kexec loader will
|
|
pass this option to capture kernel.
|
|
See Documentation/kdump/kdump.txt for details.
|
|
|
|
enable_mtrr_cleanup [X86]
|
|
The kernel tries to adjust MTRR layout from continuous
|
|
to discrete, to make X server driver able to add WB
|
|
entry later. This parameter enables that.
|
|
|
|
enable_timer_pin_1 [X86]
|
|
Enable PIN 1 of APIC timer
|
|
Can be useful to work around chipset bugs
|
|
(in particular on some ATI chipsets).
|
|
The kernel tries to set a reasonable default.
|
|
|
|
enforcing [SELINUX] Set initial enforcing status.
|
|
Format: {"0" | "1"}
|
|
See security/selinux/Kconfig help text.
|
|
0 -- permissive (log only, no denials).
|
|
1 -- enforcing (deny and log).
|
|
Default value is 0.
|
|
Value can be changed at runtime via /selinux/enforce.
|
|
|
|
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]
|
|
General fault injection mechanism.
|
|
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.
|
|
|
|
force_pal_cache_flush
|
|
[IA-64] Avoid check_sal_cache_flush which may hang on
|
|
buggy SAL_CACHE_FLUSH implementations. Using this
|
|
parameter will force ia64_sal_cache_flush to call
|
|
ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
|
|
|
|
ftrace=[tracer]
|
|
[FTRACE] will set and start the specified tracer
|
|
as early as possible in order to facilitate early
|
|
boot debugging.
|
|
|
|
ftrace_dump_on_oops
|
|
[FTRACE] will dump the trace buffers on oops.
|
|
|
|
ftrace_filter=[function-list]
|
|
[FTRACE] Limit the functions traced by the function
|
|
tracer at boot up. function-list is a comma separated
|
|
list of functions. This list can be changed at run
|
|
time by the set_ftrace_filter file in the debugfs
|
|
tracing directory.
|
|
|
|
ftrace_notrace=[function-list]
|
|
[FTRACE] Do not trace the functions specified in
|
|
function-list. This list can be changed at run time
|
|
by the set_ftrace_notrace 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)
|
|
Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
|
|
See also Documentation/input/joystick-parport.txt
|
|
|
|
gamma= [HW,DRM]
|
|
|
|
gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
|
|
Format: off | on
|
|
default: on
|
|
|
|
gcov_persist= [GCOV] When non-zero (default), profiling data for
|
|
kernel modules is saved and remains accessible via
|
|
debugfs, even when the module is unloaded/reloaded.
|
|
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.
|
|
Format: 0 | 1 (for off | on)
|
|
|
|
hcl= [IA-64] SGI's Hardware Graph compatibility layer
|
|
|
|
hd= [EIDE] (E)IDE hard drive subsystem geometry
|
|
Format: <cyl>,<head>,<sect>
|
|
|
|
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
|
|
size on bigger boxes.
|
|
|
|
highres= [KNL] Enable/disable high resolution timer mode.
|
|
Valid parameters: "on", "off"
|
|
Default: "on"
|
|
|
|
hisax= [HW,ISDN]
|
|
See Documentation/isdn/README.HiSax.
|
|
|
|
hlt [BUGS=ARM,SH]
|
|
|
|
hpet= [X86-32,HPET] option to control HPET usage
|
|
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
|
|
|
|
hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot.
|
|
hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages.
|
|
On x86-64 and powerpc, this option can be specified
|
|
multiple times interleaved with hugepages= to reserve
|
|
huge pages of different sizes. Valid pages sizes on
|
|
x86-64 are 2M (when the CPU supports "pse") and 1G
|
|
(when the CPU supports the "pdpe1gb" cpuinfo flag)
|
|
Note that 1GB pages can only be allocated at boot time
|
|
using hugepages= and not freed afterwards.
|
|
|
|
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
|
|
i8042.dumbkbd [HW] Pretend that controller can only read data from
|
|
keyboard and cannot control its state
|
|
(Don't attempt to blink the leds)
|
|
i8042.noaux [HW] Don't check for auxiliary (== mouse) port
|
|
i8042.nokbd [HW] Don't check/create keyboard port
|
|
i8042.noloop [HW] Disable the AUX Loopback command while probing
|
|
for the AUX port
|
|
i8042.nomux [HW] Don't check presence of an active multiplexing
|
|
controller
|
|
i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
|
|
controllers
|
|
i8042.panicblink=
|
|
[HW] Frequency with which keyboard LEDs should blink
|
|
when kernel panics (default is 0.5 sec)
|
|
i8042.reset [HW] Reset the controller during init and cleanup
|
|
i8042.unlock [HW] Unlock (ignore) the keylock
|
|
|
|
i810= [HW,DRM]
|
|
|
|
i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
|
|
indicates that the driver is running on unsupported
|
|
hardware.
|
|
i8k.force [HW] Activate i8k driver even if SMM BIOS signature
|
|
does not match list of supported models.
|
|
i8k.power_status
|
|
[HW] Report power status in /proc/i8k
|
|
(disabled by default)
|
|
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>]]]
|
|
|
|
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 .nohpa .noprobe .nowerr
|
|
.cdrom .chs .ignore_cable are additional options
|
|
See Documentation/ide/ide.txt.
|
|
|
|
ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
|
|
Claim all unknown PCI IDE storage controllers.
|
|
|
|
idle= [X86]
|
|
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
|
|
|
|
ignore_loglevel [KNL]
|
|
Ignore loglevel setting - this will print /all/
|
|
kernel messages to the console. Useful for debugging.
|
|
|
|
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]
|
|
Format: { "sha1" | "md5" }
|
|
default: "sha1"
|
|
|
|
ima_tcb [IMA]
|
|
Load a policy which meets the needs of the Trusted
|
|
Computing Base. This means IMA will measure all
|
|
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
|
|
process.
|
|
|
|
initcall_debug [KNL] Trace initcalls as they are executed. Useful
|
|
for working out where the kernel is dying during
|
|
startup.
|
|
|
|
initrd= [BOOT] Specify the location of the initial ramdisk
|
|
|
|
inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
|
|
Format: <irq>
|
|
|
|
intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
|
|
on
|
|
Enable intel iommu driver.
|
|
off
|
|
Disable intel iommu driver.
|
|
igfx_off [Default Off]
|
|
By default, gfx is mapped as normal device. If a gfx
|
|
device has a dedicated DMAR unit, the DMAR unit is
|
|
bypassed by not enabling DMAR with this option. In
|
|
this case, gfx device will use physical address for
|
|
DMA.
|
|
forcedac [x86_64]
|
|
With this option iommu will not optimize to look
|
|
for io virtual address below 32 bit forcing dual
|
|
address cycle on pci bus for cards supporting greater
|
|
than 32 bit addressing. The default is to look
|
|
for translation below 32 bit and if not available
|
|
then look in the higher range.
|
|
strict [Default Off]
|
|
With this option on every unmap_single operation will
|
|
result in a hardware IOTLB flush operation as opposed
|
|
to batching them for performance.
|
|
|
|
inttest= [IA64]
|
|
|
|
iomem= Disable strict checking of access to MMIO memory
|
|
strict regions from userspace.
|
|
relaxed
|
|
|
|
iommu= [x86]
|
|
off
|
|
force
|
|
noforce
|
|
biomerge
|
|
panic
|
|
nopanic
|
|
merge
|
|
nomerge
|
|
forcesac
|
|
soft
|
|
pt [x86, IA64]
|
|
|
|
io7= [HW] IO7 for Marvel based alpha systems
|
|
See comment before marvel_specify_io7 in
|
|
arch/alpha/kernel/core_marvel.c.
|
|
|
|
io_delay= [X86] I/O delay method
|
|
0x80
|
|
Standard port 0x80 based delay
|
|
0xed
|
|
Alternate port 0xed based delay (needed on some systems)
|
|
udelay
|
|
Simple two microseconds delay
|
|
none
|
|
No delay
|
|
|
|
ip= [IP_PNP]
|
|
See Documentation/filesystems/nfsroot.txt.
|
|
|
|
ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
|
|
See comment before ip2_setup() in
|
|
drivers/char/ip2/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
|
|
firmware running.
|
|
|
|
irqpoll [HW]
|
|
When an interrupt is not handled search all handlers
|
|
for it. Also check all handlers each timer
|
|
interrupt. Intended to get systems with badly broken
|
|
firmware running.
|
|
|
|
isapnp= [ISAPNP]
|
|
Format: <RDP>,<reset>,<pci_scan>,<verbosity>
|
|
|
|
isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
|
|
Format:
|
|
<cpu number>,...,<cpu number>
|
|
or
|
|
<cpu number>-<cpu number>
|
|
(must be a positive range in ascending order)
|
|
or a mixture
|
|
<cpu number>,...,<cpu number>-<cpu number>
|
|
|
|
This option can be used to specify one or more CPUs
|
|
to isolate from the general SMP balancing and scheduling
|
|
algorithms. You can move a process onto or off an
|
|
"isolated" CPU via the CPU affinity syscalls or cpuset.
|
|
<cpu number> begins at 0 and the maximum value is
|
|
"number of CPUs in system - 1".
|
|
|
|
This option is the preferred way to isolate CPUs. The
|
|
alternative -- manually setting the CPU mask of all
|
|
tasks in the system -- can cause problems and
|
|
suboptimal load balancer performance.
|
|
|
|
iucv= [HW,NET]
|
|
|
|
js= [HW,JOY] Analog joystick
|
|
See Documentation/input/joystick.txt.
|
|
|
|
keepinitrd [HW,ARM]
|
|
|
|
kernelcore=nn[KMG] [KNL,X86,IA-64,PPC] 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.
|
|
|
|
kgdboc= [HW] kgdb over consoles.
|
|
Requires a tty driver that supports console polling.
|
|
(only serial supported for now)
|
|
Format: <serial_device>[,baud]
|
|
|
|
kmac= [MIPS] korina ethernet MAC address.
|
|
Configure the RouterBoard 532 series on-chip
|
|
Ethernet adapter MAC address.
|
|
|
|
kmemleak= [KNL] Boot-time kmemleak enable/disable
|
|
Valid arguments: on, off
|
|
Default: on
|
|
|
|
kstack=N [X86] Print N words from the kernel stack
|
|
in oops dumps.
|
|
|
|
kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.
|
|
Default is 0 (don't ignore, but inject #GP)
|
|
|
|
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.
|
|
Default is 0 (off)
|
|
|
|
kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
|
|
for all guests.
|
|
Default is 1 (enabled) if in 64bit or 32bit-PAE mode
|
|
|
|
kvm-intel.bypass_guest_pf=
|
|
[KVM,Intel] Disables bypassing of guest page faults
|
|
on Intel chips. Default is 1 (enabled)
|
|
|
|
kvm-intel.ept= [KVM,Intel] Disable extended page tables
|
|
(virtualized MMU) support on capable Intel chips.
|
|
Default is 1 (enabled)
|
|
|
|
kvm-intel.emulate_invalid_guest_state=
|
|
[KVM,Intel] Enable emulation of invalid guest states
|
|
Default is 0 (disabled)
|
|
|
|
kvm-intel.flexpriority=
|
|
[KVM,Intel] Disable FlexPriority feature (TPR shadow).
|
|
Default is 1 (enabled)
|
|
|
|
kvm-intel.unrestricted_guest=
|
|
[KVM,Intel] Disable unrestricted guest feature
|
|
(virtualized real and unpaged mode) on capable
|
|
Intel chips. Default is 1 (enabled)
|
|
|
|
kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification
|
|
feature (tagged TLBs) on capable Intel chips.
|
|
Default is 1 (enabled)
|
|
|
|
l2cr= [PPC]
|
|
|
|
l3cr= [PPC]
|
|
|
|
lapic [X86-32,APIC] Enable the local APIC even if BIOS
|
|
disabled it.
|
|
|
|
lapic_timer_c2_ok [X86,APIC] trust the local apic timer
|
|
in C2 power state.
|
|
|
|
libata.dma= [LIBATA] DMA control
|
|
libata.dma=0 Disable all PATA and SATA DMA
|
|
libata.dma=1 PATA and SATA Disk DMA only
|
|
libata.dma=2 ATAPI (CDROM) DMA only
|
|
libata.dma=4 Compact Flash DMA only
|
|
Combinations also work, so libata.dma=3 enables DMA
|
|
for disks and CDROMs, but not CFs.
|
|
|
|
libata.ignore_hpa= [LIBATA] Ignore HPA limit
|
|
libata.ignore_hpa=0 keep BIOS limits (default)
|
|
libata.ignore_hpa=1 ignore limits, using full disk
|
|
|
|
libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
|
|
when set.
|
|
Format: <int>
|
|
|
|
libata.force= [LIBATA] Force configurations. The format is comma
|
|
separated list of "[ID:]VAL" where ID is
|
|
PORT[:DEVICE]. PORT and DEVICE are decimal numbers
|
|
matching port, link or device. Basically, it matches
|
|
the ATA ID string printed on console by libata. If
|
|
the whole ID part is omitted, the last PORT and DEVICE
|
|
values are used. If ID hasn't been specified yet, the
|
|
configuration applies to all ports, links and devices.
|
|
|
|
If only DEVICE is omitted, the parameter applies to
|
|
the port and all links and devices behind it. DEVICE
|
|
number of 0 either selects the first device or the
|
|
first fan-out link behind PMP device. It does not
|
|
select the host link. DEVICE number of 15 selects the
|
|
host link and device attached to it.
|
|
|
|
The VAL specifies the configuration to force. As long
|
|
as there's no ambiguity shortcut notation is allowed.
|
|
For example, both 1.5 and 1.5G would work for 1.5Gbps.
|
|
The following configurations can be forced.
|
|
|
|
* Cable type: 40c, 80c, short40c, unk, ign or sata.
|
|
Any ID with matching PORT is used.
|
|
|
|
* SATA link speed limit: 1.5Gbps or 3.0Gbps.
|
|
|
|
* Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
|
|
udma[/][16,25,33,44,66,100,133] notation is also
|
|
allowed.
|
|
|
|
* [no]ncq: Turn on or off NCQ.
|
|
|
|
* nohrst, nosrst, norst: suppress hard, soft
|
|
and both resets.
|
|
|
|
If there are multiple matching configurations changing
|
|
the same attribute, the last one is used.
|
|
|
|
lmb=debug [KNL] Enable lmb debug messages.
|
|
|
|
load_ramdisk= [RAM] List of ramdisks to load from floppy
|
|
See Documentation/blockdev/ramdisk.txt.
|
|
|
|
lockd.nlm_grace_period=P [NFS] Assign grace period.
|
|
Format: <integer>
|
|
|
|
lockd.nlm_tcpport=N [NFS] Assign TCP port.
|
|
Format: <integer>
|
|
|
|
lockd.nlm_timeout=T [NFS] Assign timeout value.
|
|
Format: <integer>
|
|
|
|
lockd.nlm_udpport=M [NFS] Assign UDP port.
|
|
Format: <integer>
|
|
|
|
logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
|
|
Format: <irq>
|
|
|
|
loglevel= All Kernel Messages with a loglevel smaller than the
|
|
console loglevel will be printed to the console. It can
|
|
also be changed with klogd or other programs. The
|
|
loglevels are defined as follows:
|
|
|
|
0 (KERN_EMERG) system is unusable
|
|
1 (KERN_ALERT) action must be taken immediately
|
|
2 (KERN_CRIT) critical conditions
|
|
3 (KERN_ERR) error conditions
|
|
4 (KERN_WARNING) warning conditions
|
|
5 (KERN_NOTICE) normal but significant condition
|
|
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.
|
|
|
|
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
|
|
lp=auto printer driver. 'lp=reset' (which can be
|
|
specified in addition to the ports) causes
|
|
attached printers to be reset. Using
|
|
lp=port1,port2,... specifies the parallel ports
|
|
to associate lp devices with, starting with
|
|
lp0. A port specification may be 'none' to skip
|
|
that lp device, or a parport name such as
|
|
'parport0'. Specifying 'lp=auto' instead of a
|
|
port specification list means that device IDs
|
|
from each port should be examined, to see if
|
|
an IEEE 1284-compliant printer is attached; if
|
|
so, the driver will manage that printer.
|
|
See also header of drivers/char/lp.c.
|
|
|
|
lpj=n [KNL]
|
|
Sets loops_per_jiffy to given constant, thus avoiding
|
|
time-consuming boot-time autodetection (up to 250 ms per
|
|
CPU). 0 enables autodetection (default). To determine
|
|
the correct value for your kernel, boot with normal
|
|
autodetection and see what value is printed. Note that
|
|
on SMP systems the preset will be applied to all CPUs,
|
|
which is likely to cause problems if your CPUs need
|
|
significantly divergent settings. An incorrect value
|
|
will cause delays in the kernel to be wrong, leading to
|
|
unpredictable I/O errors and other breakage. Although
|
|
unlikely, in the extreme case this might damage your
|
|
hardware.
|
|
|
|
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
|
|
|
|
machtype= [Loongson] Share the same kernel image file between different
|
|
yeeloong laptop.
|
|
Example: machtype=lemote-yeeloong-2f-7inch
|
|
|
|
max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater
|
|
than or equal to this physical address is ignored.
|
|
|
|
maxcpus= [SMP] Maximum number of processors that an SMP kernel
|
|
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_loop= [LOOP] Maximum number of loopback devices that can
|
|
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
|
|
|
|
mce=option [X86-64] See Documentation/x86/x86_64/boot-options.txt
|
|
|
|
md= [HW] RAID subsystems devices and level
|
|
See Documentation/md.txt.
|
|
|
|
mdacon= [MDA]
|
|
Format: <first>,<last>
|
|
Specifies range of consoles to be captured by the MDA.
|
|
|
|
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.
|
|
[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=X86-32] Disable usage of 4MB pages for kernel
|
|
memory.
|
|
|
|
memchunk=nn[KMG]
|
|
[KNL,SH] Allow user to override the default size for
|
|
per-device physically contiguous DMA buffers.
|
|
|
|
memmap=exactmap [KNL,X86] 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
|
|
option description.
|
|
|
|
memmap=nn[KMG]@ss[KMG]
|
|
[KNL] Force usage of a specific region of memory
|
|
Region of memory to be used, from ss to ss+nn.
|
|
|
|
memmap=nn[KMG]#ss[KMG]
|
|
[KNL,ACPI] Mark specific memory as ACPI data.
|
|
Region of memory to be used, from ss to ss+nn.
|
|
|
|
memmap=nn[KMG]$ss[KMG]
|
|
[KNL,ACPI] Mark specific memory as reserved.
|
|
Region of memory to be used, from ss to ss+nn.
|
|
Example: Exclude memory from 0x18690000-0x1869ffff
|
|
memmap=64K$0x18690000
|
|
or
|
|
memmap=0x10000$0x18690000
|
|
|
|
memory_corruption_check=0/1 [X86]
|
|
Some BIOSes seem to corrupt the first 64k of
|
|
memory when doing things like suspend/resume.
|
|
Setting this option will scan the memory
|
|
looking for corruption. Enabling this will
|
|
both detect corruption and prevent the kernel
|
|
from using the memory being corrupted.
|
|
However, its intended as a diagnostic tool; if
|
|
repeatable BIOS-originated corruption always
|
|
affects the same memory, you can use memmap=
|
|
to prevent the kernel from using that memory.
|
|
|
|
memory_corruption_check_size=size [X86]
|
|
By default it checks for corruption in the low
|
|
64k, making this memory unavailable for normal
|
|
use. Use this parameter to scan for
|
|
corruption in more or less memory.
|
|
|
|
memory_corruption_check_period=seconds [X86]
|
|
By default it checks for corruption every 60
|
|
seconds. Use this parameter to check at some
|
|
other rate. 0 disables periodic checking.
|
|
|
|
memtest= [KNL,X86] Enable memtest
|
|
Format: <integer>
|
|
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.
|
|
|
|
mfgpt_irq= [IA-32] Specify the IRQ to use for the
|
|
Multi-Function General Purpose Timers on AMD Geode
|
|
platforms.
|
|
|
|
mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
|
|
the BIOS has incorrectly applied a workaround. TinyBIOS
|
|
version 0.98 is known to be affected, 0.99 fixes the
|
|
problem by letting the user disable the workaround.
|
|
|
|
mga= [HW,DRM]
|
|
|
|
min_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory below this
|
|
physical address is ignored.
|
|
|
|
mini2440= [ARM,HW,KNL]
|
|
Format:[0..2][b][c][t]
|
|
Default: "0tb"
|
|
MINI2440 configuration specification:
|
|
0 - The attached screen is the 3.5" TFT
|
|
1 - The attached screen is the 7" TFT
|
|
2 - The VGA Shield is attached (1024x768)
|
|
Leaving out the screen size parameter will not load
|
|
the TFT driver, and the framebuffer will be left
|
|
unconfigured.
|
|
b - Enable backlight. The TFT backlight pin will be
|
|
linked to the kernel VESA blanking code and a GPIO
|
|
LED. This parameter is not necessary when using the
|
|
VGA shield.
|
|
c - Enable the s3c camera interface.
|
|
t - Reserved for enabling touchscreen support. The
|
|
touchscreen support is not enabled in the mainstream
|
|
kernel as of 2.6.30, a preliminary port can be found
|
|
in the "bleeding edge" mini2440 support kernel at
|
|
http://repo.or.cz/w/linux-2.6/mini2440.git
|
|
|
|
mminit_loglevel=
|
|
[KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
|
|
parameter allows control of the logging verbosity for
|
|
the additional memory initialisation checks. A value
|
|
of 0 disables mminit logging and a level of 4 will
|
|
log everything. Information is printed at KERN_DEBUG
|
|
so loglevel=8 may also need to be specified.
|
|
|
|
mousedev.tap_time=
|
|
[MOUSE] Maximum time between finger touching and
|
|
leaving touchpad surface for touch to be considered
|
|
a tap and be reported as a left button click (for
|
|
touchpads working in absolute mode only).
|
|
Format: <msecs>
|
|
mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
|
|
reporting absolute coordinates, such as tablets
|
|
mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
|
|
reporting absolute coordinates, such as tablets
|
|
|
|
movablecore=nn[KMG] [KNL,X86,IA-64,PPC] 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.
|
|
|
|
mpu401= [HW,OSS]
|
|
Format: <io>,<irq>
|
|
|
|
MTD_Partition= [MTD]
|
|
Format: <name>,<region-number>,<size>,<offset>
|
|
|
|
MTD_Region= [MTD] Format:
|
|
<name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
|
|
|
|
mtdparts= [MTD]
|
|
See drivers/mtd/cmdlinepart.c.
|
|
|
|
onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
|
|
|
|
Format: [die0_boundary][,die0_lock][,die1_boundary][,die1_lock]
|
|
|
|
boundary - index of last SLC block on Flex-OneNAND.
|
|
The remaining blocks are configured as MLC blocks.
|
|
lock - Configure if Flex-OneNAND boundary should be locked.
|
|
Once locked, the boundary cannot be changed.
|
|
1 indicates lock status, 0 indicates unlock status.
|
|
|
|
mtdset= [ARM]
|
|
ARM/S3C2412 JIVE boot control
|
|
|
|
See arch/arm/mach-s3c2412/mach-jive.c
|
|
|
|
mtouchusb.raw_coordinates=
|
|
[HW] Make the MicroTouch USB driver use raw coordinates
|
|
('y', default) or cooked coordinates ('n')
|
|
|
|
mtrr_chunk_size=nn[KMG] [X86]
|
|
used for mtrr cleanup. It is largest continuous chunk
|
|
that could hold holes aka. UC entries.
|
|
|
|
mtrr_gran_size=nn[KMG] [X86]
|
|
Used for mtrr cleanup. It is granularity of mtrr block.
|
|
Default is 1.
|
|
Large value could prevent small alignment from
|
|
using up MTRRs.
|
|
|
|
mtrr_spare_reg_nr=n [X86]
|
|
Format: <integer>
|
|
Range: 0,7 : spare reg number
|
|
Default : 1
|
|
Used for mtrr cleanup. It is spare mtrr entries number.
|
|
Set to 2 or more if your graphical card needs more.
|
|
|
|
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
|
|
something different and driver-specific.
|
|
This usage is only documented in each driver source
|
|
file if at all.
|
|
|
|
nf_conntrack.acct=
|
|
[NETFILTER] Enable connection tracking flow accounting
|
|
0 to disable accounting
|
|
1 to enable accounting
|
|
Default value depends on CONFIG_NF_CT_ACCT that is
|
|
going to be removed in 2.6.29.
|
|
|
|
nfsaddrs= [NFS]
|
|
See Documentation/filesystems/nfsroot.txt.
|
|
|
|
nfsroot= [NFS] nfs root filesystem for disk-less boxes.
|
|
See Documentation/filesystems/nfsroot.txt.
|
|
|
|
nfs.callback_tcpport=
|
|
[NFS] set the TCP port on which the NFSv4 callback
|
|
channel should listen.
|
|
|
|
nfs.cache_getent=
|
|
[NFS] sets the pathname to the program which is used
|
|
to update the NFS client cache entries.
|
|
|
|
nfs.cache_getent_timeout=
|
|
[NFS] sets the timeout after which an attempt to
|
|
update a cache entry is deemed to have failed.
|
|
|
|
nfs.idmap_cache_timeout=
|
|
[NFS] set the maximum lifetime for idmapper cache
|
|
entries.
|
|
|
|
nfs.enable_ino64=
|
|
[NFS] enable 64-bit inode numbers.
|
|
If zero, the NFS client will fake up a 32-bit inode
|
|
number for the readdir() and stat() syscalls instead
|
|
of returning the full 64-bit number.
|
|
The default is to return 64-bit inode numbers.
|
|
|
|
nmi_debug= [KNL,AVR32,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
|
|
0 - turn nmi_watchdog off
|
|
1 - use the IO-APIC timer for the NMI watchdog
|
|
2 - use the local APIC for the NMI watchdog using
|
|
a performance counter. Note: This will use one
|
|
performance counter and the local APIC's performance
|
|
vector.
|
|
When panic is specified, panic when an NMI watchdog
|
|
timeout occurs.
|
|
This is useful when you use a panic=... timeout and
|
|
need the box quickly up again.
|
|
Instead of 1 and 2 it is possible to use the following
|
|
symbolic names: lapic and ioapic
|
|
Example: nmi_watchdog=2 or nmi_watchdog=panic,lapic
|
|
|
|
netpoll.carrier_timeout=
|
|
[NET] Specifies amount of time (in seconds) that
|
|
netpoll should wait for a carrier. By default netpoll
|
|
waits 4 seconds.
|
|
|
|
no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
|
|
emulation library even if a 387 maths coprocessor
|
|
is present.
|
|
|
|
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.
|
|
|
|
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]
|
|
|
|
noapic [SMP,APIC] Tells the kernel to not make use of any
|
|
IOAPICs that may be present in the system.
|
|
|
|
nobats [PPC] Do not use BATs for mapping kernel lowmem
|
|
on "Classic" PPC cores.
|
|
|
|
nocache [ARM]
|
|
|
|
noclflush [BUGS=X86] Don't use the CLFLUSH instruction
|
|
|
|
nodelayacct [KNL] Disable per-task delay accounting
|
|
|
|
nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
|
|
|
|
nodsp [SH] Disable hardware DSP at boot time.
|
|
|
|
noefi [X86] Disable EFI runtime services support.
|
|
|
|
noexec [IA-64]
|
|
|
|
noexec [X86]
|
|
On X86-32 available only on PAE configured kernels.
|
|
noexec=on: enable non-executable mappings (default)
|
|
noexec=off: disable non-executable mappings
|
|
|
|
noexec32 [X86-64]
|
|
This affects only 32-bit executables.
|
|
noexec32=on: enable non-executable mappings (default)
|
|
read doesn't imply executable mappings
|
|
noexec32=off: disable non-executable mappings
|
|
read implies executable mappings
|
|
|
|
nofpu [SH] Disable hardware FPU at boot time.
|
|
|
|
nofxsr [BUGS=X86-32] Disables x86 floating point extended
|
|
register save and restore. The kernel will only save
|
|
legacy floating-point registers on task switch.
|
|
|
|
noxsave [BUGS=X86] Disables x86 extended register state save
|
|
and restore using xsave. The kernel will fallback to
|
|
enabling legacy floating-point and sse state.
|
|
|
|
nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or
|
|
wfi(ARM) instruction doesn't work correctly and not to
|
|
use it. This is also useful when using JTAG debugger.
|
|
|
|
no-hlt [BUGS=X86-32] Tells the kernel that the hlt
|
|
instruction doesn't work correctly and not to
|
|
use it.
|
|
|
|
no_file_caps Tells the kernel not to honor file capabilities. The
|
|
only way then for a file to be executed with privilege
|
|
is to be setuid root or executed by root.
|
|
|
|
nohalt [IA-64] Tells the kernel not to use the power saving
|
|
function PAL_HALT_LIGHT when idle. This increases
|
|
power-consumption. On the positive side, it reduces
|
|
interrupt wake-up latency, which may improve performance
|
|
in certain environments such as networked servers or
|
|
real-time systems.
|
|
|
|
nohz= [KNL] Boottime enable/disable dynamic ticks
|
|
Valid arguments: on, off
|
|
Default: on
|
|
|
|
noiotrap [SH] Disables trapped I/O port accesses.
|
|
|
|
noirqdebug [X86-32] Disables the code which attempts to detect and
|
|
disable unhandled interrupt sources.
|
|
|
|
no_timer_check [X86,APIC] Disables the code which tests for
|
|
broken timer IRQ sources.
|
|
|
|
noisapnp [ISAPNP] Disables ISA PnP code.
|
|
|
|
noinitrd [RAM] Tells the kernel not to load any configured
|
|
initial RAM disk.
|
|
|
|
nointremap [X86-64, Intel-IOMMU] Do not enable interrupt
|
|
remapping.
|
|
|
|
nointroute [IA-64]
|
|
|
|
nojitter [IA64] Disables jitter checking for ITC timers.
|
|
|
|
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 [X86-32] Machine Check Exception
|
|
|
|
nomfgpt [X86-32] Disable Multi-Function General Purpose
|
|
Timer usage (for AMD Geode machines).
|
|
|
|
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-smp [X86-32,SMP] Don't replace SMP instructions
|
|
with UP alternatives
|
|
|
|
noresidual [PPC] Don't use residual data on PReP machines.
|
|
|
|
noresume [SWSUSP] Disables resume and restores original swap
|
|
space.
|
|
|
|
no-scroll [VGA] Disables scrollback.
|
|
This is required for the Braillex ib80-piezo Braille
|
|
reader made by F.H. Papenmeier (Germany).
|
|
|
|
nosbagart [IA-64]
|
|
|
|
nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
|
|
|
|
nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
|
|
and disable the IO APIC. legacy for "maxcpus=0".
|
|
|
|
nosoftlockup [KNL] Disable the soft-lockup detector.
|
|
|
|
noswapaccount [KNL] Disable accounting of swap in memory resource
|
|
controller. (See Documentation/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
|
|
|
|
nowb [ARM]
|
|
|
|
nox2apic [X86-64,APIC] Do not enable x2APIC mode.
|
|
|
|
nptcg= [IA64] Override max number of concurrent global TLB
|
|
purges which is reported from either PAL_VM_SUMMARY or
|
|
SAL PALO.
|
|
|
|
nr_uarts= [SERIAL] maximum number of UARTs to be registered.
|
|
|
|
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.
|
|
|
|
ohci1394_dma=early [HW] enable debugging via the ohci1394 driver.
|
|
See Documentation/debugging-via-ohci1394.txt for more
|
|
info.
|
|
|
|
olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
|
|
Rather than timing out after 20 ms if an EC
|
|
command is not properly ACKed, override the length
|
|
of the timeout. We have interrupts disabled while
|
|
waiting for the ACK, so if this is set too high
|
|
interrupts *may* be lost!
|
|
|
|
opl3= [HW,OSS]
|
|
Format: <io>
|
|
|
|
oprofile.timer= [HW]
|
|
Use timer interrupt instead of performance counters
|
|
|
|
oprofile.cpu_type= Force an oprofile cpu type
|
|
This might be useful if you have an older oprofile
|
|
userland or if you want common events.
|
|
Format: { arch_perfmon }
|
|
arch_perfmon: [X86] Force use of architectural
|
|
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.
|
|
|
|
panic= [KNL] Kernel behaviour on panic
|
|
Format: <timeout>
|
|
|
|
parkbd.port= [HW] Parallel port number the keyboard adapter is
|
|
connected to, default is 0.
|
|
Format: <parport#>
|
|
parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
|
|
0 for XT, 1 for AT (default is AT).
|
|
Format: <mode>
|
|
|
|
parport= [HW,PPT] Specify parallel ports. 0 disables.
|
|
Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
|
|
Use 'auto' to force the driver to use any
|
|
IRQ/DMA settings detected (the default is to
|
|
ignore detected IRQ/DMA settings because of
|
|
possible conflicts). You can specify the base
|
|
address, IRQ, and DMA settings; IRQ and DMA
|
|
should be numbers, or 'auto' (for using detected
|
|
settings on that particular port), or 'nofifo'
|
|
(to avoid using a FIFO even if it is detected).
|
|
Parallel ports are assigned in the order they
|
|
are specified on the command line, starting
|
|
with parport0.
|
|
|
|
parport_init_mode= [HW,PPT]
|
|
Configure VIA parallel port to operate in
|
|
a specific mode. This is necessary on Pegasos
|
|
computer where firmware has no options for setting
|
|
up parallel port mode and sets it to spp.
|
|
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
|
|
your oopses keep scrolling off the screen.
|
|
|
|
pcbit= [HW,ISDN]
|
|
|
|
pcd. [PARIDE]
|
|
See header of drivers/block/paride/pcd.c.
|
|
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
|
|
has a non-standard PCI host bridge.
|
|
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 [X86] Force use of PCI Configuration
|
|
Mechanism 1.
|
|
conf2 [X86] Force use of PCI Configuration
|
|
Mechanism 2.
|
|
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] Disable use of MMCONFIG for PCI
|
|
Configuration
|
|
check_enable_amd_mmconf [X86] check for and enable
|
|
properly configured MMIO access to PCI
|
|
config space on AMD family 10h CPU
|
|
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.
|
|
noioapicquirk [APIC] Disable all boot interrupt quirks.
|
|
Safety option to keep boot IRQs enabled. This
|
|
should never be necessary.
|
|
ioapicreroute [APIC] Enable rerouting of boot IRQs to the
|
|
primary IO-APIC for bridges that cannot disable
|
|
boot IRQs. This fixes a source of spurious IRQs
|
|
when the system masks IRQs.
|
|
noioapicreroute [APIC] Disable workaround that uses the
|
|
boot IRQ equivalent of an IRQ that connects to
|
|
a chipset where boot IRQs cannot be disabled.
|
|
The opposite of ioapicreroute.
|
|
biosirq [X86-32] Use PCI BIOS calls to get the interrupt
|
|
routing table. These calls are known to be buggy
|
|
on several machines and they hang the machine
|
|
when used, but on other computers it's the only
|
|
way to get the interrupt routing table. Try
|
|
this option if the kernel is unable to allocate
|
|
IRQs or discover secondary PCI buses on your
|
|
motherboard.
|
|
rom [X86] Assign address space to expansion ROMs.
|
|
Use with caution as certain devices share
|
|
address decoders between ROMs and other
|
|
resources.
|
|
norom [X86] Do not assign address space to
|
|
expansion ROMs that do not already have
|
|
BIOS assigned address ranges.
|
|
irqmask=0xMMMM [X86] Set a bit mask of IRQs allowed to be
|
|
assigned automatically to PCI devices. You can
|
|
make the kernel exclude IRQs of your ISA cards
|
|
this way.
|
|
pirqaddr=0xAAAAA [X86] Specify the physical address
|
|
of the PIRQ table (normally generated
|
|
by the BIOS) if it is outside the
|
|
F0000h-100000h range.
|
|
lastbus=N [X86] Scan all buses thru bus #N. Can be
|
|
useful if the kernel is unable to find your
|
|
secondary buses and you want to tell it
|
|
explicitly which ones they are.
|
|
assign-busses [X86] Always assign all PCI bus
|
|
numbers ourselves, overriding
|
|
whatever the firmware may have done.
|
|
usepirqmask [X86] Honor the possible IRQ mask stored
|
|
in the BIOS $PIR table. This is needed on
|
|
some systems with broken BIOSes, notably
|
|
some HP Pavilion N5400 and Omnibook XE3
|
|
notebooks. This will have no effect if ACPI
|
|
IRQ routing is enabled.
|
|
noacpi [X86] Do not use ACPI for IRQ routing
|
|
or for PCI scanning.
|
|
use_crs [X86] Use _CRS for PCI resource
|
|
allocation.
|
|
routeirq Do IRQ routing for all PCI devices.
|
|
This is normally done in pci_enable_device(),
|
|
so this option is a temporary workaround
|
|
for broken drivers that don't call it.
|
|
skip_isa_align [X86] do not align io start addr, so can
|
|
handle more pci cards
|
|
firmware [ARM] Do not re-enumerate the bus but instead
|
|
just use the configuration from the
|
|
bootloader. This is currently used on
|
|
IXP2000 systems where the bus has to be
|
|
configured a certain way for adjunct CPUs.
|
|
noearly [X86] Don't do any early type 1 scanning.
|
|
This might help on some broken boards which
|
|
machine check when some devices' config space
|
|
is read. But various workarounds are disabled
|
|
and some IOMMU drivers will not work.
|
|
bfsort Sort PCI devices into breadth-first order.
|
|
This sorting is done to get a device
|
|
order compatible with older (<= 2.4) kernels.
|
|
nobfsort Don't sort PCI devices into breadth-first order.
|
|
cbiosize=nn[KMG] The fixed amount of bus space which is
|
|
reserved for the CardBus bridge's IO window.
|
|
The default value is 256 bytes.
|
|
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.
|
|
ecrc= Enable/disable PCIe ECRC (transaction layer
|
|
end-to-end CRC checking).
|
|
bios: Use BIOS/firmware settings. This is the
|
|
the default.
|
|
off: Turn ECRC off
|
|
on: Turn ECRC on.
|
|
|
|
pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
|
|
Management.
|
|
off Disable ASPM.
|
|
force Enable ASPM even on devices that claim not to support it.
|
|
WARNING: Forcing ASPM on may cause system lockups.
|
|
|
|
pcmv= [HW,PCMCIA] BadgePAD 4
|
|
|
|
pd. [PARIDE]
|
|
See Documentation/blockdev/paride.txt.
|
|
|
|
pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
|
|
boot time.
|
|
Format: { 0 | 1 }
|
|
See arch/parisc/kernel/pdc_chassis.c
|
|
|
|
percpu_alloc= Select which percpu first chunk allocator to use.
|
|
Currently supported values are "embed" and "page".
|
|
Archs may support subset or none of the selections.
|
|
See comments in mm/percpu.c for details on each
|
|
allocator. This parameter is primarily for debugging
|
|
and performance comparison.
|
|
|
|
pf. [PARIDE]
|
|
See Documentation/blockdev/paride.txt.
|
|
|
|
pg. [PARIDE]
|
|
See Documentation/blockdev/paride.txt.
|
|
|
|
pirq= [SMP,APIC] Manual mp-table setup
|
|
See Documentation/x86/i386/IO-APIC.txt.
|
|
|
|
plip= [PPT,NET] Parallel port network link
|
|
Format: { parport<nr> | timid | 0 }
|
|
See also Documentation/parport.txt.
|
|
|
|
pmtmr= [X86] Manual setup of pmtmr I/O Port.
|
|
Override pmtimer IOPort with a hex value.
|
|
e.g. pmtmr=0x508
|
|
|
|
pnp.debug [PNP]
|
|
Enable PNP debug messages. This depends on the
|
|
CONFIG_PNP_DEBUG_MESSAGES option.
|
|
|
|
pnpacpi= [ACPI]
|
|
{ off }
|
|
|
|
pnpbios= [ISAPNP]
|
|
{ on | off | curr | res | no-curr | no-res }
|
|
|
|
pnp_reserve_irq=
|
|
[ISAPNP] Exclude IRQs for the autoconfiguration
|
|
|
|
pnp_reserve_dma=
|
|
[ISAPNP] Exclude DMAs for the autoconfiguration
|
|
|
|
pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
|
|
Ranges are in pairs (I/O port base and size).
|
|
|
|
pnp_reserve_mem=
|
|
[ISAPNP] Exclude memory regions for the
|
|
autoconfiguration.
|
|
Ranges are in pairs (memory base and size).
|
|
|
|
ports= [IP_VS_FTP] IPVS ftp helper module
|
|
Default is 21.
|
|
Up to 8 (IP_VS_APP_MAX_PORTS) ports
|
|
may be specified.
|
|
Format: <port>,<port>....
|
|
|
|
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)
|
|
|
|
processor.max_cstate= [HW,ACPI]
|
|
Limit processor to maximum C-state
|
|
max_cstate=9 overrides any DMI blacklist limit.
|
|
|
|
processor.nocst [HW,ACPI]
|
|
Ignore the _CST method to determine C-states,
|
|
instead using the legacy FADT method
|
|
|
|
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).
|
|
Requires CONFIG_SCHEDSTATS
|
|
Param: "kvm" - profile VM exits.
|
|
|
|
prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
|
|
before loading.
|
|
See Documentation/blockdev/ramdisk.txt.
|
|
|
|
psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
|
|
probe for; one of (bare|imps|exps|lifebook|any).
|
|
psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
|
|
per second.
|
|
psmouse.resetafter= [HW,MOUSE]
|
|
Try to reset the device after so many bad packets
|
|
(0 = never).
|
|
psmouse.resolution=
|
|
[HW,MOUSE] Set desired mouse resolution, in dpi.
|
|
psmouse.smartscroll=
|
|
[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.
|
|
|
|
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_blocksize= [RAM]
|
|
See Documentation/blockdev/ramdisk.txt.
|
|
|
|
ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
|
|
See Documentation/blockdev/ramdisk.txt.
|
|
|
|
rcupdate.blimit= [KNL,BOOT]
|
|
Set maximum number of finished RCU callbacks to process
|
|
in one batch.
|
|
|
|
rcupdate.qhimark= [KNL,BOOT]
|
|
Set threshold of queued
|
|
RCU callbacks over which batch limiting is disabled.
|
|
|
|
rcupdate.qlowmark= [KNL,BOOT]
|
|
Set threshold of queued RCU callbacks below which
|
|
batch limiting is re-enabled.
|
|
|
|
rdinit= [KNL]
|
|
Format: <full_path>
|
|
Run specified binary instead of /init from the ramdisk,
|
|
used for early userspace startup. See initrd.
|
|
|
|
reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
|
|
Format: <reboot_mode>[,<reboot_mode2>[,...]]
|
|
See arch/*/kernel/reboot.c or arch/*/kernel/process.c
|
|
|
|
relax_domain_level=
|
|
[KNL, SMP] Set scheduler's default relax_domain_level.
|
|
See Documentation/cgroups/cpusets.txt.
|
|
|
|
reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
|
|
|
|
reservetop= [X86-32]
|
|
Format: nn[KMG]
|
|
Reserves a hole at the top of the kernel virtual
|
|
address space.
|
|
|
|
reset_devices [KNL] Force drivers to reset the underlying device
|
|
during initialization.
|
|
|
|
resume= [SWSUSP]
|
|
Specify the partition device for software suspend
|
|
|
|
resume_offset= [SWSUSP]
|
|
Specify the offset from the beginning of the partition
|
|
given by "resume=" at which the swap header is located,
|
|
in <PAGE_SIZE> units (needed only for swap files).
|
|
See Documentation/power/swsusp-and-swap-files.txt
|
|
|
|
retain_initrd [RAM] Keep initrd memory after extraction
|
|
|
|
rhash_entries= [KNL,NET]
|
|
Set number of hash buckets for route cache
|
|
|
|
riscom8= [HW,SERIAL]
|
|
Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
|
|
|
|
ro [KNL] Mount root device read-only on boot
|
|
|
|
root= [KNL] Root filesystem
|
|
|
|
rootdelay= [KNL] Delay (in seconds) to pause before attempting to
|
|
mount the root filesystem
|
|
|
|
rootflags= [KNL] Set root filesystem mount option string
|
|
|
|
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.
|
|
|
|
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.
|
|
|
|
security= [SECURITY] Choose a security module to enable at boot.
|
|
If this boot parameter is not specified, only the first
|
|
security module asking for security registration will be
|
|
loaded. An invalid security module name will be treated
|
|
as if no module has been chosen.
|
|
|
|
selinux= [SELINUX] Disable or enable SELinux at boot time.
|
|
Format: { "0" | "1" }
|
|
See security/selinux/Kconfig help text.
|
|
0 -- disable.
|
|
1 -- enable.
|
|
Default value is set via kernel config option.
|
|
If enabled at boot time, /selinux/disable can be used
|
|
later to disable prior to initial policy load.
|
|
|
|
serialnumber [BUGS=X86-32]
|
|
|
|
shapers= [NET]
|
|
Maximal number of shapers.
|
|
|
|
show_msr= [x86] show boot-time MSR settings
|
|
Format: { <integer> }
|
|
Show boot-time (BIOS-initialized) MSR settings.
|
|
The parameter means the number of CPUs to show,
|
|
for example 1 means boot CPU only.
|
|
|
|
sim710= [SCSI,HW]
|
|
See header of drivers/scsi/sim710.c.
|
|
|
|
simeth= [IA-64]
|
|
simscsi=
|
|
|
|
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 [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
|
|
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-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.
|
|
|
|
sonypi.*= [HW] Sony Programmable I/O Control Device driver
|
|
See Documentation/sonypi.txt
|
|
|
|
specialix= [HW,SERIAL] Specialix multi-serial port adapter
|
|
See Documentation/serial/specialix.txt.
|
|
|
|
spia_io_base= [HW,MTD]
|
|
spia_fio_base=
|
|
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.
|
|
|
|
sti= [PARISC,HW]
|
|
Format: <num>
|
|
Set the STI (builtin display/keyboard on the HP-PARISC
|
|
machines) console (graphic card) which should be used
|
|
as the initial boot-console.
|
|
See also comment in drivers/video/console/sticore.c.
|
|
|
|
sti_font= [HW]
|
|
See comment in drivers/video/console/sticore.c.
|
|
|
|
stifb= [HW]
|
|
Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
|
|
|
|
sunrpc.min_resvport=
|
|
sunrpc.max_resvport=
|
|
[NFS,SUNRPC]
|
|
SunRPC servers often require that client requests
|
|
originate from a privileged port (i.e. a port in the
|
|
range 0 < portnr < 1024).
|
|
An administrator who wishes to reserve some of these
|
|
ports for other uses may adjust the range that the
|
|
kernel's sunrpc client considers to be privileged
|
|
using these two parameters to set the minimum and
|
|
maximum port values.
|
|
|
|
sunrpc.pool_mode=
|
|
[NFS]
|
|
Control how the NFS server code allocates CPUs to
|
|
service thread pools. Depending on how many NICs
|
|
you have and where their interrupts are bound, this
|
|
option will affect which CPUs will do NFS serving.
|
|
Note: this parameter cannot be changed while the
|
|
NFS server is running.
|
|
|
|
auto the server chooses an appropriate mode
|
|
automatically using heuristics
|
|
global a single global pool contains all CPUs
|
|
percpu one pool for each CPU
|
|
pernode one pool for each NUMA node (equivalent
|
|
to global on non-NUMA machines)
|
|
|
|
sunrpc.tcp_slot_table_entries=
|
|
sunrpc.udp_slot_table_entries=
|
|
[NFS,SUNRPC]
|
|
Sets the upper limit on the number of simultaneous
|
|
RPC calls that can be sent from the client to a
|
|
server. Increasing these values may allow you to
|
|
improve throughput, but will also increase the
|
|
amount of memory reserved for use by the client.
|
|
|
|
swiotlb= [IA-64] Number of I/O TLB slabs
|
|
|
|
switches= [HW,M68k]
|
|
|
|
sym53c416= [HW,SCSI]
|
|
See header of drivers/scsi/sym53c416.c.
|
|
|
|
sysrq_always_enabled
|
|
[KNL]
|
|
Ignore sysrq setting - this boot parameter will
|
|
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]
|
|
Specify "mem" (for Suspend-to-RAM) or "standby" (for
|
|
standby suspend) as the system sleep state to briefly
|
|
enter during system startup. The system is woken from
|
|
this state using a wakeup-capable RTC alarm.
|
|
|
|
thash_entries= [KNL,NET]
|
|
Set number of hash buckets for TCP connection
|
|
|
|
thermal.act= [HW,ACPI]
|
|
-1: disable all active trip points in all thermal zones
|
|
<degrees C>: override all lowest active trip points
|
|
|
|
thermal.crt= [HW,ACPI]
|
|
-1: disable all critical trip points in all thermal zones
|
|
<degrees C>: override all critical trip points
|
|
|
|
thermal.nocrt= [HW,ACPI]
|
|
Set to disable actions on ACPI thermal zone
|
|
critical and hot trip points.
|
|
|
|
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)
|
|
|
|
tmscsim= [HW,SCSI]
|
|
See comment before function dc390_setup() in
|
|
drivers/scsi/tmscsim.c.
|
|
|
|
topology= [S390]
|
|
Format: {off | on}
|
|
Specify if the kernel should make use of the cpu
|
|
topology informations if the hardware supports these.
|
|
The scheduler will make use of these informations and
|
|
e.g. base its process migration decisions on it.
|
|
Default is off.
|
|
|
|
tp720= [HW,PS2]
|
|
|
|
trace_buf_size=nn[KMG]
|
|
[FTRACE] will set tracing buffer size.
|
|
|
|
trace_event=[event-list]
|
|
[FTRACE] Set and start specified trace events in order
|
|
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.
|
|
Format: <string>
|
|
[x86] reliable: mark tsc clocksource as reliable, this
|
|
disables clocksource verification at runtime.
|
|
Used to enable high-resolution timer mode on older
|
|
hardware, and in virtualized environment.
|
|
|
|
turbografx.map[2|3]= [HW,JOY]
|
|
TurboGraFX parallel port interface
|
|
Format:
|
|
<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>
|
|
|
|
uhci-hcd.ignore_oc=
|
|
[USB] Ignore overcurrent events (default N).
|
|
Some badly-designed motherboards generate lots of
|
|
bogus events, for ports that aren't wired to
|
|
anything. Set this parameter to avoid log spamming.
|
|
Note that genuine overcurrent events won't be
|
|
reported either.
|
|
|
|
unknown_nmi_panic
|
|
[X86]
|
|
Set unknown_nmi_panic=1 early on boot.
|
|
|
|
usbcore.autosuspend=
|
|
[USB] The autosuspend time delay (in seconds) used
|
|
for newly-detected USB devices (default 2). This
|
|
is the time required before an idle device will be
|
|
autosuspended. Devices for which the delay is set
|
|
to a negative value won't be autosuspended at all.
|
|
|
|
usbcore.usbfs_snoop=
|
|
[USB] Set to log all usbfs traffic (default 0 = off).
|
|
|
|
usbcore.blinkenlights=
|
|
[USB] Set to cycle leds on hubs (default 0 = off).
|
|
|
|
usbcore.old_scheme_first=
|
|
[USB] Start with the old device initialization
|
|
scheme (default 0 = off).
|
|
|
|
usbcore.use_both_schemes=
|
|
[USB] Try the other device initialization scheme
|
|
if the first one fails (default 1 = enabled).
|
|
|
|
usbcore.initial_descriptor_timeout=
|
|
[USB] Specifies timeout for the initial 64-byte
|
|
USB_REQ_GET_DESCRIPTOR request in milliseconds
|
|
(default 5000 = 5.0 seconds).
|
|
|
|
usbhid.mousepoll=
|
|
[USBHID] The interval which mice are to be polled at.
|
|
|
|
usb-storage.delay_use=
|
|
[UMS] The delay in seconds before a new device is
|
|
scanned for Logical Units (default 5).
|
|
|
|
usb-storage.quirks=
|
|
[UMS] A list of quirks entries to supplement or
|
|
override the built-in unusual_devs list. List
|
|
entries are separated by commas. Each entry has
|
|
the form VID:PID:Flags where VID and PID are Vendor
|
|
and Product ID values (4-digit hex numbers) and
|
|
Flags is a set of characters, each corresponding
|
|
to a common usb-storage quirk flag as follows:
|
|
a = SANE_SENSE (collect more than 18 bytes
|
|
of sense data);
|
|
c = FIX_CAPACITY (decrease the reported
|
|
device capacity by one sector);
|
|
h = CAPACITY_HEURISTICS (decrease the
|
|
reported device capacity by one
|
|
sector if the number is odd);
|
|
i = IGNORE_DEVICE (don't bind to this
|
|
device);
|
|
l = NOT_LOCKABLE (don't try to lock and
|
|
unlock ejectable media);
|
|
m = MAX_SECTORS_64 (don't transfer more
|
|
than 64 sectors = 32 KB at a time);
|
|
o = CAPACITY_OK (accept the capacity
|
|
reported by the device);
|
|
r = IGNORE_RESIDUE (the device reports
|
|
bogus residue values);
|
|
s = SINGLE_LUN (the device has only one
|
|
Logical Unit);
|
|
w = NO_WP_DETECT (don't test whether the
|
|
medium is write-protected).
|
|
Example: quirks=0419:aaf5:rl,0421:0433:rc
|
|
|
|
vdso= [X86,SH]
|
|
vdso=2: enable compat VDSO (default with COMPAT_VDSO)
|
|
vdso=1: enable VDSO (default)
|
|
vdso=0: disable VDSO mapping
|
|
|
|
vdso32= [X86]
|
|
vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
|
|
vdso32=1: enable 32-bit VDSO (default)
|
|
vdso32=0: disable 32-bit VDSO mapping
|
|
|
|
vector= [IA-64,SMP]
|
|
vector=percpu: enable percpu vector domain
|
|
|
|
video= [FB] Frame buffer configuration
|
|
See Documentation/fb/modedb.txt.
|
|
|
|
vga= [BOOT,X86-32] Select a particular video mode
|
|
See Documentation/x86/boot.txt and
|
|
Documentation/svga.txt.
|
|
Use vga=ask for menu.
|
|
This is actually a boot loader parameter; the value is
|
|
passed to the kernel using a special protocol.
|
|
|
|
vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
|
|
size of <nn>. This can be used to increase the
|
|
minimum size (128MB on x86). It can also be used to
|
|
decrease the size and leave more room for directly
|
|
mapped kernel RAM.
|
|
|
|
vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
|
|
Format: <command>
|
|
|
|
vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
|
|
Format: <command>
|
|
|
|
vmpoff= [KNL,S390] Perform z/VM CP command after power off.
|
|
Format: <command>
|
|
|
|
vt.default_blu= [VT]
|
|
Format: <blue0>,<blue1>,<blue2>,...,<blue15>
|
|
Change the default blue palette of the console.
|
|
This is a 16-member array composed of values
|
|
ranging from 0-255.
|
|
|
|
vt.default_grn= [VT]
|
|
Format: <green0>,<green1>,<green2>,...,<green15>
|
|
Change the default green palette of the console.
|
|
This is a 16-member array composed of values
|
|
ranging from 0-255.
|
|
|
|
vt.default_red= [VT]
|
|
Format: <red0>,<red1>,<red2>,...,<red15>
|
|
Change the default red palette of the console.
|
|
This is a 16-member array composed of values
|
|
ranging from 0-255.
|
|
|
|
vt.default_utf8=
|
|
[VT]
|
|
Format=<0|1>
|
|
Set system-wide default UTF-8 mode for all tty's.
|
|
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.
|
|
|
|
x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
|
|
default x2apic cluster mode on platforms
|
|
supporting x2apic.
|
|
|
|
xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
|
|
xd_geo= See header of drivers/block/xd.c.
|
|
|
|
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.
|