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.
strict -- Be less tolerant of platforms that are not
strictly ACPI specification compliant.
- See also Documentation/pm.txt, pci=noacpi
+ See also Documentation/power/pm.txt, pci=noacpi
acpi_apic_instance= [ACPI, IOAPIC]
Format: <int>
default: 0
acpi_sleep= [HW,ACPI] Sleep options
- Format: { s3_bios, s3_mode }
- See Documentation/power/video.txt
+ Format: { s3_bios, s3_mode, s3_beep }
+ See Documentation/power/video.txt for 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.
acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
Format: { level | edge | high | low }
acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
Format: <irq>,<irq>...
+ acpi_new_pts_ordering [HW,ACPI]
+ Enforce the ACPI 2.0 ordering of the _PTS control
+ method wrt putting devices into low power states
+ default: pre ACPI 2.0 ordering of _PTS
+
acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
+ acpi_no_initrd_override [KNL,ACPI]
+ Disable loading custom ACPI tables from the initramfs
+
acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
Format: To spoof as Windows 98: ="Microsoft Windows"
configured. Potentially dangerous and should only be
used if you are entirely sure of the consequences.
- chandev= [HW,NET] Generic channel device initialisation
+ ccw_timeout_log [S390]
+ See Documentation/s390/CommonIO for details.
checkreqprot [SELINUX] Set initial checkreqprot flag value.
Format: { "0" | "1" }
Value can be changed at runtime via
/selinux/checkreqprot.
+ cio_ignore= [S390]
+ See Documentation/s390/CommonIO for details.
+
+ cio_msg= [S390]
+ See Documentation/s390/CommonIO for details.
+
clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
[Deprecated]
Forces specified clocksource (if available) to be used
[SPARC64] tick
[X86-64] hpet,tsc
- code_bytes [IA32] How many bytes of object code to print in an
- oops report.
+ clearcpuid=BITNUM [X86]
+ Disable CPUID feature X for the kernel. See
+ include/asm-x86/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.
+
+ code_bytes [IA32/X86_64] How many bytes of object code to print
+ in an oops report.
Range: 0 - 8192
Default: 64
1 will print _a lot_ more information - normally
only useful to kernel developers.
- decnet= [HW,NET]
+ decnet.addr= [HW,NET]
Format: <area>[,<node>]
See also Documentation/networking/decnet.txt.
- default_blu= [VT]
+ 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.
- default_grn= [VT]
+ 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.
- default_red= [VT]
+ 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.
- default_utf8= [VT]
+ vt.default_utf8=
+ [VT]
Format=<0|1>
Set system-wide default UTF-8 mode for all tty's.
- Default is 0 and by setting to 1, it enables UTF-8
- mode for all newly opened or allocated terminals.
+ Default is 1, i.e. UTF-8 mode is enabled for all
+ newly opened terminals.
dhash_entries= [KNL]
Set number of hash buckets for dentry cache.
See drivers/char/README.epca and
Documentation/digiepca.txt.
+ 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.
+
dmasound= [HW,OSS] Sound subsystem buffers
dscc4.setup= [NET]
gamma= [HW,DRM]
+ gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
+ Format: off | on
+ default: on
+
gdth= [HW,SCSI]
See header of drivers/scsi/gdth.c.
Format: <cyl>,<head>,<sect>
hd?= [HW] (E)IDE subsystem
- hd?lun= See Documentation/ide.txt.
+ hd?lun= See Documentation/ide/ide.txt.
highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
size of <nn>. This works even on boxes that have no
ide= [HW] (E)IDE subsystem
Format: ide=nodma or ide=doubler or ide=reverse
- See Documentation/ide.txt.
+ See Documentation/ide/ide.txt.
ide?= [HW] (E)IDE subsystem
Format: ide?=noprobe or chipset specific parameters.
- See Documentation/ide.txt.
+ See Documentation/ide/ide.txt.
idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
- See Documentation/ide.txt.
+ See Documentation/ide/ide.txt.
idle= [X86]
Format: idle=poll or idle=mwait
loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
as idle=poll.
+ ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
+ Claim all unknown PCI IDE storage controllers.
+
ignore_loglevel [KNL]
Ignore loglevel setting - this will print /all/
kernel messages to the console. Useful for debugging.
for translation below 32 bit and if not available
then look in the higher range.
+ io_delay= [X86-32,X86-64] 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
+
io7= [HW] IO7 for Marvel based alpha systems
See comment before marvel_specify_io7 in
arch/alpha/kernel/core_marvel.c.
lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in
C2 power state.
+ libata.dma= [LIBATA] DMA control
+ libata.dma=0 Disable all PATA and SATA DMA
+ 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.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.
+
+ If there are multiple matching configurations changing
+ the same attribute, the last one is used.
+
load_ramdisk= [RAM] List of ramdisks to load from floppy
See Documentation/ramdisk.txt.
[SCSI] Maximum number of LUNs received.
Should be between 1 and 16384.
- mca-pentium [BUGS=X86-32]
-
mcatest= [IA-64]
mce [X86-32] Machine Check Exception
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]
mousedev.tap_time=
of returning the full 64-bit number.
The default is to return 64-bit inode numbers.
+ nmi_debug= [KNL,AVR32] Specify one or more actions to take
+ when a NMI is triggered.
+ Format: [state][,regs][,debounce][,die]
+
nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels
no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
+ noefi [X86-32,X86-64] Disable EFI runtime services support.
+
noexec [IA-64]
noexec [X86-32,X86-64]
register save and restore. The kernel will only save
legacy floating-point registers on task switch.
+ noclflush [BUGS=X86] Don't use the CLFLUSH instruction
+
nohlt [BUGS=ARM]
no-hlt [BUGS=X86-32] Tells the kernel that the hlt
ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
See Documentation/ramdisk.txt.
- rcu.blimit= [KNL,BOOT] Set maximum number of finished
- RCU callbacks to process in one batch.
+ rcupdate.blimit= [KNL,BOOT]
+ Set maximum number of finished RCU callbacks to process
+ in one batch.
- rcu.qhimark= [KNL,BOOT] Set threshold of queued
+ rcupdate.qhimark= [KNL,BOOT]
+ Set threshold of queued
RCU callbacks over which batch limiting is disabled.
- rcu.qlowmark= [KNL,BOOT] Set threshold of queued
- RCU callbacks below which batch limiting is re-enabled.
+ rcupdate.qlowmark= [KNL,BOOT]
+ Set threshold of queued RCU callbacks below which
+ batch limiting is re-enabled.
rdinit= [KNL]
Format: <full_path>
Format: <vendor>:<model>:<flags>
(flags are integer value)
- scsi_logging= [SCSI]
+ 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,
st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
See Documentation/scsi/st.txt.
- st0x= [HW,SCSI]
- See header of drivers/scsi/seagate.c.
-
sti= [PARISC,HW]
Format: <num>
Set the STI (builtin display/keyboard on the HP-PARISC
<deci-seconds>: poll all this frequency
0: no polling (default)
- time Show timing data prefixed to each printk message line
- [deprecated, see 'printk.time']
-
tipar.timeout= [HW,PPT]
Set communications timeout in tenths of a second
(default 15).
tipar.delay= [HW,PPT]
Set inter-bit delay in microseconds (default 10).
- tmc8xx= [HW,SCSI]
- See header of drivers/scsi/seagate.c.
-
tmscsim= [HW,SCSI]
See comment before function dc390_setup() in
drivers/scsi/tmscsim.c.
vdso=1: enable VDSO (default)
vdso=0: disable VDSO mapping
+ vdso32= [X86-32,X86-64]
+ 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