-February 2003 Kernel Parameters v2.5.59
+ Kernel Parameters
~~~~~~~~~~~~~~~~~
The following is a consolidated list of the kernel parameters as implemented
usbcore.blinkenlights=1
-The text in square brackets at the beginning of the description states the
-restrictions on the kernel for the said kernel parameter to be valid. The
-restrictions referred to are that the relevant option is valid if:
+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.
ALSA ALSA sound support is enabled.
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 support is enabled.
NET Appropriate network support is enabled.
NUMA NUMA support is enabled.
timesource is not avalible, it defaults to PIT.
Format: { pit | tsc | cyclone | pmtmr }
+ disable_8254_timer
+ enable_8254_timer
+ [IA32/X86_64] Disable/Enable interrupt 0 timer routing
+ over the 8254 in addition to over the IO-APIC. The
+ kernel tries to set a sensible default.
+
hpet= [IA-32,HPET] option to disable HPET and use PIT.
Format: disable
tty<n> Use the virtual console device <n>.
ttyS<n>[,options]
+ ttyUSB0[,options]
Use the specified serial port. The options are of
- the form "bbbbpn", where "bbbb" is the baud rate,
- "p" is parity ("n", "o", or "e"), and "n" is bits.
- Default is "9600n8".
+ 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 also Documentation/serial-console.txt.
+ See Documentation/serial-console.txt for more
+ information. See
+ Documentation/networking/netconsole.txt for an
+ alternative.
uart,io,<addr>[,options]
uart,mmio,<addr>[,options]
noexec=on: enable non-executable mappings (default)
noexec=off: disable nn-executable mappings
- nofxsr [BUGS=IA-32]
+ nofxsr [BUGS=IA-32] Disables x86 floating point extended
+ register save and restore. The kernel will only save
+ legacy floating-point registers on task switch.
nohlt [BUGS=ARM]
noltlbs [PPC] Do not use large page/tlb entries for kernel
lowmem mapping on PPC40x.
+ nomca [IA-64] Disable machine check abort handling
+
nomce [IA-32] Machine Check Exception
noresidual [PPC] Don't use residual data on PReP machines.
nosbagart [IA-64]
+ nosep [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
+
nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
nosync [HW,M68K] Disables sync negotiation for all devices.
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]
Mechanism 2.
nommconf [IA-32,X86_64] Disable use of MMCONFIG for PCI
Configuration
+ 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.
nosort [IA-32] Don't sort PCI devices according to
order given by the PCI BIOS. This sorting is
done to get a device order compatible with
New name for the ramdisk parameter.
See Documentation/ramdisk.txt.
+ rcu.blimit= [KNL,BOOT] Set maximum number of finished
+ RCU callbacks to process in one batch.
+
+ rcu.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.
+
+ rcu.rsinterval= [KNL,BOOT,SMP] Set the number of additional
+ RCU callbacks to queued before forcing reschedule
+ on all cpus.
+
rdinit= [KNL]
Format: <full_path>
Run specified binary instead of /init from the ramdisk,
If enabled at boot time, /selinux/disable can be used
later to disable prior to initial policy load.
+ selinux_compat_net =
+ [SELINUX] Set initial selinux_compat_net flag value.
+ Format: { "0" | "1" }
+ 0 -- use new secmark-based packet controls
+ 1 -- use legacy packet controls
+ Default value is 0 (preferred).
+ Value can be changed at runtime via
+ /selinux/compat_net.
+
serialnumber [BUGS=IA-32]
sg_def_reserved_size= [SCSI]
______________________________________________________________________
-Changelog:
-
-2000-06-?? Mr. Unknown
- The last known update (for 2.4.0) - the changelog was not kept before.
-
-2002-11-24 Petr Baudis <pasky@ucw.cz>
- Randy Dunlap <randy.dunlap@verizon.net>
- Update for 2.5.49, description for most of the options introduced,
- references to other documentation (C files, READMEs, ..), added S390,
- PPC, SPARC, MTD, ALSA and OSS category. Minor corrections and
- reformatting.
-
-2005-10-19 Randy Dunlap <rdunlap@xenotime.net>
- Lots of typos, whitespace, some reformatting.
TODO: