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-rw-r--r--Documentation/kernel-parameters.txt149
1 files changed, 121 insertions, 28 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index fa4faeb7597..92e1ab8178a 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -17,6 +17,12 @@ are specified on the kernel command line with the module name plus
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
@@ -42,6 +48,7 @@ parameter is applicable:
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.
@@ -50,7 +57,6 @@ parameter is applicable:
ISAPNP ISA PnP code is enabled.
ISDN Appropriate ISDN support is enabled.
JOY Appropriate joystick support is enabled.
- KMEMTRACE kmemtrace is enabled.
LIBATA Libata driver is enabled
LP Printer support is enabled.
LOOP Loopback device support is enabled.
@@ -323,11 +329,6 @@ and is between 256 and 4096 characters. It is defined in the file
flushed before they will be reused, which
is a lot of faster
- amd_iommu_size= [HW,X86-64]
- Define the size of the aperture for the AMD IOMMU
- driver. Possible values are:
- '32M', '64M' (default), '128M', '256M', '512M', '1G'
-
amijoy.map= [HW,JOY] Amiga joystick support
Map of devices attached to JOY0DAT and JOY1DAT
Format: <a>,<b>
@@ -345,7 +346,7 @@ and is between 256 and 4096 characters. It is defined in the file
not play well with APC CPU idle - disable it if you have
APC and your system crashes randomly.
- apic= [APIC,i386] Advanced Programmable Interrupt Controller
+ 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
@@ -491,6 +492,13 @@ and is between 256 and 4096 characters. It is defined in the file
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
@@ -539,6 +547,10 @@ and is between 256 and 4096 characters. It is defined in the file
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.
@@ -640,6 +652,13 @@ and is between 256 and 4096 characters. It is defined in the file
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]
@@ -702,7 +721,7 @@ and is between 256 and 4096 characters. It is defined in the file
to discrete, to make X server driver able to add WB
entry later. This parameter enables that.
- enable_timer_pin_1 [i386,x86-64]
+ 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).
@@ -746,12 +765,25 @@ and is between 256 and 4096 characters. It is defined in the file
ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
ftrace=[tracer]
- [ftrace] will set and start the specified 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] 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
@@ -765,6 +797,12 @@ and is between 256 and 4096 characters. It is defined in the file
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.
@@ -775,7 +813,7 @@ and is between 256 and 4096 characters. It is defined in the file
hashdist= [KNL,NUMA] Large hashes allocated during boot
are distributed across NUMA nodes. Defaults on
- for IA-64, off otherwise.
+ for 64bit NUMA, off otherwise.
Format: 0 | 1 (for off | on)
hcl= [IA-64] SGI's Hardware Graph compatibility layer
@@ -867,11 +905,8 @@ and is between 256 and 4096 characters. It is defined in the file
ide-core.nodma= [HW] (E)IDE subsystem
Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc
- .vlb_clock .pci_clock .noflush .noprobe .nowerr .cdrom
- .chs .ignore_cable are additional options
- See Documentation/ide/ide.txt.
-
- idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
+ .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
@@ -908,6 +943,12 @@ and is between 256 and 4096 characters. It is defined in the file
Formt: { "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.
@@ -1049,24 +1090,19 @@ and is between 256 and 4096 characters. It is defined in the file
use the HighMem zone if it exists, and the Normal
zone if it does not.
- kmemtrace.enable= [KNL,KMEMTRACE] Format: { yes | no }
- Controls whether kmemtrace is enabled
- at boot-time.
-
- kmemtrace.subbufs=n [KNL,KMEMTRACE] Overrides the number of
- subbufs kmemtrace's relay channel has. Set this
- higher than default (KMEMTRACE_N_SUBBUFS in code) if
- you experience buffer overruns.
-
kgdboc= [HW] kgdb over consoles.
Requires a tty driver that supports console polling.
- (only serial suported for now)
+ (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.
@@ -1334,6 +1370,27 @@ and is between 256 and 4096 characters. It is defined in the file
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
@@ -1375,6 +1432,16 @@ and is between 256 and 4096 characters. It is defined in the file
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
@@ -1385,7 +1452,7 @@ and is between 256 and 4096 characters. It is defined in the file
('y', default) or cooked coordinates ('n')
mtrr_chunk_size=nn[KMG] [X86]
- used for mtrr cleanup. It is largest continous chunk
+ used for mtrr cleanup. It is largest continuous chunk
that could hold holes aka. UC entries.
mtrr_gran_size=nn[KMG] [X86]
@@ -1530,6 +1597,10 @@ and is between 256 and 4096 characters. It is defined in the file
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.
@@ -1566,6 +1637,9 @@ and is between 256 and 4096 characters. It is defined in the file
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.
@@ -1621,6 +1695,8 @@ and is between 256 and 4096 characters. It is defined in the file
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.
@@ -1649,6 +1725,14 @@ and is between 256 and 4096 characters. It is defined in the file
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: { archperfmon }
+ archperfmon: [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.
@@ -1724,6 +1808,9 @@ and is between 256 and 4096 characters. It is defined in the file
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.
@@ -1776,7 +1863,7 @@ and is between 256 and 4096 characters. It is defined in the file
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
+ nocrs [X86] Don't use _CRS for PCI resource
allocation.
routeirq Do IRQ routing for all PCI devices.
This is normally done in pci_enable_device(),
@@ -1813,6 +1900,12 @@ and is between 256 and 4096 characters. It is defined in the file
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.