aboutsummaryrefslogtreecommitdiff
path: root/Documentation/kernel-parameters.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/kernel-parameters.txt')
-rw-r--r--Documentation/kernel-parameters.txt122
1 files changed, 92 insertions, 30 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index a2d8805c03d..8511d3532c2 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -91,6 +91,7 @@ parameter is applicable:
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.
@@ -140,6 +141,7 @@ and is between 256 and 4096 characters. It is defined in the file
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
@@ -150,16 +152,20 @@ and is between 256 and 4096 characters. It is defined in the file
default: 0
acpi_sleep= [HW,ACPI] Sleep options
- Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig, old_ordering }
- See Documentation/power/video.txt for s3_bios and s3_mode.
+ Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
+ old_ordering, s4_nonvs }
+ See Documentation/power/video.txt for information on
+ s3_bios and s3_mode.
s3_beep is for debugging; it makes the PC's speaker beep
as soon as the kernel's real-mode entry point is called.
s4_nohwsig prevents ACPI hardware signature from being
used during resume from hibernation.
old_ordering causes the ACPI 1.0 ordering of the _PTS
- control method, wrt putting devices into low power
- states, to be enforced (the ACPI 2.0 ordering of _PTS is
- used by default).
+ control method, with respect to putting devices into
+ low power states, to be enforced (the ACPI 2.0 ordering
+ of _PTS is used by default).
+ s4_nonvs prevents the kernel from saving/restoring the
+ ACPI NVS memory during hibernation.
acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
Format: { level | edge | high | low }
@@ -194,7 +200,7 @@ and is between 256 and 4096 characters. It is defined in the file
acpi_skip_timer_override [HW,ACPI]
Recognize and ignore IRQ0/pin2 Interrupt Override.
For broken nForce2 BIOS resulting in XT-PIC timer.
- acpi_use_timer_override [HW,ACPI}
+ acpi_use_timer_override [HW,ACPI]
Use timer override. For some broken Nvidia NF5 boards
that require a timer override, but don't have
HPET
@@ -469,8 +475,8 @@ and is between 256 and 4096 characters. It is defined in the file
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
+ 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
@@ -551,6 +557,11 @@ and is between 256 and 4096 characters. It is defined in the file
not work reliably with all consoles, but is known
to work with serial and VGA consoles.
+ 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>]
@@ -823,8 +834,8 @@ and is between 256 and 4096 characters. It is defined in the file
hlt [BUGS=ARM,SH]
- hvc_iucv= [S390] Number of z/VM IUCV Hypervisor console (HVC)
- back-ends. Valid parameters: 0..8
+ hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC)
+ terminal devices. Valid values: 0..8
i8042.debug [HW] Toggle i8042 debug mode
i8042.direct [HW] Put keyboard port into non-translated mode
@@ -872,17 +883,19 @@ and is between 256 and 4096 characters. It is defined in the file
See Documentation/ide/ide.txt.
idle= [X86]
- Format: idle=poll or idle=mwait, idle=halt, idle=nomwait
- Poll forces a polling idle loop that can slightly improves the performance
- of waking up a idle CPU, but will use a lot of power and make the system
- run hot. Not recommended.
- idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose
- to not use it because it doesn't save as much power as a normal idle
- loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
- as idle=poll.
- idle=halt. Halt is forced to be used for CPU idle.
+ Format: idle=poll, idle=mwait, idle=halt, idle=nomwait
+ Poll forces a polling idle loop that can slightly
+ improve the performance of waking up a idle CPU, but
+ will use a lot of power and make the system run hot.
+ Not recommended.
+ idle=mwait: On systems which support MONITOR/MWAIT but
+ the kernel chose to not use it because it doesn't save
+ as much power as a normal idle loop, use the
+ MONITOR/MWAIT idle loop anyways. Performance should be
+ the same as idle=poll.
+ idle=halt: Halt is forced to be used for CPU idle.
In such case C2/C3 won't be used again.
- idle=nomwait. Disable mwait for CPU C-states
+ idle=nomwait: Disable mwait for CPU C-states
ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
Claim all unknown PCI IDE storage controllers.
@@ -913,6 +926,10 @@ and is between 256 and 4096 characters. It is defined in the file
inttest= [IA64]
+ iomem= Disable strict checking of access to MMIO memory
+ strict regions from userspace.
+ relaxed
+
iommu= [x86]
off
force
@@ -1064,8 +1081,8 @@ and is between 256 and 4096 characters. It is defined in the file
lapic [X86-32,APIC] Enable the local APIC even if BIOS
disabled it.
- lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in
- C2 power state.
+ lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer
+ in C2 power state.
libata.dma= [LIBATA] DMA control
libata.dma=0 Disable all PATA and SATA DMA
@@ -1117,6 +1134,8 @@ and is between 256 and 4096 characters. It is defined in the file
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.
@@ -1550,6 +1569,9 @@ and is between 256 and 4096 characters. It is defined in the file
nosoftlockup [KNL] Disable the soft-lockup detector.
+ noswapaccount [KNL] Disable accounting of swap in memory resource
+ controller. (See Documentation/controllers/memory.txt)
+
nosync [HW,M68K] Disables sync negotiation for all devices.
notsc [BUGS=X86-32] Disable Time Stamp Counter
@@ -1569,6 +1591,10 @@ and is between 256 and 4096 characters. It is defined in the file
nr_uarts= [SERIAL] maximum number of UARTs to be registered.
+ 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
@@ -1793,10 +1819,10 @@ and is between 256 and 4096 characters. It is defined in the file
autoconfiguration.
Ranges are in pairs (memory base and size).
- dynamic_printk
- Enables pr_debug()/dev_dbg() calls if
- CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled. These can also
- be switched on/off via <debugfs>/dynamic_printk/modules
+ dynamic_printk Enables pr_debug()/dev_dbg() calls if
+ CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled.
+ These can also be switched on/off via
+ <debugfs>/dynamic_printk/modules
print-fatal-signals=
[KNL] debug: print fatal signals
@@ -1884,7 +1910,7 @@ and is between 256 and 4096 characters. It is defined in the file
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
+ See arch/*/kernel/reboot.c or arch/*/kernel/process.c
relax_domain_level=
[KNL, SMP] Set scheduler's default relax_domain_level.
@@ -2284,7 +2310,8 @@ and is between 256 and 4096 characters. It is defined in the file
thermal.psv= [HW,ACPI]
-1: disable all passive trip points
- <degrees C>: override all passive trip points to this value
+ <degrees C>: override all passive trip points to this
+ value
thermal.tzp= [HW,ACPI]
Specify global default ACPI thermal zone polling rate
@@ -2372,6 +2399,41 @@ and is between 256 and 4096 characters. It is defined in the file
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
+
add_efi_memmap [EFI; x86-32,X86-64] Include EFI memory map in
kernel's map of available physical RAM.
@@ -2432,8 +2494,8 @@ and is between 256 and 4096 characters. It is defined in the file
Format:
<irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
- norandmaps Don't use address space randomization
- Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
+ norandmaps Don't use address space randomization. Equivalent to
+ echo 0 > /proc/sys/kernel/randomize_va_space
______________________________________________________________________