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-rw-r--r--Documentation/kernel-parameters.txt148
1 files changed, 113 insertions, 35 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index cd7c861..a0c5c5f 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -40,6 +40,7 @@ parameter is applicable:
ALSA ALSA sound support is enabled.
APIC APIC support is enabled.
APM Advanced Power Management support is enabled.
+ ARM ARM architecture is enabled.
AVR32 AVR32 architecture is enabled.
AX25 Appropriate AX.25 support is enabled.
BLACKFIN Blackfin architecture is enabled.
@@ -50,6 +51,7 @@ parameter is applicable:
EIDE EIDE/ATAPI support is enabled.
EVM Extended Verification Module
FB The frame buffer device is enabled.
+ FTRACE Function tracing enabled.
GCOV GCOV profiling is enabled.
HW Appropriate hardware is enabled.
IA-64 IA-64 architecture is enabled.
@@ -70,6 +72,7 @@ parameter is applicable:
Documentation/m68k/kernel-options.txt.
MCA MCA bus support is enabled.
MDA MDA console support is enabled.
+ MIPS MIPS architecture is enabled.
MOUSE Appropriate mouse support is enabled.
MSI Message Signaled Interrupts (PCI).
MTD MTD (Memory Technology Device) support is enabled.
@@ -101,7 +104,6 @@ parameter is applicable:
SPARC Sparc architecture is enabled.
SWSUSP Software suspend (hibernation) is enabled.
SUSPEND System suspend states are enabled.
- FTRACE Function tracing enabled.
TPM TPM drivers are enabled.
TS Appropriate touchscreen support is enabled.
UMS USB Mass Storage support is enabled.
@@ -116,7 +118,7 @@ parameter is applicable:
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)
+ X86 Either 32-bit or 64-bit x86 (same as X86-32+X86-64)
XEN Xen support is enabled
In addition, the following text indicates that the option:
@@ -162,7 +164,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
rsdt -- prefer RSDT over (default) XSDT
copy_dsdt -- copy DSDT to memory
- See also Documentation/power/pm.txt, pci=noacpi
+ See also Documentation/power/runtime_pm.txt, pci=noacpi
acpi_rsdp= [ACPI,EFI,KEXEC]
Pass the RSDP address to the kernel, mostly used
@@ -305,6 +307,19 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
behaviour to be specified. Bit 0 enables warnings,
bit 1 enables fixups, and bit 2 sends a segfault.
+ align_va_addr= [X86-64]
+ Align virtual addresses by clearing slice [14:12] when
+ allocating a VMA at process creation time. This option
+ gives you up to 3% performance improvement on AMD F15h
+ machines (where it is enabled by default) for a
+ CPU-intensive style benchmark, and it can vary highly in
+ a microbenchmark depending on workload and compiler.
+
+ 1: only for 32-bit processes
+ 2: only for 64-bit processes
+ on: enable for both 32- and 64-bit processes
+ off: disable for both 32- and 64-bit processes
+
amd_iommu= [HW,X86-84]
Pass parameters to the AMD IOMMU driver in the system.
Possible values are:
@@ -318,7 +333,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
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
+ See also Documentation/input/joystick.txt
analog.map= [HW,JOY] Analog joystick and gamepad support
Specifies type or capabilities of an analog joystick
@@ -377,7 +392,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
atkbd.softrepeat= [HW]
Use software keyboard repeat
- autotest [IA64]
+ autotest [IA-64]
baycom_epp= [HW,AX25]
Format: <io>,<mode>
@@ -407,7 +422,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
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
+ bttv.tuner=
bulk_remove=off [PPC] This parameter disables the use of the pSeries
firmware feature for flushing multiple hpte entries
@@ -682,8 +697,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
uart[8250],mmio32,<addr>[,options]
Start an early, polled-mode console on the 8250/16550
UART at the specified I/O port or MMIO address.
- MMIO inter-register address stride is either 8bit (mmio)
- or 32bit (mmio32).
+ MMIO inter-register address stride is either 8-bit
+ (mmio) or 32-bit (mmio32).
The options are the same as for ttyS, above.
earlyprintk= [X86,SH,BLACKFIN]
@@ -723,13 +738,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
elevator= [IOSCHED]
Format: {"cfq" | "deadline" | "noop"}
- See Documentation/block/as-iosched.txt and
+ See Documentation/block/cfq-iosched.txt and
Documentation/block/deadline-iosched.txt for details.
- elfcorehdr= [IA64,PPC,SH,X86]
+ elfcorehdr=[size[KMG]@]offset[KMG] [IA64,PPC,SH,X86,S390]
Specifies physical address of start of kernel core
- image elf header. Generally kexec loader will
- pass this option to capture kernel.
+ image elf header and optionally the size. Generally
+ kexec loader will pass this option to capture kernel.
See Documentation/kdump/kdump.txt for details.
enable_mtrr_cleanup [X86]
@@ -769,7 +784,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
fail_make_request=[KNL]
General fault injection mechanism.
Format: <interval>,<probability>,<space>,<times>
- See also /Documentation/fault-injection/.
+ See also Documentation/fault-injection/.
floppy= [HW]
See Documentation/blockdev/floppy.txt.
@@ -797,7 +812,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
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.
+ tracing directory.
ftrace_notrace=[function-list]
[FTRACE] Do not trace the functions specified in
@@ -835,7 +850,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
hashdist= [KNL,NUMA] Large hashes allocated during boot
are distributed across NUMA nodes. Defaults on
- for 64bit NUMA, off otherwise.
+ for 64-bit NUMA, off otherwise.
Format: 0 | 1 (for off | on)
hcl= [IA-64] SGI's Hardware Graph compatibility layer
@@ -958,6 +973,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
ignore_loglevel [KNL]
Ignore loglevel setting - this will print /all/
kernel messages to the console. Useful for debugging.
+ We also add it as printk module parameter, so users
+ could change it dynamically, usually by
+ /sys/module/printk/parameters/ignore_loglevel.
ihash_entries= [KNL]
Set number of hash buckets for inode cache.
@@ -1004,10 +1022,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
DMA.
forcedac [x86_64]
With this option iommu will not optimize to look
- for io virtual address below 32 bit forcing dual
+ 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
+ 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
@@ -1018,12 +1036,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
has the capability. With this option, super page will
not be supported.
intremap= [X86-64, Intel-IOMMU]
- Format: { on (default) | off | nosid }
on enable Interrupt Remapping (default)
off disable Interrupt Remapping
nosid disable Source ID checking
+ no_x2apic_optout
+ BIOS x2APIC opt-out request will be ignored
- inttest= [IA64]
+ inttest= [IA-64]
iomem= Disable strict checking of access to MMIO memory
strict regions from userspace.
@@ -1040,7 +1059,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
nomerge
forcesac
soft
- pt [x86, IA64]
+ pt [x86, IA-64]
io7= [HW] IO7 for Marvel based alpha systems
See comment before marvel_specify_io7 in
@@ -1171,7 +1190,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
for all guests.
- Default is 1 (enabled) if in 64bit or 32bit-PAE mode
+ Default is 1 (enabled) if in 64-bit or 32-bit PAE mode.
kvm-intel.ept= [KVM,Intel] Disable extended page tables
(virtualized MMU) support on capable Intel chips.
@@ -1185,6 +1204,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
[KVM,Intel] Disable FlexPriority feature (TPR shadow).
Default is 1 (enabled)
+ kvm-intel.nested=
+ [KVM,Intel] Enable VMX nesting (nVMX).
+ Default is 0 (disabled)
+
kvm-intel.unrestricted_guest=
[KVM,Intel] Disable unrestricted guest feature
(virtualized real and unpaged mode) on capable
@@ -1208,10 +1231,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
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
+ 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
@@ -1337,7 +1360,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
ltpc= [NET]
Format: <io>,<irq>,<dma>
- machvec= [IA64] Force the use of a particular machine-vector
+ machvec= [IA-64] Force the use of a particular machine-vector
(machvec) in a generic kernel.
Example: machvec=hpzx1_swiotlb
@@ -1354,9 +1377,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
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_loop= [LOOP] The number of loop block devices that get
+ (loop.max_loop) unconditionally pre-created at init time. The default
+ number is configured by BLK_DEV_LOOP_MIN_COUNT. Instead
+ of statically allocating a predefined number, loop
+ devices can be requested on-demand with the
+ /dev/loop-control interface.
mcatest= [IA-64]
@@ -1643,6 +1669,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
debugging driver suspend/resume hooks). This may
not work reliably with all consoles, but is known
to work with serial and VGA consoles.
+ To facilitate more flexible debugging, we also add
+ console_suspend, a printk module parameter to control
+ it. Users could use console_suspend (usually
+ /sys/module/printk/parameters/console_suspend) to
+ turn on/off it dynamically.
noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
caches in the slab allocator. Saves per-node memory,
@@ -1740,7 +1771,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
nointroute [IA-64]
- nojitter [IA64] Disables jitter checking for ITC timers.
+ nojitter [IA-64] Disables jitter checking for ITC timers.
no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
@@ -1778,6 +1809,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
noresidual [PPC] Don't use residual data on PReP machines.
+ nordrand [X86] Disable the direct use of the RDRAND
+ instruction even if it is supported by the
+ processor. RDRAND is still available to user
+ space applications.
+
noresume [SWSUSP] Disables resume and restores original swap
space.
@@ -1806,7 +1842,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
nox2apic [X86-64,APIC] Do not enable x2APIC mode.
- nptcg= [IA64] Override max number of concurrent global TLB
+ nptcg= [IA-64] Override max number of concurrent global TLB
purges which is reported from either PAL_VM_SUMMARY or
SAL PALO.
@@ -2083,13 +2119,16 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
Format: { parport<nr> | timid | 0 }
See also Documentation/parport.txt.
- pmtmr= [X86] Manual setup of pmtmr I/O Port.
+ 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.
+ pnp.debug=1 [PNP]
+ Enable PNP debug messages (depends on the
+ CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
+ via /sys/module/pnp/parameters/debug. We always show
+ current resource usage; turning this on also shows
+ possible settings and some assignment information.
pnpacpi= [ACPI]
{ off }
@@ -2238,6 +2277,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
in <PAGE_SIZE> units (needed only for swap files).
See Documentation/power/swsusp-and-swap-files.txt
+ resumedelay= [HIBERNATION] Delay (in seconds) to pause before attempting to
+ read the resume files
+
+ resumewait [HIBERNATION] Wait (indefinitely) for resume device to show up.
+ Useful for devices that are detected asynchronously
+ (e.g. USB and MMC devices).
+
hibernate= [HIBERNATION]
noresume Don't check if there's a hibernation image
present during boot.
@@ -2373,7 +2419,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
Format: <integer>
sonypi.*= [HW] Sony Programmable I/O Control Device driver
- See Documentation/sonypi.txt
+ See Documentation/laptops/sonypi.txt
specialix= [HW,SERIAL] Specialix multi-serial port adapter
See Documentation/serial/specialix.txt.
@@ -2641,6 +2687,16 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
medium is write-protected).
Example: quirks=0419:aaf5:rl,0421:0433:rc
+ user_debug= [KNL,ARM]
+ Format: <int>
+ See arch/arm/Kconfig.debug help text.
+ 1 - undefined instruction events
+ 2 - system calls
+ 4 - invalid data aborts
+ 8 - SIGSEGV faults
+ 16 - SIGBUS faults
+ Example: user_debug=31
+
userpte=
[X86] Flags controlling user PTE allocations.
@@ -2686,6 +2742,28 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
vmpoff= [KNL,S390] Perform z/VM CP command after power off.
Format: <command>
+ vsyscall= [X86-64]
+ Controls the behavior of vsyscalls (i.e. calls to
+ fixed addresses of 0xffffffffff600x00 from legacy
+ code). Most statically-linked binaries and older
+ versions of glibc use these calls. Because these
+ functions are at fixed addresses, they make nice
+ targets for exploits that can control RIP.
+
+ emulate Vsyscalls turn into traps and are emulated
+ reasonably safely.
+
+ native [default] Vsyscalls are native syscall
+ instructions.
+ This is a little bit faster than trapping
+ and makes a few dynamic recompilers work
+ better than they would in emulation mode.
+ It also makes exploits much easier to write.
+
+ none Vsyscalls don't work at all. This makes
+ them quite hard to use for exploits but
+ might break your system.
+
vt.cur_default= [VT] Default cursor shape.
Format: 0xCCBBAA, where AA, BB, and CC are the same as
the parameters of the <Esc>[?A;B;Cc escape sequence;