summaryrefslogtreecommitdiff
path: root/Documentation/kernel-parameters.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/kernel-parameters.txt')
-rw-r--r--Documentation/kernel-parameters.txt125
1 files changed, 107 insertions, 18 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 9107b38..d80930d 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -54,6 +54,7 @@ parameter is applicable:
IMA Integrity measurement architecture is enabled.
IOSCHED More than one I/O scheduler is enabled.
IP_PNP IP DHCP, BOOTP, or RARP is enabled.
+ IPV6 IPv6 support is enabled.
ISAPNP ISA PnP code is enabled.
ISDN Appropriate ISDN support is enabled.
JOY Appropriate joystick support is enabled.
@@ -85,7 +86,6 @@ parameter is applicable:
PPT Parallel port support is enabled.
PS2 Appropriate PS/2 support is enabled.
RAM RAM disk support is enabled.
- ROOTPLUG The example Root Plug LSM is enabled.
S390 S390 architecture is enabled.
SCSI Appropriate SCSI support is enabled.
A lot of drivers has their options described inside of
@@ -200,6 +200,10 @@ and is between 256 and 4096 characters. It is defined in the file
acpi_display_output=video
See above.
+ acpi_early_pdc_eval [HW,ACPI] Evaluate processor _PDC methods
+ early. Needed on some platforms to properly
+ initialize the EC.
+
acpi_irq_balance [HW,ACPI]
ACPI will balance active IRQs
default in APIC mode
@@ -241,7 +245,7 @@ and is between 256 and 4096 characters. It is defined in the file
acpi_sleep= [HW,ACPI] Sleep options
Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
- old_ordering, s4_nonvs }
+ old_ordering, s4_nonvs, sci_force_enable }
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
@@ -254,6 +258,9 @@ and is between 256 and 4096 characters. It is defined in the file
of _PTS is used by default).
s4_nonvs prevents the kernel from saving/restoring the
ACPI NVS memory during hibernation.
+ sci_force_enable causes the kernel to set SCI_EN directly
+ on resume from S1/S3 (which is against the ACPI spec,
+ but some broken systems don't work without it).
acpi_use_timer_override [HW,ACPI]
Use timer override. For some broken Nvidia NF5 boards
@@ -309,6 +316,11 @@ and is between 256 and 4096 characters. It is defined in the file
aic79xx= [HW,SCSI]
See Documentation/scsi/aic79xx.txt.
+ alignment= [KNL,ARM]
+ Allow the default userspace alignment fault handler
+ behaviour to be specified. Bit 0 enables warnings,
+ bit 1 enables fixups, and bit 2 sends a segfault.
+
amd_iommu= [HW,X86-84]
Pass parameters to the AMD IOMMU driver in the system.
Possible values are:
@@ -345,6 +357,18 @@ and is between 256 and 4096 characters. It is defined in the file
Change the amount of debugging information output
when initialising the APIC and IO-APIC components.
+ autoconf= [IPV6]
+ See Documentation/networking/ipv6.txt.
+
+ show_lapic= [APIC,X86] Advanced Programmable Interrupt Controller
+ Limit apic dumping. The parameter defines the maximal
+ number of local apics being dumped. Also it is possible
+ to set it to "all" by meaning -- no limit here.
+ Format: { 1 (default) | 2 | ... | all }.
+ The parameter valid if only apic=debug or
+ apic=verbose is specified.
+ Example: apic=debug show_lapic=all
+
apm= [APM] Advanced Power Management
See header of arch/x86/kernel/apm_32.c.
@@ -618,6 +642,12 @@ and is between 256 and 4096 characters. It is defined in the file
See drivers/char/README.epca and
Documentation/serial/digiepca.txt.
+ disable= [IPV6]
+ See Documentation/networking/ipv6.txt.
+
+ disable_ipv6= [IPV6]
+ See Documentation/networking/ipv6.txt.
+
disable_mtrr_cleanup [X86]
The kernel tries to adjust MTRR layout from continuous
to discrete, to make X server driver able to add WB
@@ -779,6 +809,13 @@ and is between 256 and 4096 characters. It is defined in the file
by the set_ftrace_notrace file in the debugfs
tracing directory.
+ ftrace_graph_filter=[function-list]
+ [FTRACE] Limit the top level callers functions traced
+ by the function graph tracer at boot up.
+ function-list is a comma separated list of functions
+ that can be changed at run time by the
+ set_graph_function file in the debugfs tracing directory.
+
gamecon.map[2|3]=
[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
support via parallel port (up to 5 devices per port)
@@ -1017,7 +1054,7 @@ and is between 256 and 4096 characters. It is defined in the file
No delay
ip= [IP_PNP]
- See Documentation/filesystems/nfsroot.txt.
+ See Documentation/filesystems/nfs/nfsroot.txt.
ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
See comment before ip2_setup() in
@@ -1538,10 +1575,10 @@ and is between 256 and 4096 characters. It is defined in the file
going to be removed in 2.6.29.
nfsaddrs= [NFS]
- See Documentation/filesystems/nfsroot.txt.
+ See Documentation/filesystems/nfs/nfsroot.txt.
nfsroot= [NFS] nfs root filesystem for disk-less boxes.
- See Documentation/filesystems/nfsroot.txt.
+ See Documentation/filesystems/nfs/nfsroot.txt.
nfs.callback_tcpport=
[NFS] set the TCP port on which the NFSv4 callback
@@ -1711,6 +1748,9 @@ and is between 256 and 4096 characters. It is defined in the file
nomfgpt [X86-32] Disable Multi-Function General Purpose
Timer usage (for AMD Geode machines).
+ nopat [X86] Disable PAT (page attribute table extension of
+ pagetables) support.
+
norandmaps Don't use address space randomization. Equivalent to
echo 0 > /proc/sys/kernel/randomize_va_space
@@ -1754,6 +1794,12 @@ and is between 256 and 4096 characters. It is defined in the file
purges which is reported from either PAL_VM_SUMMARY or
SAL PALO.
+ nr_cpus= [SMP] Maximum number of processors that an SMP kernel
+ could support. nr_cpus=n : n >= 1 limits the kernel to
+ supporting 'n' processors. Later in runtime you can not
+ use hotplug cpu feature to put more cpu back to online.
+ just like you compile the kernel NR_CPUS=n
+
nr_uarts= [SERIAL] maximum number of UARTs to be registered.
numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
@@ -1772,6 +1818,11 @@ and is between 256 and 4096 characters. It is defined in the file
waiting for the ACK, so if this is set too high
interrupts *may* be lost!
+ omap_mux= [OMAP] Override bootloader pin multiplexing.
+ Format: <mux_mode0.mode_name=value>...
+ For example, to override I2C bus2:
+ omap_mux=i2c2_scl.i2c2_scl=0x100,i2c2_sda.i2c2_sda=0x100
+
opl3= [HW,OSS]
Format: <io>
@@ -1916,8 +1967,12 @@ 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
- allocation.
+ use_crs [X86] Use PCI host bridge window information
+ from ACPI. On BIOSes from 2008 or later, this
+ is enabled by default. If you need to use this,
+ please report a bug.
+ nocrs [X86] Ignore PCI host bridge windows from ACPI.
+ If you need to use this, please report a bug.
routeirq Do IRQ routing for all PCI devices.
This is normally done in pci_enable_device(),
so this option is a temporary workaround
@@ -1966,6 +2021,14 @@ and is between 256 and 4096 characters. It is defined in the file
force Enable ASPM even on devices that claim not to support it.
WARNING: Forcing ASPM on may cause system lockups.
+ pcie_pme= [PCIE,PM] Native PCIe PME signaling options:
+ off Do not use native PCIe PME signaling.
+ force Use native PCIe PME signaling even if the BIOS refuses
+ to allow the kernel to control the relevant PCIe config
+ registers.
+ nomsi Do not use MSI for native PCIe PME signaling (this makes
+ all PCIe root ports use INTx for everything).
+
pcmv= [HW,PCMCIA] BadgePAD 4
pd. [PARIDE]
@@ -2032,8 +2095,15 @@ and is between 256 and 4096 characters. It is defined in the file
print-fatal-signals=
[KNL] debug: print fatal signals
- print-fatal-signals=1: print segfault info to
- the kernel console.
+
+ If enabled, warn about various signal handling
+ related application anomalies: too many signals,
+ too many POSIX.1 timers, fatal signals causing a
+ coredump - etc.
+
+ If you hit the warning due to signal overflow,
+ you might want to try "ulimit -i unlimited".
+
default: off.
printk.time= Show timing data prefixed to each printk message line
@@ -2164,15 +2234,6 @@ and is between 256 and 4096 characters. It is defined in the file
Useful for devices that are detected asynchronously
(e.g. USB and MMC devices).
- root_plug.vendor_id=
- [ROOTPLUG] Override the default vendor ID
-
- root_plug.product_id=
- [ROOTPLUG] Override the default product ID
-
- root_plug.debug=
- [ROOTPLUG] Enable debugging output
-
rw [KNL] Mount root device read-write on boot
S [KNL] Run init in single mode
@@ -2182,6 +2243,8 @@ and is between 256 and 4096 characters. It is defined in the file
sbni= [NET] Granch SBNI12 leased line adapter
+ sched_debug [KNL] Enables verbose scheduler debug messages.
+
sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
Format: <io>[,<timeout>[,<isapnp>]]
@@ -2590,6 +2653,9 @@ and is between 256 and 4096 characters. It is defined in the file
uart6850= [HW,OSS]
Format: <io>,<irq>
+ uhash_entries= [KNL,NET]
+ Set number of hash buckets for UDP/UDP-Lite connections
+
uhci-hcd.ignore_oc=
[USB] Ignore overcurrent events (default N).
Some badly-designed motherboards generate lots of
@@ -2645,6 +2711,8 @@ and is between 256 and 4096 characters. It is defined in the file
to a common usb-storage quirk flag as follows:
a = SANE_SENSE (collect more than 18 bytes
of sense data);
+ b = BAD_SENSE (don't collect more than 18
+ bytes of sense data);
c = FIX_CAPACITY (decrease the reported
device capacity by one sector);
h = CAPACITY_HEURISTICS (decrease the
@@ -2666,6 +2734,13 @@ and is between 256 and 4096 characters. It is defined in the file
medium is write-protected).
Example: quirks=0419:aaf5:rl,0421:0433:rc
+ userpte=
+ [X86] Flags controlling user PTE allocations.
+
+ nohigh = do not allocate PTE pages in
+ HIGHMEM regardless of setting
+ of CONFIG_HIGHPTE.
+
vdso= [X86,SH]
vdso=2: enable compat VDSO (default with COMPAT_VDSO)
vdso=1: enable VDSO (default)
@@ -2704,6 +2779,11 @@ and is between 256 and 4096 characters. It is defined in the file
vmpoff= [KNL,S390] Perform z/VM CP command after power off.
Format: <command>
+ 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;
+ see VGA-softcursor.txt. Default: 2 = underline.
+
vt.default_blu= [VT]
Format: <blue0>,<blue1>,<blue2>,...,<blue15>
Change the default blue palette of the console.
@@ -2729,6 +2809,15 @@ and is between 256 and 4096 characters. It is defined in the file
Default is 1, i.e. UTF-8 mode is enabled for all
newly opened terminals.
+ vt.global_cursor_default=
+ [VT]
+ Format=<-1|0|1>
+ Set system-wide default for whether a cursor
+ is shown on new VTs. Default is -1,
+ i.e. cursors will be created by default unless
+ overridden by individual drivers. 0 will hide
+ cursors, 1 will display them.
+
waveartist= [HW,OSS]
Format: <io>,<irq>,<dma>,<dma2>