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authorIngo Molnar <mingo@elte.hu>2008-10-28 16:26:12 +0100
committerIngo Molnar <mingo@elte.hu>2008-10-28 16:26:12 +0100
commit7a9787e1eba95a166265e6a260cf30af04ef0a99 (patch)
treee730a4565e0318140d2fbd2f0415d18a339d7336 /Documentation/kernel-parameters.txt
parent41b9eb264c8407655db57b60b4457fe1b2ec9977 (diff)
parent0173a3265b228da319ceb9c1ec6a5682fd1b2d92 (diff)
Merge commit 'v2.6.28-rc2' into x86/pci-ioapic-boot-irq-quirks
Diffstat (limited to 'Documentation/kernel-parameters.txt')
-rw-r--r--Documentation/kernel-parameters.txt253
1 files changed, 204 insertions, 49 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 62b6e8067a5b..63bac584f9cb 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -87,7 +87,8 @@ parameter is applicable:
SH SuperH architecture is enabled.
SMP The kernel is an SMP kernel.
SPARC Sparc architecture is enabled.
- SWSUSP Software suspend is enabled.
+ SWSUSP Software suspend (hibernation) is enabled.
+ SUSPEND System suspend states are enabled.
TS Appropriate touchscreen support is enabled.
USB USB support is enabled.
USBHID USB Human Interface Device support is enabled.
@@ -100,6 +101,7 @@ parameter is applicable:
X86-64 X86-64 architecture is enabled.
More X86-64 boot options can be found in
Documentation/x86_64/boot-options.txt .
+ X86 Either 32bit or 64bit x86 (same as X86-32+X86-64)
In addition, the following text indicates that the option:
@@ -147,10 +149,12 @@ 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, old_ordering }
+ Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig, old_ordering }
See Documentation/power/video.txt for 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
@@ -214,20 +218,47 @@ and is between 256 and 4096 characters. It is defined in the file
acpi.debug_level= [HW,ACPI]
Format: <int>
Each bit of the <int> indicates an ACPI debug level,
- 1: enable, 0: disable. It is useful for boot time
- debugging. After system has booted up, it can be set
- via /sys/module/acpi/parameters/debug_level.
- CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
- Available bits (add the numbers together) to enable different
- debug output levels of the ACPI subsystem:
- 0x01 error 0x02 warn 0x04 init 0x08 debug object
- 0x10 info 0x20 init names 0x40 parse 0x80 load
- 0x100 dispatch 0x200 execute 0x400 names 0x800 operation region
- 0x1000 bfield 0x2000 tables 0x4000 values 0x8000 objects
- 0x10000 resources 0x20000 user requests 0x40000 package.
- The number can be in decimal or prefixed with 0x in hex.
- Warning: Many of these options can produce a lot of
- output and make your system unusable. Be very careful.
+ which corresponds to the level in an ACPI_DEBUG_PRINT
+ statement. After system has booted up, this mask
+ can be set via /sys/module/acpi/parameters/debug_level.
+
+ CONFIG_ACPI_DEBUG must be enabled for this to produce
+ any output. The number can be in decimal or prefixed
+ with 0x in hex. Some of these options produce so much
+ output that the system is unusable.
+
+ The following global components are defined by the
+ ACPI CA:
+ 0x01 error
+ 0x02 warn
+ 0x04 init
+ 0x08 debug object
+ 0x10 info
+ 0x20 init names
+ 0x40 parse
+ 0x80 load
+ 0x100 dispatch
+ 0x200 execute
+ 0x400 names
+ 0x800 operation region
+ 0x1000 bfield
+ 0x2000 tables
+ 0x4000 values
+ 0x8000 objects
+ 0x10000 resources
+ 0x20000 user requests
+ 0x40000 package
+ The number can be in decimal or prefixed with 0x in hex.
+ Warning: Many of these options can produce a lot of
+ output and make your system unusable. Be very careful.
+
+ acpi.power_nocheck= [HW,ACPI]
+ Format: 1/0 enable/disable the check of power state.
+ On some bogus BIOS the _PSC object/_STA object of
+ power resource can't return the correct device power
+ state. In such case it is unneccessary to check its
+ power state again in power transition.
+ 1 : disable the power state check
acpi_pm_good [X86-32,X86-64]
Override the pmtimer bug detection: force the kernel
@@ -281,6 +312,11 @@ and is between 256 and 4096 characters. It is defined in the file
isolate - enable device isolation (each device, as far
as possible, will get its own protection
domain)
+ fullflush - enable flushing of IO/TLB entries when
+ they are unmapped. Otherwise they are
+ 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:
@@ -362,6 +398,8 @@ and is between 256 and 4096 characters. It is defined in the file
no delay (0).
Format: integer
+ bootmem_debug [KNL] Enable bootmem allocator debug messages.
+
bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
bttv.radio= Most important insmod options are available as
kernel args too.
@@ -458,12 +496,6 @@ and is between 256 and 4096 characters. It is defined in the file
Range: 0 - 8192
Default: 64
- 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= [X86-32,HPET] option to control HPET usage
Format: { enable (default) | disable | force }
disable: disable HPET and use PIT instead
@@ -654,11 +686,12 @@ and is between 256 and 4096 characters. It is defined in the file
earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
earlyprintk=vga
earlyprintk=serial[,ttySn[,baudrate]]
+ earlyprintk=dbgp
Append ",keep" to not disable it when the real console
takes over.
- Only vga or serial at a time, not both.
+ Only vga or serial or usb debug port at a time.
Currently only ttyS0 and ttyS1 are supported.
@@ -685,7 +718,7 @@ and is between 256 and 4096 characters. It is defined in the file
See Documentation/block/as-iosched.txt and
Documentation/block/deadline-iosched.txt for details.
- elfcorehdr= [X86-32, X86_64]
+ elfcorehdr= [IA64,PPC,SH,X86-32,X86_64]
Specifies physical address of start of kernel core
image elf header. Generally kexec loader will
pass this option to capture kernel.
@@ -774,9 +807,26 @@ and is between 256 and 4096 characters. It is defined in the file
hisax= [HW,ISDN]
See Documentation/isdn/README.HiSax.
- hugepages= [HW,X86-32,IA-64] Maximal number of HugeTLB pages.
- hugepagesz= [HW,IA-64,PPC] The size of the HugeTLB pages.
-
+ hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot.
+ hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages.
+ On x86-64 and powerpc, this option can be specified
+ multiple times interleaved with hugepages= to reserve
+ huge pages of different sizes. Valid pages sizes on
+ x86-64 are 2M (when the CPU supports "pse") and 1G
+ (when the CPU supports the "pdpe1gb" cpuinfo flag)
+ Note that 1GB pages can only be allocated at boot time
+ using hugepages= and not freed afterwards.
+ default_hugepagesz=
+ [same as hugepagesz=] The size of the default
+ HugeTLB page size. This is the size represented by
+ the legacy /proc/ hugepages APIs, used for SHM, and
+ default size when mounting hugetlbfs filesystems.
+ Defaults to the default architecture's huge page size
+ if not specified.
+
+ hlt [BUGS=ARM,SH]
+
+ i8042.debug [HW] Toggle i8042 debug mode
i8042.direct [HW] Put keyboard port into non-translated mode
i8042.dumbkbd [HW] Pretend that controller can only read data from
keyboard and cannot control its state
@@ -1001,6 +1051,10 @@ and is between 256 and 4096 characters. It is defined in the file
(only serial suported for now)
Format: <serial_device>[,baud]
+ kmac= [MIPS] korina ethernet MAC address.
+ Configure the RouterBoard 532 series on-chip
+ Ethernet adapter MAC address.
+
l2cr= [PPC]
l3cr= [PPC]
@@ -1055,6 +1109,9 @@ and is between 256 and 4096 characters. It is defined in the file
* [no]ncq: Turn on or off NCQ.
+ * nohrst, nosrst, norst: suppress hard, soft
+ and both resets.
+
If there are multiple matching configurations changing
the same attribute, the last one is used.
@@ -1184,6 +1241,10 @@ and is between 256 and 4096 characters. It is defined in the file
mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
memory.
+ memchunk=nn[KMG]
+ [KNL,SH] Allow user to override the default size for
+ per-device physically contiguous DMA buffers.
+
memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
E820 memory map, as specified by the user.
Such memmap=exactmap lines can be constructed based on
@@ -1206,7 +1267,30 @@ and is between 256 and 4096 characters. It is defined in the file
or
memmap=0x10000$0x18690000
- memtest= [KNL,X86_64] Enable memtest
+ memory_corruption_check=0/1 [X86]
+ Some BIOSes seem to corrupt the first 64k of
+ memory when doing things like suspend/resume.
+ Setting this option will scan the memory
+ looking for corruption. Enabling this will
+ both detect corruption and prevent the kernel
+ from using the memory being corrupted.
+ However, its intended as a diagnostic tool; if
+ repeatable BIOS-originated corruption always
+ affects the same memory, you can use memmap=
+ to prevent the kernel from using that memory.
+
+ memory_corruption_check_size=size [X86]
+ By default it checks for corruption in the low
+ 64k, making this memory unavailable for normal
+ use. Use this parameter to scan for
+ corruption in more or less memory.
+
+ memory_corruption_check_period=seconds [X86]
+ By default it checks for corruption every 60
+ seconds. Use this parameter to check at some
+ other rate. 0 disables periodic checking.
+
+ memtest= [KNL,X86] Enable memtest
Format: <integer>
range: 0,4 : pattern number
default : 0 <disable>
@@ -1225,6 +1309,14 @@ and is between 256 and 4096 characters. It is defined in the file
mga= [HW,DRM]
+ mminit_loglevel=
+ [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
+ parameter allows control of the logging verbosity for
+ the additional memory initialisation checks. A value
+ of 0 disables mminit logging and a level of 4 will
+ log everything. Information is printed at KERN_DEBUG
+ so loglevel=8 may also need to be specified.
+
mousedev.tap_time=
[MOUSE] Maximum time between finger touching and
leaving touchpad surface for touch to be considered
@@ -1279,6 +1371,13 @@ and is between 256 and 4096 characters. It is defined in the file
This usage is only documented in each driver source
file if at all.
+ nf_conntrack.acct=
+ [NETFILTER] Enable connection tracking flow accounting
+ 0 to disable accounting
+ 1 to enable accounting
+ Default value depends on CONFIG_NF_CT_ACCT that is
+ going to be removed in 2.6.29.
+
nfsaddrs= [NFS]
See Documentation/filesystems/nfsroot.txt.
@@ -1328,6 +1427,8 @@ and is between 256 and 4096 characters. It is defined in the file
nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
+ nodsp [SH] Disable hardware DSP at boot time.
+
noefi [X86-32,X86-64] Disable EFI runtime services support.
noexec [IA-64]
@@ -1344,13 +1445,15 @@ and is between 256 and 4096 characters. It is defined in the file
noexec32=off: disable non-executable mappings
read implies executable mappings
+ nofpu [SH] Disable hardware FPU at boot time.
+
nofxsr [BUGS=X86-32] Disables x86 floating point extended
register save and restore. The kernel will only save
legacy floating-point registers on task switch.
noclflush [BUGS=X86] Don't use the CLFLUSH instruction
- nohlt [BUGS=ARM]
+ nohlt [BUGS=ARM,SH]
no-hlt [BUGS=X86-32] Tells the kernel that the hlt
instruction doesn't work correctly and not to
@@ -1388,6 +1491,12 @@ and is between 256 and 4096 characters. It is defined in the file
nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
+ nox2apic [X86-64,APIC] Do not enable x2APIC mode.
+
+ x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
+ default x2apic cluster mode on platforms
+ supporting x2apic.
+
noltlbs [PPC] Do not use large page/tlb entries for kernel
lowmem mapping on PPC40x.
@@ -1507,7 +1616,7 @@ and is between 256 and 4096 characters. It is defined in the file
See also Documentation/paride.txt.
pci=option[,option...] [PCI] various PCI subsystem options:
- off [X86-32] don't probe for the PCI bus
+ off [X86] don't probe for the PCI bus
bios [X86-32] force use of PCI BIOS, don't access
the hardware directly. Use this if your machine
has a non-standard PCI host bridge.
@@ -1515,9 +1624,9 @@ and is between 256 and 4096 characters. It is defined in the file
hardware access methods are allowed. Use this
if you experience crashes upon bootup and you
suspect they are caused by the BIOS.
- conf1 [X86-32] Force use of PCI Configuration
+ conf1 [X86] Force use of PCI Configuration
Mechanism 1.
- conf2 [X86-32] Force use of PCI Configuration
+ conf2 [X86] Force use of PCI Configuration
Mechanism 2.
noaer [PCIE] If the PCIEAER kernel config parameter is
enabled, this kernel boot option can be used to
@@ -1548,37 +1657,37 @@ and is between 256 and 4096 characters. It is defined in the file
this option if the kernel is unable to allocate
IRQs or discover secondary PCI buses on your
motherboard.
- rom [X86-32] Assign address space to expansion ROMs.
+ rom [X86] Assign address space to expansion ROMs.
Use with caution as certain devices share
address decoders between ROMs and other
resources.
- norom [X86-32,X86_64] Do not assign address space to
+ norom [X86] Do not assign address space to
expansion ROMs that do not already have
BIOS assigned address ranges.
- irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be
+ irqmask=0xMMMM [X86] Set a bit mask of IRQs allowed to be
assigned automatically to PCI devices. You can
make the kernel exclude IRQs of your ISA cards
this way.
- pirqaddr=0xAAAAA [X86-32] Specify the physical address
+ pirqaddr=0xAAAAA [X86] Specify the physical address
of the PIRQ table (normally generated
by the BIOS) if it is outside the
F0000h-100000h range.
- lastbus=N [X86-32] Scan all buses thru bus #N. Can be
+ lastbus=N [X86] Scan all buses thru bus #N. Can be
useful if the kernel is unable to find your
secondary buses and you want to tell it
explicitly which ones they are.
- assign-busses [X86-32] Always assign all PCI bus
+ assign-busses [X86] Always assign all PCI bus
numbers ourselves, overriding
whatever the firmware may have done.
- usepirqmask [X86-32] Honor the possible IRQ mask stored
+ usepirqmask [X86] Honor the possible IRQ mask stored
in the BIOS $PIR table. This is needed on
some systems with broken BIOSes, notably
some HP Pavilion N5400 and Omnibook XE3
notebooks. This will have no effect if ACPI
IRQ routing is enabled.
- noacpi [X86-32] Do not use ACPI for IRQ routing
+ noacpi [X86] Do not use ACPI for IRQ routing
or for PCI scanning.
- use_crs [X86-32] Use _CRS for PCI resource
+ use_crs [X86] Use _CRS for PCI resource
allocation.
routeirq Do IRQ routing for all PCI devices.
This is normally done in pci_enable_device(),
@@ -1607,6 +1716,12 @@ and is between 256 and 4096 characters. It is defined in the file
reserved for the CardBus bridge's memory
window. The default value is 64 megabytes.
+ pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
+ Management.
+ off Disable ASPM.
+ force Enable ASPM even on devices that claim not to support it.
+ WARNING: Forcing ASPM on may cause system lockups.
+
pcmv= [HW,PCMCIA] BadgePAD 4
pd. [PARIDE]
@@ -1634,6 +1749,10 @@ and is between 256 and 4096 characters. It is defined in the file
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.
+
pnpacpi= [ACPI]
{ off }
@@ -1654,6 +1773,11 @@ 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
+
print-fatal-signals=
[KNL] debug: print fatal signals
print-fatal-signals=1: print segfault info to
@@ -1856,6 +1980,12 @@ and is between 256 and 4096 characters. It is defined in the file
shapers= [NET]
Maximal number of shapers.
+ show_msr= [x86] show boot-time MSR settings
+ Format: { <integer> }
+ Show boot-time (BIOS-initialized) MSR settings.
+ The parameter means the number of CPUs to show,
+ for example 1 means boot CPU only.
+
sim710= [SCSI,HW]
See header of drivers/scsi/sim710.c.
@@ -2038,6 +2168,9 @@ and is between 256 and 4096 characters. It is defined in the file
snd-ymfpci= [HW,ALSA]
+ softlockup_panic=
+ [KNL] Should the soft-lockup detector generate panics.
+
sonypi.*= [HW] Sony Programmable I/O Control Device driver
See Documentation/sonypi.txt
@@ -2102,6 +2235,12 @@ and is between 256 and 4096 characters. It is defined in the file
tdfx= [HW,DRM]
+ test_suspend= [SUSPEND]
+ Specify "mem" (for Suspend-to-RAM) or "standby" (for
+ standby suspend) as the system sleep state to briefly
+ enter during system startup. The system is woken from
+ this state using a wakeup-capable RTC alarm.
+
thash_entries= [KNL,NET]
Set number of hash buckets for TCP connection
@@ -2111,7 +2250,7 @@ and is between 256 and 4096 characters. It is defined in the file
thermal.crt= [HW,ACPI]
-1: disable all critical trip points in all thermal zones
- <degrees C>: lower all critical trip points
+ <degrees C>: override all critical trip points
thermal.nocrt= [HW,ACPI]
Set to disable actions on ACPI thermal zone
@@ -2129,13 +2268,6 @@ and is between 256 and 4096 characters. It is defined in the file
<deci-seconds>: poll all this frequency
0: no polling (default)
- tipar.timeout= [HW,PPT]
- Set communications timeout in tenths of a second
- (default 15).
-
- tipar.delay= [HW,PPT]
- Set inter-bit delay in microseconds (default 10).
-
tmscsim= [HW,SCSI]
See comment before function dc390_setup() in
drivers/scsi/tmscsim.c.
@@ -2169,6 +2301,10 @@ and is between 256 and 4096 characters. It is defined in the file
Note that genuine overcurrent events won't be
reported either.
+ unknown_nmi_panic
+ [X86-32,X86-64]
+ Set unknown_nmi_panic=1 early on boot.
+
usbcore.autosuspend=
[USB] The autosuspend time delay (in seconds) used
for newly-detected USB devices (default 2). This
@@ -2176,6 +2312,25 @@ and is between 256 and 4096 characters. It is defined in the file
autosuspended. Devices for which the delay is set
to a negative value won't be autosuspended at all.
+ usbcore.usbfs_snoop=
+ [USB] Set to log all usbfs traffic (default 0 = off).
+
+ usbcore.blinkenlights=
+ [USB] Set to cycle leds on hubs (default 0 = off).
+
+ usbcore.old_scheme_first=
+ [USB] Start with the old device initialization
+ scheme (default 0 = off).
+
+ usbcore.use_both_schemes=
+ [USB] Try the other device initialization scheme
+ if the first one fails (default 1 = enabled).
+
+ usbcore.initial_descriptor_timeout=
+ [USB] Specifies timeout for the initial 64-byte
+ USB_REQ_GET_DESCRIPTOR request in milliseconds
+ (default 5000 = 5.0 seconds).
+
usbhid.mousepoll=
[USBHID] The interval which mice are to be polled at.