- Kernel Parameters
- ~~~~~~~~~~~~~~~~~
+ Kernel Parameters
+ ~~~~~~~~~~~~~~~~~
The following is a consolidated list of the kernel parameters as implemented
(mostly) by the __setup() macro and sorted into English Dictionary order
APIC APIC support is enabled.
APM Advanced Power Management support is enabled.
AX25 Appropriate AX.25 support is enabled.
+ BLACKFIN Blackfin architecture is enabled.
DRM Direct Rendering Management support is enabled.
EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
EFI EFI Partitioning (GPT) is enabled
PARIDE The ParIDE (parallel port IDE) subsystem is enabled.
PARISC The PA-RISC architecture is enabled.
PCI PCI bus support is enabled.
+ PCIE PCI Express support is enabled.
PCMCIA The PCMCIA subsystem is enabled.
PNP Plug & Play support is enabled.
PPC PowerPC architecture is enabled.
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
Documentation/scsi/.
+ SECURITY Different security models are enabled.
SELINUX SELinux support is enabled.
SERIAL Serial support is enabled.
SH SuperH architecture is enabled.
blkmtd_bs=
blkmtd_count=
+ boot_delay= Milliseconds to delay each printk during boot.
+ Values larger than 10 seconds (10000) are changed to
+ no delay (0).
+ Format: integer
+
bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
bttv.radio= Most important insmod options are available as
kernel args too.
possible to determine what the correct size should be.
This option provides an override for these situations.
+ capability.disable=
+ [SECURITY] Disable capabilities. This would normally
+ be used only if an alternative security model is to be
+ configured. Potentially dangerous and should only be
+ used if you are entirely sure of the consequences.
+
chandev= [HW,NET] Generic channel device initialisation
checkreqprot [SELINUX] Set initial checkreqprot flag value.
UART at the specified I/O port or MMIO address.
The options are the same as for ttyS, above.
+ no_console_suspend
+ [HW] Never suspend the console
+ Disable suspending of consoles during suspend and
+ hibernate operations. Once disabled, debugging
+ messages can reach various consoles while the rest
+ of the system is being put to sleep (ie, while
+ debugging driver suspend/resume hooks). This may
+ not work reliably with all consoles, but is known
+ to work with serial and VGA consoles.
+
cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
Format:
<first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
dtc3181e= [HW,SCSI]
- earlyprintk= [X86-32,X86-64,SH]
+ earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
earlyprintk=vga
earlyprintk=serial[,ttySn[,baudrate]]
lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip
Format: addr:<io>,irq:<irq>
+ libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
+ when set.
+ Format: <int>
+
load_ramdisk= [RAM] List of ramdisks to load from floppy
See Documentation/ramdisk.txt.
n must be a power of two. The default size
is set in the kernel config file.
+ logo.nologo [FB] Disables display of the built-in Linux logo.
+ This may be used to provide more screen space for
+ kernel log messages and is useful when debugging
+ kernel boot problems.
+
lp=0 [LP] Specify parallel ports to use, e.g,
lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
lp=reset first parallel port). 'lp=0' disables the
mce [X86-32] Machine Check Exception
+ mce=option [X86-64] See Documentation/x86_64/boot-options.txt
+
md= [HW] RAID subsystems devices and level
See Documentation/md.txt.
meye.*= [HW] Set MotionEye Camera parameters
See Documentation/video4linux/meye.txt.
+ mfgpt_irq= [IA-32] Specify the IRQ to use for the
+ Multi-Function General Purpose Timers on AMD Geode
+ platforms.
+
mga= [HW,DRM]
mousedev.tap_time=
[NFS] set the maximum lifetime for idmapper cache
entries.
+ nfs.enable_ino64=
+ [NFS] enable 64-bit inode numbers.
+ If zero, the NFS client will fake up a 32-bit inode
+ number for the readdir() and stat() syscalls instead
+ of returning the full 64-bit number.
+ The default is to return 64-bit inode numbers.
+
nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels
no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
emulation library even if a 387 maths coprocessor
is present.
- noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
- when set.
- Format: <int>
-
noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
caches in the slab allocator. Saves per-node memory,
but will impact performance.
nomce [X86-32] Machine Check Exception
+ nomfgpt [X86-32] Disable Multi-Function General Purpose
+ Timer usage (for AMD Geode machines).
+
noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
noreplace-smp [X86-32,SMP] Don't replace SMP instructions
Mechanism 1.
conf2 [X86-32] 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
+ disable the use of PCIE advanced error reporting.
+ nodomains [PCI] Disable support for multiple PCI
+ root domains (aka PCI segments, in ACPI-speak).
nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
Configuration
nomsi [MSI] If the PCI_MSI kernel config parameter is
IRQ routing is enabled.
noacpi [X86-32] Do not use ACPI for IRQ routing
or for PCI scanning.
+ use_crs [X86-32] Use _CRS for PCI resource
+ allocation.
routeirq Do IRQ routing for all PCI devices.
This is normally done in pci_enable_device(),
so this option is a temporary workaround
pt. [PARIDE]
See Documentation/paride.txt.
+ pty.legacy_count=
+ [KNL] Number of legacy pty's. Overwrites compiled-in
+ default number.
+
quiet [KNL] Disable most log messages
r128= [HW,DRM]
raid= [HW,RAID]
See Documentation/md.txt.
- ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]
- See Documentation/ramdisk.txt.
-
ramdisk_blocksize= [RAM]
See Documentation/ramdisk.txt.
ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
- New name for the ramdisk parameter.
See Documentation/ramdisk.txt.
rcu.blimit= [KNL,BOOT] Set maximum number of finished
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
reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
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
selinux_compat_net =
[SELINUX] Set initial selinux_compat_net flag value.
- Format: { "0" | "1" }
- 0 -- use new secmark-based packet controls
- 1 -- use legacy packet controls
- Default value is 0 (preferred).
- Value can be changed at runtime via
- /selinux/compat_net.
+ Format: { "0" | "1" }
+ 0 -- use new secmark-based packet controls
+ 1 -- use legacy packet controls
+ Default value is 0 (preferred).
+ Value can be changed at runtime via
+ /selinux/compat_net.
serialnumber [BUGS=X86-32]
Format:
<io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
- tsdev.xres= [TS] Horizontal screen resolution.
- tsdev.yres= [TS] Vertical screen resolution.
-
turbografx.map[2|3]= [HW,JOY]
TurboGraFX parallel port interface
Format:
norandmaps Don't use address space randomization
Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
- unwind_debug=N N > 0 will enable dwarf2 unwinder debugging
+ unwind_debug=N N > 0 will enable dwarf2 unwinder debugging
This is useful to get more information why
you got a "dwarf2 unwinder stuck"