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.
+ DRM Direct Rendering Management support is enabled.
+ DYNAMIC_DEBUG Build in debug messages and enable them at runtime
EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
EFI EFI Partitioning (GPT) is enabled
EIDE EIDE/ATAPI support is enabled.
- DRM Direct Rendering Management support is enabled.
- DYNAMIC_DEBUG Build in debug messages and enable them at runtime
+ 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.
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.
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.
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:
and is between 256 and 4096 characters. It is defined in the file
./include/asm/setup.h as COMMAND_LINE_SIZE.
+Finally, the [KMG] suffix is commonly described after a number of kernel
+parameter values. These 'K', 'M', and 'G' letters represent the _binary_
+multipliers 'Kilo', 'Mega', and 'Giga', equalling 2^10, 2^20, and 2^30
+bytes respectively. Such letter suffixes can also be entirely omitted.
+
acpi= [HW,ACPI,X86]
Advanced Configuration and Power Interface
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
+ on machines running EFI runtime service to boot the
+ second kernel for kdump.
acpi_apic_instance= [ACPI, IOAPIC]
Format: <int>
unusable. The "log_buf_len" parameter may be useful
if you need to capture more output.
- acpi_display_output= [HW,ACPI]
- acpi_display_output=vendor
- acpi_display_output=video
- See above.
-
acpi_irq_balance [HW,ACPI]
ACPI will balance active IRQs
default in APIC mode
For broken nForce2 BIOS resulting in XT-PIC timer.
acpi_sleep= [HW,ACPI] Sleep options
- Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
- old_ordering, s4_nonvs, sci_force_enable }
+ Format: { s3_bios, s3_mode, s3_beep, s3_leds, s4_nohwsig,
+ old_ordering, 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
as soon as the kernel's real-mode entry point is called.
+ s3_leds is for debugging; it flashes the keyboard LEDs
+ 3 times 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
behaviour to be specified. Bit 0 enables warnings,
bit 1 enables fixups, and bit 2 sends a segfault.
- amd_iommu= [HW,X86-84]
+ 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.
+
+ 32: only for 32-bit processes
+ 64: 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,X86-64]
Pass parameters to the AMD IOMMU driver in the system.
Possible values are:
fullflush - enable flushing of IO/TLB entries when
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
atkbd.softrepeat= [HW]
Use software keyboard repeat
- autotest [IA64]
+ autotest [IA-64]
baycom_epp= [HW,AX25]
Format: <io>,<mode>
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
+ at a time.
c101= [NET] Moxa C101 synchronous serial card
/proc/<pid>/coredump_filter.
See also Documentation/filesystems/proc.txt.
+ cpufreq_driver= [X86] Allow only the named cpu frequency scaling driver
+ to register. Example: cpufreq_driver=powernow-k8
+ Format: { none | STRING }
+
+ cpuidle.off=1 [CPU_IDLE]
+ disable the cpuidle sub-system
+
cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
Format:
<first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
- crashkernel=nn[KMG]@ss[KMG]
- [KNL] Reserve a chunk of physical memory to
- hold a kernel to switch to with kexec on panic.
+ crashkernel=size[KMG][@offset[KMG]]
+ [KNL] Using kexec, Linux can switch to a 'crash kernel'
+ upon panic. This parameter reserves the physical
+ memory region [offset, offset + size] for that kernel
+ image. If '@offset' is omitted, then a suitable offset
+ is selected automatically. Check
+ Documentation/kdump/kdump.txt for further details.
crashkernel=range1:size1[,range2:size2,...][@offset]
[KNL] Same as above, but depends on the memory
in the running system. The syntax of range is
start-[end] where start and end are both
a memory unit (amount[KMG]). See also
- Documentation/kdump/kdump.txt for a example.
+ Documentation/kdump/kdump.txt for an example.
cs89x0_dma= [HW,NET]
Format: <dma>
disable= [IPV6]
See Documentation/networking/ipv6.txt.
+ disable_ddw [PPC/PSERIES]
+ Disable Dynamic DMA Window support. Use this if
+ to workaround buggy firmware.
+
disable_ipv6= [IPV6]
See Documentation/networking/ipv6.txt.
The filter can be disabled or changed to another
driver later using sysfs.
- dscc4.setup= [NET]
+ drm_kms_helper.edid_firmware=[<connector>:]<file>
+ Broken monitors, graphic adapters and KVMs may
+ send no or incorrect EDID data sets. This parameter
+ allows to specify an EDID data set in the
+ /lib/firmware directory that is used instead.
+ Generic built-in EDID data sets are used, if one of
+ edid/1024x768.bin, edid/1280x1024.bin,
+ edid/1680x1050.bin, or edid/1920x1080.bin is given
+ and no file with the same name exists. Details and
+ instructions how to build your own EDID data are
+ available in Documentation/EDID/HOWTO.txt. An EDID
+ data set will only be used for a particular connector,
+ if its name and a colon are prepended to the EDID
+ name.
- 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
+ dscc4.setup= [NET]
earlycon= [KNL] Output early console device and options.
uart[8250],io,<addr>[,options]
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]
ekgdboc= [X86,KGDB] Allow early kernel console debugging
ekgdboc=kbd
- This is desgined to be used in conjunction with
+ This is designed to be used in conjunction with
the boot argument: earlyprintk=vga
edd= [EDD]
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]
This option is obsoleted by the "netdev=" option, which
has equivalent usage. See its documentation for details.
+ evm= [EVM]
+ Format: { "fix" }
+ Permit 'security.evm' to be updated regardless of
+ current integrity status.
+
failslab=
fail_page_alloc=
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.
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
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
If specified, z/VM IUCV HVC accepts connections
from listed z/VM user IDs only.
+ keep_bootcon [KNL]
+ Do not unregister boot console at start. This is only
+ useful for debugging when something happens in the window
+ between unregistering the boot console and initializing
+ the real console.
+
i2c_bus= [HW] Override the default board specific I2C bus speed
or register an additional I2C bus that is not
registered from board initialization code.
controller
i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
controllers
+ i8042.notimeout [HW] Ignore timeout condition signalled by conroller
i8042.reset [HW] Reset the controller during init and cleanup
i8042.unlock [HW] Unlock (ignore) the keylock
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.
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
result in a hardware IOTLB flush operation as opposed
to batching them for performance.
-
+ sp_off [Default Off]
+ By default, super page will be supported if Intel IOMMU
+ 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.
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
kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
for all guests.
- Default is 1 (enabled) if in 64bit or 32bit-PAE mode
-
- kvm-intel.bypass_guest_pf=
- [KVM,Intel] Disables bypassing of guest page faults
- on Intel chips. Default is 1 (enabled)
+ 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.
[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
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
6 (KERN_INFO) informational
7 (KERN_DEBUG) debug-level messages
- log_buf_len=n Sets the size of the printk ring buffer, in bytes.
- Format: { n | nk | nM }
- n must be a power of two. The default size
- is set in the kernel config file.
+ log_buf_len=n[KMG] Sets the size of the printk ring buffer,
+ in bytes. 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
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
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]
mtdparts= [MTD]
See drivers/mtd/cmdlinepart.c.
+ multitce=off [PPC] This parameter disables the use of the pSeries
+ firmware feature for updating multiple TCE entries
+ at a time.
+
onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
Format: [die0_boundary][,die0_lock][,die1_boundary][,die1_lock]
of returning the full 64-bit number.
The default is to return 64-bit inode numbers.
+ nfs.nfs4_disable_idmapping=
+ [NFSv4] When set, this option disables the NFSv4
+ idmapper on the client, but only if the mount
+ is using the 'sec=sys' security flavour. This may
+ make migration from legacy NFSv2/v3 systems easier
+ provided that the server has the appropriate support.
+ The default is to always enable NFSv4 idmapping.
+
nmi_debug= [KNL,AVR32,SH] Specify one or more actions to take
when a NMI is triggered.
Format: [state][,regs][,debounce][,die]
nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels
- Format: [panic,][num]
+ Format: [panic,][nopanic,][num]
Valid num: 0
0 - turn nmi_watchdog off
When panic is specified, panic when an NMI watchdog
- timeout occurs.
+ timeout occurs (or 'nopanic' to override the opposite
+ default).
This is useful when you use a panic=... timeout and
need the box quickly up again.
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,
noapic [SMP,APIC] Tells the kernel to not make use of any
IOAPICs that may be present in the system.
+ noautogroup Disable scheduler automatic task group creation.
+
nobats [PPC] Do not use BATs for mapping kernel lowmem
on "Classic" PPC cores.
noexec=on: enable non-executable mappings (default)
noexec=off: disable non-executable mappings
+ nosmep [X86]
+ Disable SMEP (Supervisor Mode Execution Protection)
+ even if it is supported by processor.
+
noexec32 [X86-64]
This affects only 32-bit executables.
noexec32=on: enable non-executable mappings (default)
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
+ no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page
+ fault handling.
+
+ no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting.
+ steal time is computed, but won't influence scheduler
+ behaviour
+
nolapic [X86-32,APIC] Do not enable or use the local APIC.
nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
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.
nosoftlockup [KNL] Disable the soft-lockup detector.
- noswapaccount [KNL] Disable accounting of swap in memory resource
- controller. (See Documentation/cgroups/memory.txt)
-
nosync [HW,M68K] Disables sync negotiation for all devices.
notsc [BUGS=X86-32] Disable Time Stamp Counter
nousb [USB] Disable the USB subsystem
- nowatchdog [KNL] Disable the lockup detector.
+ nowatchdog [KNL] Disable the lockup detector (NMI watchdog).
nowb [ARM]
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.
perfmon on Intel CPUs instead of the
CPU specific event set.
+ oops=panic Always panic on oopses. Default is to just kill the
+ process, but there is a small probability of
+ deadlocking the machine.
+ This will also cause panics on machine check exceptions.
+ Useful together with panic=30 to trigger a reboot.
+
OSS [HW,OSS]
See Documentation/sound/oss/oss-parameters.txt
- panic= [KNL] Kernel behaviour on panic
+ panic= [KNL] Kernel behaviour on panic: delay <timeout>
+ timeout > 0: seconds before rebooting
+ timeout = 0: wait forever
+ timeout < 0: reboot immediately
Format: <timeout>
parkbd.port= [HW] Parallel port number the keyboard adapter is
the default.
off: Turn ECRC off
on: Turn ECRC on.
+ realloc reallocate PCI resources if allocations done by BIOS
+ are erroneous.
pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
Management.
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 }
default: off.
+ printk.always_kmsg_dump=
+ Trigger kmsg_dump for cases other than kernel oops or
+ panics
+ Format: <bool> (1/Y/y=enable, 0/N/n=disable)
+ default: disabled
+
printk.time= Show timing data prefixed to each printk message line
Format: <bool> (1/Y/y=enable, 0/N/n=disable)
[HW,MOUSE] Controls Logitech smartscroll autorepeat.
0 = disabled, 1 = enabled (default).
+ pstore.backend= Specify the name of the pstore backend to use
+
pt. [PARIDE]
See Documentation/blockdev/paride.txt.
reset_devices [KNL] Force drivers to reset the underlying device
during initialization.
- resource_alloc_from_bottom
- Allocate new resources from the beginning of available
- space, not the end. If you need to use this, please
- report a bug.
-
resume= [SWSUSP]
Specify the partition device for software suspend
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.
ro [KNL] Mount root device read-only on boot
root= [KNL] Root filesystem
+ See name_to_dev_t comment in init/do_mounts.c.
rootdelay= [KNL] Delay (in seconds) to pause before attempting to
mount the root filesystem
softlockup_panic=
[KNL] Should the soft-lockup detector generate panics.
+ 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.
<deci-seconds>: poll all this frequency
0: no polling (default)
+ threadirqs [KNL]
+ Force threading of all interrupt handlers except those
+ marked explicitely IRQF_NO_THREAD.
+
topology= [S390]
Format: {off | on}
Specify if the kernel should make use of the cpu
- topology informations if the hardware supports these.
- The scheduler will make use of these informations and
+ topology information if the hardware supports this.
+ The scheduler will make use of this information and
e.g. base its process migration decisions on it.
Default is on.
to facilitate early boot debugging.
See also Documentation/trace/events.txt
- tsc= Disable clocksource-must-verify flag for TSC.
+ tsc= Disable clocksource stability checks for TSC.
Format: <string>
[x86] reliable: mark tsc clocksource as reliable, this
- disables clocksource verification at runtime.
- Used to enable high-resolution timer mode on older
- hardware, and in virtualized environment.
+ disables clocksource verification at runtime, as well
+ as the stability checks done at bootup. Used to enable
+ high-resolution timer mode on older hardware, and in
+ virtualized environment.
[x86] noirqtime: Do not use TSC to do irq accounting.
Used to run time disable IRQ_TIME_ACCOUNTING on any
platforms where RDTSC is slow and this accounting
<port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
See also Documentation/input/joystick-parport.txt
+ udbg-immortal [PPC] When debugging early kernel crashes that
+ happen after console_init() and before a proper
+ console driver takes over, this boot options might
+ help "seeing" what's going on.
+
uhash_entries= [KNL,NET]
Set number of hash buckets for UDP/UDP-Lite connections
reported either.
unknown_nmi_panic
- [X86]
- Set unknown_nmi_panic=1 early on boot.
+ [X86] Cause panic on unknown NMI.
+
+ usbcore.authorized_default=
+ [USB] Default USB device authorization:
+ (default -1 = authorized except for wireless USB,
+ 0 = not authorized, 1 = authorized)
usbcore.autosuspend=
[USB] The autosuspend time delay (in seconds) used
bytes of sense data);
c = FIX_CAPACITY (decrease the reported
device capacity by one sector);
+ d = NO_READ_DISC_INFO (don't use
+ READ_DISC_INFO command);
+ e = NO_READ_CAPACITY_16 (don't use
+ READ_CAPACITY_16 command);
h = CAPACITY_HEURISTICS (decrease the
reported device capacity by one
sector if the number is odd);
unlock ejectable media);
m = MAX_SECTORS_64 (don't transfer more
than 64 sectors = 32 KB at a time);
+ n = INITIAL_READ10 (force a retry of the
+ initial READ(10) command);
o = CAPACITY_OK (accept the capacity
reported by the device);
r = IGNORE_RESIDUE (the device reports
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.
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;
projects / linux-flexiantxendom0.git / blobdiff