(e.g. thinkpad_acpi, sony_acpi, etc.) instead
of the ACPI video.ko driver.
+ acpi_force_32bit_fadt_addr
+ force FADT to use 32 bit addresses rather than the
+ 64 bit X_* addresses. Some firmware have broken 64
+ bit addresses for force ACPI ignore these and use
+ the older legacy 32 bit addresses.
+
acpica_no_return_repair [HW, ACPI]
Disable AML predefined validation mechanism
This mechanism can repair the evaluation result to make
clearcpuid=BITNUM [X86]
Disable CPUID feature X for the kernel. See
- arch/x86/include/asm/cpufeature.h for the valid bit
+ arch/x86/include/asm/cpufeatures.h for the valid bit
numbers. Note the Linux specific bits are not necessarily
stable over kernel options, but the vendor specific
ones should be.
A valid base address must be provided, and the serial
port must already be setup and configured.
+ armada3700_uart,<addr>
+ Start an early, polled-mode console on the
+ Armada 3700 serial port at the specified
+ address. The serial port must already be setup
+ and configured. Options are not yet supported.
+
earlyprintk= [X86,SH,BLACKFIN,ARM,M68k]
earlyprintk=vga
earlyprintk=efi
In such case C2/C3 won't be used again.
idle=nomwait: Disable mwait for CPU C-states
+ ieee754= [MIPS] Select IEEE Std 754 conformance mode
+ Format: { strict | legacy | 2008 | relaxed }
+ Default: strict
+
+ Choose which programs will be accepted for execution
+ based on the IEEE 754 NaN encoding(s) supported by
+ the FPU and the NaN encoding requested with the value
+ of an ELF file header flag individually set by each
+ binary. Hardware implementations are permitted to
+ support either or both of the legacy and the 2008 NaN
+ encoding mode.
+
+ Available settings are as follows:
+ strict accept binaries that request a NaN encoding
+ supported by the FPU
+ legacy only accept legacy-NaN binaries, if supported
+ by the FPU
+ 2008 only accept 2008-NaN binaries, if supported
+ by the FPU
+ relaxed accept any binaries regardless of whether
+ supported by the FPU
+
+ The FPU emulator is always able to support both NaN
+ encodings, so if no FPU hardware is present or it has
+ been disabled with 'nofpu', then the settings of
+ 'legacy' and '2008' strap the emulator accordingly,
+ 'relaxed' straps the emulator for both legacy-NaN and
+ 2008-NaN, whereas 'strict' enables legacy-NaN only on
+ legacy processors and both NaN encodings on MIPS32 or
+ MIPS64 CPUs.
+
+ The setting for ABS.fmt/NEG.fmt instruction execution
+ mode generally follows that for the NaN encoding,
+ except where unsupported by hardware.
+
ignore_loglevel [KNL]
Ignore loglevel setting - this will print /all/
kernel messages to the console. Useful for debugging.
could change it dynamically, usually by
/sys/module/printk/parameters/ignore_loglevel.
+ ignore_rlimit_data
+ Ignore RLIMIT_DATA setting for data mappings,
+ print warning at first misuse. Can be changed via
+ /sys/module/kernel/parameters/ignore_rlimit_data.
+
ihash_entries= [KNL]
Set number of hash buckets for inode cache.
ip= [IP_PNP]
See Documentation/filesystems/nfs/nfsroot.txt.
+ irqaffinity= [SMP] Set the default irq affinity mask
+ Format:
+ <cpu number>,...,<cpu number>
+ or
+ <cpu number>-<cpu number>
+ (must be a positive range in ascending order)
+ or a mixture
+ <cpu number>,...,<cpu number>-<cpu number>
+
irqfixup [HW]
When an interrupt is not handled search all handlers
for it. Intended to get systems with badly broken
keepinitrd [HW,ARM]
- kernelcore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter
+ kernelcore= [KNL,X86,IA-64,PPC]
+ Format: nn[KMGTPE] | "mirror"
+ This parameter
specifies the amount of memory usable by the kernel
for non-movable allocations. The requested amount is
spread evenly throughout all nodes in the system. The
use the HighMem zone if it exists, and the Normal
zone if it does not.
+ Instead of specifying the amount of memory (nn[KMGTPE]),
+ you can specify "mirror" option. In case "mirror"
+ option is specified, mirrored (reliable) memory is used
+ for non-movable allocations and remaining memory is used
+ for Movable pages. nn[KMGTPE] and "mirror" are exclusive,
+ so you can NOT specify nn[KMGTPE] and "mirror" at the same
+ time.
+
kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port.
Format: <Controller#>[,poll interval]
The controller # is the number of the ehci usb debug
nointroute [IA-64]
+ noinvpcid [X86] Disable the INVPCID cpu feature.
+
nojitter [IA-64] Disables jitter checking for ITC timers.
no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
we can turn it on.
on: enable the feature
+ page_poison= [KNL] Boot-time parameter changing the state of
+ poisoning on the buddy allocator.
+ off: turn off poisoning
+ on: turn on poisoning
+
panic= [KNL] Kernel behaviour on panic: delay <timeout>
timeout > 0: seconds before rebooting
timeout = 0: wait forever
ro [KNL] Mount root device read-only on boot
+ rodata= [KNL]
+ on Mark read-only kernel memory as read-only (default).
+ off Leave read-only kernel memory writable for debugging.
+
+ rockchip.usb_uart
+ Enable the uart passthrough on the designated usb port
+ on Rockchip SoCs. When active, the signals of the
+ debug-uart get routed to the D+ and D- pins of the usb
+ port and the regular usb controller gets disabled.
+
root= [KNL] Root filesystem
See name_to_dev_t comment in init/do_mounts.c.
sched_debug [KNL] Enables verbose scheduler debug messages.
+ schedstats= [KNL,X86] Enable or disable scheduled statistics.
+ Allowed values are enable and disable. This feature
+ incurs a small amount of overhead in the scheduler
+ but is useful for debugging and performance tuning.
+
skew_tick= [KNL] Offset the periodic timer tick per cpu to mitigate
xtime_lock contention on larger systems, and/or RCU lock
contention on all systems with CONFIG_MAXSMP set.
The default value of this parameter is determined by
the config option CONFIG_WQ_POWER_EFFICIENT_DEFAULT.
+ workqueue.debug_force_rr_cpu
+ Workqueue used to implicitly guarantee that work
+ items queued without explicit CPU specified are put
+ on the local CPU. This guarantee is no longer true
+ and while local CPU is still preferred work items
+ may be put on foreign CPUs. This debug option
+ forces round-robin CPU selection to flush out
+ usages which depend on the now broken guarantee.
+ When enabled, memory and cache locality will be
+ impacted.
+
x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
default x2apic cluster mode on platforms
supporting x2apic.