Lines Matching +full:ras +full:- +full:to +full:- +full:cas

4 			By default, unaccepted memory is accepted lazily to
9 			accept_memory=eager can be used to accept all memory
16 			force -- enable ACPI if default was off
17 			on -- enable ACPI but allow fallback to DT [arm64,riscv64]
18 			off -- disable ACPI if default was on
19 			noirq -- do not use ACPI for IRQ routing
20 			strict -- Be less tolerant of platforms that are not
22 			rsdt -- prefer RSDT over (default) XSDT
23 			copy_dsdt -- copy DSDT to memory
24 			nocmcff -- Disable firmware first mode for corrected
26 			source to check if firmware has set the FF flag. This
28 			nospcr -- disable console in ACPI SPCR table as
45 			If set to vendor, prefer vendor-specific driver
48 			If set to video, use the ACPI video.ko driver.
49 			If set to native, use the device's native backlight mode.
50 			If set to none, disable the ACPI backlight interface.
53 			force FADT to use 32 bit addresses rather than the
60 			This mechanism can repair the evaluation result to make
62 			This option is useful for developers to identify the
64 			has something to do with the repair mechanism.
69 			CONFIG_ACPI_DEBUG must be enabled to produce any ACPI
70 			debug output.  Bits in debug_layer correspond to a
73 			Bits in debug_level correspond to a level in
76 			The debug_level mask defaults to "info".  See
77 			Documentation/firmware-guide/acpi/debug.rst for more information about
82 			Enable AML "Debug" output, i.e., stores to the Debug
85 			Enable all messages related to ACPI hardware:
90 			if you need to capture more output.
99 			strict (default): access to resources claimed by ACPI
100 			is denied; legacy drivers trying to access reserved
101 			resources will fail to bind to device using them.
102 			lax: access to resources claimed by ACPI is allowed;
103 			legacy drivers trying to access reserved resources
110 			By default, this is disabled due to x86 early mapping
129 			Due to the existence of _Lxx/_Exx, some GPEs triggered
133 			This facility can be used to prevent such uncontrolled
135 			Format: <byte> or <bitmap-list>
138 			Disable auto-serialization of AML methods
139 			AML control methods that contain the opcodes to create
141 			auto-serialization feature.
143 			This option allows to turn off the feature.
156 			tables to /sys/firmware/acpi/tables/dynamic.
159 			Ignore the ACPI-based watchdog interface (WDAT) and let
163 			Pass the RSDP address to the kernel, mostly used
164 			on machines running EFI runtime service to boot the
168 			Format: To spoof as Windows 98: ="Microsoft Windows"
170 	acpi_rev_override [ACPI] Override the _REV object to return 5 (instead
173 			be necessary to carry out a cold reboot _twice_ in a
174 			row to make it take effect on the platform firmware).
180 			acpi_osi=!		# disable all built-in OS vendor
182 			acpi_osi=!!		# enable all built-in OS vendor
187 			multiple 'acpi_osi="string1"' to support specific OS
198 			     to 'acpi_osi="Windows 2000" acpi_osi=!', they all
212 			multiple 'acpi_osi="string1"' to support specific
217 			still not able to affect the final state of a string if
218 			there are quirks related to this string.  This command
219 			is useful when one want to control the state of the
220 			feature group strings to debug BIOS issues related to
228 			     equivalent to
236 			to assume that this machine's pmtimer latches its value
244 			For broken nForce2 BIOS resulting in XT-PIC timer.
253 			as soon as the kernel's real-mode entry point is called.
254 			s4_hwsig causes the kernel to check the ACPI hardware
256 			refuse to resume if it has changed. This complies with
259 			on docking. So the default behaviour is to allow resume
265 			control method, with respect to putting devices into
266 			low power states, to be enforced (the ACPI 2.0 ordering
270 			sci_force_enable causes the kernel to set SCI_EN directly
273 			nobl causes the internal blacklist of systems known to
274 			behave incorrectly in some ways with respect to system
275 			suspend and resume to be ignored (use wisely).
287 			try_unsupported: try to drive unsupported chipsets
291 			See Documentation/sound/alsa-configuration.rst
295 			behaviour to be specified.  Bit 0 enables warnings,
298 	align_va_addr=	[X86-64]
301 			gives you up to 3% performance improvement on AMD F15h
303 			CPU-intensive style benchmark, and it can vary highly in
306 			32: only for 32-bit processes
307 			64: only for 64-bit processes
308 			on: enable for both 32- and 64-bit processes
309 			off: disable for both 32- and 64-bit processes
314 			and you need to use tracing_snapshot() on boot up, and
315 			do not want to use tracing_snapshot_alloc() as it needs
316 			to be done where GFP_KERNEL allocations are allowed.
319 			Allow execve() of 32-bit applications and setting of the
321 			subset of the CPUs support 32-bit EL0. When this
322 			parameter is present, the set of CPUs supporting 32-bit
324 			and hot-unplug operations may be restricted.
326 			See Documentation/arch/arm64/asymmetric-32bit.rst for more
329 	amd_iommu=	[HW,X86-64]
330 			Pass parameters to the AMD IOMMU driver in the system.
332 			fullflush - Deprecated, equivalent to iommu.strict=1
333 			off	  - do not initialize any AMD IOMMU found in
335 			force_isolation - Force device isolation for all
337 					  allowed anymore to lift isolation
340 			force_enable    - Force enable the IOMMU on platforms known
341 				          to be buggy with IOMMU enabled. Use this
343 			pgtbl_v1        - Use v1 page table for DMA-API (Default).
344 			pgtbl_v2        - Use v2 page table for DMA-API.
345 			irtcachedis     - Disable Interrupt Remapping Table (IRT) caching.
346 			nohugepages     - Limit page-sizes used for v1 page-tables
347 				          to 4 KiB.
348 			v2_pgsizes_only - Limit page-sizes used for v1 page-tables
349 				          to 4KiB/2Mib/1GiB.
352 	amd_iommu_dump=	[HW,X86-64]
353 			Enable AMD IOMMU driver option to dump the ACPI table
358 	amd_iommu_intr=	[HW,X86-64]
361 			legacy     - Use legacy interrupt remapping mode.
362 			vapic      - Use virtual APIC mode, which allows IOMMU
363 			             to inject interrupts directly into guest.
364 			             This mode requires kvm-amd.avic=1.
375 			  tries to match the same performance level if it is
379 			  driver provides a hint to the hardware if software wants
380 			  to bias toward performance (0x0) or energy efficiency (0xff)
381 			  to the CPPC firmware. then CPPC power algorithm will
388 			  to the current workload.
393 			  Disable amd-pstate preferred core.
396 			Map of devices attached to JOY0DAT and JOY1DAT
402 			connected to one of 16 gameports
406 			Power management functions (SPARCstation-4/5 + deriv.)
408 			Disable APC CPU standby support. SPARCstation-Fox does
409 			not play well with APC CPU idle - disable it if you have
412 	apic		[APIC,X86-64] Use IO-APIC. Default.
418 			when initialising the APIC and IO-APIC components.
422 			bsp:  External NMI is delivered only to CPU 0
423 			all:  External NMIs are broadcast to all CPUs as a
442 			0 -- disable.
443 			1 -- enable.
446 	arcrimi=	[HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
497 	audit=		[KNL] Enable the audit sub-system
499 			0 | off - kernel audit is disabled and can not be
501 			unset - kernel audit is initialized but disabled and
503 			1 | on - kernel audit is initialized and partially
514 			behavior is to disable the BAU (i.e. bau=0).
516 			0 - Disable the BAU.
517 			1 - Enable the BAU.
518 			unset - Disable the BAU.
539 			Control the ability to open a mounted block device
541 			the FS. This was implemented as a means to prevent
553 			Disable BGRT to avoid flickering OEM logo.
557 			See Documentation/block/cmdline-partition.rst
560 			Milliseconds to delay each printk during boot.
562 			and you may also have to specify "lpj=".  Boot_delay
568 			Extended command line options can be added to an initrd
569 			and this will cause the kernel to look for it.
571 			See Documentation/admin-guide/bootconfig.rst
576 	bttv.pll=	See Documentation/admin-guide/media/bttv.rst
585 	cachesize=	[BUGS=X86-32] Override level 2 CPU cache size detection.
588 			to fix known problems, but for some CPUs it is not
589 			possible to determine what the correct size should be.
598 			the system trusted keyring to be used for certificate
603 			algorithm.  Accepted values range from 0 to 7
604 			inclusive. See arch/mips/include/asm/pgtable-bits.h
612 			Format: {name of the controller(s) or feature(s) to disable}
614 			- foo isn't auto-mounted if you mount all cgroups in
616 			- foo isn't visible as an individually mountable
618 			- if foo is an optional feature then the feature is
624 			Specifying "pressure" disables per-cgroup pressure
630 			Like cgroup_disable, but only applies to cgroup v1;
641 			semi-legacy software can check this file to decide
646 			Defaults to the value of CONFIG_CGROUP_FAVOR_DYNMODS.
648 	cgroup.memory=	[KNL] Pass options to the cgroup memory controller.
650 			nosocket -- Disable socket memory accounting.
651 			nokmem -- Disable kernel memory accounting.
652 			nobpf -- Disable BPF memory accounting.
657 			0 -- check protection applied by kernel (includes
659 			1 -- check protection requested by application.
663 			Setting checkreqprot to 1 is deprecated.
671 			numbers X. Note the Linux-specific bits are not necessarily
672 			stable over kernel options, but the vendor-specific
692 			force such clocks to be always-on nor does it reserve
696 			information, see Documentation/driver-api/clk.rst.
698 	clock=		[BUGS=X86-32, HW] gettimeofday clocksource override.
700 			Forces specified clocksource (if available) to be used
702 			clocksource is not available, it defaults to PIT.
709 			Some clocksource names to choose from, depending on
715 			[X86-32] pit,hpet,tsc;
722 			[X86-64] hpet,tsc
728 			architected timer so that code using WFE-based polling
735 			are marked unstable due to excessive skew.
736 			A negative value says to check all CPUs, while
737 			zero says not to check any.  Values larger than
738 			nr_cpu_ids are silently truncated to nr_cpu_ids.
742 	clocksource-wdtest.holdoff= [KNL]
745 			Defaults to zero when built as a module and to
748 	cma=nn[MG]@[start[MG][-end[MG]]]
759 			Sets the size of kernel per-numa memory area for
761 			per-numa CMA altogether. And If this option is not
763 			With per-numa CMA enabled, DMA users on node nid will
764 			first try to allocate buffer from the pernuma area
766 			they will fallback to the global default memory area.
775 			first try to allocate buffer from the numa area
777 			they will fallback to the global default memory area.
782 			to determine OS memory pressure for page stealing by
788 			allocations, by default set to 256K.
790 	com20020=	[HW,NET] ARCnet - COM20020 chipset
794 	com90io=	[HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
798 			ARCnet - COM90xx chipset (memory-mapped buffers)
806 			When set to true, drop data on the 3215 console when
809 			x3270) does not have to enter the clear key for the
810 			console output to advance and the kernel to continue.
811 			This leads to a much faster boot time when a 3270
827 			See Documentation/admin-guide/serial-console.rst for more
839 			The mapping of the serial ports to the tty instances
842 			$ ls -d /sys/bus/serial-base/devices/*:*.*/tty/*
843 			/sys/bus/serial-base/devices/00:04:0.0/tty/ttyS0
848 			is ready. The use of an earlycon parameter in addition to
856 			Start an early, polled-mode console on the 8250/16550
858 			switching to the matching ttyS device later.
859 			MMIO inter-register address stride is either 8-bit
860 			(mmio), 16-bit (mmio16), or 32-bit (mmio32).
862 			to be equivalent to 'mmio'. 'options' are specified in
864 			the h/w is not re-initialized.
870 			Use to disable console output, i.e., to have kernel
875 		If the device connected to the port is not a TTY but a braille
888 			Switch to syslog format: "<%u>[time stamp] text\n"
890 			prefix. The format is similar to one used by syslog()
891 			syscall, or to executing "dmesg -S --raw" or to reading
896 			Defaults to 0.
915 			disable the cpuidle sub-system
918 			[CPU_IDLE] Name of the cpuidle governor to use.
921 			disable the cpufreq sub-system
925 			policy to use. This governor must be registered in the
929 			[X86,EARLY] Delay for N microsec between assert and de-assert
930 			of APIC INIT to start processors.  This delay occurs
941 			Only jump to kdump kernel after running the panic
950 			like Hyper-V, PowerPC (fadump) and AMD SEV-SNP.
953 			[KNL,EARLY] Using kexec, Linux can switch to a 'crash kernel'
958 			[KNL, X86-64, ARM64, RISCV, LoongArch] Select a region
959 			under 4G first, and fall back to reserve region above
961 			See Documentation/admin-guide/kdump/kdump.rst for further details.
966 			start-[end] where start and end are both
968 			Documentation/admin-guide/kdump/kdump.rst for an example.
971 			[KNL, X86-64, ARM64, RISCV, LoongArch] range could be
973 			Allow kernel to allocate physical memory region from top,
979 			[KNL, X86-64, ARM64, RISCV, LoongArch] range under 4G.
984 			enough extra low memory is needed to make sure DMA buffers
985 			for 32-bit devices won't run out. Kernel would try to allocate
988 			  --> x86: max(swiotlb_size_or_default() + 8MiB, 256MiB)
989 			  --> arm64: 128MiB
990 			  --> riscv: 128MiB
991 			  --> loongarch: 128MiB
994 			0: to disable low allocation.
1004 			it has to be expected that some movable kernel pages
1008 			is still needed to hold the crash kernel and initrd.
1015 			can't afford to sacrifice enough memory for standard
1017 			possibly incomplete kdump is preferable to no kdump at
1021 			[KNL] Disable crypto self-tests
1029 	csdlock_debug=	[KNL] Enable or disable debug add-ons of cross-CPU
1031 			additional debug data is printed to the console
1033 			CPU is pinged again in order to try to resolve
1044 			See also Documentation/input/devices/joystick-parport.rst
1051 			of siphash to hash pointers.  Use this option if you are
1052 			seeing instances of '(___ptrval___)') and need to see a
1057 			[KNL] verbose locking self-tests
1060 			self-tests.
1061 			Bitmask for the various LOCKTYPE_ tests. Defaults to 0
1062 			(no extra messages), setting it to -1 (all bits set)
1063 			will print _a_lot_ more information - normally only
1064 			useful to lockdep developers.
1076 			parameter to 1 or 2 should be enough to identify most
1078 			kernel or driver code when a CPU writes to (or reads
1092 			Note: to get most of debug_pagealloc error reports, it's
1093 			useful to also enable the page_owner functionality.
1096 	debugfs=    	[KNL,EARLY] This parameter enables what is exposed to
1098 			Format: { on, no-mount, off }
1100 			no-mount:
1102 			        access APIs and a crashkernel can be used to read
1103 				its content. There is nothing to mount.
1105 			        get a -EPERM as result when trying to register files
1109 			Default value is set in build-time with a kernel configuration.
1118 			filesystems.  If not specified, defaults to the
1121 			Documentation/admin-guide/mm/hugetlbpage.rst.
1125 			[KNL] Debugging option to set a timeout in seconds for
1126 			deferred probe to give up waiting on dependencies to
1135 	delayacct	[KNL] Enable per-task delay accounting
1156 			[HW] Factor to multiply fan speed with.
1178 			causes the kernel to fall back to 256MB segments which
1180 			miss to occur.
1194 			to workaround buggy firmware.
1200 			The kernel tries to adjust MTRR layout from continuous
1201 			to discrete, to make X server driver able to add WB
1208 			possibly causing your machine to run very slowly.
1212 			Can be useful to work around chipset bugs.
1220 			This option allows to tune the number of preallocated
1221 			entries for DMA-API debugging code. One entry is
1222 			required per DMA-API allocation. Use this if the
1223 			DMA-API debugging code disables itself because the
1227 			With this option the DMA-API debugging driver
1229 			pass the driver to filter for as the parameter.
1230 			The filter can be disabled or changed to another
1236 			vulnerability which may allow userspace to infer
1247 			are enabled. In order to disable RFDS mitigation all
1248 			VERW based mitigations need to be disabled.
1251 			Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst
1254 			List of driver names to be probed asynchronously. *
1263 			This parameter allows to specify an EDID data sets
1266 			connector, if its name and a colon are prepended to
1276 			Control how the dt_cpu_ftrs device-tree binding is
1279 			off: Do not use it, fall back to legacy cpu table.
1280 			known: Do not pass through unknown features to guests
1285 			x86 Macs.  Useful for driver authors to determine
1286 			what data is available or for reverse-engineering.
1291 			Documentation/admin-guide/dynamic-debug-howto.rst
1302 			determined by stdout-path property in device tree's
1307 			Start an early, polled-mode console on a Cadence
1318 			Start an early, polled-mode console on the 8250/16550
1320 			MMIO inter-register address stride is either 8-bit
1321 			(mmio) or 32-bit (mmio32 or mmio32be).
1323 			to be equivalent to 'mmio'. 'options' are specified
1327 			to 'BASE_BAUD' * 16.
1331 			Start an early, polled-mode console on a pl011 serial
1335 			the driver will use only 32-bit accessors to read/write
1344 			Start an early, polled-mode console on a meson serial
1350 			Start an early, polled-mode console on an msm serial
1356 			Start an early, polled-mode console on an msm serial
1362 			Start an early, polled-mode console on a serial port
1368 			Start an early, polled-mode console on a serial port
1374 			Use RISC-V SBI (Supervisor Binary Interface) for early
1392 			Start an early, polled-mode console on a lantiq serial
1406 			Start an early, polled-mode, output-only console on the
1411 			Start an early, polled-mode console on the
1417 			Start an early, polled-mode console on a Qualcomm
1425 			coherent non-x86 systems that use system memory for
1452 			Use "nocfg" to skip UART configuration, assume
1455 			Append ",keep" to not disable it when the real console
1482 			The optional "force" to "pciserial" enables use of a
1486 	edac_report=	[HW,EDAC] Control how to report EDAC event
1488 			on: enable EDAC to report H/W event. May be overridden
1491 			force: enforce the use of EDAC to report H/W event.
1509 			attribute may cause the kernel to reserve the
1510 			memory range for a memory mapping driver to
1511 			claim. Specify efi=nosoftreserve to disable this
1525 			that is to be dynamically loaded by Linux. If there are
1528 			Documentation/admin-guide/acpi/ssdt-overlays.rst for details.
1537 			This is designed to be used in conjunction with
1545 	elanfreq=	[X86-32]
1552 			kexec loader will pass this option to capture kernel.
1553 			See Documentation/admin-guide/kdump/kdump.rst for details.
1556 			The kernel tries to adjust MTRR layout from continuous
1557 			to discrete, to make X server driver able to add WB
1562 			Can be useful to work around chipset bugs
1564 			The kernel tries to set a reasonable default.
1569 			0 -- permissive (log only, no denials).
1570 			1 -- enforcing (deny and log).
1585 			Permit 'security.evm' to be updated regardless of
1588 	early_page_ext [KNL,EARLY] Enforces page_ext initialization to earlier
1591 			might be disabled to achieve that (e.g. parallelized
1603 			See also Documentation/fault-injection/.
1607 			See Documentation/admin-guide/sysctl/net.rst for
1611 			See Documentation/admin-guide/blockdev/floppy.rst.
1613 	forcepae	[X86-32]
1620 	fred=		[X86-64]
1628 			as early as possible in order to facilitate early
1636 			boot up that is likely to be overridden by user space
1645 			The above will cause the "foo" tracing instance to trigger
1658 			oops by passing 2 or orig_cpu to it.
1671 	ftrace_filter=[function-list]
1673 			tracer at boot up. function-list is a comma-separated
1678 	ftrace_notrace=[function-list]
1680 			function-list. This list can be changed at run time
1684 	ftrace_graph_filter=[function-list]
1687 			function-list is a comma-separated list of functions
1691 	ftrace_graph_notrace=[function-list]
1693 			function-list.  This list is a comma-separated list of
1704 			devices by scanning the firmware to infer the
1713 			off --	Don't create device links from firmware info.
1714 			permissive -- Create device links from firmware info
1717 			on -- 	Create device links from firmware info and use it
1718 				to enforce probe and suspend/resume ordering.
1719 			rpm --	Like "on", but also use to order runtime PM.
1728 			probing, this parameter controls what to do with
1732 			strict -- Default. Continue waiting on consumers to
1734 			timeout -- Give up waiting on consumers and call
1742 			support via parallel port (up to 5 devices per port)
1744 			See also Documentation/input/devices/joystick-parport.rst
1748 	gart_fix_e820=	[X86-64,EARLY] disable the fix e820 for K8 GART
1757 			allows unprivileged speculative access to data which was
1765 			force:	Disable AVX to mitigate systems without
1767 				mitigation is present. Known to cause crashes in
1774 	gcov_persist=	[GCOV] When non-zero (default), profiling data for
1784 	gpio-mockup.gpio_mockup_ranges
1787 	gpio-mockup.gpio_mockup_named_lines
1791 			invalid Protective MBR to be treated as GPT. If the
1793 			GPT to be used instead.
1803 	grcan.select=	[HW] Select which physical interface to use.
1816 			usercopy checking is used to protect the kernel
1819 			against bounds-checking flaws in the kernel's
1827 			[KNL] Should the hard-lockup detector generate
1833 			By default, when pointers are printed to the console
1843 			auto   - Hash pointers unless slab_debug is enabled.
1844 			always - Always hash pointers (even if slab_debug is
1846 			never  - Never hash pointers. This option should only
1854 			for 64-bit NUMA, off otherwise.
1862 			corresponding firmware-first mode error processing
1872 				during restoration read-only).
1874 	hibernate.compressor= 	[HIBERNATION] Compression algorithm to be
1879 				lzo: Select LZO compression algorithm to
1882 				lz4: Select LZ4 compression algorithm to
1887 			Sets the number of seconds to remain in a hibernation test
1892 	highmem=nn[KMG]	[KNL,BOOT,EARLY] forces the highmem zone to have an exact
1894 			highmem otherwise. This also works to reduce highmem
1907 			Using this parameter to set the hostname makes it
1908 			possible to ensure the hostname is correctly set before
1916 	hpet=		[X86-32,HPET] option to control HPET usage
1924 	hpet_mmap=	[X86, HPET_MMAP] Allow userspace to mmap HPET
1927 	hugepages=	[HW,EARLY] Number of HugeTLB pages to allocate at boot.
1929 			the number of pages of hugepagesz to be allocated.
1931 			line, it specifies the number of pages to allocate for
1933 			number of pages to allocate per-node can be specified.
1934 			See also Documentation/admin-guide/mm/hugetlbpage.rst.
1940 			used in conjunction with hugepages (above) to
1945 			Documentation/admin-guide/mm/hugetlbpage.rst.
1949 			[HW] The number of threads that should be used to
1951 			used to improve system bootup time when allocating
1955 			Note that this parameter only applies to non-gigantic huge pages.
1965 			boot-time allocation of gigantic hugepages is skipped.
1969 			try to allocate from the CMA areas.
1978 			Allows heavy hugetlb users to free up some more
1998 			A value of 1 instructs the kernel to panic when a
2000 			by the CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time
2006 	hvc_iucv_allow=	[S390]	Comma-separated list of z/VM user IDs.
2012 			which allow the hypervisor to 'idle' the guest
2028 			Set device-properties for ACPI-enumerated I2C-attached
2029 			touchscreen, to e.g. fix coordinates of upside-down
2037 			Omit "=<val>" entirely	Set a boolean device-property
2038 			Unsigned number		Set a u32 device-property
2039 			Anything else		Set a string device-property
2042 			i2c_touchscreen_props=GDIX1001:touchscreen-inverted-x:
2043 			touchscreen-inverted-y
2045 			i2c_touchscreen_props=MSSL1680:touchscreen-size-x=1920:
2046 			touchscreen-size-y=1080:touchscreen-inverted-y:
2047 			firmware-name=gsl1680-vendor-model.fw:silead,home-button
2052 			     (disabled by default, and as a pre-condition
2054 	i8042.direct	[HW] Put keyboard port into non-translated mode
2057 			     (Don't attempt to blink the leds)
2064 	i8042.nopnp	[HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
2068 			     suspend-to-ram transitions, only during s2r
2074 			architectures force reset to be always executed
2076 	i8042.kbdreset	[HW] Reset device connected to KBD port
2083 			[DRM] Invert the sense of the variable that is used to
2087 			to maximum brightness. If this parameter is set to 0
2089 			is set to 1, a brightness value of 0 sets the backlight
2090 			to maximum brightness, and the maximum of the brightness
2092 			-1 -- never invert brightness
2093 			 0 -- machine default
2094 			 1 -- force brightness inversion
2096 	ia32_emulation=	[X86-64]
2098 			When true, allows loading 32-bit programs and executing 32-bit
2112 			to get slightly better performance in multiprocessor
2120 			idle=halt: Halt is forced to be used for CPU idle.
2123 			idle=nomwait: Disable mwait for CPU C-states
2128 			support for the idxd driver. By default it is set to
2134 			for the device. By default it is set to false (0).
2144 			binary.  Hardware implementations are permitted to
2151 			legacy	only accept legacy-NaN binaries, if supported
2153 			2008	only accept 2008-NaN binaries, if supported
2160 			The FPU emulator is always able to support both NaN
2164 			'relaxed' straps the emulator for both legacy-NaN and
2165 			2008-NaN, whereas 'strict' enables legacy-NaN only on
2174 			Ignore loglevel setting - this will print /all/
2175 			kernel messages to the console. Useful for debugging.
2209 			The builtin policies to load during IMA setup.
2241 			Formats: { "ima" | "ima-ng" | "ima-ngv2" | "ima-sig" |
2242 				   "ima-sigv2" }
2243 			Default: "ima-ng"
2256 			to achieve the best performance for a particular HW.
2264 			to achieve best performance for particular HW.
2269 			Note that disabling IMA is limited to kdump kernel.
2281 			stuff:	Deploy RSB-fill mitigation when retpoline is
2286 			Documentation/admin-guide/hw-vuln/indirect-target-selection.rst
2297 	initcall_blacklist=  [KNL] Do not execute a comma-separated list of
2298 			initcall functions.  Useful for debugging built-in
2315 	initrdmem=	[KNL,EARLY] Specify a physical address and size from which to
2333 			default (disallow access to all but pkey 0).  Can
2343 			0 -- basic integrity auditing messages. (Default)
2344 			1 -- additional integrity auditing messages.
2358 			Deprecated, equivalent to iommu.strict=1.
2372 			could harm performance of some high-throughput
2377 			vulnerable to DMA attacks.
2381 			1 to 9	specify maximum depth of C-state.
2388                           Use intel_pstate driver to bypass the scaling
2390                           algorithms for p-state selection. There are two
2391                           P-state selection algorithms provided by
2394                           on whether or not the hardware managed P-states
2399 			  to work with generic cpufreq governors (instead of
2401 			  used along with the hardware-managed P-states (HWP)
2405 			  in favor of acpi-cpufreq. Forcing the intel_pstate driver
2406 			  instead of acpi-cpufreq may disable platform features, such
2408 			  P-States information being indicated to OSPM and therefore
2411 			  or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
2424 			  Allow per-logical-CPU P-State performance control limits using
2427 			  Do not enable capacity-aware scheduling (CAS) on
2430 	intremap=	[X86-64,Intel-IOMMU,EARLY]
2435 				BIOS x2APIC opt-out request will be ignored
2440 	iomem=		Disable strict checking of access to MMIO memory
2466 			Intel machines). This can be used to prevent the usage
2478 		AMD Gart HW IOMMU-specific options:
2497 			Do scatter-gather (SG) merging. Implies "force"
2501 			Don't do scatter-gather (SG) merging.
2504 			Ask the IOMMU not to touch the aperture for AGP.
2514 			0 - Try to allocate a 32-bit DMA address first, before
2515 			  falling back to the full range if needed.
2516 			1 - Allocate directly from the full usable range,
2518 			  greater than 32-bit addressing.
2522 			0 - Lazy mode.
2526 			  Will fall back to strict mode if not supported by
2528 			1 - Strict mode.
2531 			unset - Use value of CONFIG_IOMMU_DEFAULT_DMA_{LAZY,STRICT}.
2533 			legacy driver-specific options takes precedence.
2536 			[ARM64,X86,EARLY] Configure DMA to bypass the IOMMU by default.
2538 			0 - Use IOMMU translation for DMA.
2539 			1 - Bypass the IOMMU for DMA.
2540 			unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
2542 	io7=		[HW] IO7 for Marvel-based Alpha systems
2557 			See Documentation/admin-guide/nfs/nfsroot.rst.
2560 			IPC identifiers from 32,768 to 16,777,216.
2580 			Force the kernel to look for the second 4kB page
2586 			Force the kernel to ignore the availability of
2589 			to let secondary kernels in charge of setting up
2593 			Enables support for pseudo-NMIs in the kernel. This
2594 			requires the kernel to be built with
2598 			[RISC-V,EARLY]
2599 			Force the kernel to not use IMSIC software injected MSIs
2600 			as IPIs. Intended for system where IMSIC is trap-n-emulated,
2601 			and thus want to reduce MMIO traps when triggering IPIs
2602 			to multiple harts.
2606 			for it. Intended to get systems with badly broken
2612 			long-running IRQs in the system.
2617 			interrupt. Intended to get systems with badly broken
2624 			[Deprecated - use cpusets instead]
2625 			Format: [flag-list,]<cpu-list>
2627 			Specify one or more CPUs to isolate from disturbances
2633 			  offloaded. This is equivalent to the nohz_full parameter.
2635 			  A residual 1Hz tick is offloaded to workqueues, which you
2636 			  need to affine to housekeeping through the global
2642 			  so to protect individual CPUs the 'cpumask' file has to
2648 			  is irreversible: it's not possible to bring back a CPU to
2650 			  advised to use cpusets instead to disable scheduler load
2658 			  "number of CPUs in system - 1".
2672 			  interrupts are directed to the housekeeping CPU
2684 			The format of <cpu-list> is described above.
2688 	ivrs_ioapic	[HW,X86-64]
2689 			Provide an override to the IOAPIC-ID<->DEVICE-ID
2693 			For example, to map IOAPIC-ID decimal 10 to
2699 			* To map IOAPIC-ID decimal 10 to PCI device 00:14.0
2702 			* To map IOAPIC-ID decimal 10 to PCI segment 0x1 and
2706 	ivrs_hpet	[HW,X86-64]
2707 			Provide an override to the HPET-ID<->DEVICE-ID
2711 			For example, to map HPET-ID decimal 10 to
2717 			* To map HPET-ID decimal 0 to PCI device 00:14.0
2720 			* To map HPET-ID decimal 10 to PCI segment 0x1 and
2724 	ivrs_acpihid	[HW,X86-64]
2725 			Provide an override to the ACPI-HID:UID<->DEVICE-ID
2729 			For example, to map UART-HID:UID AMD0020:0 to
2735 			* To map UART-HID:UID AMD0020:0 to PCI segment is 0,
2738 			* To map UART-HID:UID AMD0020:0 to PCI segment 0x1 and
2746 			[KNL] Enforce KASAN (Kernel Address Sanitizer) to print
2762 			the kernel for non-movable allocations.  The requested
2766 			event, a node is too small to have both ZONE_NORMAL and
2772 			subsystem.  Note that allocations like PTEs-from-HighMem
2776 			It is possible to specify the exact amount of memory in
2780 			for non-movable allocations and remaining memory is used
2789 			each poll cycle to the debug port in case you need
2791 			gdb or control-c on the dbgp connection.  When
2792 			not using this parameter you use sysrq-g to break into
2797 			or a supported polling keyboard driver (non-usb).
2806 			If the boot console provides the ability to read
2808 			this parameter to tell kgdb to use it as a backend
2809 			until the normal console is registered. Intended to
2811 			specifies the normal console to transition to.
2816 			name passed to kgdboc. It's OK to leave the value
2826 			"0" | "off" | "n" - kexec handover is disabled
2827 			"1" | "on" | "y" - kexec handover is enabled
2833 			ranges that can only be used for non-kernel
2836 			kernel will always have enough contiguous ranges to
2839 			It is possible to specify the exact amount of
2844 			parameter defines the size of additional per-node
2849 			Configure the RouterBoard 532 series on-chip
2852 	kmemleak=	[KNL,EARLY] Boot-time kmemleak enable/disable
2858 	kprobe_event=[probe-list]
2860 			The probe-list is a semicolon delimited list of probe
2863 			For example, to add a kprobe event on vfs_read with
2864 			arg1 and arg2, add to the command line;
2878 			CONFIG_KUNIT to be set to be fully enabled. The
2883 	kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.
2887 			[KVM,X86] Controls whether or not KVM will try to
2889 			Eager page splitting reduces interruptions to vCPU
2890 			execution by eliminating the write-protection faults
2892 			required to split huge pages lazily.
2895 			only to a small region of VM memory may benefit from
2896 			disabling eager page splitting to allow huge pages to
2917 			virtualization on-demand when creating and destroying
2925 			is that doing so may interfere with using out-of-tree
2926 			hypervisors that want to "own" virtualization hardware.
2942 			guests do need not to enable it for nested guests.
2946 			back to huge pages.  0 disables the recovery, otherwise if
2952 			back to huge pages. If the value is a non-zero N, KVM will
2957 	kvm-amd.nested=	[KVM,AMD] Control nested virtualization feature in
2960 	kvm-amd.npt=	[KVM,AMD] Control KVM's use of Nested Page Tables,
2961 			a.k.a. Two-Dimensional Page Tables. Default is 1
2965 	kvm-amd.ciphertext_hiding_asids=
2967 			to SNP private memory from reading ciphertext.  Instead,
2970 			If ciphertext hiding is enabled, the joint SEV-ES and
2971 			SEV-SNP ASID space is partitioned into separate SEV-ES
2972 			and SEV-SNP ASID ranges, with the SEV-SNP range being
2973 			[1..max_snp_asid] and the SEV-ES range being
2977 			A non-zero value enables SEV-SNP ciphertext hiding and
2978 			adjusts the ASID ranges for SEV-ES and SEV-SNP guests.
2979 			KVM caps the number of SEV-SNP ASIDs at the maximum
2980 			possible value, e.g. specifying -1u will assign all
2981 			joint SEV-ES and SEV-SNP ASIDs to SEV-SNP.  Note,
2982 			assigning all joint ASIDs to SEV-SNP, i.e. configuring
2983 			max_snp_asid == min_sev_asid-1, will effectively make
2984 			SEV-ES unusable.
2986 	kvm-arm.mode=
2992 			nvhe: Standard nVHE-based mode, without support for
2999 			nested: VHE-based mode with support for nested
3003 			Defaults to VHE/nVHE based on hardware support. Setting
3004 			mode to "protected" will disable kexec and hibernation
3005 			for the host. To force nVHE on VHE hardware, add
3006 			"arm64_sw.hvhe=0 id_aa64mmfr1.vh=0" to the
3007 			command-line.
3011 	kvm-arm.vgic_v3_group0_trap=
3012 			[KVM,ARM,EARLY] Trap guest accesses to GICv3 group-0
3015 	kvm-arm.vgic_v3_group1_trap=
3016 			[KVM,ARM,EARLY] Trap guest accesses to GICv3 group-1
3019 	kvm-arm.vgic_v3_common_trap=
3020 			[KVM,ARM,EARLY] Trap guest accesses to GICv3 common
3023 	kvm-arm.vgic_v4_enable=
3027 	kvm-arm.wfe_trap_policy=
3028 			[KVM,ARM] Control when to set WFE instruction trap for
3036 	kvm-arm.wfi_trap_policy=
3037 			[KVM,ARM] Control when to set WFI instruction trap for
3053 	kvm-intel.ept=	[KVM,Intel] Control KVM's use of Extended Page Tables,
3054 			a.k.a. Two-Dimensional Page Tables.  Default is 1
3058 	kvm-intel.emulate_invalid_guest_state=
3059 			[KVM,Intel] Control whether to emulate invalid guest
3060 			state. Ignored if kvm-intel.enable_unrestricted_guest=1,
3062 			guests. This param doesn't apply to nested guests (L2),
3066 	kvm-intel.flexpriority=
3071 	kvm-intel.nested=
3075 	kvm-intel.unrestricted_guest=
3081 	kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
3082 			CVE-2018-3620.
3093 	kvm-intel.vpid=	[KVM,Intel] Control KVM's use of Virtual Processor
3101 			Certain CPUs are vulnerable to an exploit against CPU
3102 			internal buffers which can forward information to a
3107 			attack, to access data to which the attacker does
3113 			on         - enable the interface for the mitigation
3178 			For details see: Documentation/admin-guide/hw-vuln/l1tf.rst
3184 	lapic		[X86-32,APIC,EARLY] Enable the local APIC even if BIOS
3188 			value for LAPIC timer one-shot implementation. Default
3189 			back to the programmable timer unit in the LAPIC.
3211 	libata.force=	[LIBATA] Force configurations.  The format is a comma-
3218 			to all ports, links and devices.
3220 			If only DEVICE is omitted, the parameter applies to
3223 			first fan-out link behind PMP device.  It does not
3225 			host link and device attached to it.
3227 			The VAL specifies the configuration to force.  As long
3237 			* Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
3244 			* rstonce: only attempt one reset during hot-unplug
3271 			  READ LOG DMA EXT command to access logs.
3273 			* [no]iddevlog: Enable or disable access to the
3276 			* [no]logdir: Enable or disable access to the general
3279 			* max_sec_128: Set transfer size limit to 128 sectors.
3281 			* max_sec_1024: Set or clear transfer size limit to
3284 			* max_sec_lba48: Set or clear transfer size limit to
3287 			* external: Mark port as external (hotplug-capable).
3320 			Enable the kernel lockdown feature. If set to
3321 			integrity, kernel features that allow userland to
3322 			modify the running kernel are disabled. If set to
3324 			to extract confidential information from the kernel
3333 			Specify the list of CPUs to which the readers are
3334 			to be bound.
3337 			Specify the list of CPUs to which the writers are
3338 			to be bound.
3341 			Specify the number of self-propagating call_rcu()
3342 			chains to set up.  These are used to ensure that
3344 			in progress at any given time.	Defaults to 0,
3349 			occasional long-duration lock hold time.  Defaults
3350 			to 100 milliseconds.  Select 0 to disable.
3354 			locktorture is to exercise, up to a limit of 8
3355 			(MAX_NESTED_LOCKS).  Specify zero to disable.
3360 			Set the number of locking read-acquisition kthreads.
3361 			Defaults to being automatically set based on the
3365 			Set the number of locking write-acquisition kthreads.
3368 			Set time (s) after boot for CPU-hotplug testing.
3371 			Set time (s) between CPU-hotplug operations, or
3372 			zero to disable CPU-hotplug testing.
3375 			Do periodic testing of real-time lock priority
3376 			boosting.  Select 0 to disable, 1 to boost
3377 			only rt_mutex, and 2 to boost unconditionally.
3378 			Defaults to 2, which might seem to be an
3380 			non-real-time spinlocks, due to their disabling
3381 			of preemption.	Note that non-realtime mutexes
3394 			Set task-shuffle interval (jiffies).  Shuffling
3395 			tasks allows some CPUs to go into dyntick-idle
3400 			is useful for hands-off automated testing.
3406 			Time (s) to stutter testing, for example,
3407 			specifying five seconds causes the test to run for
3409 			This tests the locking primitive's ability to
3410 			transition abruptly to and from idle.
3413 			Specify the locking implementation to test.
3419 			Run the write-side locktorture kthreads at
3420 			sched_set_fifo() real-time priority.
3427 			console loglevel will be printed to the console. It can
3438 			7 (KERN_DEBUG)		debug-level messages
3446 			parameter that allows to increase the default size
3450 	logo.nologo	[FB] Disables display of the built-in Linux logo.
3451 			This may be used to provide more screen space for
3455 	lp=0		[LP]	Specify parallel ports to use, e.g,
3459 				specified in addition to the ports) causes
3460 				attached printers to be reset. Using
3462 				to associate lp devices with, starting with
3463 				lp0. A port specification may be 'none' to skip
3467 				from each port should be examined, to see if
3468 				an IEEE 1284-compliant printer is attached; if
3473 			Sets loops_per_jiffy to given constant, thus avoiding
3474 			time-consuming boot-time autodetection (up to 250 ms per
3475 			CPU). 0 enables autodetection (default). To determine
3478 			on SMP systems the preset will be applied to all CPUs,
3479 			which is likely to cause problems if your CPUs need
3481 			will cause delays in the kernel to be wrong, leading to
3494 			Example: machtype=lemote-yeeloong-2f-7inch
3498 			the kernel to bring up 'n' processors. Surely after
3502 			While n=0 is a special case, it is equivalent to "nosmp",
3506 	(loop.max_loop)	unconditionally pre-created at init time. The default
3509 			devices can be requested on-demand with the
3510 			/dev/loop-control interface.
3512 	mce=		[X86-{32,64}]
3526 			with due to the shared banks, i.e. you might get
3549 			do not opt-in to Local MCE delivery. Use legacy method
3550 			to broadcast MCEs.
3557 			If your BIOS doesn't do that it's a good idea to
3558 			enable though to make sure you log even machine check
3566 			sets the time in us to wait for other CPUs on machine
3567 			checks. 0 to disable.
3570 			don't overwrite the bios-set CMCI threshold. This boot
3573 			always sets the CMCI threshold to 1. Enabling this may
3579 			force-enable recoverable machine check code paths
3585 			See Documentation/admin-guide/md.rst.
3589 			Specifies range of consoles to be captured by the MDA.
3592 			Control mitigation for the Micro-architectural Data
3595 			Certain CPUs are vulnerable to an exploit against CPU
3596 			internal buffers which can forward information to a
3601 			attack, to access data to which the attacker does
3607 			full       - Enable MDS mitigation on vulnerable CPUs
3608 			full,nosmt - Enable MDS mitigation and disable
3610 			off        - Unconditionally disable MDS mitigation
3612 			On TAA-affected machines, mds=off can be prevented by
3614 			mitigated with the same mechanism so in order to disable
3615 			this mitigation, you need to specify tsx_async_abort=off
3618 			Not specifying this option is equivalent to
3621 			For details see: Documentation/admin-guide/hw-vuln/mds.rst
3627 			of memory Amount of memory to be used in cases
3631 			2 when the kernel is not able to see the whole system memory;
3633 			 the hypervisor, then assigned to KVM guests.
3634 			4 to limit the memory available for kdump kernel.
3636 			[ARC,MICROBLAZE] - the limit applies only to low memory,
3639 			[ARM64] - only limits memory covered by the linear
3643 			with memmap= to avoid physical address space collisions.
3645 			belonging to unused RAM.
3652 			[ARM,MIPS,EARLY] - override the memory layout
3659 	mem=nopentium	[BUGS=X86-32] Disable usage of 4MB pages for kernel
3665 			[KNL,SH] Allow user to override the default size for
3666 			per-device physically contiguous DMA buffers.
3671 			set according to the
3674 			See Documentation/admin-guide/mm/memory-hotplug.rst.
3684 			Region of memory to be used is from ss to ss+nn.
3685 			If @ss[KMG] is omitted, it is equivalent to mem=nn[KMG],
3686 			which limits max address to nn[KMG].
3694 			Region of memory to be marked is from ss to ss+nn.
3698 			Region of memory to be reserved is from ss to ss+nn.
3699 			Example: Exclude memory from 0x18690000-0x1869ffff
3709 			Region of memory to be used, from ss to ss+nn.
3713 	memmap=<size>%<offset>-<oldtype>+<newtype>
3715 			from <oldtype> to <newtype>. If "-<oldtype>" is left
3723 			Some BIOSes seem to corrupt the first 64k of
3730 			repeatable BIOS-originated corruption always
3732 			to prevent the kernel from using that memory.
3737 			use.  Use this parameter to scan for
3742 			seconds.  Use this parameter to check at some
3746 			[KNL,X86,ARM] Boolean flag to enable this feature.
3752 			hotadded memory which will allow to hotadd a
3754 			memory to do so.
3767 			Specifies the number of memtest passes to be
3774 	mem_encrypt=	[X86-64] AMD Secure Memory Encryption (SME) control
3780 			Refer to Documentation/virt/kvm/x86/amd-memory-encryption.rst
3784 			s2idle  - Suspend-To-Idle
3785 			shallow - Power-On Suspend or equivalent (if supported)
3786 			deep    - Suspend-To-RAM or equivalent (if supported)
3787 			See Documentation/admin-guide/pm/sleep-states.rst.
3789 	mfgptfix	[X86-32] Fix MFGPT timers on AMD Geode platforms when
3791 			version 0.98 is known to be affected, 0.99 fixes the
3799 			base_rev=X - with <X> with format: <u32>
3813 			0 - The attached screen is the 3.5" TFT
3814 			1 - The attached screen is the 7" TFT
3815 			2 - The VGA Shield is attached (1024x768)
3819 			b - Enable backlight. The TFT backlight pin will be
3820 			linked to the kernel VESA blanking code and a GPIO
3823 			c - Enable the s3c camera interface.
3824 			t - Reserved for enabling touchscreen support. The
3828 			https://repo.or.cz/w/linux-2.6/mini2440.git
3833 			arch-independent options, each of which is an
3834 			aggregation of existing arch-specific options.
3842 				expose users to several CPU vulnerabilities.
3843 				Equivalent to: if nokaslr then kpti=0 [ARM64]
3864 					       ssbd=force-off [ARM64]
3876 				users who don't want to be surprised by SMT
3878 				have other ways of avoiding SMT-based attacks.
3879 				Equivalent to: (default behavior)
3883 				if needed.  This is for users who always want to
3885 				Equivalent to: l1tf=flush,nosmt [X86]
3892 			supports attack-vector based controls as documented in
3893 			Documentation/admin-guide/hw-vuln/attack_vector_controls.rst
3901 			so loglevel=8 may also need to be specified.
3911 			Therefore, similar to MDS and TAA, the mitigation
3912 			is to clear the affected CPU buffers.
3917 			full       - Enable mitigation on vulnerable CPUs
3919 			full,nosmt - Enable mitigation and disable SMT on
3922 			off        - Unconditionally disable mitigation
3927 			mitigated with the same mechanism so in order to
3928 			disable this mitigation, you need to specify
3931 			Not specifying this option is equivalent to
3935 			Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst
3945 			[KNL] When set to true, modules will use async probing
3946 			by default. To enable/disable async probing for a
3961 			modules without (valid) signatures will fail to load.
3965 	module_blacklist=  [KNL] Do not load a comma-separated list of
3970 			leaving touchpad surface for touch to be considered
3981 			This parameter is the complement to kernelcore=, it
3990 	movable_node	[KNL,EARLY] Boot-time switch to make hotplugable memory
3991 			NUMA nodes to be movable. This means that the memory
3997 			Format: <name>,<region-number>,<size>,<offset>
4000 			<name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
4010 			Enable printing debug information related to MTRR
4028 			Set to 2 or more if your graphical card needs more.
4038 			Note that mem_start is often overloaded to mean
4039 			something different and driver-specific.
4050 			0 to disable accounting
4051 			1 to enable accounting
4055 			[NFS] sets the pathname to the program which is used
4056 			to update the NFS client cache entries.
4059 			[NFS] sets the timeout after which an attempt to
4060 			update a cache entry is deemed to have failed.
4064 			NFS client will assign to service NFSv4 callback
4079 			[NFS] enable 64-bit inode numbers.
4080 			If zero, the NFS client will fake up a 32-bit inode
4082 			of returning the full 64-bit number.
4083 			The default is to return 64-bit inode numbers.
4091 			slots the client will assign to the callback
4098 			the client will attempt to negotiate with the server.
4100 			that the client can send to the NFSv4.1 server.
4105 			[NFSv4] When set to the default of '1', this option
4107 			scheme and the NFS level operations agree to use
4111 			legacy NFSv2/v3 systems to NFSv4 easier.
4114 			back to using the idmapper.
4115 			To turn off this behaviour, set the value to '0'.
4118 			[NFS4] Specify an additional fixed unique ident-
4124 			[NFSv4] Attempt to recover locks that were lost due
4125 			to a lease timeout on the server. Please note that
4129 			If you want to enable the kernel legacy behaviour of
4130 			attempting to recover these locks, then set this
4131 			parameter to '1'.
4133 			not to attempt recovery of lost locks.
4140 			The default is to send the implementation identification
4145 			layoutstats to the pNFS metadata server.
4147 			Setting this to value to 0 causes the kernel to use
4149 			driver. A non-zero value sets the minimum interval
4153 			[NFSv4.2] When set to 1, the server will support
4154 			server-to-server copies for which this server is
4158 			[NFSv4] When set to the default of '1', the NFSv4
4159 			server will return only numeric uids and gids to
4161 			and gids from such clients.  This is intended to ease
4166 			server-to-server copy, knfsd temporarily mounts
4173 			See Documentation/admin-guide/nfs/nfsroot.rst.
4175 	nfsroot=	[NFS] nfs root filesystem for disk-less boxes.
4176 			See Documentation/admin-guide/nfs/nfsroot.rst.
4179 			See Documentation/admin-guide/nfs/nfsroot.rst.
4182 			Dump stacks even of idle CPUs in response to an
4183 			NMI stack-backtrace request.
4185 	nmi_debug=	[KNL,SH] Specify one or more actions to take
4192 			0 - turn hardlockup detector in nmi_watchdog off
4193 			1 - turn hardlockup detector in nmi_watchdog on
4194 			rNNN - configure the watchdog with raw perf event 0xNNN
4197 			timeout occurs (or 'nopanic' to not panic on an NMI
4199 			To disable both hard and soft lockup detectors,
4207 	no387		[BUGS=X86-32] Tells the kernel to use the 387 maths
4211 	no4lvl		[RISCV,EARLY] Disable 4-level and 5-level paging modes.
4212 			Forces kernel to use 3-level paging instead.
4214 	no5lvl		[X86-64,RISCV,EARLY] Disable 5-level paging mode. Forces
4215 			kernel to use 4-level paging instead.
4219 	noapic		[SMP,APIC,EARLY] Tells the kernel to not make use of any
4233 			of the system is being put to sleep (ie, while
4236 			to work with serial and VGA consoles.
4237 			To facilitate more flexible debugging, we also add
4238 			console_suspend, a printk module parameter to control
4240 			/sys/module/printk/parameters/console_suspend) to
4250 	no_entry_flush  [PPC,EARLY] Don't flush the L1-D cache when entering the kernel.
4252 	noexec32	[X86-64]
4253 			This affects only 32-bit executables.
4254 			noexec32=on: enable non-executable mappings (default)
4256 			noexec32=off: disable non-executable mappings
4259 	no_file_caps	Tells the kernel not to honor file capabilities.  The
4260 			only way then for a file to be executed with privilege
4261 			is to be setuid root or executed by root.
4267 	nofxsr		[BUGS=X86-32] Disables x86 floating point extended
4269 			legacy floating-point registers on task switch.
4279 	nohlt		[ARM,ARM64,MICROBLAZE,MIPS,PPC,RISCV,SH] Forces the kernel to
4282 			to be effective. This is useful on platforms where the
4284 			correctly or when doing power measurements to evaluate
4303 			the range to maintain the timekeeping.  Any CPUs
4311 	noinitrd	[RAM] Tells the kernel not to load any configured
4314 	nointremap	[X86-64,Intel-IOMMU,EARLY] Do not enable interrupt
4316 			[Deprecated - use intremap=off]
4322 	noirqdebug	[X86-32] Disables the code which attempts to detect and
4332 	no-kvmapf	[X86,KVM,EARLY] Disable paravirtualized asynchronous page
4335 	no-kvmclock	[X86,KVM,EARLY] Disable paravirtualized KVM clock driver
4337 	nolapic		[X86-32,APIC,EARLY] Do not enable or use the local APIC.
4339 	nolapic_timer	[X86-32,APIC,EARLY] Do not use the local APIC timer.
4341 	nomce		[X86-32] Disable Machine Check Exception
4343 	nomfgpt		[X86-32] Disable Multi-Function General Purpose
4349 			not load if they could possibly displace the pre-
4352 			perform display-mode changes or accelerated rendering.
4358 	nonmi_ipi	[X86] Disable using NMI IPIs during panic/reboot to
4365 	nopcid		[X86-64,EARLY] Disable the PCID cpu feature.
4370 	nopti		[X86-64,EARLY]
4371 			Equivalent to pti=off
4374 			Disables the PV optimizations forcing the guest to run
4380 			which allow the hypervisor to 'idle' the guest on lock
4383 	norandmaps	Don't use address space randomization.  Equivalent to
4386 	noreplace-smp	[X86-32,SMP] Don't replace SMP instructions
4392 	no-scroll	[VGA] Disables scrollback.
4393 			This is required for the Braillex ib80-piezo Braille
4396 	nosgx		[X86-64,SGX,EARLY] Disables Intel SGX kernel support.
4406 	nosmp		[SMP,EARLY] Tells an SMP kernel to act as a UP kernel,
4410 			Equivalent to smt=1.
4416 	nosoftlockup	[KNL] Disable the soft-lockup detector.
4422 	nospectre_bhb	[ARM64,EARLY] Disable all mitigations for Spectre-BHB (branch
4435 	no-steal-acc	[X86,PV_OPS,ARM64,PPC/PSERIES,RISCV,LOONGARCH,EARLY]
4442 			timer IRQ sources, i.e., the IO-APIC timer. This can
4447 	                [PPC,EARLY] Don't flush the L1-D cache after accessing user data.
4450 			Disable device dump. Device dump allows drivers to
4451 			append dump data to vmcore so you can collect driver
4460 	no-vmw-sched-clock
4465 			soft-lockup and NMI watchdog (hard-lockup).
4469 	nox2apic	[X86-64,APIC,EARLY] Do not enable x2APIC mode.
4476 			and restore using xsave. The kernel will fallback to
4477 			enabling legacy floating-point and sse state.
4480 			register states. The kernel will fall back to use
4481 			xsave to save the states. By using this parameter,
4488 			form of xsave area. The kernel will fall back to use
4489 			xsaveopt and xrstor to save and restore the states
4495 			could support.  nr_cpus=n : n >= 1 limits the kernel to
4499 			n. So during boot up some boot time memory for per-cpu
4500 			variables need be pre-allocated for later physical cpu
4503 	nr_uarts=	[SERIAL] maximum number of UARTs to be registered.
4527 			soft-reserved memory partitioning.
4536 			See Documentation/admin-guide/sysctl/vm.rst for details.
4539 			See Documentation/core-api/debugging-via-ohci1394.rst for more
4551 			For example, to override I2C bus2:
4554 	onenand.bdry=	[HW,MTD] Flex-OneNAND Boundary Configuration
4558 			boundary - index of last SLC block on Flex-OneNAND.
4560 			lock	 - Configure if Flex-OneNAND boundary should be locked.
4565 			Always panic on oopses. Default is to just kill the
4569 			Useful together with panic=30 to trigger a reboot.
4572 			[KNL] Boolean flag to control whether the page allocator
4574 			used to enable/disable page randomization. The state of
4579 	page_owner=	[KNL,EARLY] Boot-time page_owner enabling option.
4585 	page_poison=	[KNL,EARLY] Boot-time parameter changing the state of
4607 			that will cause the kernel to panic when add_taint() is
4609 			The optional switch "nousertaint" can be utilized to
4610 			prevent userspace forced crashes by writing to sysctl
4613 			See Documentation/admin-guide/tainted-kernels.rst for
4615 			to compose the bitmask to assign to panic_on_taint.
4617 	panic_on_warn=1	panic() instead of WARN().  Useful to cause kdump
4632 			Use this option carefully, maybe worth to setup a
4635 	panic_sys_info= A comma separated list of extra information to be dumped
4648                         This is a human readable alternative to the 'panic_print' option.
4655 			connected to, default is 0.
4663 			Use 'auto' to force the driver to use any
4664 			IRQ/DMA settings detected (the default is to
4670 			(to avoid using a FIFO even if it is detected).
4676 			Configure VIA parallel port to operate in
4679 			up parallel port mode and sets it to spp.
4685 			Set to non-zero to probe primary and secondary ISA
4691 			Set to non-zero if a chip is present that snoops speed
4696 			Set to 1, 2, or 3 for HT 6560A on the primary channel,
4702 			Set to 1, 2, or 3 for HT 6560B on the primary channel,
4708 			IORDY enable mask.  Set individual bits to allow IORDY
4712 			correspond to the primary legacy channel, the secondary
4720 			Set to 1, 2, or 3 for Opti 82c611A on the primary
4726 			Set to 1, 2, or 3 for Opti 82c465MV on the primary
4733 			bits to allow the use of the respective PIO modes.
4739 			Set to non-zero to probe tertiary and further ISA
4746 			options up to 6 legacy ports are supported: 0x1f0,
4749 			corresponding bits in the mask to 1.  Bit 0 is for
4755 			Set to non-zero to probe QDI controllers.  By default
4756 			set to 1 if CONFIG_PATA_QDI_MODULE, 0 otherwise.
4760 			Set to non-zero to probe Winbond controllers.  Use
4762 			value given is the I/O port to use (typically 0x1b0).
4763 			By default set to 1 if CONFIG_PATA_WINBOND_VLB_MODULE,
4768 			Supported PIO mode mask.  Set individual bits to allow
4775 			the specified number of seconds.  This is to be used if
4792 				firmware changes, or due to changes caused
4795 				taken to be zero. Optionally, a path
4796 				to a device through multiple device/function
4807 		bios		[X86-32] force use of PCI BIOS, don't access
4809 				has a non-standard PCI host bridge.
4810 		nobios		[X86-32] disallow use of PCI BIOS, only direct
4816 				data in IO port 0xCFC, both 32-bit).
4818 				Mechanism 2 (IO port 0xCF8 is an 8-bit port for
4819 				the function, IO port 0xCFA, also 8-bit, sets
4821 				through ports 0xC000-0xCFFF).
4825 				enabled, this kernel boot option can be used to
4828 				root domains (aka PCI segments, in ACPI-speak).
4832 				properly configured MMIO access to PCI
4835 				enabled, this kernel boot option can be used to
4836 				disable the use of MSI interrupts system-wide.
4838 				Safety option to keep boot IRQs enabled. This
4840 		ioapicreroute	[APIC] Enable rerouting of boot IRQs to the
4841 				primary IO-APIC for bridges that cannot disable
4845 				boot IRQ equivalent of an IRQ that connects to
4848 		biosirq		[X86-32] Use PCI BIOS calls to get the interrupt
4849 				routing table. These calls are known to be buggy
4852 				way to get the interrupt routing table. Try
4853 				this option if the kernel is unable to allocate
4856 		rom		[X86] Assign address space to expansion ROMs.
4860 		norom		[X86] Do not assign address space to
4863 		nobar		[X86] Do not assign address space to the
4865 		irqmask=0xMMMM	[X86] Set a bit mask of IRQs allowed to be
4866 				assigned automatically to PCI devices. You can
4872 				F0000h-100000h range.
4874 				useful if the kernel is unable to find your
4875 				secondary buses and you want to tell it
4877 		assign-busses	[X86] Always assign all PCI bus
4890 				is enabled by default.  If you need to use this,
4893 				If you need to use this, please report a bug.
4894 		use_e820	[X86] Use E820 reservations to exclude parts of
4897 				If you need to use this, please report a bug to
4898 				<linux-pci@vger.kernel.org>.
4901 				hardware. If you need to use this, please report
4902 				a bug to <linux-pci@vger.kernel.org>.
4914 		bfsort		Sort PCI devices into breadth-first order.
4915 				This sorting is done to get a device
4917 		nobfsort	Don't sort PCI devices into breadth-first order.
4919 				tuning and use the BIOS-configured MPS defaults.
4920 		pcie_bus_safe	Set every device's MPS to the largest value
4922 		pcie_bus_perf	Set device MPS to the largest allowable MPS
4924 				Read Request Size) to the largest supported
4927 		pcie_bus_peer2peer	Set every device's MPS to 128B, which
4928 				every device is guaranteed to support. This
4929 				configuration allows peer-to-peer DMA between
4932 				that hot-added devices will work.
4942 				Specifies alignment and device to reassign
4943 				aligned memory resources. How to
4947 				A PCI-PCI bridge can be specified if resource
4948 				windows need to be expanded.
4949 				To specify the alignment for several
4953 				for 4096-byte alignment.
4955 				end-to-end CRC checking). Only effective if
4979 				if allocations done by BIOS are too small to
4986 		noats		[PCIE, Intel-IOMMU, AMD-IOMMU]
4991 		big_root_window	Try to add a big 64bit memory window to the PCIe
4993 				can resize a BAR to allow access to all VRAM.
5017 				  bit-0 : ACS Source Validation
5018 				  bit-1 : ACS Translation Blocking
5019 				  bit-2 : ACS P2P Request Redirect
5020 				  bit-3 : ACS P2P Completion Redirect
5021 				  bit-4 : ACS Upstream Forwarding
5022 				  bit-5 : ACS P2P Egress Control
5023 				  bit-6 : ACS Direct Translated P2P
5031 				ACS to enable P2P Request Redirect, disable
5033 				Validation unchanged from whatever power-up
5034 				or firmware set it to.
5044 				to disable PCIe TLP Processing Hints support
5045 				system-wide.
5051 		force	Enable ASPM even on devices that claim not to support it.
5056 			even if the platform doesn't give the OS permission to
5058 			also tries to use these services.
5059 		dpc-native	Use native PCIe service for DPC only.  May
5076 			Keep all power-domains already enabled by bootloader on,
5087 			Select which percpu first chunk allocator to use.
5094 	pirq=		[SMP,APIC] Manual mp-table setup
5095 			See Documentation/arch/x86/i386/IO-APIC.rst.
5099 			See also Documentation/admin-guide/parport.rst.
5108 			PMU counters by setting MMCR0 to 0 (the FC bit is
5109 			cleared). If a number is given, then MMCR1 is set to
5117 			If set to "off", disables asynchronous suspend and
5118 			resume of devices during system-wide power transitions.
5120 			dependencies are not well-defined, or for debugging
5130 			CONFIG_PNP_DEBUG_MESSAGES option).  Change at run-time
5139 			{ on | off | curr | res | no-curr | no-res }
5157 			Up to 8 (IP_VS_APP_MAX_PORTS) ports
5169 			function to NULL. On Idle the CPU just reduces
5184 			none - Limited to cond_resched() calls
5185 			voluntary - Limited to cond_resched() and might_sleep() calls
5186 			full - Any section that isn't explicitly preempt disabled
5190 			lazy - Scheduler controlled. Similar to full but instead
5192 			       one HZ tick time to yield itself before the
5194 			       task returns to user space.
5196 	print-fatal-signals=
5202 			coredump - etc.
5204 			If you hit the warning due to signal overflow,
5205 			you might want to try "ulimit -i unlimited".
5217 			or lockdep-detected issues (only if lock debug is on).
5218 			With an exception to setups with low baudrate on
5220 			in order to provide more debug information.
5225 			Allows storing messages from non-panic CPUs into
5227 			flushed to consoles by the panic-CPU on
5228 			a best-effort basis.
5233 			Control writing to /dev/kmsg.
5234 			on - unlimited logging to /dev/kmsg from userspace
5235 			off - logging to /dev/kmsg disabled
5236 			ratelimit - ratelimit the logging
5239 	printk.time=	Show timing data prefixed to each printk message line
5244 			Traditionally /proc/pid/mem allows memory permissions to be
5245 			overridden without restrictions. This option may be set to
5247 			- 'always': traditional behavior always allows mem overrides.
5248 			- 'ptrace': only allow mem overrides for active ptracers.
5249 			- 'never':  never allow mem overrides.
5253 			Limit processor to maximum C-state
5257 			Ignore the _CST method to determine C-states,
5263 				[defaults to kernel profiling]
5264 			Param: "schedule" - profile schedule points.
5265 			Param: "kvm" - profile VM exits.
5266 			Param: <number> - step/bucket size as a power of 2 for
5282 	psmouse.proto=	[HW,MOUSE] Highest PS2 mouse protocol extension to
5287 			Try to reset the device after so many bad packets
5295 	pstore.backend=	Specify the name of the pstore backend to use
5297 	pti=		[X86-64] Control Page Table Isolation of user and
5302 			on   - unconditionally enable
5303 			off  - unconditionally disable
5304 			auto - kernel detects whether your CPU model is
5305 			       vulnerable to issues that PTI mitigates
5307 			Not specifying this option is equivalent to pti=auto.
5310 			[KNL] Number of legacy pty's. Overwrites compiled-in
5322 			See Documentation/admin-guide/md.rst.
5325 			See Documentation/admin-guide/blockdev/ramdisk.rst.
5331 			random number generator (if available) to
5336 			passed by the bootloader (if available) to
5344 			cross-syscall address exposures. This is only
5350 	ras=option[,option,...]	[KNL] RAS-specific options
5356 	rcu_nocbs[=cpu-list]
5361 			enable the no-callback CPU mode, which prevents
5364 			callbacks will instead be offloaded to "rcuox/N"
5366 			"p" for RCU-preempt, "s" for RCU-sched, and "g"
5370 			and real-time workloads.  It can also improve
5374 			list of	CPUs is set to no-callback mode from boot.
5377 			arguments are omitted, no CPU will be set to
5378 			no-callback mode from boot but the mode may be
5389 			This improves the real-time response for the
5390 			offloaded CPUs by relieving them of the need to
5393 			periodically wake up to do the polling.
5396 			Set maximum number of finished RCU callbacks to
5400 			Do only a one-line RCU CPU stall warning when
5401 			there is an ongoing too-long CSD-lock wait.
5404 			Request a call to rcu_barrier().  This is
5407 			If triggered before the RCU grace-period machinery
5413 			purposes, to verify correct tree setup.
5416 			Set the number of jiffies to delay each step of
5417 			RCU grace-period cleanup.
5420 			Set the number of jiffies to delay each step of
5421 			RCU grace-period initialization.
5424 			Set the number of jiffies to delay each step of
5425 			RCU grace-period pre-initialization, that is,
5426 			the propagation of recent CPU-hotplug changes up
5430 			Set delay from grace-period initialization to
5431 			first attempt to force quiescent states.
5436 			Set delay between subsequent attempts to force
5443 			soliciting quiescent-state help from
5450 			rcutree.jiffies_to_sched_qs.  Any attempt to set
5455 			Set the SCHED_FIFO priority of the RCU per-CPU
5458 			and for the RCU grace-period kthreads (rcu_bh,
5460 			set, valid values are 1-99 and the default is 1
5461 			(the least-favored priority).  Otherwise, when
5462 			RCU_BOOST is not set, valid values are 0-99 and
5463 			the default is zero (non-realtime operation).
5468 			On callback-offloaded (rcu_nocbs) CPUs,
5471 			use of the ->nocb_bypass list.	However, in the
5472 			common non-flooded case, RCU queues directly to
5473 			the main ->cblist in order to avoid the extra
5474 			overhead of the ->nocb_bypass list and its lock.
5476 			a single jiffy, RCU pre-queues the callbacks into
5477 			the ->nocb_bypass queue.  The definition of "too
5481 			On callback-offloaded (rcu_nocbs) CPUs, avoid
5484 			Defaults to zero.  Large values will be capped
5486 			to the nearest value representable by jiffies.
5494 			batch limiting is re-enabled.
5498 			RCU's force-quiescent-state scan will aggressively
5499 			enlist help from cond_resched() and sched IPIs to
5501 			Set to less than zero to make this be set based
5502 			on rcutree.qhimark at boot time and to zero to
5506 			Set the page-cache refill delay (in milliseconds)
5507 			in response to low-memory conditions.  The range
5511 			Set the shift-right count to use to compute
5512 			the callback-invocation batch limit bl from
5517 			order to allow the CPU to do other work.
5519 			Please note that this callback-invocation batch
5520 			limit applies only to non-offloaded callback
5529 			cache-to-cache transfer latencies.
5532 			Change the number of CPUs assigned to each
5535 			and for NUMA systems with large remote-access
5542 			to PAGE_SIZE. The cache allows to reduce the
5543 			pressure to page allocator, also it makes the
5544 			whole algorithm to behave better in low memory
5549 			each group, which defaults to the square root
5551 			the wakeup overhead on the global grace-period
5553 			each group's NOCB grace-period kthread.
5556 			Cause the grace-period kthread to get an extra
5558 			it should at force-quiescent-state time.
5564 			callbacks to the specified number of nanoseconds.
5566 			every 32 callbacks in order to limit the pain
5571 			this specifies an rcu_read_unlock()-time delay
5572 			in microseconds.  This defaults to zero.
5575 			of RCU-protected pointers after the relevant
5579 			Commandeer a sysrq key to dump out Tree RCU's
5584 			If set to zero, move all RCU_SOFTIRQ processing to
5585 			per-CPU rcuc kthreads.  Defaults to a non-zero
5587 			Specify rcutree.use_softirq=0 to use rcuc kthreads.
5591 			to zero.
5594 			To save power, batch RCU callbacks and flush after
5605 			How to enable it:
5615 			grace-period primitives such as call_rcu().
5621 			corresponding flavor of rcu_barrier() to allow
5622 			previously posted callbacks to drain.
5626 			grace-period primitives.
5629 			Set test-start holdoff period.  The purpose of
5630 			this parameter is to delay the start of the
5631 			test until boot completes in order to avoid
5641 			Defaults to 1.
5644 			Set to measure performance of kfree_rcu() flooding.
5647 			Test the double-argument variant of kfree_rcu().
5649 			rcuscale.kfree_rcu_test_single, both the single-
5650 			and double-argument variants are tested.
5653 			Test the single-argument variant of kfree_rcu().
5655 			rcuscale.kfree_rcu_test_double, both the single-
5656 			and double-argument variants are tested.
5670 			does not affect the data-collection interval,
5675 			Set number of RCU readers.  The value -1 selects
5677 			"n" less than -1 selects N-n+1, where N is again
5678 			the number of CPUs.  For example, -2 selects N
5679 			(the number of CPUs), -3 selects N+1, and so on.
5680 			A value of "n" less than or equal to -N selects
5689 			Specify the RCU implementation to test.
5693 			complete.  This is useful for hands-off automated
5700 			Write-side holdoff between grace periods,
5705 			Additional write-side holdoff between grace
5722 			Specifies the number of kthreads to be used
5723 			for  RCU grace-period forward-progress testing
5725 			Defaults to 1 kthread, values less than zero or
5727 			of CPUs to be used.
5730 			Specify the fraction of a CPU-stall-warning
5731 			period to do tight-loop forward-progress testing.
5734 			Number of seconds to wait between successive
5735 			forward-progress tests.
5739 			need_resched() during tight-loop forward-progress
5743 			Use conditional/asynchronous update-side
5744 			normal-grace-period primitives, if available.
5747 			Use conditional/asynchronous update-side
5748 			expedited-grace-period primitives, if available.
5751 			Use conditional/asynchronous update-side
5752 			normal-grace-period primitives that also take
5757 			Use conditional/asynchronous update-side
5758 			expedited-grace-period primitives that also take
5767 			be randomly selected to nanosecond granularity up
5768 			to this wait interval.	Defaults to 16 jiffies,
5777 			interval will be randomly selected to nanosecond
5778 			granularity up to this wait interval.  Defaults to
5782 			Use expedited update-side primitives, if available.
5785 			Use normal (non-expedited) asynchronous
5786 			update-side primitives, if available.
5789 			Use polled update-side normal-grace-period
5793 			Use polled update-side expedited-grace-period
5797 			Use polled update-side normal-grace-period
5802 			Use polled update-side expedited-grace-period
5811 			be randomly selected to nanosecond granularity up
5812 			to this wait interval.	Defaults to 16 jiffies,
5821 			interval will be randomly selected to nanosecond
5822 			granularity up to this wait interval.  Defaults to
5826 			Use normal (non-expedited) synchronous
5827 			update-side primitives, if available.  If all
5831 			they are all non-zero.
5834 			Enable grace-period wrap lag testing. Setting
5835 			to false prevents the gpwrap lag test from
5839 			Set the value for grace-period wrap lag during
5843 			The default is always set to 8.
5854 			the grace-period wrap lag will be set to the
5861 			flavors take kindly to this sort of thing.
5864 			Leak an RCU-protected pointer out of the reader.
5866 			intended to test the ability of things like
5867 			CONFIG_RCU_STRICT_GRACE_PERIOD=y to detect
5879 			Set number of RCU callback-offload togglers.
5884 			callback-offload toggling attempts.
5887 			Set number of RCU readers.  The value -1 selects
5888 			N-1, where N is the number of CPUs.  A value
5889 			"n" less than -1 selects N-n-2, where N is again
5890 			the number of CPUs.  For example, -2 selects N
5891 			(the number of CPUs), -3 selects N+1, and so on.
5894 			Enable debug-object double-call_rcu() testing.
5897 			Set time (s) after boot for CPU-hotplug testing.
5900 			Set time (jiffies) between CPU-hotplug operations,
5901 			or zero to disable CPU-hotplug testing.
5905 			by a high-priority FIFO real-time task.  Set to
5906 			zero (the default) to disable.	The CPUs to
5913 			Set interval (in milliseconds, defaulting to one
5914 			second) between preemptions by a high-priority
5915 			FIFO real-time task.  This delay is mediated
5916 			by an hrtimer and is further fuzzed to avoid
5920 			The number of times in a given read-then-exit
5921 			episode that a set of read-then-exit kthreads
5926 			read-then-exit testing episodes.
5929 			A bit mask indicating which readers to use.
5931 			are entered from low-order bit up, and are
5933 			0x1 bit is normal readers, 0x2 NMI-safe readers,
5934 			and 0x4 light-weight readers.
5937 			Set task-shuffle interval (s).  Shuffling tasks
5938 			allows some CPUs to go into dyntick-idle mode
5943 			is useful for hands-off automated testing.
5946 			Duration of CPU stall (s) to test RCU CPU stall
5947 			warnings, zero to disable.
5951 			in warnings from preemptible RCU in addition to
5952 			any other stall-related activity.  Note that
5955 			cause the CPU to pass through a quiescent state.
5958 			in scheduling-while-atomic splats.
5964 			Time to wait (s) after boot before inducing stall.
5971 			Number of times to repeat the stall sequence,
5977 			grace-period kthread to test RCU CPU stall
5978 			warnings, zero to disable.  If both stall_cpu
5986 			Time (s) to stutter testing, for example, specifying
5987 			five seconds causes the test to run for five seconds,
5989 			ability to transition abruptly to and from idle.
6000 			Holdoff time (s) from start of test to the start
6001 			of RCU priority-boost testing.	Defaults to zero,
6008 			Test RCU's dyntick-idle handling.  See also the
6012 			Specify the RCU implementation to test.
6046 			adjusted to an arch timer tick resolution.
6047 			Setting this to zero causes the value from
6048 			rcupdate.rcu_cpu_stall_timeout to be used (after
6049 			conversion from seconds to milliseconds).
6063 			Use expedited grace-period primitives, for
6067 			real-time latency, and degrade energy efficiency.
6071 			Use only normal grace-period primitives,
6074 			real-time latency, CPU utilization, and
6075 			energy efficiency, but can expose users to
6076 			increased grace-period latency.  This parameter
6083 			only normal grace-period primitives.  No effect
6088 			it to the value one, that is, converting any
6089 			post-boot attempt at an expedited RCU grace
6090 			period to instead use normal non-expedited
6091 			grace-period processing.
6096 			the RCU Tasks flavors to collapse back to using
6099 			set to the default value of -1.
6102 			Set the minimum number of callback-queuing-time
6103 			lock-contention events per jiffy required to
6104 			cause the RCU Tasks flavors to switch to per-CPU
6106 			when rcupdate.rcu_task_enqueue_lim is set to
6107 			the default value of -1.
6110 			Set the number of callback queues to use for the
6112 			of -1 allows this to be automatically (and
6120 			number avoids disturbing real-time workloads,
6125 			cancel laziness on that CPU.  Use -1 to disable
6127 			doing so increases the danger of OOM due to
6133 			of the problem for those not patient enough to
6135 			only printed prior to the stall-warning message
6137 			less than or equal to zero.  Defaults to ten
6145 			to one through ten, inclusive.	It defaults to
6155 			than or equal to zero.	Defaults to ten minutes.
6183 			force - Override the decision by the kernel to hide the
6193 			E.g. to turn on cmt and turn off mba use:
6203 					(prefix with 'panic_' to set mode for panic
6208 					to be used for rebooting.
6222 			There are some built-in platform specific "quirks"
6223 			- you may see: "reboot: <name> series board detected.
6227 			built-in quirk table, and use the generic default
6243 			Use a write to the PCI config space register 0xcf9 to
6260 			Set test-start holdoff period.  The purpose of
6261 			this parameter is to delay the start of the
6262 			test until boot completes in order to avoid
6266 			Number of data elements to use for the forms of
6274 			reduces noise due to loop start/end overhead,
6275 			but the default has already reduced the per-pass
6276 			noise to a handful of picoseconds on ca. 2020
6280 			Set number of readers.  The default value of -1
6289 			Set the read-side critical-section duration,
6293 			Specify the read-protection implementation to test.
6297 			test.  This defaults to 1 (shut it down) when
6298 			refscale is built into the kernel and to 0 (leave
6319 			See Documentation/admin-guide/cgroup-v1/cpusets.rst.
6321 	reserve=	[KNL,BUGS] Force kernel to ignore I/O ports or memory
6325 			is assumed to be I/O ports; otherwise it is memory.
6330 			other subsystems can use to access it. This is typically
6332 			line will try to reserve the same physical memory on
6333 			soft reboots. Note, it is not guaranteed to be the same
6339 			Any subsystem using this feature must add a way to verify
6344 			The format is size:align:label for example, to request
6349 	reservetop=	[X86-32,EARLY]
6354 	reset_devices	[KNL] Force drivers to reset the underlying device
6366 			See  Documentation/power/swsusp-and-swap-files.rst
6368 	resumedelay=	[HIBERNATION] Delay (in seconds) to pause before attempting to
6371 	resumewait	[HIBERNATION] Wait (indefinitely) for resume device to show up.
6382 			AMD-based UNRET and IBPB mitigations alone do not stop
6384 			sibling threads. For that reason, STIBP is used on pro-
6388 			off          - no mitigation
6389 			auto         - automatically select a migitation
6390 			auto,nosmt   - automatically select a mitigation,
6394 			ibpb         - On AMD, mitigate short speculation
6399 			ibpb,nosmt   - Like "ibpb" above but will disable SMT
6403 			unret        - Force enable untrained return thunks,
6404 				       only effective on AMD f15h-f17h based
6406 			unret,nosmt  - Like unret, but will disable SMT when STIBP
6411 			time according to the CPU.
6413 			Not specifying this option is equivalent to retbleed=auto.
6433 			falling back to detecting extension support by parsing
6438 	ro		[KNL] Mount root device read-only on boot
6441 		on	Mark read-only kernel memory as read-only (default).
6442 		off	Leave read-only kernel memory writable for debugging.
6443 		noalias	Mark read-only kernel memory as read-only but retain
6451 			debug-uart get routed to the D+ and D- pins of the usb
6457 			block/early-lookup.c for details.
6462 	rootdelay=	[KNL] Delay (in seconds) to pause before attempting to
6472 	rootwait	[KNL] Wait (indefinitely) for root device to show up.
6476 	rootwait=	[KNL] Maximum time (in seconds) to wait for root device
6477 			to show up before attempting to mount the root
6482 			Memory area to be used by remote processor image,
6486 			when CONFIG_RT_GROUP_SCHED=y. Defaults to
6490 	rw		[KNL] Mount root device read-write on boot
6499 			reuse, which is faster. Deprecated, equivalent to
6519 			solution to mutex-based priority inversion.
6547 			Number of seconds to hold off before starting
6548 			test.  Defaults to zero for module insertion and
6549 			to 10 seconds for built-in smp_call_function()
6554 			up to the chosen limit in seconds.  Zero (the
6556 			that requesting even small non-zero numbers of
6561 			Number of kthreads to spawn to invoke the
6563 			The default of -1 specifies a number of kthreads
6564 			equal to the number of CPUs.
6567 			Number seconds to wait after the start of the
6568 			test before initiating CPU-hotplug operations.
6571 			Number seconds to wait between successive
6572 			CPU-hotplug operations.  Specifying zero (which
6573 			is the default) disables CPU-hotplug operations.
6577 			test after which to shut down the system.  The
6579 			Non-zero values are useful for automated tests.
6583 			current test statistics to the console.  A value
6587 			The number of jiffies to wait between each change
6588 			to the set of CPUs under test.
6592 			preempt_disable() to disable CPU hotplug
6600 			The probability weighting to use for the
6602 			"wait" parameter.  A value of -1 selects the
6603 			default if all other weights are -1.  However,
6605 			value of -1 will instead select a weight of zero.
6608 			The probability weighting to use for the
6610 			non-zero "wait" parameter.  See weight_single.
6613 			The probability weighting to use for the
6621 			The probability weighting to use for the
6623 			non-zero "wait" parameter.  See weight_single
6627 			The probability weighting to use for the
6633 			The probability weighting to use for the
6635 			non-zero "wait" parameter.  See weight_single
6642 	skew_tick=	[KNL,EARLY] Offset the periodic timer tick per cpu to mitigate
6646 			0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
6647 			1 -- enable.
6651 	security=	[SECURITY] Choose a legacy "major" security module to
6658 			0 -- disable.
6659 			1 -- enable.
6662 	serialnumber	[BUGS=X86-32]
6664 	sev=option[,option...] [X86-64]
6670 			Do not enable SEV-SNP (applies to host/hypervisor
6672 			in memory accesses when users do not want to run
6673 			SEV-SNP guests.
6681 			to set it to "all" by meaning -- no limit here.
6688 			Enabling slab_debug allows one to determine the
6693 			Documentation/admin-guide/mm/slab.rst.
6702 			A high setting may cause OOMs due to memory
6704 			Documentation/admin-guide/mm/slab.rst.
6714 			increase the slab order up to slab_max_order to
6715 			generate a sufficiently large slab able to contain
6718 			and the less frequently locks need to be acquired.
6720 			Documentation/admin-guide/mm/slab.rst.
6725 			lower or equal to slab_max_order. For more information see
6726 			Documentation/admin-guide/mm/slab.rst.
6731 			necessary if there is some reason to distinguish
6732 			allocs to different slabs, especially in hardened
6736 			most of the exposure of a heap attack to a single
6741 			Documentation/admin-guide/mm/slab.rst.
6747 			policies to be applied at the folio level when
6762 			for a CPU to release the CSD lock.  This is
6765 			of time.  Defaults to 5,000 milliseconds, and
6768 			using the csdlock_debug- kernel parameter.
6773 			system.  By default, let CSD-lock acquisition
6775 			for this value provides a 5-minute timeout.
6777 	smsc-ircc2.nopnp	[HW] Don't use PNP to discover SMC devices
6778 	smsc-ircc2.ircc_cfg=	[HW] Device configuration I/O port
6779 	smsc-ircc2.ircc_sir=	[HW] SIR base I/O port
6780 	smsc-ircc2.ircc_fir=	[HW] FIR base I/O port
6781 	smsc-ircc2.ircc_irq=	[HW] IRQ line
6782 	smsc-ircc2.ircc_dma=	[HW] DMA channel
6783 	smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
6789 			(logical CPUs) to use per physical CPU on systems
6791 			be capped to the actual hardware limit.
6793 			Default: -1 (no limit)
6796 			[KNL] Should the soft-lockup detector generate panics.
6799 			A value of 1 instructs the soft-lockup detector
6800 			to panic the machine when a soft-lockup occurs. It is
6803 			respective build-time switch to that functionality.
6806 			[KNL] Should the soft-lockup detector generate
6811 			See Documentation/admin-guide/laptops/sonypi.rst
6818 			on     - (default) Enable the HW or SW mitigation as
6821 			vmexit - On systems which don't have the HW mitigation
6824 				 protected from VM-originated BHI attacks, but
6825 				 may still be vulnerable to syscall attacks.
6826 			off    - Disable the mitigation.
6833 			on   - unconditionally enable, implies
6835 			off  - unconditionally disable, implies
6837 			auto - kernel detects whether your CPU model is
6841 			mitigation method at run time according to the
6847 			against user space to user space task attacks.
6856 			retpoline	  - replace indirect branches
6857 			retpoline,generic - Retpolines
6858 			retpoline,lfence  - LFENCE; indirect branch
6859 			retpoline,amd     - alias for retpoline,lfence
6860 			eibrs		  - Enhanced/Auto IBRS
6861 			eibrs,retpoline   - Enhanced/Auto IBRS + Retpolines
6862 			eibrs,lfence      - Enhanced/Auto IBRS + LFENCE
6863 			ibrs		  - use IBRS to protect kernel
6865 			Not specifying this option is equivalent to
6873 			on	- Unconditionally enable mitigations. Is
6876 			off     - Unconditionally disable mitigations. Is
6879 			prctl   - Indirect branch speculation is enabled,
6885 				- Like "prctl" above, but only STIBP is
6891 				- Same as "prctl" above, but all seccomp
6896 				- Like "seccomp" above, but only STIBP is
6901 			auto    - Kernel selects the mitigation depending on
6906 			Not specifying this option is equivalent to
6910 			[X86,EARLY] Control RAS overflow mitigation on AMD Zen CPUs
6912 			off		- Disable mitigation
6913 			microcode	- Enable microcode mitigation only
6914 			safe-ret	- Enable sw-only safe RET mitigation (default)
6915 			ibpb		- Enable mitigation by issuing IBPB on
6917 			ibpb-vmexit	- Issue IBPB only on VMEXIT
6918 					  (cloud-specific mitigation)
6924 			Certain CPUs are vulnerable to an exploit against a
6927 			to the same memory location may not be observed by
6930 			be detected prior to instruction retirement at the
6935 			example to read memory to which the attacker does not
6943 			on      - Unconditionally disable Speculative Store Bypass
6944 			off     - Unconditionally enable Speculative Store Bypass
6945 			auto    - Kernel detects whether the CPU model contains an
6951 			prctl   - Control Speculative Store Bypass per thread
6955 			seccomp - Same as "prctl" above, but all seccomp threads
6963 			on,auto - On Power8 and Power9 insert a store-forwarding
6967 			off	- No action.
6969 			Not specifying this option is equivalent to
6981 			off	- not enabled
6983 			warn	- the kernel will emit rate-limited warnings
6991 			fatal	- the kernel will send SIGBUS to applications
6996 			ratelimit:N -
6997 				  Set system wide rate limit to N bus locks
7016 			Certain CPUs are vulnerable to an MDS-like
7022 			the RDRAND and RDSEED instructions to become
7030 				performance impact to RDRAND and RDSEED
7036 			This kernel-boot parameter defaults to 128,
7037 			but takes effect only when the low-order four
7038 			bits of srcutree.convert_to_big is equal to 3
7043 			srcu_struct structure will be converted to big
7048 				   2:  When rcutorture decides to.
7054 			instead of the compile-time CONFIG_NR_CPUS.
7057 			Specifies how frequently to check for
7058 			grace-period sequence counter wrap for the
7059 			srcu_data structure's ->srcu_gp_seq_needed field.
7070 			expediting.  Set to zero to disable automatic
7074 			Specifies the number of no-delay instances
7081 			Specifies the per-grace-period phase, number of
7082 			non-sleeping polls of readers. Beyond this limit,
7088 			Specifies number of microseconds of non-sleeping
7089 			delay between each non-sleeping poll of readers.
7092 			Specifies the number of update-side contention
7095 			structure to big form.	Note that the value of
7097 			set for contention-based conversions to occur.
7102 			On CPUs that are vulnerable to the Speculative
7107 			force-on:  Unconditionally enable mitigation for
7109 			force-off: Unconditionally disable mitigation for
7113 				   to allow userspace to register its
7119 			to (for stacks growing down) resp. after (for stacks
7124 			Setting this to true through kernel command line will
7127 			to false.
7130 			Specify the maximum number of pools to use for storing
7131 			stack traces. Pools are allocated on-demand up to this
7137 	stacktrace_filter=[function-list]
7139 			will trace at boot up. function-list is a comma-separated
7147 			Set the STI (builtin display/keyboard on the HP-PARISC
7149 			as the initial boot-console.
7164 			be used to filter out binaries which have
7169 			page table to increase the rate of hash page table
7174 			them frequently to increase the rate of SLB faults
7183 			An administrator who wishes to reserve some of these
7185 			kernel's sunrpc client considers to be privileged
7186 			using these two parameters to set the minimum and
7197 			Control how the NFS server code allocates CPUs to
7209 				    to global on non-NUMA machines)
7215 			RPC calls that can be sent from the client to a
7216 			server. Increasing these values may allow you to
7222 			Sets the number of seconds to remain in a suspend test
7234 			<int> -- Number of I/O TLB slabs
7235 			<int> -- Second integer after comma. Number of swiotlb
7237 				 to a power of 2.
7238 			force -- force using of bounce buffers even if they
7240 			noforce -- Never use bounce buffers (for debugging)
7246 			process, as if the value was written to the respective
7255 			Ignore sysrq setting - this boot parameter will
7262 			ram pages. This is used to specify the TCP metrics
7263 			cache size. See Documentation/networking/ip-sysctl.rst
7270 			Specify "mem" (for Suspend-to-RAM) or "standby" (for
7273 			the optional capability to repeat N number of times.
7275 			wakeup-capable RTC alarm.
7281 			-1: disable all active trip points in all thermal zones
7285 			-1: disable all critical trip points in all thermal zones
7292 			-1: disable all passive trip points
7293 			<degrees C>: override all passive trip points to this
7298 			<deci-seconds>: poll all this frequency
7302 			Format: <size>[KMG],<size>[KMG]:<state>;<size>[KMG]-<size>[KMG]:<state>
7305 			to anonymous transparent hugepages.
7307 			See Documentation/admin-guide/mm/transhuge.rst for more
7315 			Format: <size>[KMG],<size>[KMG]:<policy>;<size>[KMG]-<size>[KMG]:<policy>
7321 			See Documentation/admin-guide/mm/transhuge.rst for more
7333 			Prevent the CPU-hotplug component of torturing
7337 			Dump the ftrace buffer at torture-test shutdown,
7341 			with rotating-rust storage.
7346 			disables verbose-printk() sleeping.
7349 			Duration of each verbose-printk() sleep in jiffies.
7361 			Maximum time in milliseconds to retry sending a message
7362 			to the TPM service before giving up. This parameter controls
7372 			as a workaround for some chips which fail to
7379 			for the FIFO interface. By default it is set to false
7382 			https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/
7385 			Have the tracepoints sent to printk as well as the
7391 			To turn off having tracepoints sent to printk,
7397 			to stop the printing of events to console at
7402 			Having tracepoints sent to printk() and activating high
7404 			the system to live lock.
7408 			on the console. It may be useful to only include the
7413 			to console at the late_initcall_sync() time frame.
7420 			local - Use the per CPU time stamp counter
7424 			global - Event time stamps are synchronized across
7427 			counter - Simple counting of events (1, 2, ..)
7428 				note, some counts may be skipped due to the
7431 			uptime - Use jiffies as the time stamp.
7432 			perf - Use the same clock that perf uses.
7433 			mono - Use ktime_get_mono_fast_ns() for time stamps.
7434 			mono_raw - Use ktime_get_raw_fast_ns() for time
7436 			boot - Use ktime_get_boot_fast_ns() for time stamps.
7440 	trace_event=[event-list]
7442 			to facilitate early boot debugging. The event-list is a
7443 			comma-separated list of trace events to enable. See
7446 			To enable modules, use :mod: keyword:
7454 	trace_instance=[instance-info]
7474 			Flags can be added to the instance to modify its behavior when it is
7479 			    traceoff	- Have the tracing instance tracing disabled after it is created.
7480 			    traceprintk	- Have trace_printk() write into this trace instance
7501 			and place the ring buffer in this memory. Note that due to KASLR, the
7510 			it is recommend to disable tracing so that events from a previous boot do not
7517 			is set up to not wipe memory. For instance, CONFIG_RESET_ATTACK_MITIGATION
7527 	trace_options=[option-list]
7529 			The option-list is a comma delimited list of options
7531 			to echo the option name into
7535 			For example, to enable stacktrace option (to dump the
7536 			stack trace of each event), add to the command line:
7543 	trace_trigger=[trigger-list]
7563 			[FTRACE] Sometimes tracing is used to debug issues
7565 			limited amount of storage, it may be prudent to
7572 			[FTRACE] enable this option to disable tracing when a
7578 			the WARNING dump is called, which prevents the trace to
7587 			Can be used to control the default behavior of the system
7588 			with respect to transparent hugepages.
7589 			See Documentation/admin-guide/mm/transhuge.rst
7594 			Can be used to control the hugepage allocation policy for
7596 			See Documentation/admin-guide/mm/transhuge.rst
7601 			Can be used to control the default hugepage allocation policy
7603 			See Documentation/admin-guide/mm/transhuge.rst
7611 			- "tpm"
7612 			- "tee"
7613 			- "caam"
7614 			- "dcp"
7615 			If not specified then it defaults to iterating through
7622 			The RNG used to generate key material for trusted keys.
7624 			- "kernel"
7625 			- the same value as trusted.source: "tpm" or "tee"
7626 			- "default"
7628 			the RNG's choice is left to each individual trust source.
7631 			This is intended to be used in combination with
7636 			This is intended to be used in combination with
7649 			off		- disable the mitigation
7650 			on		- enable the mitigation (default)
7651 			user		- mitigate only user/kernel transitions
7652 			vm		- mitigate only guest/host transitions
7659 			as the stability checks done at bootup.	Used to enable
7660 			high-resolution timer mode on older hardware, and in
7662 			[x86] noirqtime: Do not use TSC to do irq accounting.
7663 			Used to run time disable IRQ_TIME_ACCOUNTING on any
7678 			which to check other HW timers (HPET or PM timer), but
7696 			on	- Enable TSX on the system. Although there are
7698 				TSX has been known to be an accelerator for
7699 				several previous speculation-related CVEs, and
7703 			off	- Disable TSX on the system. (Note that this
7705 				not vulnerable to MDS, i.e., have
7711 			auto	- Disable TSX if X86_BUG_TAA is present,
7714 			Not specifying this option is equivalent to tsx=off.
7716 			See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
7722 			Similar to Micro-architectural Data Sampling (MDS)
7724 			Synchronization Extensions (TSX) are vulnerable to an
7726 			information to a disclosure gadget under certain
7730 			data can be used in a cache side channel attack, to
7731 			access data to which the attacker does not have direct
7737 			full       - Enable TAA mitigation on vulnerable CPUs
7740 			full,nosmt - Enable TAA mitigation and disable SMT on
7743 				     vulnerable to cross-thread TAA attacks.
7744 			off        - Unconditionally disable TAA mitigation
7746 			On MDS-affected machines, tsx_async_abort=off can be
7748 			are mitigated with the same mechanism so in order to disable
7749 			this mitigation, you need to specify mds=off too.
7751 			Not specifying this option is equivalent to
7758 			Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
7764 			See also Documentation/input/devices/joystick-parport.rst
7766 	udbg-immortal	[PPC] When debugging early kernel crashes that
7772 			Set number of hash buckets for UDP/UDP-Lite connections
7774 	uhci-hcd.ignore_oc=
7776 			Some badly-designed motherboards generate lots of
7777 			bogus events, for ports that aren't wired to
7778 			anything.  Set this parameter to avoid log spamming.
7786 			is useful for testing alternative code paths and to skip
7794 			is useful for testing alternative code paths and to skip
7801 	unwind_debug	[X86-64,EARLY]
7809 			(default -1 = authorized (same as 1),
7811 			if device connected to internal port)
7815 			for newly-detected USB devices (default 2).  This
7818 			to a negative value won't be autosuspended at all.
7821 			[USB] Set to log all usbfs traffic (default 0 = off).
7824 			[USB] Maximum number of bytes to snoop in each URB
7828 			[USB] Set to cycle leds on hubs (default 0 = off).
7843 			[USB] Specifies timeout for the initial 64-byte
7850 			[USB] A list of quirk entries to augment the built-in
7853 			VendorID:ProductID:Flags. The IDs are 4-digit hex
7855 			will change the built-in quirk; setting it if it is
7860 					a 255-byte read);
7864 					Set-Interface requests);
7873 					talking to these interfaces);
7881 					microframe = 125 microseconds) to be
7883 					(bInterval-1).
7901 					to be disconnected before suspend to
7909 					request from 5000 ms to 500 ms);
7913 			[USBHID] The interval which mice are to be polled at.
7916 			[USBHID] The interval which joysticks are to be polled at.
7919 			[USBHID] The interval which keyboards are to be polled at.
7921 	usb-storage.delay_use=
7928 	usb-storage.quirks=
7929 			[UMS] A list of quirks entries to supplement or
7930 			override the built-in unusual_devs list.  List
7933 			and Product ID values (4-digit hex numbers) and
7935 			to a common usb-storage quirk flag as follows:
7953 				i = IGNORE_DEVICE (don't bind to this
7958 				l = NOT_LOCKABLE (don't try to lock and
7975 				u = IGNORE_UAS (don't bind to the uas driver);
7977 					medium is write-protected).
7986 				 1 - undefined instruction events
7987 				 2 - system calls
7988 				 4 - invalid data aborts
7989 				 8 - SIGSEGV faults
7990 				16 - SIGBUS faults
7999 	vdso32=		[X86] Control the 32-bit vDSO
8000 			vdso32=1: enable 32-bit VDSO
8001 			vdso32=0 or vdso32=2: disable 32-bit VDSO
8011 			dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
8018 			If set to 1, on receiving an ACPI notify event
8020 			level and then send out the event to user space through
8021 			the allocated input device. If set to 0, video driver
8034 				<irq>      := interrupt number (as passed to
8042 	vga=		[BOOT,X86-32] Select a particular video mode
8044 			Documentation/admin-guide/svga.rst.
8047 			passed to the kernel using a special protocol.
8053 			interface is meant to allow for selectively
8059 			  -	Disable all of the above options
8061 	vmalloc=nn[KMG]	[KNL,BOOT,EARLY] Forces the vmalloc area to have an
8062 			exact size of <nn>. This can be used to increase
8064 			It can also be used to decrease the size and leave more room
8085 			hypervisor to a guest via speculative side-channels.
8087 			off		- disable the mitigation
8088 			ibpb		- use Indirect Branch Prediction Barrier
8090 			force		- force vulnerability detection even on
8093 	vsyscall=	[X86-64,EARLY]
8094 			Controls the behavior of vsyscalls (i.e. calls to
8096 			code).  Most statically-linked binaries and older
8110 			            them quite hard to use for exploits but
8120 			see vga-softcursor.rst. Default: 2 = underline.
8125 			This is a 16-member array composed of values
8126 			ranging from 0-255.
8131 			This is a 16-member array composed of values
8132 			ranging from 0-255.
8137 			This is a 16-member array composed of values
8138 			ranging from 0-255.
8143 			Set system-wide default UTF-8 mode for all tty's.
8144 			Default is 1, i.e. UTF-8 mode is enabled for all
8149 			Format=<-1|0|1>
8150 			Set system-wide default for whether a cursor
8151 			is shown on new VTs. Default is -1,
8156 	vt.italic=	[VT] Default color for italic text; 0-15.
8159 	vt.underline=	[VT] Default color for underlined text; 0-15.
8163 			see Documentation/watchdog/watchdog-parameters.rst
8164 			or other driver-specific files in the
8171 			threshold is set to twice the value. A value of 0
8176 			[KNL,SMP] Specify to constrain one or some CPUs
8177 			to use in unbound workqueues.
8178 			Format: <cpu-list>
8184 			warn stall conditions and dump internal state to
8188 			it can be updated at runtime by writing to the
8194 			stall to trigger panic.
8199 			Per-cpu work items which run for longer than this
8201 			and excluded from concurrency management to prevent
8202 			them from noticeably delaying other per-cpu work
8213 			intensive_threshold_us repeatedly. In order to prevent
8220 			Per-cpu workqueues are generally preferred because
8221 			they show better performance thanks to cache
8222 			locality; unfortunately, per-cpu workqueues tend to
8225 			Enabling this makes the per-cpu workqueues which
8226 			were observed to contribute significantly to power
8227 			consumption unbound, leading to measurably lower
8235 			Select the default affinity scope to use for unbound
8239 			Documentation/core-api/workqueue.rst.
8241 			This can be changed after boot by writing to the
8247 			Workqueue used to implicitly guarantee that work
8252 			forces round-robin CPU selection to flush out
8260 			on   - Enable writecombine, use WUC for ioremap_wc()
8261 			off  - Disable writecombine, use SUC for ioremap_wc()
8263 	x2apic_phys	[X86-64,APIC,EARLY] Use x2apic physical mode instead of
8267 	xen_512gb_limit		[KNL,X86-64,XEN]
8269 			to use only up to 512 GB of RAM. The reason to do so is
8271 			save/restore/migration must be enabled to handle larger
8277 			ide-disks -- unplug primary master IDE devices
8278 			aux-ide-disks -- unplug non-primary-master IDE devices
8279 			nics -- unplug network devices
8280 			all -- unplug all emulated devices (NICs and IDE disks)
8281 			unnecessary -- unplugging emulated devices is
8282 				unnecessary even if the host did not respond to
8284 			never -- do not unplug even if version check succeeds
8298 			Select whether to always use non-faulting (safe) MSR
8303 			Disables the PV optimizations forcing the HVM guest to
8313 			Boolean option to control scrubbing pages before giving them back
8314 			to Xen, for use by other domains. Can be also changed at runtime
8318 	xen_timer_slop=	[X86-64,XEN,EARLY]
8326 			The time (in seconds) to wait before giving up to boot
8327 			in case initial ballooning fails to free enough memory.
8333 			How long to delay EOI handling in case of event
8338 			should start to delay EOI handling. Default is 2.
8341 			Boolean parameter to disable using fifo event handling
8343 			preferred over the 2-level event handling, as it is
8354 			allows the fallback firmware mode to be used:
8356 			off       Fallback to firmware control of XIVE interrupt
8360 	xive.store-eoi=off	[PPC]
8363 			is active. This option allows the XIVE driver to use
8366 	xhci-hcd.quirks		[USB,KNL]
8374 			Passing only "xmon" is equivalent to "xmon=early".