Lines Matching +full:no +full:- +full:tick +full:- +full:in +full:- +full:suspend
5 force -- enable ACPI if default was off
6 on -- enable ACPI but allow fallback to DT [arm64]
7 off -- disable ACPI if default was on
8 noirq -- do not use ACPI for IRQ routing
9 strict -- Be less tolerant of platforms that are not
11 rsdt -- prefer RSDT over (default) XSDT
12 copy_dsdt -- copy DSDT to memory
49 debug output. Bits in debug_layer correspond to a
50 _COMPONENT in an ACPI source file, e.g.,
52 Bits in debug_level correspond to a level in
56 Documentation/firmware-guide/acpi/debug.rst for more information about
74 { strict | lax | no }
77 only). IO ports and memory declared in ACPI might be
78 used by the ACPI subsystem in arbitrary AML code and
86 no: ACPI OperationRegions are not marked as reserved,
87 no further checks are performed.
96 default in APIC mode
100 default in PIC mode
111 by unsupported hardware/firmware features can result in
119 Disable auto-serialization of AML methods
122 auto-serialization feature.
131 By default, SSDTs contained in the RSDT/XSDT will be
150 be necessary to carry out a cold reboot _twice_ in a
157 acpi_osi=! # disable all built-in OS vendor
159 acpi_osi=!! # enable all built-in OS vendor
163 'acpi_osi=!' can be used in combination with single or
178 'acpi_osi=' cannot be used in combination with other
180 exist in the ACPI namespace. NOTE that such command can
188 'acpi_osi=!*' can be used in combination with single or
221 For broken nForce2 BIOS resulting in XT-PIC timer.
229 as soon as the kernel's real-mode entry point is called.
237 ACPI NVS memory during suspend/hibernation and resume.
242 behave incorrectly in some ways with respect to system
243 suspend and resume to be ignored (use wisely).
249 add_efi_memmap [EFI; X86] Include EFI memory map in
259 See Documentation/sound/alsa-configuration.rst
266 align_va_addr= [X86-64]
271 CPU-intensive style benchmark, and it can vary highly in
274 32: only for 32-bit processes
275 64: only for 64-bit processes
276 on: enable for both 32- and 64-bit processes
277 off: disable for both 32- and 64-bit processes
286 amd_iommu= [HW,X86-64]
287 Pass parameters to the AMD IOMMU driver in the system.
289 fullflush - enable flushing of IO/TLB entries when
293 off - do not initialize any AMD IOMMU found in
295 force_isolation - Force device isolation for all
301 amd_iommu_dump= [HW,X86-64]
307 amd_iommu_intr= [HW,X86-64]
310 legacy - Use legacy interrupt remapping mode.
311 vapic - Use virtual APIC mode, which allows IOMMU
313 This mode requires kvm-amd.avic=1.
327 Power management functions (SPARCstation-4/5 + deriv.)
329 Disable APC CPU standby support. SPARCstation-Fox does
330 not play well with APC CPU idle - disable it if you have
337 when initialising the APIC and IO-APIC components.
338 For X86-32, this can also be used to specify an APIC
358 to set it to "all" by meaning -- no limit here.
367 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
391 audit= [KNL] Enable the audit sub-system
393 0 | off - kernel audit is disabled and can not be
395 unset - kernel audit is initialized but disabled and
397 1 | on - kernel audit is initialized and partially
399 messages in RAM until it is fully enabled by the
410 0 - Disable the BAU.
411 1 - Enable the BAU.
412 unset - Disable the BAU.
433 See Documentation/block/cmdline-partition.rst
437 no delay (0).
448 bttv.pll= See Documentation/media/v4l-drivers/bttv.rst
457 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
465 [NET] Specifies amount of time (in seconds) that
476 inclusive. See arch/mips/include/asm/pgtable-bits.h
486 - foo isn't auto-mounted if you mount all cgroups in
488 - foo isn't visible as an individually mountable
494 cgroup_no_v1= [KNL] Disable cgroup controllers and named hierarchies in v1
498 the blacklisted controllers remain available in cgroup2.
505 nosocket -- Disable socket memory accounting.
506 nokmem -- Disable kernel memory accounting.
511 0 -- check protection applied by kernel (includes
513 1 -- check protection requested by application.
524 device driver but are enabled in hardware at reset or
526 force such clocks to be always-on nor does it reserve
527 those clocks in any way. This parameter is useful for
530 information, see Documentation/driver-api/clk.rst.
532 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
549 [X86-32] pit,hpet,tsc;
555 [SPARC64] tick
556 [X86-64] hpet,tsc
562 architected timer so that code using WFE-based polling
575 being used by the kernel or shown in /proc/cpuinfo.
579 cma=nn[MG]@[start[MG][-end[MG]]]
586 include/linux/dma-contiguous.h
588 cmo_free_hint= [PPC] Format: { yes | no }
590 when they are freed. This is used in CMO environments
599 com20020= [HW,NET] ARCnet - COM20020 chipset
603 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
607 ARCnet - COM90xx chipset (memory-mapped buffers)
625 See Documentation/admin-guide/serial-console.rst for more
635 Start an early, polled-mode console on the 8250/16550
638 MMIO inter-register address stride is either 8-bit
639 (mmio), 16-bit (mmio16), or 32-bit (mmio32).
641 to be equivalent to 'mmio'. 'options' are specified in
643 the h/w is not re-initialized.
656 By default we print messages on consoles in
664 syscall, or to executing "dmesg -S --raw" or to reading
667 consoleblank= [KNL] The console blank (screen saver) timeout in
684 disable the cpuidle sub-system
690 disable the cpufreq sub-system
693 [X86] Delay for N microsec between assert and de-assert
695 on every CPU online, such as boot, and resume from suspend.
711 See Documentation/admin-guide/kdump/kdump.rst for further details.
715 in the running system. The syntax of range is
716 start-[end] where start and end are both
718 Documentation/admin-guide/kdump/kdump.rst for an example.
733 low memory is needed to make sure DMA buffers for 32-bit
743 [KNL] Disable crypto self-tests
757 See also Documentation/input/devices/joystick-parport.rst
761 Documentation/admin-guide/dynamic-debug-howto.rst for
767 [KNL] Enable printing [hashed] pointers early in the
775 [KNL] verbose self-tests
778 self-tests.
779 We default to 0 (no extra messages), setting it to
780 1 will print _a lot_ more information - normally
797 memory corruption problems caused by bugs in kernel or
831 [KNL] Debugging option to set a timeout in seconds for
834 drivers) that have opted in will be ignored. A timeout of 0
857 against bounds-checking flaws in the kernel's
913 entries for DMA-API debugging code. One entry is
914 required per DMA-API allocation. Use this if the
915 DMA-API debugging code disables itself because the
919 With this option the DMA-API debugging driver
931 panels may send no or incorrect EDID data sets.
933 in the /lib/firmware directory that are used instead.
934 Generic built-in EDID data sets are used, if one of
937 and no file with the same name exists. Details and
939 available in Documentation/driver-api/edid.rst. An EDID
944 data set with no connector name will be used for
951 Control how the dt_cpu_ftrs device-tree binding is
961 what data is available or for reverse-engineering.
966 Documentation/admin-guide/dynamic-debug-howto.rst
974 in some Intel CPUs.
980 Enable debug messages in early_ioremap support. This
987 stdout-path property in device tree's chosen node,
990 [X86] When used with no options the early console is
994 Start an early, polled-mode console on a Cadence
1005 Start an early, polled-mode console on the 8250/16550
1007 MMIO inter-register address stride is either 8-bit
1008 (mmio) or 32-bit (mmio32 or mmio32be).
1011 in the same format described for "console=ttyS<n>"; if
1016 Start an early, polled-mode console on a pl011 serial
1020 the driver will use only 32-bit accessors to read/write
1024 Start an early, polled-mode console on a meson serial
1030 Start an early, polled-mode console on an msm serial
1036 Start an early, polled-mode console on an msm serial
1042 Start an early, polled-mode console on a serial port
1048 Start an early, polled-mode console on a serial port
1054 Use RISC-V SBI (Supervisor Binary Interface) for early
1072 Start an early, polled-mode console on a lantiq serial
1085 Start an early, polled-mode console on the
1091 Start an early, polled-mode console on a Qualcomm
1099 coherent non-x86 systems that use system memory for
1135 You can find the port for a given device in
1164 This is designed to be used in conjunction with
1172 old_map [X86-64]: switch to the old ioremap-based EFI
1173 runtime services mapping. 32-bit still uses this one by
1175 nochunk: disable reading files in "chunks" in the EFI
1194 attribute is added to range 0x100000000-0x180000000 and
1195 0x10a0000000-0x1120000000.
1206 Documentation/admin-guide/acpi/ssdt-overlays.rst for details.
1212 elanfreq= [X86-32]
1213 See comment before function elanfreq_setup() in
1220 See Documentation/admin-guide/kdump/kdump.rst for details.
1230 (in particular on some ATI chipsets).
1236 0 -- permissive (log only, no denials).
1237 1 -- enforcing (deny and log).
1259 See also Documentation/fault-injection/.
1262 See Documentation/admin-guide/blockdev/floppy.rst.
1265 [IA-64] Avoid check_sal_cache_flush which may hang on
1270 forcepae [X86-32]
1279 as early as possible in order to facilitate early
1284 If no parameter is passed, ftrace will dump
1289 ftrace_filter=[function-list]
1291 tracer at boot up. function-list is a comma separated
1293 time by the set_ftrace_filter file in the debugfs
1296 ftrace_notrace=[function-list]
1297 [FTRACE] Do not trace the functions specified in
1298 function-list. This list can be changed at run time
1299 by the set_ftrace_notrace file in the debugfs
1302 ftrace_graph_filter=[function-list]
1305 function-list is a comma separated list of functions
1307 set_graph_function file in the debugfs tracing directory.
1309 ftrace_graph_notrace=[function-list]
1310 [FTRACE] Do not trace from the functions specified in
1311 function-list. This list is a comma separated list of
1313 set_graph_notrace file in the debugfs tracing directory.
1319 in the tracefs tracing directory. default: 0 (no limit)
1325 See also Documentation/input/devices/joystick-parport.rst
1333 gcov_persist= [GCOV] When non-zero (default), profiling data for
1366 gpio-mockup.gpio_mockup_ranges
1371 [KNL] Should the hard-lockup detector generate
1377 for 64-bit NUMA, off otherwise.
1380 hcl= [IA-64] SGI's Hardware Graph compatibility layer
1387 corresponding firmware-first mode error processing
1391 size of <nn>. This works even on boxes that have no
1401 hpet= [X86-32,HPET] option to control HPET usage
1412 hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot.
1413 hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages.
1414 On x86-64 and powerpc, this option can be specified
1417 x86-64 are 2M (when the CPU supports "pse") and 1G
1426 by the CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time
1432 hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
1442 useful for debugging when something happens in the window
1455 (disabled by default, and as a pre-condition
1457 i8042.direct [HW] Put keyboard port into non-translated mode
1471 suspend-to-ram transitions, only during s2r
1489 [HW] Report power status in /proc/i8k
1504 -1 -- never invert brightness
1505 0 -- machine default
1506 1 -- force brightness inversion
1511 ide-core.nodma= [HW] (E)IDE subsystem
1517 ide-generic.probe-mask= [HW] (E)IDE subsystem
1521 setting corresponding bits in the mask to 1. The
1529 ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
1539 In such case C2/C3 won't be used again.
1540 idle=nomwait: Disable mwait for CPU C-states
1557 legacy only accept legacy-NaN binaries, if supported
1559 2008 only accept 2008-NaN binaries, if supported
1565 encodings, so if no FPU hardware is present or it has
1568 'relaxed' straps the emulator for both legacy-NaN and
1569 2008-NaN, whereas 'strict' enables legacy-NaN only on
1578 Ignore loglevel setting - this will print /all/
1610 in crypto/hash_info.h.
1642 Formats: { "ima" | "ima-ng" | "ima-sig" }
1643 Default: "ima-ng"
1675 initcall_blacklist= [KNL] Do not execute a comma-separated list of
1676 initcall functions. Useful for debugging built-in
1693 override in debugfs after boot.
1702 0 -- basic integrity auditing messages. (Default)
1703 1 -- additional integrity auditing messages.
1713 bypassed by not enabling DMAR with this option. In
1718 for io virtual address below 32-bit forcing dual
1720 than 32-bit addressing. The default is to look
1721 for translation below 32-bit and if not available
1722 then look in the higher range.
1725 result in a hardware IOTLB flush operation as opposed
1739 could harm performance of some high-throughput
1753 1 to 9 specify maximum depth of C-state.
1763 used along with the hardware-managed P-states (HWP)
1767 in favor of acpi-cpufreq. Forcing the intel_pstate driver
1768 instead of acpi-cpufreq may disable platform features, such
1770 P-States information being indicated to OSPM and therefore
1773 or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
1786 Allow per-logical-CPU P-State performance control limits using
1789 intremap= [X86-64, Intel-IOMMU]
1794 BIOS x2APIC opt-out request will be ignored
1818 0 - Lazy mode.
1824 1 - Strict mode (default).
1831 0 - Use IOMMU translation for DMA.
1832 1 - Bypass the IOMMU for DMA.
1833 unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
1836 See comment before marvel_specify_io7 in
1847 No delay
1870 to let secondary kernels in charge of setting up
1874 Enables support for pseudo-NMIs in the kernel. This
1893 [Deprecated - use cpusets instead]
1894 Format: [flag-list,]<cpu-list>
1897 specified in the flag list (default: domain):
1900 Disable the tick when a single task runs.
1902 A residual 1Hz tick is offloaded to workqueues, which you
1920 move in and out of an isolated set anytime.
1925 "number of CPUs in system - 1".
1927 The format of <cpu-list> is described above.
1934 Provide an override to the IOAPIC-ID<->DEVICE-ID
1935 mapping provided in the IVRS ACPI table. For
1936 example, to map IOAPIC-ID decimal 10 to
1941 Provide an override to the HPET-ID<->DEVICE-ID
1942 mapping provided in the IVRS ACPI table. For
1943 example, to map HPET-ID decimal 0 to
1948 Provide an override to the ACPI-HID:UID<->DEVICE-ID
1949 mapping provided in the IVRS ACPI table. For
1950 example, to map UART-HID:UID AMD0020:0 to
1970 kernelcore= [KNL,X86,IA-64,PPC]
1973 the kernel for non-movable allocations. The requested
1974 amount is spread evenly throughout all nodes in the
1976 movable memory in its own zone, ZONE_MOVABLE. In the
1983 subsystem. Note that allocations like PTEs-from-HighMem
1987 It is possible to specify the exact amount of memory in
1989 memory in the form of "nn%", or "mirror". If "mirror"
1991 for non-movable allocations and remaining memory is used
1999 optional and is the number seconds in between
2000 each poll cycle to the debug port in case you need
2002 gdb or control-c on the dbgp connection. When
2003 not using this parameter you use sysrq-g to break into
2008 or a supported polling keyboard driver (non-usb).
2020 Configure the RouterBoard 532 series on-chip
2023 kmemleak= [KNL] Boot-time kmemleak enable/disable
2029 kprobe_event=[probe-list]
2031 The probe-list is a semicolon delimited list of probe
2077 kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM.
2080 kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
2082 Default is 1 (enabled) if in 64-bit or 32-bit PAE mode.
2084 kvm-arm.vgic_v3_group0_trap=
2085 [KVM,ARM] Trap guest accesses to GICv3 group-0
2088 kvm-arm.vgic_v3_group1_trap=
2089 [KVM,ARM] Trap guest accesses to GICv3 group-1
2092 kvm-arm.vgic_v3_common_trap=
2096 kvm-arm.vgic_v4_enable=
2100 kvm-intel.ept= [KVM,Intel] Disable extended page tables
2104 kvm-intel.emulate_invalid_guest_state=
2108 kvm-intel.flexpriority=
2112 kvm-intel.nested=
2116 kvm-intel.unrestricted_guest=
2121 kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
2122 CVE-2018-3620.
2131 Default is cond (do L1 cache flush in specific instances)
2133 kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification
2146 enables all mitigations in the
2152 when the first VM is started in a
2170 when the first VM is started in a
2182 when the first VM is started in a
2188 warn when a VM is started in a potentially
2200 For details see: Documentation/admin-guide/hw-vuln/l1tf.rst
2206 lapic [X86-32,APIC] Enable the local APIC even if BIOS
2210 value for LAPIC timer one-shot implementation. Default
2211 back to the programmable timer unit in the LAPIC.
2214 in C2 power state.
2228 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
2244 first fan-out link behind PMP device. It does not
2249 as there's no ambiguity shortcut notation is allowed.
2258 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
2262 * [no]ncq: Turn on or off NCQ.
2264 * [no]ncqtrim: Turn off queued DSM TRIM.
2270 hot-unplug link recovery
2284 See Documentation/admin-guide/blockdev/ramdisk.rst.
2308 Set the number of locking read-acquisition kthreads.
2313 Set the number of locking write-acquisition kthreads.
2316 Set time (s) after boot for CPU-hotplug testing.
2319 Set time (s) between CPU-hotplug operations, or
2320 zero to disable CPU-hotplug testing.
2323 Set task-shuffle interval (jiffies). Shuffling
2324 tasks allows some CPUs to go into dyntick-idle
2329 is useful for hands-off automated testing.
2362 7 (KERN_DEBUG) debug-level messages
2365 in bytes. n must be a power of two and greater
2372 logo.nologo [FB] Disables display of the built-in Linux logo.
2381 specified in addition to the ports) causes
2390 an IEEE 1284-compliant printer is attached; if
2396 time-consuming boot-time autodetection (up to 250 ms per
2403 will cause delays in the kernel to be wrong, leading to
2405 unlikely, in the extreme case this might damage your
2417 machvec= [IA-64] Force the use of a particular machine-vector
2418 (machvec) in a generic kernel.
2423 Example: machtype=lemote-yeeloong-2f-7inch
2438 (loop.max_loop) unconditionally pre-created at init time. The default
2441 devices can be requested on-demand with the
2442 /dev/loop-control interface.
2444 mce [X86-32] Machine Check Exception
2446 mce=option [X86-64] See Documentation/x86/x86_64/boot-options.rst
2449 See Documentation/admin-guide/md.rst.
2456 Control mitigation for the Micro-architectural Data
2463 In vulnerable processors, the speculatively
2464 forwarded data can be used in a cache side channel
2471 full - Enable MDS mitigation on vulnerable CPUs
2472 full,nosmt - Enable MDS mitigation and disable
2474 off - Unconditionally disable MDS mitigation
2476 On TAA-affected machines, mds=off can be prevented by
2478 mitigated with the same mechanism so in order to disable
2485 For details see: Documentation/admin-guide/hw-vuln/mds.rst
2495 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
2500 per-device physically contiguous DMA buffers.
2508 See Documentation/admin-guide/mm/memory-hotplug.rst.
2533 Example: Exclude memory from 0x18690000-0x1869ffff
2547 memmap=<size>%<offset>-<oldtype>+<newtype>
2549 from <oldtype> to <newtype>. If "-<oldtype>" is left
2558 memory when doing things like suspend/resume.
2564 repeatable BIOS-originated corruption always
2569 By default it checks for corruption in the low
2572 corruption in more or less memory.
2589 mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control
2597 Refer to Documentation/virt/kvm/amd-memory-encryption.rst
2600 mem_sleep_default= [SUSPEND] Default system suspend mode:
2601 s2idle - Suspend-To-Idle
2602 shallow - Power-On Suspend or equivalent (if supported)
2603 deep - Suspend-To-RAM or equivalent (if supported)
2604 See Documentation/admin-guide/pm/sleep-states.rst.
2607 See Documentation/media/v4l-drivers/meye.rst.
2609 mfgpt_irq= [IA-32] Specify the IRQ to use for the
2610 Multi-Function General Purpose Timers on AMD Geode
2613 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
2627 0 - The attached screen is the 3.5" TFT
2628 1 - The attached screen is the 7" TFT
2629 2 - The VGA Shield is attached (1024x768)
2633 b - Enable backlight. The TFT backlight pin will be
2637 c - Enable the s3c camera interface.
2638 t - Reserved for enabling touchscreen support. The
2639 touchscreen support is not enabled in the mainstream
2641 in the "bleeding edge" mini2440 support kernel at
2642 http://repo.or.cz/w/linux-2.6/mini2440.git
2647 arch-independent options, each of which is an
2648 aggregation of existing arch-specific options.
2661 ssbd=force-off [ARM64]
2677 have other ways of avoiding SMT-based attacks.
2702 module_blacklist= [KNL] Do not load a comma-separated list of
2709 touchpads working in absolute mode only).
2716 movablecore= [KNL,X86,IA-64,PPC]
2727 movable_node [KNL] Boot-time switch to make hotplugable memory
2734 Format: <name>,<region-number>,<size>,<offset>
2737 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
2746 onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
2750 boundary - index of last SLC block on Flex-OneNAND.
2752 lock - Configure if Flex-OneNAND boundary should be locked.
2759 See arch/arm/mach-s3c2412/mach-jive.c
2787 something different and driver-specific.
2788 This usage is only documented in each driver source
2800 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
2828 [NFS] enable 64-bit inode numbers.
2829 If zero, the NFS client will fake up a 32-bit inode
2831 of returning the full 64-bit number.
2832 The default is to return 64-bit inode numbers.
2838 callbacks the client will process in parallel for
2846 Note that there is little point in setting this
2854 'sec=sys' security flavour. In effect it is
2862 [NFS4] Specify an additional fixed unique ident-
2869 information in exchange_id requests.
2870 If zero, no implementation identification information
2879 no guarantees that the file will remain unchanged
2893 driver. A non-zero value sets the minimum interval
2894 in seconds between layoutstats transmissions.
2910 0 - turn hardlockup detector in nmi_watchdog off
2911 1 - turn hardlockup detector in nmi_watchdog on
2924 [NET] Specifies amount of time (in seconds) that
2928 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
2932 no5lvl [X86-64] Disable 5-level paging mode. Forces
2933 kernel to use 4-level paging instead.
2936 [HW] Never suspend the console
2937 Disable suspending of consoles during suspend and
2941 debugging driver suspend/resume hooks). This may
2954 without any limit and this data is stored in memory,
2957 data will be no longer available. This parameter
2962 caches in the slab allocator. Saves per-node memory,
2971 IOAPICs that may be present in the system.
2982 nodelayacct [KNL] Disable per-task delay accounting
2988 noexec [IA-64]
2991 On X86-32 available only on PAE configured kernels.
2992 noexec=on: enable non-executable mappings (default)
2993 noexec=off: disable non-executable mappings
3003 noexec32 [X86-64]
3004 This affects only 32-bit executables.
3005 noexec32=on: enable non-executable mappings (default)
3007 noexec32=off: disable non-executable mappings
3012 nofxsr [BUGS=X86-32] Disables x86 floating point extended
3014 legacy floating-point registers on task switch.
3027 possible in the system.
3039 enabling legacy floating-point and sse state.
3041 noxsaveopt [X86] Disables xsaveopt used in saving x86 extended
3048 noxsaves [X86] Disables xsaves and xrstors used in saving and
3049 restoring x86 extended register state in compacted
3052 in standard form of xsave area. By using this
3064 nohalt [IA-64] Tells the kernel not to use the power saving
3066 power-consumption. On the positive side, it reduces
3067 interrupt wake-up latency, which may improve performance
3068 in certain environments such as networked servers or
3069 real-time systems.
3079 In kernels built with CONFIG_NO_HZ_FULL=y, set
3080 the specified list of CPUs whose tick will be stopped
3083 in this list will have their RCU callbacks offloaded,
3084 just as if they had also been called out in the
3089 noirqdebug [X86-32] Disables the code which attempts to detect and
3100 nointremap [X86-64, Intel-IOMMU] Do not enable interrupt
3102 [Deprecated - use intremap=off]
3104 nointroute [IA-64]
3108 nojitter [IA-64] Disables jitter checking for ITC timers.
3110 no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
3112 no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page
3115 no-vmw-sched-clock
3119 no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting.
3123 nolapic [X86-32,APIC] Do not enable or use the local APIC.
3125 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
3130 nomca [IA-64] Disable machine check abort handling
3132 nomce [X86-32] Disable Machine Check Exception
3134 nomfgpt [X86-32] Disable Multi-Function General Purpose
3146 nopcid [X86-64] Disable the PCID cpu feature.
3151 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
3162 no-scroll [VGA] Disables scrollback.
3163 This is required for the Braillex ib80-piezo Braille
3166 nosbagart [IA-64]
3168 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
3173 nosoftlockup [KNL] Disable the soft-lockup detector.
3178 soft-lockup and NMI watchdog (hard-lockup).
3182 nox2apic [X86-64,APIC] Do not enable x2APIC mode.
3187 1. Resume from suspend/hibernate depends on CPU0.
3188 Suspend/hibernate will fail if CPU0 is offline and you
3189 need to online CPU0 before suspend/hibernate.
3199 This parameter sets the maximum duration, in
3207 nptcg= [IA-64] Override max number of concurrent global TLB
3214 number of already plugged CPU during bootup, later in
3216 n. So during boot up some boot time memory for per-cpu
3217 variables need be pre-allocated for later physical cpu
3228 See Documentation/admin-guide/sysctl/vm.rst for details.
3237 See Documentation/debugging-via-ohci1394.txt for more
3276 running on a platform with a direct-mapped memory-side
3282 page_owner= [KNL] Boot-time page_owner enabling option.
3284 each page is disabled in default. With this switch,
3288 page_poison= [KNL] Boot-time parameter changing the state of
3307 bit 5: print all printk messages in buffer
3313 Run kdump after running panic-notifiers and dumping
3315 succeeds in any situation.
3337 Parallel ports are assigned in the order they
3342 Configure VIA parallel port to operate in
3344 computer where firmware has no options for setting
3358 See also Documentation/admin-guide/blockdev/paride.rst.
3364 specified in one of the following formats:
3382 devices in the system.
3387 bios [X86-32] force use of PCI BIOS, don't access
3389 has a non-standard PCI host bridge.
3390 nobios [X86-32] disallow use of PCI BIOS, only direct
3395 Mechanism 1 (config address in IO port 0xCF8,
3396 data in IO port 0xCFC, both 32-bit).
3398 Mechanism 2 (IO port 0xCF8 is an 8-bit port for
3399 the function, IO port 0xCFA, also 8-bit, sets
3401 through ports 0xC000-0xCFFF).
3408 root domains (aka PCI segments, in ACPI-speak).
3416 disable the use of MSI interrupts system-wide.
3421 primary IO-APIC for bridges that cannot disable
3428 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
3452 F0000h-100000h range.
3457 assign-busses [X86] Always assign all PCI bus
3461 in the BIOS $PIR table. This is needed on
3464 notebooks. This will have no effect if ACPI
3475 This is normally done in pci_enable_device(),
3485 bfsort Sort PCI devices into breadth-first order.
3488 nobfsort Don't sort PCI devices into breadth-first order.
3490 tuning and use the BIOS-configured MPS defaults.
3496 value (no larger than the MPS that the device
3500 configuration allows peer-to-peer DMA between
3503 that hot-added devices will work.
3518 A PCI-PCI bridge can be specified if resource
3524 for 4096-byte alignment.
3526 end-to-end CRC checking).
3548 noats [PCIE, Intel-IOMMU, AMD-IOMMU]
3560 Specify one or more PCI devices (in the format
3567 may put more devices in an IOMMU group.
3597 Keep all power-domains already enabled by bootloader on,
3598 even if no driver has claimed them. This is useful
3603 See Documentation/admin-guide/blockdev/paride.rst.
3613 See comments in mm/percpu.c for details on each
3618 See Documentation/admin-guide/blockdev/paride.rst.
3621 See Documentation/admin-guide/blockdev/paride.rst.
3623 pirq= [SMP,APIC] Manual mp-table setup
3624 See Documentation/x86/i386/IO-APIC.rst.
3628 See also Documentation/admin-guide/parport.rst.
3636 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
3645 { on | off | curr | res | no-curr | no-res }
3654 Ranges are in pairs (I/O port base and size).
3659 Ranges are in pairs (memory base and size).
3683 print-fatal-signals=
3689 coredump - etc.
3692 you might want to try "ulimit -i unlimited".
3704 on - unlimited logging to /dev/kmsg from userspace
3705 off - logging to /dev/kmsg disabled
3706 ratelimit - ratelimit the logging
3713 Limit processor to maximum C-state
3717 Ignore the _CST method to determine C-states,
3724 Param: "schedule" - profile schedule points.
3725 Param: "sleep" - profile D-state sleeping (millisecs).
3727 Param: "kvm" - profile VM exits.
3728 Param: <number> - step/bucket size as a power of 2 for
3733 See Documentation/admin-guide/blockdev/ramdisk.rst.
3741 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
3747 [HW,MOUSE] Set desired mouse resolution, in dpi.
3755 See Documentation/admin-guide/blockdev/paride.rst.
3762 on - unconditionally enable
3763 off - unconditionally disable
3764 auto - kernel detects whether your CPU model is
3773 [KNL] Number of legacy pty's. Overwrites compiled-in
3781 See Documentation/admin-guide/md.rst.
3783 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
3784 See Documentation/admin-guide/blockdev/ramdisk.rst.
3792 ras=option[,option,...] [KNL] RAS-specific options
3803 In kernels built with CONFIG_RCU_NOCB_CPU=y, set
3804 the specified list of CPUs to be no-callback CPUs.
3807 purpose, where "x" is "p" for RCU-preempt, and
3808 "s" for RCU-sched, and "N" is the CPU number.
3810 which can be useful for HPC and real-time
3819 This improves the real-time response for the
3827 process in one batch.
3836 RCU grace-period cleanup.
3840 RCU grace-period initialization.
3844 RCU grace-period pre-initialization, that is,
3845 the propagation of recent CPU-hotplug changes up
3850 per-CPU rcuc kthreads. Defaults to a non-zero
3858 cache-to-cache transfer latencies.
3864 and for NUMA systems with large remote-access
3869 Set delay from grace-period initialization to
3880 Set required age in jiffies for a
3882 soliciting quiescent-state help from
3888 This calculated value may be viewed in
3894 Set the SCHED_FIFO priority of the RCU per-CPU
3897 and for the RCU grace-period kthreads (rcu_bh,
3899 set, valid values are 1-99 and the default is 1
3900 (the least-favored priority). Otherwise, when
3901 RCU_BOOST is not set, valid values are 0-99 and
3902 the default is zero (non-realtime operation).
3905 Set the number of NOCB callback kthreads in
3908 the wakeup overhead on the global grace-period
3910 each group's NOCB grace-period kthread.
3918 batch limiting is re-enabled.
3931 Cause the grace-period kthread to get an extra
3933 it should at force-quiescent-state time.
3944 grace-period primitives such as call_rcu().
3955 grace-period primitives.
3958 Set test-start holdoff period. The purpose of
3960 test until boot completes in order to avoid
3964 Set number of RCU readers. The value -1 selects
3966 "n" less than -1 selects N-n+1, where N is again
3967 the number of CPUs. For example, -2 selects N
3968 (the number of CPUs), -3 selects N+1, and so on.
3969 A value of "n" less than or equal to -N selects
3982 complete. This is useful for hands-off automated
3989 Write-side holdoff between grace periods,
3990 in microseconds. The default of zero says
3991 no holdoff.
3995 in microseconds.
3999 in microseconds.
4003 in seconds.
4006 Enable RCU grace-period forward-progress testing
4010 Specify the fraction of a CPU-stall-warning
4011 period to do tight-loop forward-progress testing.
4015 forward-progress tests.
4019 need_resched() during tight-loop forward-progress
4023 Use conditional/asynchronous update-side
4027 Use expedited update-side primitives, if available.
4030 Use normal (non-expedited) asynchronous
4031 update-side primitives, if available.
4034 Use normal (non-expedited) synchronous
4035 update-side primitives, if available. If all
4039 they are all non-zero.
4046 stress RCU, they don't participate in the actual
4050 Set number of RCU readers. The value -1 selects
4051 N-1, where N is the number of CPUs. A value
4052 "n" less than -1 selects N-n-2, where N is again
4053 the number of CPUs. For example, -2 selects N
4054 (the number of CPUs), -3 selects N+1, and so on.
4057 Enable debug-object double-call_rcu() testing.
4060 Set time (s) after boot for CPU-hotplug testing.
4063 Set time (jiffies) between CPU-hotplug operations,
4064 or zero to disable CPU-hotplug testing.
4067 Set task-shuffle interval (s). Shuffling tasks
4068 allows some CPUs to go into dyntick-idle mode
4073 is useful for hands-off automated testing.
4095 Test RCU priority boosting? 0=no, 1=maybe, 2=yes.
4106 Test RCU's dyntick-idle handling. See also the
4126 Use expedited grace-period primitives, for
4130 real-time latency, and degrade energy efficiency.
4131 No effect on CONFIG_TINY_RCU kernels.
4134 Use only normal grace-period primitives,
4137 real-time latency, CPU utilization, and
4139 increased grace-period latency. This parameter
4140 overrides rcupdate.rcu_expedited. No effect on
4146 only normal grace-period primitives. No effect
4150 Set timeout in jiffies for RCU task stall warning
4163 force - Override the decision by the kernel to hide the
4166 support, specifically around the suspend/resume
4192 See Documentation/admin-guide/cgroup-v1/cpusets.rst.
4200 reservetop= [X86-32]
4214 Specify the partition device for software suspend
4221 in <PAGE_SIZE> units (needed only for swap files).
4222 See Documentation/power/swsusp-and-swap-files.rst
4224 resumedelay= [HIBERNATION] Delay (in seconds) to pause before attempting to
4235 no Disable hibernation and resume.
4238 during restoration read-only).
4261 ro [KNL] Mount root device read-only on boot
4264 on Mark read-only kernel memory as read-only (default).
4265 off Leave read-only kernel memory writable for debugging.
4270 debug-uart get routed to the D+ and D- pins of the usb
4274 See name_to_dev_t comment in init/do_mounts.c.
4276 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
4292 rw [KNL] Mount root device read-write on boot
4294 S [KNL] Run init in single mode
4299 With strict flushing every unmap operation will result in
4312 incurs a small amount of overhead in the scheduler
4315 skew_tick= [KNL] Offset the periodic timer tick per cpu to mitigate
4319 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
4320 1 -- enable.
4331 0 -- disable.
4332 1 -- enable.
4340 0 -- disable.
4341 1 -- enable.
4344 serialnumber [BUGS=X86-32]
4349 simeth= [IA-64]
4357 allocs to different slabs, especially in hardened
4377 may poison objects when not in use. Also tracks the
4383 memory cgroup sub-caches. 1 to enable, 0 to disable.
4416 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
4417 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
4418 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
4419 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
4420 smsc-ircc2.ircc_irq= [HW] IRQ line
4421 smsc-ircc2.ircc_dma= [HW] DMA channel
4422 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
4432 Default: -1 (no limit)
4435 [KNL] Should the soft-lockup detector generate panics.
4438 A nonzero value instructs the soft-lockup detector
4439 to panic the machine when a soft-lockup occurs. This
4441 which is the respective build-time switch to that
4445 [KNL] Should the soft-lockup detector generate
4450 See Documentation/admin-guide/laptops/sonypi.rst
4457 on - unconditionally enable, implies
4459 off - unconditionally disable, implies
4461 auto - kernel detects whether your CPU model is
4478 retpoline - replace indirect branches
4479 retpoline,generic - google's original retpoline
4480 retpoline,amd - AMD-specific minimal thunk
4490 on - Unconditionally enable mitigations. Is
4493 off - Unconditionally disable mitigations. Is
4496 prctl - Indirect branch speculation is enabled,
4502 - Like "prctl" above, but only STIBP is
4508 - Same as "prctl" above, but all seccomp
4513 - Like "seccomp" above, but only STIBP is
4518 auto - Kernel selects the mitigation depending on
4533 as "Speculative Store Bypass" in which recent stores
4540 In vulnerable processors, the speculatively forwarded
4541 store can be used in a cache side channel attack, for
4550 on - Unconditionally disable Speculative Store Bypass
4551 off - Unconditionally enable Speculative Store Bypass
4552 auto - Kernel detects whether the CPU model contains an
4558 prctl - Control Speculative Store Bypass per thread
4562 seccomp - Same as "prctl" above, but all seccomp threads
4570 on,auto - On Power8 and Power9 insert a store-forwarding
4574 off - No action.
4586 grace-period sequence counter wrap for the
4587 srcu_data structure's ->srcu_gp_seq_needed field.
4588 The greater the number of bits set in this kernel
4609 force-on: Unconditionally enable mitigation for
4611 force-off: Unconditionally disable mitigation for
4613 kernel: Always enable mitigation in the
4616 interest in being mitigated too.
4620 is in page units and it defines how many pages prior
4622 growing up) the main stack are reserved for no other
4628 stacktrace_filter=[function-list]
4630 will trace at boot up. function-list is a comma separated
4632 time by the stack_trace_filter file in the debugfs
4638 Set the STI (builtin display/keyboard on the HP-PARISC
4640 as the initial boot-console.
4641 See also comment in drivers/video/console/sticore.c.
4644 See comment in drivers/video/console/sticore.c.
4653 originate from a privileged port (i.e. a port in the
4664 process in parallel from a single connection.
4665 The default value is 0 (no limit).
4681 to global on non-NUMA machines)
4692 suspend.pm_test_delay=
4693 [SUSPEND]
4694 Sets the number of seconds to remain in a suspend test
4705 [KNL] Enable accounting of swap in memory resource
4706 controller if no parameter or 1 is given or disable
4707 it if 0 is given (See Documentation/admin-guide/cgroup-v1/memory.rst)
4709 swiotlb= [ARM,IA-64,PPC,MIPS,X86]
4711 <int> -- Number of I/O TLB slabs
4712 force -- force using of bounce buffers even if they
4714 noforce -- Never use bounce buffers (for debugging)
4723 in older udev will not work anymore.
4724 Default depends on CONFIG_SYSFS_DEPRECATED_V2 set in
4729 Ignore sysrq setting - this boot parameter will
4737 cache size. See Documentation/networking/ip-sysctl.txt
4742 test_suspend= [SUSPEND][,N]
4743 Specify "mem" (for Suspend-to-RAM) or "standby" (for
4744 standby suspend) or "freeze" (for suspend type freeze)
4748 wakeup-capable RTC alarm.
4754 -1: disable all active trip points in all thermal zones
4758 -1: disable all critical trip points in all thermal zones
4769 -1: disable all passive trip points
4775 <deci-seconds>: poll all this frequency
4776 0: no polling (default)
4800 Specify that at suspend time, the tpm driver
4810 trace_event=[event-list]
4811 [FTRACE] Set and start specified trace events in order
4812 to facilitate early boot debugging. The event-list is a
4816 trace_options=[option-list]
4818 The option-list is a comma delimited list of options
4842 tracepoint_printk kernel cmdline option has no effect.
4854 file located in /sys/kernel/debug/tracing/
4868 See Documentation/admin-guide/mm/transhuge.rst
4876 high-resolution timer mode on older hardware, and in
4886 in situations with strict latency requirements (where
4891 Extensions (TSX) feature in Intel processors that
4896 on - Enable TSX on the system. Although there are
4899 several previous speculation-related CVEs, and
4903 off - Disable TSX on the system. (Note that this
4911 auto - Disable TSX if X86_BUG_TAA is present,
4916 See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
4922 Similar to Micro-architectural Data Sampling (MDS)
4929 In vulnerable processors, the speculatively forwarded
4930 data can be used in a cache side channel attack, to
4937 full - Enable TAA mitigation on vulnerable CPUs
4940 full,nosmt - Enable TAA mitigation and disable SMT on
4943 vulnerable to cross-thread TAA attacks.
4944 off - Unconditionally disable TAA mitigation
4946 On MDS-affected machines, tsx_async_abort=off can be
4948 are mitigated with the same mechanism so in order to disable
4958 Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
4964 See also Documentation/input/devices/joystick-parport.rst
4966 udbg-immortal [PPC] When debugging early kernel crashes that
4972 Set number of hash buckets for UDP/UDP-Lite connections
4974 uhci-hcd.ignore_oc=
4976 Some badly-designed motherboards generate lots of
4987 (default -1 = authorized except for wireless USB,
4992 [USB] The autosuspend time delay (in seconds) used
4993 for newly-detected USB devices (default 2). This
5002 [USB] Maximum number of bytes to snoop in each URB
5010 scheme, applies only to low and full-speed devices
5014 [USB] Memory limit (in MB) for buffers allocated by
5022 [USB] Specifies timeout for the initial 64-byte
5023 USB_REQ_GET_DESCRIPTOR request in milliseconds
5029 [USB] A list of quirk entries to augment the built-in
5032 VendorID:ProductID:Flags. The IDs are 4-digit hex
5034 will change the built-in quirk; setting it if it is
5039 a 255-byte read);
5043 Set-Interface requests);
5059 require the interval in microframes (1
5062 (bInterval-1).
5066 variable used in the calculation);
5080 to be disconnected before suspend to
5097 usb-storage.delay_use=
5098 [UMS] The delay in seconds before a new device is
5101 usb-storage.quirks=
5103 override the built-in unusual_devs list. List
5106 and Product ID values (4-digit hex numbers) and
5108 to a common usb-storage quirk flag as follows:
5149 medium is write-protected).
5151 even if the device claims no cache,
5158 1 - undefined instruction events
5159 2 - system calls
5160 4 - invalid data aborts
5161 8 - SIGSEGV faults
5162 16 - SIGBUS faults
5168 nohigh = do not allocate PTE pages in
5178 vdso32= [X86] Control the 32-bit vDSO
5179 vdso32=1: enable 32-bit VDSO
5180 vdso32=0 or vdso32=2: disable 32-bit VDSO
5190 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
5192 vector= [IA-64,SMP]
5223 vga= [BOOT,X86-32] Select a particular video mode
5225 Documentation/admin-guide/svga.rst.
5240 - Disable all of the above options
5261 vsyscall= [X86-64]
5264 code). Most statically-linked binaries and older
5288 see VGA-softcursor.txt. Default: 2 = underline.
5293 This is a 16-member array composed of values
5294 ranging from 0-255.
5299 This is a 16-member array composed of values
5300 ranging from 0-255.
5305 This is a 16-member array composed of values
5306 ranging from 0-255.
5311 Set system-wide default UTF-8 mode for all tty's.
5312 Default is 1, i.e. UTF-8 mode is enabled for all
5317 Format=<-1|0|1>
5318 Set system-wide default for whether a cursor
5319 is shown on new VTs. Default is -1,
5324 vt.italic= [VT] Default color for italic text; 0-15.
5327 vt.underline= [VT] Default color for underlined text; 0-15.
5331 see Documentation/watchdog/watchdog-parameters.rst
5332 or other driver-specific files in the
5338 threshold in seconds. The soft lockup detector
5348 duration in seconds. The default value is 30 and
5355 issued on, which results in better behavior in
5358 that this also can be controlled per-workqueue for
5362 Per-cpu workqueues are generally preferred because
5364 locality; unfortunately, per-cpu workqueues tend to
5367 Enabling this makes the per-cpu workqueues which
5379 on the local CPU. This guarantee is no longer true
5382 forces round-robin CPU selection to flush out
5387 x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
5391 x86_intel_mid_timer= [X86-32,APBT]
5397 xen_512gb_limit [KNL,X86-64,XEN]
5407 ide-disks -- unplug primary master IDE devices
5408 aux-ide-disks -- unplug non-primary-master IDE devices
5409 nics -- unplug network devices
5410 all -- unplug all emulated devices (NICs and IDE disks)
5411 unnecessary -- unplugging emulated devices is
5414 never -- do not unplug even if version check succeeds
5426 run as generic HVM guest with no PV drivers.
5436 xen_timer_slop= [X86-64,XEN]
5437 Set the timer slop (in nanoseconds) for the virtual Xen
5445 as generic guest with no PV drivers. Currently support
5461 xhci-hcd.quirks [USB,KNL]
5464 consulted in header drivers/usb/host/xhci.h.