Lines Matching +full:kbd +full:- +full:led +full:- +full:backlight
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
28 nospcr -- disable console in ACPI SPCR table as
45 If set to vendor, prefer vendor-specific driver
49 If set to native, use the device's native backlight mode.
50 If set to none, disable the ACPI backlight interface.
77 Documentation/firmware-guide/acpi/debug.rst for more information about
135 Format: <byte> or <bitmap-list>
138 Disable auto-serialization of AML methods
141 auto-serialization feature.
159 Ignore the ACPI-based watchdog interface (WDAT) and let
180 acpi_osi=! # disable all built-in OS vendor
182 acpi_osi=!! # enable all built-in OS vendor
244 For broken nForce2 BIOS resulting in XT-PIC timer.
253 as soon as the kernel's real-mode entry point is called.
291 See Documentation/sound/alsa-configuration.rst
298 align_va_addr= [X86-64]
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
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]
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
340 force_enable - Force enable the IOMMU on platforms known
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
348 v2_pgsizes_only - Limit page-sizes used for v1 page-tables
352 amd_iommu_dump= [HW,X86-64]
358 amd_iommu_intr= [HW,X86-64]
361 legacy - Use legacy interrupt remapping mode.
362 vapic - Use virtual APIC mode, which allows IOMMU
364 This mode requires kvm-amd.avic=1.
393 Disable amd-pstate preferred core.
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.
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
516 0 - Disable the BAU.
517 1 - Enable the BAU.
518 unset - Disable the BAU.
557 See Documentation/block/cmdline-partition.rst
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.
604 inclusive. See arch/mips/include/asm/pgtable-bits.h
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
642 nosocket -- Disable socket memory accounting.
643 nokmem -- Disable kernel memory accounting.
644 nobpf -- Disable BPF memory accounting.
649 0 -- check protection applied by kernel (includes
651 1 -- check protection requested by application.
663 numbers X. Note the Linux-specific bits are not necessarily
664 stable over kernel options, but the vendor-specific
684 force such clocks to be always-on nor does it reserve
688 information, see Documentation/driver-api/clk.rst.
690 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
707 [X86-32] pit,hpet,tsc;
714 [X86-64] hpet,tsc
720 architected timer so that code using WFE-based polling
734 clocksource-wdtest.holdoff= [KNL]
740 cma=nn[MG]@[start[MG][-end[MG]]]
751 Sets the size of kernel per-numa memory area for
753 per-numa CMA altogether. And If this option is not
755 With per-numa CMA enabled, DMA users on node nid will
782 com20020= [HW,NET] ARCnet - COM20020 chipset
786 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
790 ARCnet - COM90xx chipset (memory-mapped buffers)
819 See Documentation/admin-guide/serial-console.rst for more
834 $ ls -d /sys/bus/serial-base/devices/*:*.*/tty/*
835 /sys/bus/serial-base/devices/00:04:0.0/tty/ttyS0
848 Start an early, polled-mode console on the 8250/16550
851 MMIO inter-register address stride is either 8-bit
852 (mmio), 16-bit (mmio16), or 32-bit (mmio32).
856 the h/w is not re-initialized.
883 syscall, or to executing "dmesg -S --raw" or to reading
907 disable the cpuidle sub-system
913 disable the cpufreq sub-system
921 [X86,EARLY] Delay for N microsec between assert and de-assert
942 like Hyper-V, PowerPC (fadump) and AMD SEV-SNP.
950 [KNL, X86-64, ARM64, RISCV, LoongArch] Select a region
953 See Documentation/admin-guide/kdump/kdump.rst for further details.
958 start-[end] where start and end are both
960 Documentation/admin-guide/kdump/kdump.rst for an example.
963 [KNL, X86-64, ARM64, RISCV, LoongArch] range could be
971 [KNL, X86-64, ARM64, RISCV, LoongArch] range under 4G.
977 for 32-bit devices won't run out. Kernel would try to allocate
980 --> x86: max(swiotlb_size_or_default() + 8MiB, 256MiB)
981 --> arm64: 128MiB
982 --> riscv: 128MiB
983 --> loongarch: 128MiB
991 [KNL] Disable crypto self-tests
999 csdlock_debug= [KNL] Enable or disable debug add-ons of cross-CPU
1014 See also Documentation/input/devices/joystick-parport.rst
1027 [KNL] verbose locking self-tests
1030 self-tests.
1032 (no extra messages), setting it to -1 (all bits set)
1033 will print _a_lot_ more information - normally only
1068 Format: { on, no-mount, off }
1070 no-mount:
1075 get a -EPERM as result when trying to register files
1079 Default value is set in build-time with a kernel configuration.
1091 Documentation/admin-guide/mm/hugetlbpage.rst.
1105 delayacct [KNL] Enable per-task delay accounting
1191 entries for DMA-API debugging code. One entry is
1192 required per DMA-API allocation. Use this if the
1193 DMA-API debugging code disables itself because the
1197 With this option the DMA-API debugging driver
1221 Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst
1246 Control how the dt_cpu_ftrs device-tree binding is
1256 what data is available or for reverse-engineering.
1261 Documentation/admin-guide/dynamic-debug-howto.rst
1272 determined by stdout-path property in device tree's
1277 Start an early, polled-mode console on a Cadence
1288 Start an early, polled-mode console on the 8250/16550
1290 MMIO inter-register address stride is either 8-bit
1291 (mmio) or 32-bit (mmio32 or mmio32be).
1301 Start an early, polled-mode console on a pl011 serial
1305 the driver will use only 32-bit accessors to read/write
1314 Start an early, polled-mode console on a meson serial
1320 Start an early, polled-mode console on an msm serial
1326 Start an early, polled-mode console on an msm serial
1332 Start an early, polled-mode console on a serial port
1338 Start an early, polled-mode console on a serial port
1344 Use RISC-V SBI (Supervisor Binary Interface) for early
1362 Start an early, polled-mode console on a lantiq serial
1376 Start an early, polled-mode, output-only console on the
1381 Start an early, polled-mode console on the
1387 Start an early, polled-mode console on a Qualcomm
1395 coherent non-x86 systems that use system memory for
1498 Documentation/admin-guide/acpi/ssdt-overlays.rst for details.
1505 Format: ekgdboc=kbd
1515 elanfreq= [X86-32]
1523 See Documentation/admin-guide/kdump/kdump.rst for details.
1539 0 -- permissive (log only, no denials).
1540 1 -- enforcing (deny and log).
1573 See also Documentation/fault-injection/.
1577 See Documentation/admin-guide/sysctl/net.rst for
1581 See Documentation/admin-guide/blockdev/floppy.rst.
1583 forcepae [X86-32]
1590 fred= [X86-64]
1641 ftrace_filter=[function-list]
1643 tracer at boot up. function-list is a comma-separated
1648 ftrace_notrace=[function-list]
1650 function-list. This list can be changed at run time
1654 ftrace_graph_filter=[function-list]
1657 function-list is a comma-separated list of functions
1661 ftrace_graph_notrace=[function-list]
1663 function-list. This list is a comma-separated list of
1683 off -- Don't create device links from firmware info.
1684 permissive -- Create device links from firmware info
1687 on -- Create device links from firmware info and use it
1689 rpm -- Like "on", but also use to order runtime PM.
1702 strict -- Default. Continue waiting on consumers to
1704 timeout -- Give up waiting on consumers and call
1714 See also Documentation/input/devices/joystick-parport.rst
1718 gart_fix_e820= [X86-64,EARLY] disable the fix e820 for K8 GART
1744 gcov_persist= [GCOV] When non-zero (default), profiling data for
1754 gpio-mockup.gpio_mockup_ranges
1757 gpio-mockup.gpio_mockup_named_lines
1789 against bounds-checking flaws in the kernel's
1797 [KNL] Should the hard-lockup detector generate
1803 for 64-bit NUMA, off otherwise.
1811 corresponding firmware-first mode error processing
1821 during restoration read-only).
1865 hpet= [X86-32,HPET] option to control HPET usage
1882 number of pages to allocate per-node can be specified.
1883 See also Documentation/admin-guide/mm/hugetlbpage.rst.
1894 Documentation/admin-guide/mm/hugetlbpage.rst.
1904 Note that this parameter only applies to non-gigantic huge pages.
1914 boot-time allocation of gigantic hugepages is skipped.
1949 by the CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time
1955 hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
1977 Set device-properties for ACPI-enumerated I2C-attached
1978 touchscreen, to e.g. fix coordinates of upside-down
1986 Omit "=<val>" entirely Set a boolean device-property
1987 Unsigned number Set a u32 device-property
1988 Anything else Set a string device-property
1991 i2c_touchscreen_props=GDIX1001:touchscreen-inverted-x:
1992 touchscreen-inverted-y
1994 i2c_touchscreen_props=MSSL1680:touchscreen-size-x=1920:
1995 touchscreen-size-y=1080:touchscreen-inverted-y:
1996 firmware-name=gsl1680-vendor-model.fw:silead,home-button
2000 [HW] Enable printing of interrupt data from the KBD port
2001 (disabled by default, and as a pre-condition
2003 i8042.direct [HW] Put keyboard port into non-translated mode
2013 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
2017 suspend-to-ram transitions, only during s2r
2025 i8042.kbdreset [HW] Reset device connected to KBD port
2033 set the brightness of the panel backlight. Normally a
2034 brightness value of 0 indicates backlight switched off,
2035 and the maximum of the brightness value sets the backlight
2038 is set to 1, a brightness value of 0 sets the backlight
2040 value switches the backlight off.
2041 -1 -- never invert brightness
2042 0 -- machine default
2043 1 -- force brightness inversion
2045 ia32_emulation= [X86-64]
2047 When true, allows loading 32-bit programs and executing 32-bit
2072 idle=nomwait: Disable mwait for CPU C-states
2100 legacy only accept legacy-NaN binaries, if supported
2102 2008 only accept 2008-NaN binaries, if supported
2113 'relaxed' straps the emulator for both legacy-NaN and
2114 2008-NaN, whereas 'strict' enables legacy-NaN only on
2123 Ignore loglevel setting - this will print /all/
2190 Formats: { "ima" | "ima-ng" | "ima-ngv2" | "ima-sig" |
2191 "ima-sigv2" }
2192 Default: "ima-ng"
2225 stuff: Deploy RSB-fill mitigation when retpoline is
2230 Documentation/admin-guide/hw-vuln/indirect-target-selection.rst
2241 initcall_blacklist= [KNL] Do not execute a comma-separated list of
2242 initcall functions. Useful for debugging built-in
2287 0 -- basic integrity auditing messages. (Default)
2288 1 -- additional integrity auditing messages.
2316 could harm performance of some high-throughput
2325 1 to 9 specify maximum depth of C-state.
2334 algorithms for p-state selection. There are two
2335 P-state selection algorithms provided by
2338 on whether or not the hardware managed P-states
2345 used along with the hardware-managed P-states (HWP)
2349 in favor of acpi-cpufreq. Forcing the intel_pstate driver
2350 instead of acpi-cpufreq may disable platform features, such
2352 P-States information being indicated to OSPM and therefore
2355 or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
2368 Allow per-logical-CPU P-State performance control limits using
2371 Do not enable capacity-aware scheduling (CAS) on
2374 intremap= [X86-64,Intel-IOMMU,EARLY]
2379 BIOS x2APIC opt-out request will be ignored
2422 AMD Gart HW IOMMU-specific options:
2441 Do scatter-gather (SG) merging. Implies "force"
2445 Don't do scatter-gather (SG) merging.
2458 0 - Try to allocate a 32-bit DMA address first, before
2460 1 - Allocate directly from the full usable range,
2462 greater than 32-bit addressing.
2466 0 - Lazy mode.
2472 1 - Strict mode.
2475 unset - Use value of CONFIG_IOMMU_DEFAULT_DMA_{LAZY,STRICT}.
2477 legacy driver-specific options takes precedence.
2482 0 - Use IOMMU translation for DMA.
2483 1 - Bypass the IOMMU for DMA.
2484 unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
2486 io7= [HW] IO7 for Marvel-based Alpha systems
2501 See Documentation/admin-guide/nfs/nfsroot.rst.
2537 Enables support for pseudo-NMIs in the kernel. This
2542 [RISC-V,EARLY]
2544 as IPIs. Intended for system where IMSIC is trap-n-emulated,
2563 [Deprecated - use cpusets instead]
2564 Format: [flag-list,]<cpu-list>
2597 "number of CPUs in system - 1".
2623 The format of <cpu-list> is described above.
2627 ivrs_ioapic [HW,X86-64]
2628 Provide an override to the IOAPIC-ID<->DEVICE-ID
2632 For example, to map IOAPIC-ID decimal 10 to
2638 * To map IOAPIC-ID decimal 10 to PCI device 00:14.0
2641 * To map IOAPIC-ID decimal 10 to PCI segment 0x1 and
2645 ivrs_hpet [HW,X86-64]
2646 Provide an override to the HPET-ID<->DEVICE-ID
2650 For example, to map HPET-ID decimal 10 to
2656 * To map HPET-ID decimal 0 to PCI device 00:14.0
2659 * To map HPET-ID decimal 10 to PCI segment 0x1 and
2663 ivrs_acpihid [HW,X86-64]
2664 Provide an override to the ACPI-HID:UID<->DEVICE-ID
2668 For example, to map UART-HID:UID AMD0020:0 to
2674 * To map UART-HID:UID AMD0020:0 to PCI segment is 0,
2677 * To map UART-HID:UID AMD0020:0 to PCI segment 0x1 and
2701 the kernel for non-movable allocations. The requested
2711 subsystem. Note that allocations like PTEs-from-HighMem
2719 for non-movable allocations and remaining memory is used
2730 gdb or control-c on the dbgp connection. When
2731 not using this parameter you use sysrq-g to break into
2736 or a supported polling keyboard driver (non-usb).
2738 keyboard only format: kbd
2739 keyboard and serial format: kbd,<serial_device>[,baud]
2741 kms, kbd format: kms,kbd
2742 kms, kbd and serial format: kms,kbd,<ser_dev>[,baud]
2765 "0" | "off" | "n" - kexec handover is disabled
2766 "1" | "on" | "y" - kexec handover is enabled
2772 ranges that can only be used for non-kernel
2783 parameter defines the size of additional per-node
2788 Configure the RouterBoard 532 series on-chip
2791 kmemleak= [KNL,EARLY] Boot-time kmemleak enable/disable
2797 kprobe_event=[probe-list]
2799 The probe-list is a semicolon delimited list of probe
2829 execution by eliminating the write-protection faults
2856 virtualization on-demand when creating and destroying
2864 is that doing so may interfere with using out-of-tree
2891 back to huge pages. If the value is a non-zero N, KVM will
2896 kvm-amd.nested= [KVM,AMD] Control nested virtualization feature in
2899 kvm-amd.npt= [KVM,AMD] Control KVM's use of Nested Page Tables,
2900 a.k.a. Two-Dimensional Page Tables. Default is 1
2904 kvm-arm.mode=
2910 nvhe: Standard nVHE-based mode, without support for
2917 nested: VHE-based mode with support for nested
2925 command-line.
2929 kvm-arm.vgic_v3_group0_trap=
2930 [KVM,ARM,EARLY] Trap guest accesses to GICv3 group-0
2933 kvm-arm.vgic_v3_group1_trap=
2934 [KVM,ARM,EARLY] Trap guest accesses to GICv3 group-1
2937 kvm-arm.vgic_v3_common_trap=
2941 kvm-arm.vgic_v4_enable=
2945 kvm-arm.wfe_trap_policy=
2954 kvm-arm.wfi_trap_policy=
2971 kvm-intel.ept= [KVM,Intel] Control KVM's use of Extended Page Tables,
2972 a.k.a. Two-Dimensional Page Tables. Default is 1
2976 kvm-intel.emulate_invalid_guest_state=
2978 state. Ignored if kvm-intel.enable_unrestricted_guest=1,
2984 kvm-intel.flexpriority=
2989 kvm-intel.nested=
2993 kvm-intel.unrestricted_guest=
2999 kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
3000 CVE-2018-3620.
3011 kvm-intel.vpid= [KVM,Intel] Control KVM's use of Virtual Processor
3031 on - enable the interface for the mitigation
3096 For details see: Documentation/admin-guide/hw-vuln/l1tf.rst
3102 lapic [X86-32,APIC,EARLY] Enable the local APIC even if BIOS
3106 value for LAPIC timer one-shot implementation. Default
3129 libata.force= [LIBATA] Force configurations. The format is a comma-
3141 first fan-out link behind PMP device. It does not
3155 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
3162 * rstonce: only attempt one reset during hot-unplug
3205 * external: Mark port as external (hotplug-capable).
3259 Specify the number of self-propagating call_rcu()
3267 occasional long-duration lock hold time. Defaults
3278 Set the number of locking read-acquisition kthreads.
3283 Set the number of locking write-acquisition kthreads.
3286 Set time (s) after boot for CPU-hotplug testing.
3289 Set time (s) between CPU-hotplug operations, or
3290 zero to disable CPU-hotplug testing.
3293 Do periodic testing of real-time lock priority
3298 non-real-time spinlocks, due to their disabling
3299 of preemption. Note that non-realtime mutexes
3312 Set task-shuffle interval (jiffies). Shuffling
3313 tasks allows some CPUs to go into dyntick-idle
3318 is useful for hands-off automated testing.
3337 Run the write-side locktorture kthreads at
3338 sched_set_fifo() real-time priority.
3356 7 (KERN_DEBUG) debug-level messages
3368 logo.nologo [FB] Disables display of the built-in Linux logo.
3386 an IEEE 1284-compliant printer is attached; if
3392 time-consuming boot-time autodetection (up to 250 ms per
3412 Example: machtype=lemote-yeeloong-2f-7inch
3424 (loop.max_loop) unconditionally pre-created at init time. The default
3427 devices can be requested on-demand with the
3428 /dev/loop-control interface.
3430 mce= [X86-{32,64}]
3467 do not opt-in to Local MCE delivery. Use legacy method
3488 don't overwrite the bios-set CMCI threshold. This boot
3497 force-enable recoverable machine check code paths
3503 See Documentation/admin-guide/md.rst.
3510 Control mitigation for the Micro-architectural Data
3525 full - Enable MDS mitigation on vulnerable CPUs
3526 full,nosmt - Enable MDS mitigation and disable
3528 off - Unconditionally disable MDS mitigation
3530 On TAA-affected machines, mds=off can be prevented by
3539 For details see: Documentation/admin-guide/hw-vuln/mds.rst
3554 [ARC,MICROBLAZE] - the limit applies only to low memory,
3557 [ARM64] - only limits memory covered by the linear
3570 [ARM,MIPS,EARLY] - override the memory layout
3577 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
3584 per-device physically contiguous DMA buffers.
3592 See Documentation/admin-guide/mm/memory-hotplug.rst.
3617 Example: Exclude memory from 0x18690000-0x1869ffff
3631 memmap=<size>%<offset>-<oldtype>+<newtype>
3633 from <oldtype> to <newtype>. If "-<oldtype>" is left
3648 repeatable BIOS-originated corruption always
3692 mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control
3698 Refer to Documentation/virt/kvm/x86/amd-memory-encryption.rst
3702 s2idle - Suspend-To-Idle
3703 shallow - Power-On Suspend or equivalent (if supported)
3704 deep - Suspend-To-RAM or equivalent (if supported)
3705 See Documentation/admin-guide/pm/sleep-states.rst.
3707 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
3723 0 - The attached screen is the 3.5" TFT
3724 1 - The attached screen is the 7" TFT
3725 2 - The VGA Shield is attached (1024x768)
3729 b - Enable backlight. The TFT backlight pin will be
3731 LED. This parameter is not necessary when using the
3733 c - Enable the s3c camera interface.
3734 t - Reserved for enabling touchscreen support. The
3738 https://repo.or.cz/w/linux-2.6/mini2440.git
3743 arch-independent options, each of which is an
3744 aggregation of existing arch-specific options.
3774 ssbd=force-off [ARM64]
3787 have other ways of avoiding SMT-based attacks.
3801 supports attack-vector based controls as documented in
3802 Documentation/admin-guide/hw-vuln/attack_vector_controls.rst
3826 full - Enable mitigation on vulnerable CPUs
3828 full,nosmt - Enable mitigation and disable SMT on
3831 off - Unconditionally disable mitigation
3844 Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst
3874 module_blacklist= [KNL] Do not load a comma-separated list of
3899 movable_node [KNL,EARLY] Boot-time switch to make hotplugable memory
3906 Format: <name>,<region-number>,<size>,<offset>
3909 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
3948 something different and driver-specific.
3988 [NFS] enable 64-bit inode numbers.
3989 If zero, the NFS client will fake up a 32-bit inode
3991 of returning the full 64-bit number.
3992 The default is to return 64-bit inode numbers.
4027 [NFS4] Specify an additional fixed unique ident-
4058 driver. A non-zero value sets the minimum interval
4063 server-to-server copies for which this server is
4075 server-to-server copy, knfsd temporarily mounts
4082 See Documentation/admin-guide/nfs/nfsroot.rst.
4084 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
4085 See Documentation/admin-guide/nfs/nfsroot.rst.
4088 See Documentation/admin-guide/nfs/nfsroot.rst.
4092 NMI stack-backtrace request.
4101 0 - turn hardlockup detector in nmi_watchdog off
4102 1 - turn hardlockup detector in nmi_watchdog on
4103 rNNN - configure the watchdog with raw perf event 0xNNN
4116 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
4120 no4lvl [RISCV,EARLY] Disable 4-level and 5-level paging modes.
4121 Forces kernel to use 3-level paging instead.
4123 no5lvl [X86-64,RISCV,EARLY] Disable 5-level paging mode. Forces
4124 kernel to use 4-level paging instead.
4159 no_entry_flush [PPC,EARLY] Don't flush the L1-D cache when entering the kernel.
4161 noexec32 [X86-64]
4162 This affects only 32-bit executables.
4163 noexec32=on: enable non-executable mappings (default)
4165 noexec32=off: disable non-executable mappings
4176 nofxsr [BUGS=X86-32] Disables x86 floating point extended
4178 legacy floating-point registers on task switch.
4191 compared. However, if this command-line option is
4234 nointremap [X86-64,Intel-IOMMU,EARLY] Do not enable interrupt
4236 [Deprecated - use intremap=off]
4242 noirqdebug [X86-32] Disables the code which attempts to detect and
4252 no-kvmapf [X86,KVM,EARLY] Disable paravirtualized asynchronous page
4255 no-kvmclock [X86,KVM,EARLY] Disable paravirtualized KVM clock driver
4257 nolapic [X86-32,APIC,EARLY] Do not enable or use the local APIC.
4259 nolapic_timer [X86-32,APIC,EARLY] Do not use the local APIC timer.
4261 nomce [X86-32] Disable Machine Check Exception
4263 nomfgpt [X86-32] Disable Multi-Function General Purpose
4269 not load if they could possibly displace the pre-
4272 perform display-mode changes or accelerated rendering.
4285 nopcid [X86-64,EARLY] Disable the PCID cpu feature.
4290 nopti [X86-64,EARLY]
4306 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
4312 no-scroll [VGA] Disables scrollback.
4313 This is required for the Braillex ib80-piezo Braille
4316 nosgx [X86-64,SGX,EARLY] Disables Intel SGX kernel support.
4336 nosoftlockup [KNL] Disable the soft-lockup detector.
4342 nospectre_bhb [ARM64,EARLY] Disable all mitigations for Spectre-BHB (branch
4355 no-steal-acc [X86,PV_OPS,ARM64,PPC/PSERIES,RISCV,LOONGARCH,EARLY]
4362 timer IRQ sources, i.e., the IO-APIC timer. This can
4367 [PPC,EARLY] Don't flush the L1-D cache after accessing user data.
4380 no-vmw-sched-clock
4385 soft-lockup and NMI watchdog (hard-lockup).
4389 nox2apic [X86-64,APIC,EARLY] Do not enable x2APIC mode.
4397 enabling legacy floating-point and sse state.
4419 n. So during boot up some boot time memory for per-cpu
4420 variables need be pre-allocated for later physical cpu
4447 soft-reserved memory partitioning.
4456 See Documentation/admin-guide/sysctl/vm.rst for details.
4459 See Documentation/core-api/debugging-via-ohci1394.rst for more
4474 onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
4478 boundary - index of last SLC block on Flex-OneNAND.
4480 lock - Configure if Flex-OneNAND boundary should be locked.
4499 page_owner= [KNL,EARLY] Boot-time page_owner enabling option.
4505 page_poison= [KNL,EARLY] Boot-time parameter changing the state of
4533 See Documentation/admin-guide/tainted-kernels.rst for
4586 Set to non-zero to probe primary and secondary ISA
4592 Set to non-zero if a chip is present that snoops speed
4640 Set to non-zero to probe tertiary and further ISA
4656 Set to non-zero to probe QDI controllers. By default
4661 Set to non-zero to probe Winbond controllers. Use
4708 bios [X86-32] force use of PCI BIOS, don't access
4710 has a non-standard PCI host bridge.
4711 nobios [X86-32] disallow use of PCI BIOS, only direct
4717 data in IO port 0xCFC, both 32-bit).
4719 Mechanism 2 (IO port 0xCF8 is an 8-bit port for
4720 the function, IO port 0xCFA, also 8-bit, sets
4722 through ports 0xC000-0xCFFF).
4729 root domains (aka PCI segments, in ACPI-speak).
4737 disable the use of MSI interrupts system-wide.
4742 primary IO-APIC for bridges that cannot disable
4749 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
4773 F0000h-100000h range.
4778 assign-busses [X86] Always assign all PCI bus
4799 <linux-pci@vger.kernel.org>.
4803 a bug to <linux-pci@vger.kernel.org>.
4815 bfsort Sort PCI devices into breadth-first order.
4818 nobfsort Don't sort PCI devices into breadth-first order.
4820 tuning and use the BIOS-configured MPS defaults.
4830 configuration allows peer-to-peer DMA between
4833 that hot-added devices will work.
4848 A PCI-PCI bridge can be specified if resource
4854 for 4096-byte alignment.
4856 end-to-end CRC checking). Only effective if
4887 noats [PCIE, Intel-IOMMU, AMD-IOMMU]
4918 bit-0 : ACS Source Validation
4919 bit-1 : ACS Translation Blocking
4920 bit-2 : ACS P2P Request Redirect
4921 bit-3 : ACS P2P Completion Redirect
4922 bit-4 : ACS Upstream Forwarding
4923 bit-5 : ACS P2P Egress Control
4924 bit-6 : ACS Direct Translated P2P
4934 Validation unchanged from whatever power-up
4946 system-wide.
4960 dpc-native Use native PCIe service for DPC only. May
4977 Keep all power-domains already enabled by bootloader on,
4995 pirq= [SMP,APIC] Manual mp-table setup
4996 See Documentation/arch/x86/i386/IO-APIC.rst.
5000 See also Documentation/admin-guide/parport.rst.
5019 resume of devices during system-wide power transitions.
5021 dependencies are not well-defined, or for debugging
5031 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
5040 { on | off | curr | res | no-curr | no-res }
5085 none - Limited to cond_resched() calls
5086 voluntary - Limited to cond_resched() and might_sleep() calls
5087 full - Any section that isn't explicitly preempt disabled
5091 lazy - Scheduler controlled. Similar to full but instead
5097 print-fatal-signals=
5103 coredump - etc.
5106 you might want to try "ulimit -i unlimited".
5118 or lockdep-detected issues (only if lock debug is on).
5126 Allows storing messages from non-panic CPUs into
5128 flushed to consoles by the panic-CPU on
5129 a best-effort basis.
5135 on - unlimited logging to /dev/kmsg from userspace
5136 off - logging to /dev/kmsg disabled
5137 ratelimit - ratelimit the logging
5148 - 'always': traditional behavior always allows mem overrides.
5149 - 'ptrace': only allow mem overrides for active ptracers.
5150 - 'never': never allow mem overrides.
5154 Limit processor to maximum C-state
5158 Ignore the _CST method to determine C-states,
5165 Param: "schedule" - profile schedule points.
5166 Param: "kvm" - profile VM exits.
5167 Param: <number> - step/bucket size as a power of 2 for
5198 pti= [X86-64] Control Page Table Isolation of user and
5203 on - unconditionally enable
5204 off - unconditionally disable
5205 auto - kernel detects whether your CPU model is
5211 [KNL] Number of legacy pty's. Overwrites compiled-in
5223 See Documentation/admin-guide/md.rst.
5226 See Documentation/admin-guide/blockdev/ramdisk.rst.
5245 cross-syscall address exposures. This is only
5251 ras=option[,option,...] [KNL] RAS-specific options
5257 rcu_nocbs[=cpu-list]
5262 enable the no-callback CPU mode, which prevents
5267 "p" for RCU-preempt, "s" for RCU-sched, and "g"
5271 and real-time workloads. It can also improve
5275 list of CPUs is set to no-callback mode from boot.
5279 no-callback mode from boot but the mode may be
5290 This improves the real-time response for the
5301 Do only a one-line RCU CPU stall warning when
5302 there is an ongoing too-long CSD-lock wait.
5308 If triggered before the RCU grace-period machinery
5318 RCU grace-period cleanup.
5322 RCU grace-period initialization.
5326 RCU grace-period pre-initialization, that is,
5327 the propagation of recent CPU-hotplug changes up
5331 Set delay from grace-period initialization to
5344 soliciting quiescent-state help from
5356 Set the SCHED_FIFO priority of the RCU per-CPU
5359 and for the RCU grace-period kthreads (rcu_bh,
5361 set, valid values are 1-99 and the default is 1
5362 (the least-favored priority). Otherwise, when
5363 RCU_BOOST is not set, valid values are 0-99 and
5364 the default is zero (non-realtime operation).
5369 On callback-offloaded (rcu_nocbs) CPUs,
5372 use of the ->nocb_bypass list. However, in the
5373 common non-flooded case, RCU queues directly to
5374 the main ->cblist in order to avoid the extra
5375 overhead of the ->nocb_bypass list and its lock.
5377 a single jiffy, RCU pre-queues the callbacks into
5378 the ->nocb_bypass queue. The definition of "too
5382 On callback-offloaded (rcu_nocbs) CPUs, avoid
5395 batch limiting is re-enabled.
5399 RCU's force-quiescent-state scan will aggressively
5407 Set the page-cache refill delay (in milliseconds)
5408 in response to low-memory conditions. The range
5412 Set the shift-right count to use to compute
5413 the callback-invocation batch limit bl from
5420 Please note that this callback-invocation batch
5421 limit applies only to non-offloaded callback
5430 cache-to-cache transfer latencies.
5436 and for NUMA systems with large remote-access
5452 the wakeup overhead on the global grace-period
5454 each group's NOCB grace-period kthread.
5457 Cause the grace-period kthread to get an extra
5459 it should at force-quiescent-state time.
5472 this specifies an rcu_read_unlock()-time delay
5476 of RCU-protected pointers after the relevant
5486 per-CPU rcuc kthreads. Defaults to a non-zero
5515 grace-period primitives such as call_rcu().
5526 grace-period primitives.
5529 Set test-start holdoff period. The purpose of
5547 Test the double-argument variant of kfree_rcu().
5549 rcuscale.kfree_rcu_test_single, both the single-
5550 and double-argument variants are tested.
5553 Test the single-argument variant of kfree_rcu().
5555 rcuscale.kfree_rcu_test_double, both the single-
5556 and double-argument variants are tested.
5570 does not affect the data-collection interval,
5575 Set number of RCU readers. The value -1 selects
5577 "n" less than -1 selects N-n+1, where N is again
5578 the number of CPUs. For example, -2 selects N
5579 (the number of CPUs), -3 selects N+1, and so on.
5580 A value of "n" less than or equal to -N selects
5593 complete. This is useful for hands-off automated
5600 Write-side holdoff between grace periods,
5605 Additional write-side holdoff between grace
5623 for RCU grace-period forward-progress testing
5630 Specify the fraction of a CPU-stall-warning
5631 period to do tight-loop forward-progress testing.
5635 forward-progress tests.
5639 need_resched() during tight-loop forward-progress
5643 Use conditional/asynchronous update-side
5644 normal-grace-period primitives, if available.
5647 Use conditional/asynchronous update-side
5648 expedited-grace-period primitives, if available.
5651 Use conditional/asynchronous update-side
5652 normal-grace-period primitives that also take
5657 Use conditional/asynchronous update-side
5658 expedited-grace-period primitives that also take
5682 Use expedited update-side primitives, if available.
5685 Use normal (non-expedited) asynchronous
5686 update-side primitives, if available.
5689 Use polled update-side normal-grace-period
5693 Use polled update-side expedited-grace-period
5697 Use polled update-side normal-grace-period
5702 Use polled update-side expedited-grace-period
5726 Use normal (non-expedited) synchronous
5727 update-side primitives, if available. If all
5731 they are all non-zero.
5734 Enable grace-period wrap lag testing. Setting
5739 Set the value for grace-period wrap lag during
5754 the grace-period wrap lag will be set to the
5764 Leak an RCU-protected pointer out of the reader.
5779 Set number of RCU callback-offload togglers.
5784 callback-offload toggling attempts.
5787 Set number of RCU readers. The value -1 selects
5788 N-1, where N is the number of CPUs. A value
5789 "n" less than -1 selects N-n-2, where N is again
5790 the number of CPUs. For example, -2 selects N
5791 (the number of CPUs), -3 selects N+1, and so on.
5794 Enable debug-object double-call_rcu() testing.
5797 Set time (s) after boot for CPU-hotplug testing.
5800 Set time (jiffies) between CPU-hotplug operations,
5801 or zero to disable CPU-hotplug testing.
5805 by a high-priority FIFO real-time task. Set to
5814 second) between preemptions by a high-priority
5815 FIFO real-time task. This delay is mediated
5820 The number of times in a given read-then-exit
5821 episode that a set of read-then-exit kthreads
5826 read-then-exit testing episodes.
5831 are entered from low-order bit up, and are
5833 0x1 bit is normal readers, 0x2 NMI-safe readers,
5834 and 0x4 light-weight readers.
5837 Set task-shuffle interval (s). Shuffling tasks
5838 allows some CPUs to go into dyntick-idle mode
5843 is useful for hands-off automated testing.
5852 any other stall-related activity. Note that
5858 in scheduling-while-atomic splats.
5877 grace-period kthread to test RCU CPU stall
5901 of RCU priority-boost testing. Defaults to zero,
5908 Test RCU's dyntick-idle handling. See also the
5963 Use expedited grace-period primitives, for
5967 real-time latency, and degrade energy efficiency.
5971 Use only normal grace-period primitives,
5974 real-time latency, CPU utilization, and
5976 increased grace-period latency. This parameter
5983 only normal grace-period primitives. No effect
5989 post-boot attempt at an expedited RCU grace
5990 period to instead use normal non-expedited
5991 grace-period processing.
5999 set to the default value of -1.
6002 Set the minimum number of callback-queuing-time
6003 lock-contention events per jiffy required to
6004 cause the RCU Tasks flavors to switch to per-CPU
6007 the default value of -1.
6012 of -1 allows this to be automatically (and
6020 number avoids disturbing real-time workloads,
6025 cancel laziness on that CPU. Use -1 to disable
6035 only printed prior to the stall-warning message
6083 force - Override the decision by the kernel to hide the
6105 reboot_type is one of bios, acpi, kbd, triple, efi, or pci,
6122 There are some built-in platform specific "quirks"
6123 - you may see: "reboot: <name> series board detected.
6127 built-in quirk table, and use the generic default
6139 kbd
6160 Set test-start holdoff period. The purpose of
6175 but the default has already reduced the per-pass
6180 Set number of readers. The default value of -1
6189 Set the read-side critical-section duration,
6193 Specify the read-protection implementation to test.
6219 See Documentation/admin-guide/cgroup-v1/cpusets.rst.
6249 reservetop= [X86-32,EARLY]
6266 See Documentation/power/swsusp-and-swap-files.rst
6282 AMD-based UNRET and IBPB mitigations alone do not stop
6284 sibling threads. For that reason, STIBP is used on pro-
6288 off - no mitigation
6289 auto - automatically select a migitation
6290 auto,nosmt - automatically select a mitigation,
6294 ibpb - On AMD, mitigate short speculation
6299 ibpb,nosmt - Like "ibpb" above but will disable SMT
6303 unret - Force enable untrained return thunks,
6304 only effective on AMD f15h-f17h based
6306 unret,nosmt - Like unret, but will disable SMT when STIBP
6338 ro [KNL] Mount root device read-only on boot
6341 on Mark read-only kernel memory as read-only (default).
6342 off Leave read-only kernel memory writable for debugging.
6343 full Mark read-only kernel memory and aliases as read-only
6350 debug-uart get routed to the D+ and D- pins of the usb
6356 block/early-lookup.c for details.
6386 rw [KNL] Mount root device read-write on boot
6415 solution to mutex-based priority inversion.
6445 to 10 seconds for built-in smp_call_function()
6452 that requesting even small non-zero numbers of
6459 The default of -1 specifies a number of kthreads
6464 test before initiating CPU-hotplug operations.
6468 CPU-hotplug operations. Specifying zero (which
6469 is the default) disables CPU-hotplug operations.
6475 Non-zero values are useful for automated tests.
6498 "wait" parameter. A value of -1 selects the
6499 default if all other weights are -1. However,
6501 value of -1 will instead select a weight of zero.
6506 non-zero "wait" parameter. See weight_single.
6519 non-zero "wait" parameter. See weight_single
6531 non-zero "wait" parameter. See weight_single
6542 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
6543 1 -- enable.
6554 0 -- disable.
6555 1 -- enable.
6558 serialnumber [BUGS=X86-32]
6560 sev=option[,option...] [X86-64]
6566 Do not enable SEV-SNP (applies to host/hypervisor
6569 SEV-SNP guests.
6577 to set it to "all" by meaning -- no limit here.
6658 using the csdlock_debug- kernel parameter.
6663 system. By default, let CSD-lock acquisition
6665 for this value provides a 5-minute timeout.
6667 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
6668 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
6669 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
6670 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
6671 smsc-ircc2.ircc_irq= [HW] IRQ line
6672 smsc-ircc2.ircc_dma= [HW] DMA channel
6673 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
6683 Default: -1 (no limit)
6686 [KNL] Should the soft-lockup detector generate panics.
6689 A value of 1 instructs the soft-lockup detector
6690 to panic the machine when a soft-lockup occurs. It is
6693 respective build-time switch to that functionality.
6696 [KNL] Should the soft-lockup detector generate
6701 See Documentation/admin-guide/laptops/sonypi.rst
6708 on - (default) Enable the HW or SW mitigation as
6711 vmexit - On systems which don't have the HW mitigation
6714 protected from VM-originated BHI attacks, but
6716 off - Disable the mitigation.
6723 on - unconditionally enable, implies
6725 off - unconditionally disable, implies
6727 auto - kernel detects whether your CPU model is
6746 retpoline - replace indirect branches
6747 retpoline,generic - Retpolines
6748 retpoline,lfence - LFENCE; indirect branch
6749 retpoline,amd - alias for retpoline,lfence
6750 eibrs - Enhanced/Auto IBRS
6751 eibrs,retpoline - Enhanced/Auto IBRS + Retpolines
6752 eibrs,lfence - Enhanced/Auto IBRS + LFENCE
6753 ibrs - use IBRS to protect kernel
6763 on - Unconditionally enable mitigations. Is
6766 off - Unconditionally disable mitigations. Is
6769 prctl - Indirect branch speculation is enabled,
6775 - Like "prctl" above, but only STIBP is
6781 - Same as "prctl" above, but all seccomp
6786 - Like "seccomp" above, but only STIBP is
6791 auto - Kernel selects the mitigation depending on
6802 off - Disable mitigation
6803 microcode - Enable microcode mitigation only
6804 safe-ret - Enable sw-only safe RET mitigation (default)
6805 ibpb - Enable mitigation by issuing IBPB on
6807 ibpb-vmexit - Issue IBPB only on VMEXIT
6808 (cloud-specific mitigation)
6833 on - Unconditionally disable Speculative Store Bypass
6834 off - Unconditionally enable Speculative Store Bypass
6835 auto - Kernel detects whether the CPU model contains an
6841 prctl - Control Speculative Store Bypass per thread
6845 seccomp - Same as "prctl" above, but all seccomp threads
6853 on,auto - On Power8 and Power9 insert a store-forwarding
6857 off - No action.
6871 off - not enabled
6873 warn - the kernel will emit rate-limited warnings
6881 fatal - the kernel will send SIGBUS to applications
6886 ratelimit:N -
6906 Certain CPUs are vulnerable to an MDS-like
6926 This kernel-boot parameter defaults to 128,
6927 but takes effect only when the low-order four
6944 instead of the compile-time CONFIG_NR_CPUS.
6948 grace-period sequence counter wrap for the
6949 srcu_data structure's ->srcu_gp_seq_needed field.
6964 Specifies the number of no-delay instances
6971 Specifies the per-grace-period phase, number of
6972 non-sleeping polls of readers. Beyond this limit,
6978 Specifies number of microseconds of non-sleeping
6979 delay between each non-sleeping poll of readers.
6982 Specifies the number of update-side contention
6987 set for contention-based conversions to occur.
6997 force-on: Unconditionally enable mitigation for
6999 force-off: Unconditionally disable mitigation for
7022 stacktrace_filter=[function-list]
7024 will trace at boot up. function-list is a comma-separated
7032 Set the STI (builtin display/keyboard on the HP-PARISC
7034 as the initial boot-console.
7094 to global on non-NUMA machines)
7119 <int> -- Number of I/O TLB slabs
7120 <int> -- Second integer after comma. Number of swiotlb
7123 force -- force using of bounce buffers even if they
7125 noforce -- Never use bounce buffers (for debugging)
7140 Ignore sysrq setting - this boot parameter will
7148 cache size. See Documentation/networking/ip-sysctl.rst
7155 Specify "mem" (for Suspend-to-RAM) or "standby" (for
7160 wakeup-capable RTC alarm.
7166 -1: disable all active trip points in all thermal zones
7170 -1: disable all critical trip points in all thermal zones
7177 -1: disable all passive trip points
7183 <deci-seconds>: poll all this frequency
7187 Format: <size>[KMG],<size>[KMG]:<state>;<size>[KMG]-<size>[KMG]:<state>
7192 See Documentation/admin-guide/mm/transhuge.rst for more
7200 Format: <size>[KMG],<size>[KMG]:<policy>;<size>[KMG]-<size>[KMG]:<policy>
7206 See Documentation/admin-guide/mm/transhuge.rst for more
7218 Prevent the CPU-hotplug component of torturing
7222 Dump the ftrace buffer at torture-test shutdown,
7226 with rotating-rust storage.
7231 disables verbose-printk() sleeping.
7234 Duration of each verbose-printk() sleep in jiffies.
7267 https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/
7305 local - Use the per CPU time stamp counter
7309 global - Event time stamps are synchronize across
7312 counter - Simple counting of events (1, 2, ..)
7316 uptime - Use jiffies as the time stamp.
7317 perf - Use the same clock that perf uses.
7318 mono - Use ktime_get_mono_fast_ns() for time stamps.
7319 mono_raw - Use ktime_get_raw_fast_ns() for time
7321 boot - Use ktime_get_boot_fast_ns() for time stamps.
7325 trace_event=[event-list]
7327 to facilitate early boot debugging. The event-list is a
7328 comma-separated list of trace events to enable. See
7339 trace_instance=[instance-info]
7364 traceoff - Have the tracing instance tracing disabled after it is created.
7365 traceprintk - Have trace_printk() write into this trace instance
7412 trace_options=[option-list]
7414 The option-list is a comma delimited list of options
7428 trace_trigger=[trigger-list]
7474 See Documentation/admin-guide/mm/transhuge.rst
7481 See Documentation/admin-guide/mm/transhuge.rst
7488 See Documentation/admin-guide/mm/transhuge.rst
7496 - "tpm"
7497 - "tee"
7498 - "caam"
7499 - "dcp"
7509 - "kernel"
7510 - the same value as trusted.source: "tpm" or "tee"
7511 - "default"
7534 off - disable the mitigation
7535 on - enable the mitigation (default)
7536 user - mitigate only user/kernel transitions
7537 vm - mitigate only guest/host transitions
7545 high-resolution timer mode on older hardware, and in
7581 on - Enable TSX on the system. Although there are
7584 several previous speculation-related CVEs, and
7588 off - Disable TSX on the system. (Note that this
7596 auto - Disable TSX if X86_BUG_TAA is present,
7601 See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
7607 Similar to Micro-architectural Data Sampling (MDS)
7622 full - Enable TAA mitigation on vulnerable CPUs
7625 full,nosmt - Enable TAA mitigation and disable SMT on
7628 vulnerable to cross-thread TAA attacks.
7629 off - Unconditionally disable TAA mitigation
7631 On MDS-affected machines, tsx_async_abort=off can be
7643 Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
7649 See also Documentation/input/devices/joystick-parport.rst
7651 udbg-immortal [PPC] When debugging early kernel crashes that
7657 Set number of hash buckets for UDP/UDP-Lite connections
7659 uhci-hcd.ignore_oc=
7661 Some badly-designed motherboards generate lots of
7686 unwind_debug [X86-64,EARLY]
7694 (default -1 = authorized (same as 1),
7700 for newly-detected USB devices (default 2). This
7728 [USB] Specifies timeout for the initial 64-byte
7735 [USB] A list of quirk entries to augment the built-in
7738 VendorID:ProductID:Flags. The IDs are 4-digit hex
7740 will change the built-in quirk; setting it if it is
7745 a 255-byte read);
7749 Set-Interface requests);
7768 (bInterval-1).
7806 usb-storage.delay_use=
7813 usb-storage.quirks=
7815 override the built-in unusual_devs list. List
7818 and Product ID values (4-digit hex numbers) and
7820 to a common usb-storage quirk flag as follows:
7862 medium is write-protected).
7871 1 - undefined instruction events
7872 2 - system calls
7873 4 - invalid data aborts
7874 8 - SIGSEGV faults
7875 16 - SIGBUS faults
7884 vdso32= [X86] Control the 32-bit vDSO
7885 vdso32=1: enable 32-bit VDSO
7886 vdso32=0 or vdso32=2: disable 32-bit VDSO
7896 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
7907 will only send out the event without touching backlight
7927 vga= [BOOT,X86-32] Select a particular video mode
7929 Documentation/admin-guide/svga.rst.
7944 - Disable all of the above options
7968 vsyscall= [X86-64,EARLY]
7971 code). Most statically-linked binaries and older
7995 see vga-softcursor.rst. Default: 2 = underline.
8000 This is a 16-member array composed of values
8001 ranging from 0-255.
8006 This is a 16-member array composed of values
8007 ranging from 0-255.
8012 This is a 16-member array composed of values
8013 ranging from 0-255.
8018 Set system-wide default UTF-8 mode for all tty's.
8019 Default is 1, i.e. UTF-8 mode is enabled for all
8024 Format=<-1|0|1>
8025 Set system-wide default for whether a cursor
8026 is shown on new VTs. Default is -1,
8031 vt.italic= [VT] Default color for italic text; 0-15.
8034 vt.underline= [VT] Default color for underlined text; 0-15.
8038 see Documentation/watchdog/watchdog-parameters.rst
8039 or other driver-specific files in the
8053 Format: <cpu-list>
8074 Per-cpu work items which run for longer than this
8077 them from noticeably delaying other per-cpu work
8095 Per-cpu workqueues are generally preferred because
8097 locality; unfortunately, per-cpu workqueues tend to
8100 Enabling this makes the per-cpu workqueues which
8114 Documentation/core-api/workqueue.rst.
8127 forces round-robin CPU selection to flush out
8135 on - Enable writecombine, use WUC for ioremap_wc()
8136 off - Disable writecombine, use SUC for ioremap_wc()
8138 x2apic_phys [X86-64,APIC,EARLY] Use x2apic physical mode instead of
8142 xen_512gb_limit [KNL,X86-64,XEN]
8152 ide-disks -- unplug primary master IDE devices
8153 aux-ide-disks -- unplug non-primary-master IDE devices
8154 nics -- unplug network devices
8155 all -- unplug all emulated devices (NICs and IDE disks)
8156 unnecessary -- unplugging emulated devices is
8159 never -- do not unplug even if version check succeeds
8173 Select whether to always use non-faulting (safe) MSR
8193 xen_timer_slop= [X86-64,XEN,EARLY]
8218 preferred over the 2-level event handling, as it is
8235 xive.store-eoi=off [PPC]
8241 xhci-hcd.quirks [USB,KNL]