Lines Matching +full:arc +full:- +full:timer
38 Documentation/arch/m68k/kernel-options.rst.
48 PARISC The PA-RISC architecture is enabled.
63 the Documentation/scsi/ sub-directory.
83 X86-32 X86-32, aka i386 architecture is enabled.
84 X86-64 X86-64 architecture is enabled.
85 X86 Either 32-bit or 64-bit x86 (same as X86-32+X86-64)
94 KNL Is a kernel start-up parameter.
114 force -- enable ACPI if default was off
115 on -- enable ACPI but allow fallback to DT [arm64,riscv64]
116 off -- disable ACPI if default was on
117 noirq -- do not use ACPI for IRQ routing
118 strict -- Be less tolerant of platforms that are not
120 rsdt -- prefer RSDT over (default) XSDT
121 copy_dsdt -- copy DSDT to memory
122 nocmcff -- Disable firmware first mode for corrected
126 nospcr -- disable console in ACPI SPCR table as
128 spcr -- enable console in ACPI SPCR table as
145 If set to vendor, prefer vendor-specific driver
177 Documentation/firmware-guide/acpi/debug.rst for more information about
243 Format: <byte> or <bitmap-list>
246 Disable auto-serialization of AML methods
249 auto-serialization feature.
267 Ignore the ACPI-based watchdog interface (WDAT) and let
288 acpi_osi=! # disable all built-in OS vendor
290 acpi_osi=!! # enable all built-in OS vendor
352 For broken nForce2 BIOS resulting in XT-PIC timer.
361 as soon as the kernel's real-mode entry point is called.
386 Use timer override. For some broken Nvidia NF5 boards
387 that require a timer override, but don't have HPET
399 See Documentation/sound/alsa-configuration.rst
406 align_va_addr= [X86-64]
411 CPU-intensive style benchmark, and it can vary highly in
414 32: only for 32-bit processes
415 64: only for 64-bit processes
416 on: enable for both 32- and 64-bit processes
417 off: disable for both 32- and 64-bit processes
427 Allow execve() of 32-bit applications and setting of the
429 subset of the CPUs support 32-bit EL0. When this
430 parameter is present, the set of CPUs supporting 32-bit
432 and hot-unplug operations may be restricted.
434 See Documentation/arch/arm64/asymmetric-32bit.rst for more
437 amd_iommu= [HW,X86-64]
440 fullflush - Deprecated, equivalent to iommu.strict=1
441 off - do not initialize any AMD IOMMU found in
443 force_isolation - Force device isolation for all
448 force_enable - Force enable the IOMMU on platforms known
451 pgtbl_v1 - Use v1 page table for DMA-API (Default).
452 pgtbl_v2 - Use v2 page table for DMA-API.
453 irtcachedis - Disable Interrupt Remapping Table (IRT) caching.
454 nohugepages - Limit page-sizes used for v1 page-tables
456 v2_pgsizes_only - Limit page-sizes used for v1 page-tables
460 amd_iommu_dump= [HW,X86-64]
466 amd_iommu_intr= [HW,X86-64]
469 legacy - Use legacy interrupt remapping mode.
470 vapic - Use virtual APIC mode, which allows IOMMU
472 This mode requires kvm-amd.avic=1.
501 Disable amd-pstate preferred core.
506 Disable amd-pstate dynamic EPP.
508 Enable amd-pstate dynamic EPP.
521 Power management functions (SPARCstation-4/5 + deriv.)
523 Disable APC CPU standby support. SPARCstation-Fox does
524 not play well with APC CPU idle - disable it if you have
527 apic [APIC,X86-64] Use IO-APIC. Default.
533 when initialising the APIC and IO-APIC components.
544 apicpmtimer Do APIC timer calibration using the pmtimer. Implies
545 apicmaintimer. Useful when your PIT timer is totally
557 0 -- disable.
558 1 -- enable.
561 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
612 audit= [KNL] Enable the audit sub-system
614 0 | off - kernel audit is disabled and can not be
616 unset - kernel audit is initialized but disabled and
618 1 | on - kernel audit is initialized and partially
631 0 - Disable the BAU.
632 1 - Enable the BAU.
633 unset - Disable the BAU.
655 See Documentation/block/cmdline-partition.rst
669 See Documentation/admin-guide/bootconfig.rst
674 bttv.pll= See Documentation/admin-guide/media/bttv.rst
683 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
702 inclusive. See arch/mips/include/asm/pgtable-bits.h
709 cfi= [X86-64] Set Control Flow Integrity checking features
720 norand: Do not re-randomize CFI hashes.
730 - foo isn't auto-mounted if you mount all cgroups in
732 - foo isn't visible as an individually mountable
734 - if foo is an optional feature then the feature is
740 Specifying "pressure" disables per-cgroup pressure
757 semi-legacy software can check this file to decide
766 nosocket -- Disable socket memory accounting.
767 nokmem -- Disable kernel memory accounting.
768 nobpf -- Disable BPF memory accounting.
772 double-frees, use-after-frees, and other sources of
781 0 -- check protection applied by kernel (includes
783 1 -- check protection requested by application.
795 numbers X. Note the Linux-specific bits are not necessarily
796 stable over kernel options, but the vendor-specific
816 force such clocks to be always-on nor does it reserve
820 information, see Documentation/driver-api/clk.rst.
822 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
839 [X86-32] pit,hpet,tsc;
846 [X86-64] hpet,tsc
852 architected timer so that code using WFE-based polling
866 clocksource-wdtest.holdoff= [KNL]
872 cma=nn[MG]@[start[MG][-end[MG]]]
883 Sets the size of kernel per-numa memory area for
885 per-numa CMA altogether. And If this option is not
887 With per-numa CMA enabled, DMA users on node nid will
914 com20020= [HW,NET] ARCnet - COM20020 chipset
918 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
922 ARCnet - COM90xx chipset (memory-mapped buffers)
951 See Documentation/admin-guide/serial-console.rst for more
966 $ ls -d /sys/bus/serial-base/devices/*:*.*/tty/*
967 /sys/bus/serial-base/devices/00:04:0.0/tty/ttyS0
980 Start an early, polled-mode console on the 8250/16550
983 MMIO inter-register address stride is either 8-bit
984 (mmio), 16-bit (mmio16), or 32-bit (mmio32).
988 the h/w is not re-initialized.
1015 syscall, or to executing "dmesg -S --raw" or to reading
1019 seconds. A value of 0 disables the blank timer.
1039 disable the cpuidle sub-system
1045 disable the cpufreq sub-system
1053 [X86,EARLY] Delay for N microsec between assert and de-assert
1074 like Hyper-V, PowerPC (fadump) and AMD SEV-SNP.
1082 [KNL, X86-64, ARM64, RISCV, LoongArch] Select a region
1085 See Documentation/admin-guide/kdump/kdump.rst for further details.
1090 start-[end] where start and end are both
1092 Documentation/admin-guide/kdump/kdump.rst for an example.
1095 [KNL, X86-64, ARM64, RISCV, LoongArch] range could be
1103 [KNL, X86-64, ARM64, RISCV, LoongArch] range under 4G.
1109 for 32-bit devices won't run out. Kernel would try to allocate
1112 --> x86: max(swiotlb_size_or_default() + 8MiB, 256MiB)
1113 --> arm64: 128MiB
1114 --> riscv: 128MiB
1115 --> loongarch: 128MiB
1145 [KNL] Disable crypto self-tests
1153 csdlock_debug= [KNL] Enable or disable debug add-ons of cross-CPU
1168 See also Documentation/input/devices/joystick-parport.rst
1181 [KNL] verbose locking self-tests
1184 self-tests.
1186 (no extra messages), setting it to -1 (all bits set)
1187 will print _a_lot_ more information - normally only
1225 get a -EPERM as result when trying to register files
1229 Default value is set in build-time with a kernel configuration.
1241 Documentation/admin-guide/mm/hugetlbpage.rst.
1255 delayacct [KNL] Enable per-task delay accounting
1331 Disable PIN 1 of APIC timer
1341 entries for DMA-API debugging code. One entry is
1342 required per DMA-API allocation. Use this if the
1343 DMA-API debugging code disables itself because the
1347 With this option the DMA-API debugging driver
1371 Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst
1374 [KNL] When set to 1, leave the dm-verity keyring
1403 Control how the dt_cpu_ftrs device-tree binding is
1413 what data is available or for reverse-engineering.
1418 Documentation/admin-guide/dynamic-debug-howto.rst
1429 determined by stdout-path property in device tree's
1434 Start an early, polled-mode console on a Cadence
1445 Start an early, polled-mode console on the 8250/16550
1447 MMIO inter-register address stride is either 8-bit
1448 (mmio) or 32-bit (mmio32 or mmio32be).
1458 Start an early, polled-mode console on a pl011 serial
1462 the driver will use only 32-bit accessors to read/write
1471 Start an early, polled-mode console on a meson serial
1477 Start an early, polled-mode console on an msm serial
1483 Start an early, polled-mode console on an msm serial
1489 Start an early, polled-mode console on a serial port
1495 Start an early, polled-mode console on a serial port
1501 Use RISC-V SBI (Supervisor Binary Interface) for early
1519 Start an early, polled-mode console on a lantiq serial
1533 Start an early, polled-mode, output-only console on the
1538 Start an early, polled-mode console on the
1544 Start an early, polled-mode console on a Qualcomm
1552 coherent non-x86 systems that use system memory for
1655 Documentation/admin-guide/acpi/ssdt-overlays.rst for details.
1672 elanfreq= [X86-32]
1680 See Documentation/admin-guide/kdump/kdump.rst for details.
1688 Enable PIN 1 of APIC timer
1696 0 -- permissive (log only, no denials).
1697 1 -- enforcing (deny and log).
1730 See also Documentation/fault-injection/.
1734 See Documentation/admin-guide/sysctl/net.rst for
1738 See Documentation/admin-guide/blockdev/floppy.rst.
1740 forcepae [X86-32]
1747 fred= [X86-64]
1798 ftrace_filter=[function-list]
1800 tracer at boot up. function-list is a comma-separated
1805 ftrace_notrace=[function-list]
1807 function-list. This list can be changed at run time
1811 ftrace_graph_filter=[function-list]
1814 function-list is a comma-separated list of functions
1818 ftrace_graph_notrace=[function-list]
1820 function-list. This list is a comma-separated list of
1840 off -- Don't create device links from firmware info.
1841 permissive -- Create device links from firmware info
1844 on -- Create device links from firmware info and use it
1846 rpm -- Like "on", but also use to order runtime PM.
1859 strict -- Default. Continue waiting on consumers to
1861 timeout -- Give up waiting on consumers and call
1871 See also Documentation/input/devices/joystick-parport.rst
1875 gart_fix_e820= [X86-64,EARLY] disable the fix e820 for K8 GART
1901 gcov_persist= [GCOV] When non-zero (default), profiling data for
1911 gpio-mockup.gpio_mockup_ranges
1914 gpio-mockup.gpio_mockup_named_lines
1946 against bounds-checking flaws in the kernel's
1954 [KNL] Should the hard-lockup detector generate
1970 auto - Hash pointers unless slab_debug is enabled.
1971 always - Always hash pointers (even if slab_debug is
1973 never - Never hash pointers. This option should only
1984 for 64-bit NUMA, off otherwise.
1992 corresponding firmware-first mode error processing
2002 during restoration read-only).
2037 highres= [KNL] Enable/disable high resolution timer mode.
2056 hpet= [X86-32,HPET] option to control HPET usage
2073 number of pages to allocate per-node can be specified.
2074 See also Documentation/admin-guide/mm/hugetlbpage.rst.
2085 Documentation/admin-guide/mm/hugetlbpage.rst.
2095 Note that this parameter only applies to non-gigantic huge pages.
2105 boot-time allocation of gigantic hugepages is skipped.
2138 When set to a non-zero value, a kernel panic will be triggered if
2146 CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time option. The value
2152 hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
2174 Set device-properties for ACPI-enumerated I2C-attached
2175 touchscreen, to e.g. fix coordinates of upside-down
2183 Omit "=<val>" entirely Set a boolean device-property
2184 Unsigned number Set a u32 device-property
2185 Anything else Set a string device-property
2188 i2c_touchscreen_props=GDIX1001:touchscreen-inverted-x:
2189 touchscreen-inverted-y
2191 i2c_touchscreen_props=MSSL1680:touchscreen-size-x=1920:
2192 touchscreen-size-y=1080:touchscreen-inverted-y:
2193 firmware-name=gsl1680-vendor-model.fw:silead,home-button
2198 (disabled by default, and as a pre-condition
2200 i8042.direct [HW] Put keyboard port into non-translated mode
2214 suspend-to-ram transitions, only during s2r
2238 -1 -- never invert brightness
2239 0 -- machine default
2240 1 -- force brightness inversion
2242 ia32_emulation= [X86-64]
2244 When true, allows loading 32-bit programs and executing 32-bit
2269 idle=nomwait: Disable mwait for CPU C-states
2297 legacy only accept legacy-NaN binaries, if supported
2299 2008 only accept 2008-NaN binaries, if supported
2310 'relaxed' straps the emulator for both legacy-NaN and
2311 2008-NaN, whereas 'strict' enables legacy-NaN only on
2320 Ignore loglevel setting - this will print /all/
2387 Formats: { "ima" | "ima-ng" | "ima-ngv2" | "ima-sig" |
2388 "ima-sigv2" }
2389 Default: "ima-ng"
2410 stuff: Deploy RSB-fill mitigation when retpoline is
2415 Documentation/admin-guide/hw-vuln/indirect-target-selection.rst
2426 initcall_blacklist= [KNL] Do not execute a comma-separated list of
2427 initcall functions. Useful for debugging built-in
2472 0 -- basic integrity auditing messages. (Default)
2473 1 -- additional integrity auditing messages.
2501 could harm performance of some high-throughput
2510 1 to 9 specify maximum depth of C-state.
2519 algorithms for p-state selection. There are two
2520 P-state selection algorithms provided by
2523 on whether or not the hardware managed P-states
2530 used along with the hardware-managed P-states (HWP)
2534 in favor of acpi-cpufreq. Forcing the intel_pstate driver
2535 instead of acpi-cpufreq may disable platform features, such
2537 P-States information being indicated to OSPM and therefore
2540 or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
2553 Allow per-logical-CPU P-State performance control limits using
2556 Do not enable capacity-aware scheduling (CAS) on
2559 intremap= [X86-64,Intel-IOMMU,EARLY]
2564 BIOS x2APIC opt-out request will be ignored
2603 AMD Gart HW IOMMU-specific options:
2622 Do scatter-gather (SG) merging. Implies "force"
2626 Don't do scatter-gather (SG) merging.
2639 0 - Try to allocate a 32-bit DMA address first, before
2641 1 - Allocate directly from the full usable range,
2643 greater than 32-bit addressing.
2647 0 - Lazy mode.
2653 1 - Strict mode.
2656 unset - Use value of CONFIG_IOMMU_DEFAULT_DMA_{LAZY,STRICT}.
2658 legacy driver-specific options takes precedence.
2663 0 - Use IOMMU translation for DMA.
2664 1 - Bypass the IOMMU for DMA.
2665 unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
2673 0 - Sanitizer disabled.
2674 1 - Sanitizer enabled, expect runtime overhead.
2676 io7= [HW] IO7 for Marvel-based Alpha systems
2691 See Documentation/admin-guide/nfs/nfsroot.rst.
2727 Enables support for pseudo-NMIs in the kernel. This
2732 [RISC-V,EARLY]
2734 as IPIs. Intended for system where IMSIC is trap-n-emulated,
2746 long-running IRQs in the system.
2750 for it. Also check all handlers each timer
2758 [Deprecated - use cpusets instead]
2759 Format: [flag-list,]<cpu-list>
2792 "number of CPUs in system - 1".
2818 The format of <cpu-list> is described above.
2822 ivrs_ioapic [HW,X86-64]
2823 Provide an override to the IOAPIC-ID<->DEVICE-ID
2827 For example, to map IOAPIC-ID decimal 10 to
2833 * To map IOAPIC-ID decimal 10 to PCI device 00:14.0
2836 * To map IOAPIC-ID decimal 10 to PCI segment 0x1 and
2840 ivrs_hpet [HW,X86-64]
2841 Provide an override to the HPET-ID<->DEVICE-ID
2845 For example, to map HPET-ID decimal 10 to
2851 * To map HPET-ID decimal 0 to PCI device 00:14.0
2854 * To map HPET-ID decimal 10 to PCI segment 0x1 and
2858 ivrs_acpihid [HW,X86-64]
2859 Provide an override to the ACPI-HID:UID<->DEVICE-ID
2863 For example, to map UART-HID:UID AMD0020:0 to
2869 * To map UART-HID:UID AMD0020:0 to PCI segment is 0,
2872 * To map UART-HID:UID AMD0020:0 to PCI segment 0x1 and
2896 the kernel for non-movable allocations. The requested
2906 subsystem. Note that allocations like PTEs-from-HighMem
2914 for non-movable allocations and remaining memory is used
2925 [MM,KFENCE] Whether to check all KFENCE-managed objects'
2931 [MM,KFENCE] Whether to use a deferrable timer to trigger
2932 allocations. This avoids forcing CPU wake-ups if the
2940 report - print the error report and continue (default).
2941 oops - print the error report and oops.
2942 panic - print the error report and panic.
2947 0 - Disable KFENCE.
2948 >0 - Enabled KFENCE with given sample interval.
2966 gdb or control-c on the dbgp connection. When
2967 not using this parameter you use sysrq-g to break into
2972 or a supported polling keyboard driver (non-usb).
3001 "0" | "off" | "n" - kexec handover is disabled
3002 "1" | "on" | "y" - kexec handover is enabled
3008 ranges that can only be used for non-kernel
3019 parameter defines the size of additional per-node
3024 Configure the RouterBoard 532 series on-chip
3027 kmemleak= [KNL,EARLY] Boot-time kmemleak enable/disable
3033 kprobe_event=[probe-list]
3035 The probe-list is a semicolon delimited list of probe
3065 execution by eliminating the write-protection faults
3089 can be overridden on a per-VM basis via
3097 with an in-kernel local APIC, e.g. to deliver PMIs to
3098 the guest. Running without an in-kernel local APIC is
3112 virtualization on-demand when creating and destroying
3120 is that doing so may interfere with using out-of-tree
3147 back to huge pages. If the value is a non-zero N, KVM will
3152 kvm-{amd,intel}.enable_mediated_pmu=[KVM,AMD,INTEL]
3154 instead of the default perf-based virtual PMU (if
3158 With a perf-based vPMU, KVM operates as a user of perf,
3160 KVM-created perf events are managed by perf as regular
3161 (guest-only) events, e.g. are scheduled in/out, contend
3162 for hardware resources, etc. Using a perf-based vPMU
3163 allows guest and host usage of the PMU to co-exist, but
3164 incurs non-trivial overhead and can result in silently
3176 to profile KVM guests and adds latency to most VM-Exits
3181 kvm-amd.nested= [KVM,AMD] Control nested virtualization feature in
3184 kvm-amd.npt= [KVM,AMD] Control KVM's use of Nested Page Tables,
3185 a.k.a. Two-Dimensional Page Tables. Default is 1
3189 kvm-amd.ciphertext_hiding_asids=
3194 If ciphertext hiding is enabled, the joint SEV-ES and
3195 SEV-SNP ASID space is partitioned into separate SEV-ES
3196 and SEV-SNP ASID ranges, with the SEV-SNP range being
3197 [1..max_snp_asid] and the SEV-ES range being
3201 A non-zero value enables SEV-SNP ciphertext hiding and
3202 adjusts the ASID ranges for SEV-ES and SEV-SNP guests.
3203 KVM caps the number of SEV-SNP ASIDs at the maximum
3204 possible value, e.g. specifying -1u will assign all
3205 joint SEV-ES and SEV-SNP ASIDs to SEV-SNP. Note,
3206 assigning all joint ASIDs to SEV-SNP, i.e. configuring
3207 max_snp_asid == min_sev_asid-1, will effectively make
3208 SEV-ES unusable.
3210 kvm-arm.mode=
3216 nvhe: Standard nVHE-based mode, without support for
3223 nested: VHE-based mode with support for nested
3231 command-line.
3235 kvm-arm.vgic_v3_group0_trap=
3236 [KVM,ARM,EARLY] Trap guest accesses to GICv3 group-0
3239 kvm-arm.vgic_v3_group1_trap=
3240 [KVM,ARM,EARLY] Trap guest accesses to GICv3 group-1
3243 kvm-arm.vgic_v3_common_trap=
3247 kvm-arm.vgic_v4_enable=
3251 kvm-arm.wfe_trap_policy=
3260 kvm-arm.wfi_trap_policy=
3277 kvm-intel.ept= [KVM,Intel] Control KVM's use of Extended Page Tables,
3278 a.k.a. Two-Dimensional Page Tables. Default is 1
3282 kvm-intel.emulate_invalid_guest_state=
3284 state. Ignored if kvm-intel.enable_unrestricted_guest=1,
3290 kvm-intel.flexpriority=
3295 kvm-intel.nested=
3299 kvm-intel.unrestricted_guest=
3305 kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
3306 CVE-2018-3620.
3317 kvm-intel.vpid= [KVM,Intel] Control KVM's use of Virtual Processor
3337 on - enable the interface for the mitigation
3402 For details see: Documentation/admin-guide/hw-vuln/l1tf.rst
3408 lapic [X86-32,APIC,EARLY] Enable the local APIC even if BIOS
3412 value for LAPIC timer one-shot implementation. Default
3413 back to the programmable timer unit in the LAPIC.
3416 lapic_timer_c2_ok [X86,APIC,EARLY] trust the local apic timer
3435 libata.force= [LIBATA] Force configurations. The format is a comma-
3447 first fan-out link behind PMP device. It does not
3461 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
3468 * rstonce: only attempt one reset during hot-unplug
3504 number of 512-byte sectors, to the value specified in
3506 a non-zero positive integer.
3516 * external: Mark port as external (hotplug-capable).
3573 Specify the number of self-propagating call_rcu()
3581 occasional long-duration lock hold time. Defaults
3592 Set the number of locking read-acquisition kthreads.
3597 Set the number of locking write-acquisition kthreads.
3600 Set time (s) after boot for CPU-hotplug testing.
3603 Set time (s) between CPU-hotplug operations, or
3604 zero to disable CPU-hotplug testing.
3607 Do periodic testing of real-time lock priority
3612 non-real-time spinlocks, due to their disabling
3613 of preemption. Note that non-realtime mutexes
3626 Set task-shuffle interval (jiffies). Shuffling
3627 tasks allows some CPUs to go into dyntick-idle
3632 is useful for hands-off automated testing.
3651 Run the write-side locktorture kthreads at
3652 sched_set_fifo() real-time priority.
3670 7 (KERN_DEBUG) debug-level messages
3682 logo.nologo [FB] Disables display of the built-in Linux logo.
3700 an IEEE 1284-compliant printer is attached; if
3706 time-consuming boot-time autodetection (up to 250 ms per
3726 Example: machtype=lemote-yeeloong-2f-7inch
3738 (loop.max_loop) unconditionally pre-created at init time. The default
3741 devices can be requested on-demand with the
3742 /dev/loop-control interface.
3744 mce= [X86-{32,64}]
3769 polling timer and CMCI. All events reported as
3781 do not opt-in to Local MCE delivery. Use legacy method
3802 don't overwrite the bios-set CMCI threshold. This boot
3811 force-enable recoverable machine check code paths
3817 See Documentation/admin-guide/md.rst.
3824 Control mitigation for the Micro-architectural Data
3839 full - Enable MDS mitigation on vulnerable CPUs
3840 full,nosmt - Enable MDS mitigation and disable
3842 off - Unconditionally disable MDS mitigation
3844 On TAA-affected machines, mds=off can be prevented by
3853 For details see: Documentation/admin-guide/hw-vuln/mds.rst
3868 [ARC,MICROBLAZE] - the limit applies only to low memory,
3871 [ARM64] - only limits memory covered by the linear
3884 [ARM,MIPS,EARLY] - override the memory layout
3891 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
3898 per-device physically contiguous DMA buffers.
3906 See Documentation/admin-guide/mm/memory-hotplug.rst.
3931 Example: Exclude memory from 0x18690000-0x1869ffff
3945 memmap=<size>%<offset>-<oldtype>+<newtype>
3947 from <oldtype> to <newtype>. If "-<oldtype>" is left
3962 repeatable BIOS-originated corruption always
4006 mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control
4012 Refer to Documentation/virt/kvm/x86/amd-memory-encryption.rst
4016 s2idle - Suspend-To-Idle
4017 shallow - Power-On Suspend or equivalent (if supported)
4018 deep - Suspend-To-RAM or equivalent (if supported)
4019 See Documentation/admin-guide/pm/sleep-states.rst.
4021 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
4031 base_rev=X - with <X> with format: <u32>
4045 0 - The attached screen is the 3.5" TFT
4046 1 - The attached screen is the 7" TFT
4047 2 - The VGA Shield is attached (1024x768)
4051 b - Enable backlight. The TFT backlight pin will be
4055 c - Enable the s3c camera interface.
4056 t - Reserved for enabling touchscreen support. The
4060 https://repo.or.cz/w/linux-2.6/mini2440.git
4065 arch-independent options, each of which is an
4066 aggregation of existing arch-specific options.
4096 ssbd=force-off [ARM64]
4111 have other ways of avoiding SMT-based attacks.
4125 supports attack-vector based controls as documented in
4126 Documentation/admin-guide/hw-vuln/attack_vector_controls.rst
4150 full - Enable mitigation on vulnerable CPUs
4152 full,nosmt - Enable mitigation and disable SMT on
4155 off - Unconditionally disable mitigation
4168 Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst
4198 module_blacklist= [KNL] Do not load a comma-separated list of
4223 movable_node [KNL,EARLY] Boot-time switch to make hotplugable memory
4230 Format: <name>,<region-number>,<size>,<offset>
4233 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
4272 something different and driver-specific.
4312 [NFS] enable 64-bit inode numbers.
4313 If zero, the NFS client will fake up a 32-bit inode
4315 of returning the full 64-bit number.
4316 The default is to return 64-bit inode numbers.
4351 [NFS4] Specify an additional fixed unique ident-
4382 driver. A non-zero value sets the minimum interval
4387 server-to-server copies for which this server is
4399 server-to-server copy, knfsd temporarily mounts
4406 See Documentation/admin-guide/nfs/nfsroot.rst.
4408 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
4409 See Documentation/admin-guide/nfs/nfsroot.rst.
4412 See Documentation/admin-guide/nfs/nfsroot.rst.
4416 NMI stack-backtrace request.
4425 0 - turn hardlockup detector in nmi_watchdog off
4426 1 - turn hardlockup detector in nmi_watchdog on
4427 rNNN - configure the watchdog with raw perf event 0xNNN
4440 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
4444 no4lvl [RISCV,EARLY] Disable 4-level and 5-level paging modes.
4445 Forces kernel to use 3-level paging instead.
4447 no5lvl [X86-64,RISCV,EARLY] Disable 5-level paging mode. Forces
4448 kernel to use 4-level paging instead.
4455 noapictimer [APIC,X86] Don't set up the APIC timer
4483 no_entry_flush [PPC,EARLY] Don't flush the L1-D cache when entering the kernel.
4485 noexec32 [X86-64]
4486 This affects only 32-bit executables.
4487 noexec32=on: enable non-executable mappings (default)
4489 noexec32=off: disable non-executable mappings
4500 nofxsr [BUGS=X86-32] Disables x86 floating point extended
4502 legacy floating-point registers on task switch.
4521 nohpet [X86] Don't use the HPET timer.
4549 nointremap [X86-64,Intel-IOMMU,EARLY] Do not enable interrupt
4551 [Deprecated - use intremap=off]
4557 noirqdebug [X86-32] Disables the code which attempts to detect and
4567 no-kvmapf [X86,KVM,EARLY] Disable paravirtualized asynchronous page
4570 no-kvmclock [X86,KVM,EARLY] Disable paravirtualized KVM clock driver
4572 nolapic [X86-32,APIC,EARLY] Do not enable or use the local APIC.
4574 nolapic_timer [X86-32,APIC,EARLY] Do not use the local APIC timer.
4576 nomce [X86-32] Disable Machine Check Exception
4578 nomfgpt [X86-32] Disable Multi-Function General Purpose
4579 Timer usage (for AMD Geode machines).
4584 not load if they could possibly displace the pre-
4587 perform display-mode changes or accelerated rendering.
4600 nopcid [X86-64,EARLY] Disable the PCID cpu feature.
4605 nopti [X86-64,EARLY]
4621 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
4627 no-scroll [VGA] Disables scrollback.
4628 This is required for the Braillex ib80-piezo Braille
4631 nosgx [X86-64,SGX,EARLY] Disables Intel SGX kernel support.
4651 nosoftlockup [KNL] Disable the soft-lockup detector.
4657 nospectre_bhb [ARM64,EARLY] Disable all mitigations for Spectre-BHB (branch
4670 no-steal-acc [X86,PV_OPS,ARM64,PPC/PSERIES,RISCV,LOONGARCH,EARLY]
4677 timer IRQ sources, i.e., the IO-APIC timer. This can
4678 work around problems with incorrect timer
4682 [PPC,EARLY] Don't flush the L1-D cache after accessing user data.
4695 no-vmw-sched-clock
4700 soft-lockup and NMI watchdog (hard-lockup).
4704 nox2apic [X86-64,APIC,EARLY] Do not enable x2APIC mode.
4712 enabling legacy floating-point and sse state.
4734 n. So during boot up some boot time memory for per-cpu
4735 variables need be pre-allocated for later physical cpu
4762 soft-reserved memory partitioning.
4771 See Documentation/admin-guide/sysctl/vm.rst for details.
4773 nvme.quirks= [NVME] A list of quirk entries to augment the built-in
4775 '-' character.
4777 The IDs are 4-digits hex numbers and quirk_names is a
4783 nvme.quirks=7710:2267:bogus_nid,^identify_cns-9900:7711:broken_msi
4786 See Documentation/core-api/debugging-via-ohci1394.rst for more
4801 onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
4805 boundary - index of last SLC block on Flex-OneNAND.
4807 lock - Configure if Flex-OneNAND boundary should be locked.
4826 page_owner= [KNL,EARLY] Boot-time page_owner enabling option.
4832 page_poison= [KNL,EARLY] Boot-time parameter changing the state of
4860 See Documentation/admin-guide/tainted-kernels.rst for
4873 constraints, or platform-specific requirements where only
4886 bit 2: print timer info
4947 Set to non-zero to probe primary and secondary ISA
4953 Set to non-zero if a chip is present that snoops speed
5001 Set to non-zero to probe tertiary and further ISA
5017 Set to non-zero to probe QDI controllers. By default
5022 Set to non-zero to probe Winbond controllers. Use
5069 bios [X86-32] force use of PCI BIOS, don't access
5071 has a non-standard PCI host bridge.
5072 nobios [X86-32] disallow use of PCI BIOS, only direct
5078 data in IO port 0xCFC, both 32-bit).
5080 Mechanism 2 (IO port 0xCF8 is an 8-bit port for
5081 the function, IO port 0xCFA, also 8-bit, sets
5083 through ports 0xC000-0xCFFF).
5090 root domains (aka PCI segments, in ACPI-speak).
5098 disable the use of MSI interrupts system-wide.
5103 primary IO-APIC for bridges that cannot disable
5110 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
5134 F0000h-100000h range.
5139 assign-busses [X86] Always assign all PCI bus
5160 <linux-pci@vger.kernel.org>.
5164 a bug to <linux-pci@vger.kernel.org>.
5176 bfsort Sort PCI devices into breadth-first order.
5179 nobfsort Don't sort PCI devices into breadth-first order.
5181 tuning and use the BIOS-configured MPS defaults.
5191 configuration allows peer-to-peer DMA between
5194 that hot-added devices will work.
5209 A PCI-PCI bridge can be specified if resource
5215 for 4096-byte alignment.
5217 end-to-end CRC checking). Only effective if
5248 noats [PCIE, Intel-IOMMU, AMD-IOMMU]
5279 bit-0 : ACS Source Validation
5280 bit-1 : ACS Translation Blocking
5281 bit-2 : ACS P2P Request Redirect
5282 bit-3 : ACS P2P Completion Redirect
5283 bit-4 : ACS Upstream Forwarding
5284 bit-5 : ACS P2P Egress Control
5285 bit-6 : ACS Direct Translated P2P
5295 Validation unchanged from whatever power-up
5307 system-wide.
5321 dpc-native Use native PCIe service for DPC only. May
5338 Keep all power-domains already enabled by bootloader on,
5356 pirq= [SMP,APIC] Manual mp-table setup
5357 See Documentation/arch/x86/i386/IO-APIC.rst.
5361 See also Documentation/admin-guide/parport.rst.
5380 resume of devices during system-wide power transitions.
5382 dependencies are not well-defined, or for debugging
5392 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
5401 { on | off | curr | res | no-curr | no-res }
5446 none - Limited to cond_resched() calls
5447 voluntary - Limited to cond_resched() and might_sleep() calls
5448 full - Any section that isn't explicitly preempt disabled
5452 lazy - Scheduler controlled. Similar to full but instead
5458 print-fatal-signals=
5464 coredump - etc.
5467 you might want to try "ulimit -i unlimited".
5479 or lockdep-detected issues (only if lock debug is on).
5487 Allows storing messages from non-panic CPUs into
5489 flushed to consoles by the panic-CPU on
5490 a best-effort basis.
5496 on - unlimited logging to /dev/kmsg from userspace
5497 off - logging to /dev/kmsg disabled
5498 ratelimit - ratelimit the logging
5509 - 'always': traditional behavior always allows mem overrides.
5510 - 'ptrace': only allow mem overrides for active ptracers.
5511 - 'never': never allow mem overrides.
5515 Limit processor to maximum C-state
5519 Ignore the _CST method to determine C-states,
5526 Param: "schedule" - profile schedule points.
5527 Param: "kvm" - profile VM exits.
5528 Param: <number> - step/bucket size as a power of 2 for
5557 pti= [X86-64] Control Page Table Isolation of user and
5562 on - unconditionally enable
5563 off - unconditionally disable
5564 auto - kernel detects whether your CPU model is
5570 [KNL] Number of legacy pty's. Overwrites compiled-in
5582 See Documentation/admin-guide/md.rst.
5585 See Documentation/admin-guide/blockdev/ramdisk.rst.
5604 cross-syscall address exposures. This is only
5610 ras=option[,option,...] [KNL] RAS-specific options
5616 rcu_nocbs[=cpu-list]
5621 enable the no-callback CPU mode, which prevents
5626 "p" for RCU-preempt, "s" for RCU-sched, and "g"
5630 and real-time workloads. It can also improve
5634 list of CPUs is set to no-callback mode from boot.
5638 no-callback mode from boot but the mode may be
5649 This improves the real-time response for the
5660 Do only a one-line RCU CPU stall warning when
5661 there is an ongoing too-long CSD-lock wait.
5667 If triggered before the RCU grace-period machinery
5677 RCU grace-period cleanup.
5681 RCU grace-period initialization.
5685 RCU grace-period pre-initialization, that is,
5686 the propagation of recent CPU-hotplug changes up
5690 Set delay from grace-period initialization to
5703 soliciting quiescent-state help from
5715 Set the SCHED_FIFO priority of the RCU per-CPU
5718 and for the RCU grace-period kthreads (rcu_bh,
5720 set, valid values are 1-99 and the default is 1
5721 (the least-favored priority). Otherwise, when
5722 RCU_BOOST is not set, valid values are 0-99 and
5723 the default is zero (non-realtime operation).
5728 On callback-offloaded (rcu_nocbs) CPUs,
5731 use of the ->nocb_bypass list. However, in the
5732 common non-flooded case, RCU queues directly to
5733 the main ->cblist in order to avoid the extra
5734 overhead of the ->nocb_bypass list and its lock.
5736 a single jiffy, RCU pre-queues the callbacks into
5737 the ->nocb_bypass queue. The definition of "too
5741 On callback-offloaded (rcu_nocbs) CPUs, avoid
5754 batch limiting is re-enabled.
5758 RCU's force-quiescent-state scan will aggressively
5766 Set the page-cache refill delay (in milliseconds)
5767 in response to low-memory conditions. The range
5771 Set the shift-right count to use to compute
5772 the callback-invocation batch limit bl from
5779 Please note that this callback-invocation batch
5780 limit applies only to non-offloaded callback
5789 cache-to-cache transfer latencies.
5795 and for NUMA systems with large remote-access
5811 the wakeup overhead on the global grace-period
5813 each group's NOCB grace-period kthread.
5816 Cause the grace-period kthread to get an extra
5818 it should at force-quiescent-state time.
5831 this specifies an rcu_read_unlock()-time delay
5835 of RCU-protected pointers after the relevant
5845 per-CPU rcuc kthreads. Defaults to a non-zero
5875 grace-period primitives such as call_rcu().
5886 grace-period primitives.
5889 Set test-start holdoff period. The purpose of
5907 Test the double-argument variant of kfree_rcu().
5909 rcuscale.kfree_rcu_test_single, both the single-
5910 and double-argument variants are tested.
5913 Test the single-argument variant of kfree_rcu().
5915 rcuscale.kfree_rcu_test_double, both the single-
5916 and double-argument variants are tested.
5930 does not affect the data-collection interval,
5935 Set number of RCU readers. The value -1 selects
5937 "n" less than -1 selects N-n+1, where N is again
5938 the number of CPUs. For example, -2 selects N
5939 (the number of CPUs), -3 selects N+1, and so on.
5940 A value of "n" less than or equal to -N selects
5953 complete. This is useful for hands-off automated
5960 Write-side holdoff between grace periods,
5965 Additional write-side holdoff between grace
5983 for RCU grace-period forward-progress testing
5990 Specify the fraction of a CPU-stall-warning
5991 period to do tight-loop forward-progress testing.
5995 forward-progress tests.
5999 need_resched() during tight-loop forward-progress
6003 Use conditional/asynchronous update-side
6004 normal-grace-period primitives, if available.
6007 Use conditional/asynchronous update-side
6008 expedited-grace-period primitives, if available.
6011 Use conditional/asynchronous update-side
6012 normal-grace-period primitives that also take
6017 Use conditional/asynchronous update-side
6018 expedited-grace-period primitives that also take
6042 Use expedited update-side primitives, if available.
6045 Use normal (non-expedited) asynchronous
6046 update-side primitives, if available.
6049 Use polled update-side normal-grace-period
6053 Use polled update-side expedited-grace-period
6057 Use polled update-side normal-grace-period
6062 Use polled update-side expedited-grace-period
6086 Use normal (non-expedited) synchronous
6087 update-side primitives, if available. If all
6091 they are all non-zero.
6094 Enable grace-period wrap lag testing. Setting
6099 Set the value for grace-period wrap lag during
6114 the grace-period wrap lag will be set to the
6120 accurately, from a timer handler. Not all RCU
6124 Leak an RCU-protected pointer out of the reader.
6139 Set number of RCU callback-offload togglers.
6144 callback-offload toggling attempts.
6147 Set number of RCU readers. The value -1 selects
6148 N-1, where N is the number of CPUs. A value
6149 "n" less than -1 selects N-n-2, where N is again
6150 the number of CPUs. For example, -2 selects N
6151 (the number of CPUs), -3 selects N+1, and so on.
6154 Enable debug-object double-call_rcu() testing.
6157 Set time (s) after boot for CPU-hotplug testing.
6160 Set time (jiffies) between CPU-hotplug operations,
6161 or zero to disable CPU-hotplug testing.
6165 by a high-priority FIFO real-time task. Set to
6174 second) between preemptions by a high-priority
6175 FIFO real-time task. This delay is mediated
6180 The number of times in a given read-then-exit
6181 episode that a set of read-then-exit kthreads
6186 read-then-exit testing episodes.
6191 are entered from low-order bit up, and are
6193 0x1 bit is normal readers, 0x2 NMI-safe readers,
6194 and 0x4 light-weight readers.
6197 Set task-shuffle interval (s). Shuffling tasks
6198 allows some CPUs to go into dyntick-idle mode
6203 is useful for hands-off automated testing.
6212 any other stall-related activity. Note that
6218 in scheduling-while-atomic splats.
6237 grace-period kthread to test RCU CPU stall
6261 of RCU priority-boost testing. Defaults to zero,
6268 Test RCU's dyntick-idle handling. See also the
6306 adjusted to an arch timer tick resolution.
6323 Use expedited grace-period primitives, for
6327 real-time latency, and degrade energy efficiency.
6331 Use only normal grace-period primitives,
6334 real-time latency, CPU utilization, and
6336 increased grace-period latency. This parameter
6343 only normal grace-period primitives. No effect
6349 post-boot attempt at an expedited RCU grace
6350 period to instead use normal non-expedited
6351 grace-period processing.
6359 set to the default value of -1.
6362 Set the minimum number of callback-queuing-time
6363 lock-contention events per jiffy required to
6364 cause the RCU Tasks flavors to switch to per-CPU
6367 the default value of -1.
6372 of -1 allows this to be automatically (and
6378 cancel laziness on that CPU. Use -1 to disable
6388 only printed prior to the stall-warning message
6428 force - Override the decision by the kernel to hide the
6472 There are some built-in platform specific "quirks"
6473 - you may see: "reboot: <name> series board detected.
6477 built-in quirk table, and use the generic default
6510 Set test-start holdoff period. The purpose of
6525 but the default has already reduced the per-pass
6530 Set number of readers. The default value of -1
6539 Set the read-side critical-section duration,
6543 Specify the read-protection implementation to test.
6569 See Documentation/admin-guide/cgroup-v1/cpusets.rst.
6599 reservetop= [X86-32,EARLY]
6616 See Documentation/power/swsusp-and-swap-files.rst
6632 AMD-based UNRET and IBPB mitigations alone do not stop
6634 sibling threads. For that reason, STIBP is used on pro-
6638 off - no mitigation
6639 auto - automatically select a mitigation
6640 auto,nosmt - automatically select a mitigation,
6644 ibpb - On AMD, mitigate short speculation
6649 ibpb,nosmt - Like "ibpb" above but will disable SMT
6653 unret - Force enable untrained return thunks,
6654 only effective on AMD f15h-f17h based
6656 unret,nosmt - Like unret, but will disable SMT when STIBP
6696 ro [KNL] Mount root device read-only on boot
6699 on Mark read-only kernel memory as read-only (default).
6700 off Leave read-only kernel memory writable for debugging.
6701 noalias Mark read-only kernel memory as read-only but retain
6709 debug-uart get routed to the D+ and D- pins of the usb
6715 block/early-lookup.c for details.
6757 rw [KNL] Mount root device read-write on boot
6786 solution to mutex-based priority inversion.
6816 to 10 seconds for built-in smp_call_function()
6823 that requesting even small non-zero numbers of
6830 The default of -1 specifies a number of kthreads
6835 test before initiating CPU-hotplug operations.
6839 CPU-hotplug operations. Specifying zero (which
6840 is the default) disables CPU-hotplug operations.
6846 Non-zero values are useful for automated tests.
6869 "wait" parameter. A value of -1 selects the
6870 default if all other weights are -1. However,
6872 value of -1 will instead select a weight of zero.
6877 non-zero "wait" parameter. See weight_single.
6890 non-zero "wait" parameter. See weight_single
6902 non-zero "wait" parameter. See weight_single
6909 skew_tick= [KNL,EARLY] Offset the periodic timer tick per cpu to mitigate
6913 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
6914 1 -- enable.
6925 0 -- disable.
6926 1 -- enable.
6929 serialnumber [BUGS=X86-32]
6931 sev=option[,option...] [X86-64]
6937 Do not enable SEV-SNP (applies to host/hypervisor
6940 SEV-SNP guests.
6948 to set it to "all" by meaning -- no limit here.
6960 Documentation/admin-guide/mm/slab.rst.
6971 Documentation/admin-guide/mm/slab.rst.
6987 Documentation/admin-guide/mm/slab.rst.
6993 Documentation/admin-guide/mm/slab.rst.
7008 Documentation/admin-guide/mm/slab.rst.
7035 using the csdlock_debug- kernel parameter.
7040 system. By default, let CSD-lock acquisition
7042 for this value provides a 5-minute timeout.
7044 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
7045 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
7046 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
7047 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
7048 smsc-ircc2.ircc_irq= [HW] IRQ line
7049 smsc-ircc2.ircc_dma= [HW] DMA channel
7050 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
7060 Default: -1 (no limit)
7063 [KNL] Should the soft-lockup detector generate panics.
7066 A value of non-zero instructs the soft-lockup detector
7067 to panic the machine when a soft-lockup duration exceeds
7070 respective build-time switch to that functionality.
7073 [KNL] Should the soft-lockup detector generate
7078 See Documentation/admin-guide/laptops/sonypi.rst
7085 on - (default) Enable the HW or SW mitigation as
7088 vmexit - On systems which don't have the HW mitigation
7091 protected from VM-originated BHI attacks, but
7093 off - Disable the mitigation.
7100 on - unconditionally enable, implies
7102 off - unconditionally disable, implies
7104 auto - kernel detects whether your CPU model is
7123 retpoline - replace indirect branches
7124 retpoline,generic - Retpolines
7125 retpoline,lfence - LFENCE; indirect branch
7126 retpoline,amd - alias for retpoline,lfence
7127 eibrs - Enhanced/Auto IBRS
7128 eibrs,retpoline - Enhanced/Auto IBRS + Retpolines
7129 eibrs,lfence - Enhanced/Auto IBRS + LFENCE
7130 ibrs - use IBRS to protect kernel
7140 on - Unconditionally enable mitigations. Is
7143 off - Unconditionally disable mitigations. Is
7146 prctl - Indirect branch speculation is enabled,
7152 - Like "prctl" above, but only STIBP is
7158 - Same as "prctl" above, but all seccomp
7163 - Like "seccomp" above, but only STIBP is
7168 auto - Kernel selects the mitigation depending on
7179 off - Disable mitigation
7180 microcode - Enable microcode mitigation only
7181 safe-ret - Enable sw-only safe RET mitigation (default)
7182 ibpb - Enable mitigation by issuing IBPB on
7184 ibpb-vmexit - Issue IBPB only on VMEXIT
7185 (cloud-specific mitigation)
7210 on - Unconditionally disable Speculative Store Bypass
7211 off - Unconditionally enable Speculative Store Bypass
7212 auto - Kernel detects whether the CPU model contains an
7218 prctl - Control Speculative Store Bypass per thread
7222 seccomp - Same as "prctl" above, but all seccomp threads
7230 on,auto - On Power8 and Power9 insert a store-forwarding
7234 off - No action.
7248 off - not enabled
7250 warn - the kernel will emit rate-limited warnings
7258 fatal - the kernel will send SIGBUS to applications
7263 ratelimit:N -
7283 Certain CPUs are vulnerable to an MDS-like
7303 This kernel-boot parameter defaults to 128,
7304 but takes effect only when the low-order four
7321 instead of the compile-time CONFIG_NR_CPUS.
7325 grace-period sequence counter wrap for the
7326 srcu_data structure's ->srcu_gp_seq_needed field.
7341 Specifies the number of no-delay instances
7348 Specifies the per-grace-period phase, number of
7349 non-sleeping polls of readers. Beyond this limit,
7355 Specifies number of microseconds of non-sleeping
7356 delay between each non-sleeping poll of readers.
7359 Specifies the number of update-side contention
7364 set for contention-based conversions to occur.
7374 force-on: Unconditionally enable mitigation for
7376 force-off: Unconditionally disable mitigation for
7398 stack traces. Pools are allocated on-demand up to this
7404 stacktrace_filter=[function-list]
7406 will trace at boot up. function-list is a comma-separated
7414 Set the STI (builtin display/keyboard on the HP-PARISC
7416 as the initial boot-console.
7479 to global on non-NUMA machines)
7504 <int> -- Number of I/O TLB slabs
7505 <int> -- Second integer after comma. Number of swiotlb
7508 force -- force using of bounce buffers even if they
7510 noforce -- Never use bounce buffers (for debugging)
7525 Ignore sysrq setting - this boot parameter will
7533 cache size. See Documentation/networking/ip-sysctl.rst
7540 Specify "mem" (for Suspend-to-RAM) or "standby" (for
7545 wakeup-capable RTC alarm.
7551 -1: disable all active trip points in all thermal zones
7555 -1: disable all critical trip points in all thermal zones
7562 -1: disable all passive trip points
7568 <deci-seconds>: poll all this frequency
7572 Format: <size>[KMG],<size>[KMG]:<state>;<size>[KMG]-<size>[KMG]:<state>
7577 See Documentation/admin-guide/mm/transhuge.rst for more
7585 Format: <size>[KMG],<size>[KMG]:<policy>;<size>[KMG]-<size>[KMG]:<policy>
7591 See Documentation/admin-guide/mm/transhuge.rst for more
7603 Prevent the CPU-hotplug component of torturing
7607 Dump the ftrace buffer at torture-test shutdown,
7611 with rotating-rust storage.
7616 disables verbose-printk() sleeping.
7619 Duration of each verbose-printk() sleep in jiffies.
7652 https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/
7690 local - Use the per CPU time stamp counter
7694 global - Event time stamps are synchronized across
7697 counter - Simple counting of events (1, 2, ..)
7701 uptime - Use jiffies as the time stamp.
7702 perf - Use the same clock that perf uses.
7703 mono - Use ktime_get_mono_fast_ns() for time stamps.
7704 mono_raw - Use ktime_get_raw_fast_ns() for time
7706 boot - Use ktime_get_boot_fast_ns() for time stamps.
7710 trace_event=[event-list]
7712 to facilitate early boot debugging. The event-list is a
7713 comma-separated list of trace events to enable. See
7724 trace_instance=[instance-info]
7749 traceoff - Have the tracing instance tracing disabled after it is created.
7750 traceprintk - Have trace_printk() write into this trace instance
7797 trace_options=[option-list]
7799 The option-list is a comma delimited list of options
7813 trace_trigger=[trigger-list]
7859 See Documentation/admin-guide/mm/transhuge.rst
7866 See Documentation/admin-guide/mm/transhuge.rst
7873 See Documentation/admin-guide/mm/transhuge.rst
7881 - "tpm"
7882 - "tee"
7883 - "caam"
7884 - "dcp"
7885 - "pkwm"
7895 - "kernel"
7896 - the same value as trusted.source: "tpm" or "tee"
7897 - "default"
7920 off - disable the mitigation
7921 on - enable the mitigation (default)
7922 user - mitigate only user/kernel transitions
7923 vm - mitigate only guest/host transitions
7931 high-resolution timer mode on older hardware, and in
7944 [x86] recalibrate: force recalibration against a HW timer
7945 (HPET or PM timer) on systems whose TSC frequency was
7962 on - Enable TSX on the system. Although there are
7965 several previous speculation-related CVEs, and
7969 off - Disable TSX on the system. (Note that this
7977 auto - Disable TSX if X86_BUG_TAA is present,
7982 See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
7988 Similar to Micro-architectural Data Sampling (MDS)
8003 full - Enable TAA mitigation on vulnerable CPUs
8006 full,nosmt - Enable TAA mitigation and disable SMT on
8009 vulnerable to cross-thread TAA attacks.
8010 off - Unconditionally disable TAA mitigation
8012 On MDS-affected machines, tsx_async_abort=off can be
8024 Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
8030 See also Documentation/input/devices/joystick-parport.rst
8032 udbg-immortal [PPC] When debugging early kernel crashes that
8038 Set number of hash buckets for UDP/UDP-Lite connections
8040 uhci-hcd.ignore_oc=
8042 Some badly-designed motherboards generate lots of
8067 unwind_debug [X86-64,EARLY]
8075 (default -1 = authorized (same as 1),
8081 for newly-detected USB devices (default 2). This
8109 [USB] Specifies timeout for the initial 64-byte
8116 [USB] A list of quirk entries to augment the built-in
8119 VendorID:ProductID:Flags. The IDs are 4-digit hex
8121 will change the built-in quirk; setting it if it is
8126 a 255-byte read);
8130 Set-Interface requests);
8149 (bInterval-1).
8190 usb-storage.delay_use=
8197 usb-storage.quirks=
8199 override the built-in unusual_devs list. List
8202 and Product ID values (4-digit hex numbers) and
8204 to a common usb-storage quirk flag as follows:
8246 medium is write-protected).
8255 1 - undefined instruction events
8256 2 - system calls
8257 4 - invalid data aborts
8258 8 - SIGSEGV faults
8259 16 - SIGBUS faults
8268 vdso32= [X86] Control the 32-bit vDSO
8269 vdso32=1: enable 32-bit VDSO
8270 vdso32=0 or vdso32=2: disable 32-bit VDSO
8280 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
8311 vga= [BOOT,X86-32] Select a particular video mode
8313 Documentation/admin-guide/svga.rst.
8328 - Disable all of the above options
8336 loongarch, arc, csky, hexagon, microblaze, mips, nios2, openrisc,
8354 hypervisor to a guest via speculative side-channels.
8356 off - disable the mitigation
8357 ibpb - use Indirect Branch Prediction Barrier
8359 force - force vulnerability detection even on
8362 vsyscall= [X86-64,EARLY]
8365 code). Most statically-linked binaries and older
8391 see vga-softcursor.rst. Default: 2 = underline.
8396 This is a 16-member array composed of values
8397 ranging from 0-255.
8402 This is a 16-member array composed of values
8403 ranging from 0-255.
8408 This is a 16-member array composed of values
8409 ranging from 0-255.
8414 Set system-wide default UTF-8 mode for all tty's.
8415 Default is 1, i.e. UTF-8 mode is enabled for all
8420 Format=<-1|0|1>
8421 Set system-wide default for whether a cursor
8422 is shown on new VTs. Default is -1,
8427 vt.italic= [VT] Default color for italic text; 0-15.
8430 vt.underline= [VT] Default color for underlined text; 0-15.
8434 see Documentation/watchdog/watchdog-parameters.rst
8435 or other driver-specific files in the
8449 Format: <cpu-list>
8476 The default is 0, which disables the time-based panic.
8479 Per-cpu work items which run for longer than this
8482 them from noticeably delaying other per-cpu work
8500 Per-cpu workqueues are generally preferred because
8502 locality; unfortunately, per-cpu workqueues tend to
8505 Enabling this makes the per-cpu workqueues which
8520 Documentation/core-api/workqueue.rst.
8533 forces round-robin CPU selection to flush out
8541 on - Enable writecombine, use WUC for ioremap_wc()
8542 off - Disable writecombine, use SUC for ioremap_wc()
8544 x2apic_phys [X86-64,APIC,EARLY] Use x2apic physical mode instead of
8548 xen_512gb_limit [KNL,X86-64,XEN]
8563 ide-disks -- unplug primary master IDE devices
8564 aux-ide-disks -- unplug non-primary-master IDE devices
8565 nics -- unplug network devices
8566 all -- unplug all emulated devices (NICs and IDE disks)
8567 unnecessary -- unplugging emulated devices is
8570 never -- do not unplug even if version check succeeds
8584 Select whether to always use non-faulting (safe) MSR
8604 xen_timer_slop= [X86-64,XEN,EARLY]
8605 Set the timer slop (in nanoseconds) for the virtual Xen
8608 improve timer resolution at the expense of processing
8609 more timer interrupts.
8629 preferred over the 2-level event handling, as it is
8646 xive.store-eoi=off [PPC]
8652 xhci-hcd.quirks [USB,KNL]