Lines Matching +full:riscv +full:- +full:crypto +full:- +full:spec +full:- +full:vector
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
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.
271 on resume from S1/S3 (which is against the ACPI spec,
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
473 arm64.nosve [ARM64] Unconditionally disable Scalable Vector
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
611 cfi= [X86-64] Set Control Flow Integrity checking features
622 norand: Do not re-randomize CFI hashes.
632 - foo isn't auto-mounted if you mount all cgroups in
634 - foo isn't visible as an individually mountable
636 - if foo is an optional feature then the feature is
642 Specifying "pressure" disables per-cgroup pressure
659 semi-legacy software can check this file to decide
668 nosocket -- Disable socket memory accounting.
669 nokmem -- Disable kernel memory accounting.
670 nobpf -- Disable BPF memory accounting.
675 0 -- check protection applied by kernel (includes
677 1 -- check protection requested by application.
689 numbers X. Note the Linux-specific bits are not necessarily
690 stable over kernel options, but the vendor-specific
710 force such clocks to be always-on nor does it reserve
714 information, see Documentation/driver-api/clk.rst.
716 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
733 [X86-32] pit,hpet,tsc;
740 [X86-64] hpet,tsc
746 architected timer so that code using WFE-based polling
760 clocksource-wdtest.holdoff= [KNL]
766 cma=nn[MG]@[start[MG][-end[MG]]]
777 Sets the size of kernel per-numa memory area for
779 per-numa CMA altogether. And If this option is not
781 With per-numa CMA enabled, DMA users on node nid will
808 com20020= [HW,NET] ARCnet - COM20020 chipset
812 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
816 ARCnet - COM90xx chipset (memory-mapped buffers)
845 See Documentation/admin-guide/serial-console.rst for more
860 $ ls -d /sys/bus/serial-base/devices/*:*.*/tty/*
861 /sys/bus/serial-base/devices/00:04:0.0/tty/ttyS0
874 Start an early, polled-mode console on the 8250/16550
877 MMIO inter-register address stride is either 8-bit
878 (mmio), 16-bit (mmio16), or 32-bit (mmio32).
882 the h/w is not re-initialized.
909 syscall, or to executing "dmesg -S --raw" or to reading
933 disable the cpuidle sub-system
939 disable the cpufreq sub-system
947 [X86,EARLY] Delay for N microsec between assert and de-assert
968 like Hyper-V, PowerPC (fadump) and AMD SEV-SNP.
976 [KNL, X86-64, ARM64, RISCV, LoongArch] Select a region
979 See Documentation/admin-guide/kdump/kdump.rst for further details.
984 start-[end] where start and end are both
986 Documentation/admin-guide/kdump/kdump.rst for an example.
989 [KNL, X86-64, ARM64, RISCV, LoongArch] range could be
997 [KNL, X86-64, ARM64, RISCV, LoongArch] range under 4G.
1003 for 32-bit devices won't run out. Kernel would try to allocate
1006 --> x86: max(swiotlb_size_or_default() + 8MiB, 256MiB)
1007 --> arm64: 128MiB
1008 --> riscv: 128MiB
1009 --> loongarch: 128MiB
1039 [KNL] Disable crypto self-tests
1047 csdlock_debug= [KNL] Enable or disable debug add-ons of cross-CPU
1062 See also Documentation/input/devices/joystick-parport.rst
1075 [KNL] verbose locking self-tests
1078 self-tests.
1080 (no extra messages), setting it to -1 (all bits set)
1081 will print _a_lot_ more information - normally only
1116 Format: { on, no-mount, off }
1118 no-mount:
1123 get a -EPERM as result when trying to register files
1127 Default value is set in build-time with a kernel configuration.
1139 Documentation/admin-guide/mm/hugetlbpage.rst.
1153 delayacct [KNL] Enable per-task delay accounting
1239 entries for DMA-API debugging code. One entry is
1240 required per DMA-API allocation. Use this if the
1241 DMA-API debugging code disables itself because the
1245 With this option the DMA-API debugging driver
1256 registers, vector registers, or integer registers.
1269 Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst
1294 Control how the dt_cpu_ftrs device-tree binding is
1304 what data is available or for reverse-engineering.
1309 Documentation/admin-guide/dynamic-debug-howto.rst
1320 determined by stdout-path property in device tree's
1325 Start an early, polled-mode console on a Cadence
1336 Start an early, polled-mode console on the 8250/16550
1338 MMIO inter-register address stride is either 8-bit
1339 (mmio) or 32-bit (mmio32 or mmio32be).
1349 Start an early, polled-mode console on a pl011 serial
1353 the driver will use only 32-bit accessors to read/write
1362 Start an early, polled-mode console on a meson serial
1368 Start an early, polled-mode console on an msm serial
1374 Start an early, polled-mode console on an msm serial
1380 Start an early, polled-mode console on a serial port
1386 Start an early, polled-mode console on a serial port
1392 Use RISC-V SBI (Supervisor Binary Interface) for early
1410 Start an early, polled-mode console on a lantiq serial
1424 Start an early, polled-mode, output-only console on the
1429 Start an early, polled-mode console on the
1435 Start an early, polled-mode console on a Qualcomm
1443 coherent non-x86 systems that use system memory for
1540 fulfills the spec otherwise your board may brick.
1546 Documentation/admin-guide/acpi/ssdt-overlays.rst for details.
1563 elanfreq= [X86-32]
1571 See Documentation/admin-guide/kdump/kdump.rst for details.
1587 0 -- permissive (log only, no denials).
1588 1 -- enforcing (deny and log).
1621 See also Documentation/fault-injection/.
1625 See Documentation/admin-guide/sysctl/net.rst for
1629 See Documentation/admin-guide/blockdev/floppy.rst.
1631 forcepae [X86-32]
1638 fred= [X86-64]
1689 ftrace_filter=[function-list]
1691 tracer at boot up. function-list is a comma-separated
1696 ftrace_notrace=[function-list]
1698 function-list. This list can be changed at run time
1702 ftrace_graph_filter=[function-list]
1705 function-list is a comma-separated list of functions
1709 ftrace_graph_notrace=[function-list]
1711 function-list. This list is a comma-separated list of
1731 off -- Don't create device links from firmware info.
1732 permissive -- Create device links from firmware info
1735 on -- Create device links from firmware info and use it
1737 rpm -- Like "on", but also use to order runtime PM.
1750 strict -- Default. Continue waiting on consumers to
1752 timeout -- Give up waiting on consumers and call
1762 See also Documentation/input/devices/joystick-parport.rst
1766 gart_fix_e820= [X86-64,EARLY] disable the fix e820 for K8 GART
1776 previously stored in vector registers.
1792 gcov_persist= [GCOV] When non-zero (default), profiling data for
1802 gpio-mockup.gpio_mockup_ranges
1805 gpio-mockup.gpio_mockup_named_lines
1837 against bounds-checking flaws in the kernel's
1845 [KNL] Should the hard-lockup detector generate
1861 auto - Hash pointers unless slab_debug is enabled.
1862 always - Always hash pointers (even if slab_debug is
1864 never - Never hash pointers. This option should only
1872 for 64-bit NUMA, off otherwise.
1880 corresponding firmware-first mode error processing
1890 during restoration read-only).
1934 hpet= [X86-32,HPET] option to control HPET usage
1951 number of pages to allocate per-node can be specified.
1952 See also Documentation/admin-guide/mm/hugetlbpage.rst.
1963 Documentation/admin-guide/mm/hugetlbpage.rst.
1973 Note that this parameter only applies to non-gigantic huge pages.
1983 boot-time allocation of gigantic hugepages is skipped.
2018 by the CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time
2024 hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
2046 Set device-properties for ACPI-enumerated I2C-attached
2047 touchscreen, to e.g. fix coordinates of upside-down
2055 Omit "=<val>" entirely Set a boolean device-property
2056 Unsigned number Set a u32 device-property
2057 Anything else Set a string device-property
2060 i2c_touchscreen_props=GDIX1001:touchscreen-inverted-x:
2061 touchscreen-inverted-y
2063 i2c_touchscreen_props=MSSL1680:touchscreen-size-x=1920:
2064 touchscreen-size-y=1080:touchscreen-inverted-y:
2065 firmware-name=gsl1680-vendor-model.fw:silead,home-button
2070 (disabled by default, and as a pre-condition
2072 i8042.direct [HW] Put keyboard port into non-translated mode
2086 suspend-to-ram transitions, only during s2r
2110 -1 -- never invert brightness
2111 0 -- machine default
2112 1 -- force brightness inversion
2114 ia32_emulation= [X86-64]
2116 When true, allows loading 32-bit programs and executing 32-bit
2141 idle=nomwait: Disable mwait for CPU C-states
2169 legacy only accept legacy-NaN binaries, if supported
2171 2008 only accept 2008-NaN binaries, if supported
2182 'relaxed' straps the emulator for both legacy-NaN and
2183 2008-NaN, whereas 'strict' enables legacy-NaN only on
2192 Ignore loglevel setting - this will print /all/
2224 in crypto/hash_info.h.
2259 Formats: { "ima" | "ima-ng" | "ima-ngv2" | "ima-sig" |
2260 "ima-sigv2" }
2261 Default: "ima-ng"
2273 different crypto accelerators. This option can be used
2281 different crypto accelerators. This option can be used
2299 stuff: Deploy RSB-fill mitigation when retpoline is
2304 Documentation/admin-guide/hw-vuln/indirect-target-selection.rst
2315 initcall_blacklist= [KNL] Do not execute a comma-separated list of
2316 initcall functions. Useful for debugging built-in
2361 0 -- basic integrity auditing messages. (Default)
2362 1 -- additional integrity auditing messages.
2390 could harm performance of some high-throughput
2399 1 to 9 specify maximum depth of C-state.
2408 algorithms for p-state selection. There are two
2409 P-state selection algorithms provided by
2412 on whether or not the hardware managed P-states
2419 used along with the hardware-managed P-states (HWP)
2423 in favor of acpi-cpufreq. Forcing the intel_pstate driver
2424 instead of acpi-cpufreq may disable platform features, such
2426 P-States information being indicated to OSPM and therefore
2429 or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
2442 Allow per-logical-CPU P-State performance control limits using
2445 Do not enable capacity-aware scheduling (CAS) on
2448 intremap= [X86-64,Intel-IOMMU,EARLY]
2453 BIOS x2APIC opt-out request will be ignored
2496 AMD Gart HW IOMMU-specific options:
2515 Do scatter-gather (SG) merging. Implies "force"
2519 Don't do scatter-gather (SG) merging.
2532 0 - Try to allocate a 32-bit DMA address first, before
2534 1 - Allocate directly from the full usable range,
2536 greater than 32-bit addressing.
2540 0 - Lazy mode.
2546 1 - Strict mode.
2549 unset - Use value of CONFIG_IOMMU_DEFAULT_DMA_{LAZY,STRICT}.
2551 legacy driver-specific options takes precedence.
2556 0 - Use IOMMU translation for DMA.
2557 1 - Bypass the IOMMU for DMA.
2558 unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
2560 io7= [HW] IO7 for Marvel-based Alpha systems
2575 See Documentation/admin-guide/nfs/nfsroot.rst.
2611 Enables support for pseudo-NMIs in the kernel. This
2616 [RISC-V,EARLY]
2618 as IPIs. Intended for system where IMSIC is trap-n-emulated,
2630 long-running IRQs in the system.
2642 [Deprecated - use cpusets instead]
2643 Format: [flag-list,]<cpu-list>
2676 "number of CPUs in system - 1".
2702 The format of <cpu-list> is described above.
2706 ivrs_ioapic [HW,X86-64]
2707 Provide an override to the IOAPIC-ID<->DEVICE-ID
2711 For example, to map IOAPIC-ID decimal 10 to
2717 * To map IOAPIC-ID decimal 10 to PCI device 00:14.0
2720 * To map IOAPIC-ID decimal 10 to PCI segment 0x1 and
2724 ivrs_hpet [HW,X86-64]
2725 Provide an override to the HPET-ID<->DEVICE-ID
2729 For example, to map HPET-ID decimal 10 to
2735 * To map HPET-ID decimal 0 to PCI device 00:14.0
2738 * To map HPET-ID decimal 10 to PCI segment 0x1 and
2742 ivrs_acpihid [HW,X86-64]
2743 Provide an override to the ACPI-HID:UID<->DEVICE-ID
2747 For example, to map UART-HID:UID AMD0020:0 to
2753 * To map UART-HID:UID AMD0020:0 to PCI segment is 0,
2756 * To map UART-HID:UID AMD0020:0 to PCI segment 0x1 and
2780 the kernel for non-movable allocations. The requested
2790 subsystem. Note that allocations like PTEs-from-HighMem
2798 for non-movable allocations and remaining memory is used
2809 gdb or control-c on the dbgp connection. When
2810 not using this parameter you use sysrq-g to break into
2815 or a supported polling keyboard driver (non-usb).
2844 "0" | "off" | "n" - kexec handover is disabled
2845 "1" | "on" | "y" - kexec handover is enabled
2851 ranges that can only be used for non-kernel
2862 parameter defines the size of additional per-node
2867 Configure the RouterBoard 532 series on-chip
2870 kmemleak= [KNL,EARLY] Boot-time kmemleak enable/disable
2876 kprobe_event=[probe-list]
2878 The probe-list is a semicolon delimited list of probe
2908 execution by eliminating the write-protection faults
2929 kvm.enable_virt_at_load=[KVM,ARM64,LOONGARCH,MIPS,RISCV,X86]
2935 virtualization on-demand when creating and destroying
2943 is that doing so may interfere with using out-of-tree
2970 back to huge pages. If the value is a non-zero N, KVM will
2975 kvm-amd.nested= [KVM,AMD] Control nested virtualization feature in
2978 kvm-amd.npt= [KVM,AMD] Control KVM's use of Nested Page Tables,
2979 a.k.a. Two-Dimensional Page Tables. Default is 1
2983 kvm-amd.ciphertext_hiding_asids=
2988 If ciphertext hiding is enabled, the joint SEV-ES and
2989 SEV-SNP ASID space is partitioned into separate SEV-ES
2990 and SEV-SNP ASID ranges, with the SEV-SNP range being
2991 [1..max_snp_asid] and the SEV-ES range being
2995 A non-zero value enables SEV-SNP ciphertext hiding and
2996 adjusts the ASID ranges for SEV-ES and SEV-SNP guests.
2997 KVM caps the number of SEV-SNP ASIDs at the maximum
2998 possible value, e.g. specifying -1u will assign all
2999 joint SEV-ES and SEV-SNP ASIDs to SEV-SNP. Note,
3000 assigning all joint ASIDs to SEV-SNP, i.e. configuring
3001 max_snp_asid == min_sev_asid-1, will effectively make
3002 SEV-ES unusable.
3004 kvm-arm.mode=
3010 nvhe: Standard nVHE-based mode, without support for
3017 nested: VHE-based mode with support for nested
3025 command-line.
3029 kvm-arm.vgic_v3_group0_trap=
3030 [KVM,ARM,EARLY] Trap guest accesses to GICv3 group-0
3033 kvm-arm.vgic_v3_group1_trap=
3034 [KVM,ARM,EARLY] Trap guest accesses to GICv3 group-1
3037 kvm-arm.vgic_v3_common_trap=
3041 kvm-arm.vgic_v4_enable=
3045 kvm-arm.wfe_trap_policy=
3054 kvm-arm.wfi_trap_policy=
3071 kvm-intel.ept= [KVM,Intel] Control KVM's use of Extended Page Tables,
3072 a.k.a. Two-Dimensional Page Tables. Default is 1
3076 kvm-intel.emulate_invalid_guest_state=
3078 state. Ignored if kvm-intel.enable_unrestricted_guest=1,
3084 kvm-intel.flexpriority=
3089 kvm-intel.nested=
3093 kvm-intel.unrestricted_guest=
3099 kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
3100 CVE-2018-3620.
3111 kvm-intel.vpid= [KVM,Intel] Control KVM's use of Virtual Processor
3131 on - enable the interface for the mitigation
3196 For details see: Documentation/admin-guide/hw-vuln/l1tf.rst
3202 lapic [X86-32,APIC,EARLY] Enable the local APIC even if BIOS
3206 value for LAPIC timer one-shot implementation. Default
3229 libata.force= [LIBATA] Force configurations. The format is a comma-
3241 first fan-out link behind PMP device. It does not
3255 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
3262 * rstonce: only attempt one reset during hot-unplug
3305 * external: Mark port as external (hotplug-capable).
3359 Specify the number of self-propagating call_rcu()
3367 occasional long-duration lock hold time. Defaults
3378 Set the number of locking read-acquisition kthreads.
3383 Set the number of locking write-acquisition kthreads.
3386 Set time (s) after boot for CPU-hotplug testing.
3389 Set time (s) between CPU-hotplug operations, or
3390 zero to disable CPU-hotplug testing.
3393 Do periodic testing of real-time lock priority
3398 non-real-time spinlocks, due to their disabling
3399 of preemption. Note that non-realtime mutexes
3412 Set task-shuffle interval (jiffies). Shuffling
3413 tasks allows some CPUs to go into dyntick-idle
3418 is useful for hands-off automated testing.
3437 Run the write-side locktorture kthreads at
3438 sched_set_fifo() real-time priority.
3456 7 (KERN_DEBUG) debug-level messages
3468 logo.nologo [FB] Disables display of the built-in Linux logo.
3486 an IEEE 1284-compliant printer is attached; if
3492 time-consuming boot-time autodetection (up to 250 ms per
3512 Example: machtype=lemote-yeeloong-2f-7inch
3524 (loop.max_loop) unconditionally pre-created at init time. The default
3527 devices can be requested on-demand with the
3528 /dev/loop-control interface.
3530 mce= [X86-{32,64}]
3567 do not opt-in to Local MCE delivery. Use legacy method
3588 don't overwrite the bios-set CMCI threshold. This boot
3597 force-enable recoverable machine check code paths
3603 See Documentation/admin-guide/md.rst.
3610 Control mitigation for the Micro-architectural Data
3625 full - Enable MDS mitigation on vulnerable CPUs
3626 full,nosmt - Enable MDS mitigation and disable
3628 off - Unconditionally disable MDS mitigation
3630 On TAA-affected machines, mds=off can be prevented by
3639 For details see: Documentation/admin-guide/hw-vuln/mds.rst
3654 [ARC,MICROBLAZE] - the limit applies only to low memory,
3657 [ARM64] - only limits memory covered by the linear
3670 [ARM,MIPS,EARLY] - override the memory layout
3677 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
3684 per-device physically contiguous DMA buffers.
3692 See Documentation/admin-guide/mm/memory-hotplug.rst.
3717 Example: Exclude memory from 0x18690000-0x1869ffff
3731 memmap=<size>%<offset>-<oldtype>+<newtype>
3733 from <oldtype> to <newtype>. If "-<oldtype>" is left
3748 repeatable BIOS-originated corruption always
3782 memtest= [KNL,X86,ARM,M68K,PPC,RISCV,EARLY] Enable memtest
3792 mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control
3798 Refer to Documentation/virt/kvm/x86/amd-memory-encryption.rst
3802 s2idle - Suspend-To-Idle
3803 shallow - Power-On Suspend or equivalent (if supported)
3804 deep - Suspend-To-RAM or equivalent (if supported)
3805 See Documentation/admin-guide/pm/sleep-states.rst.
3807 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
3817 base_rev=X - with <X> with format: <u32>
3831 0 - The attached screen is the 3.5" TFT
3832 1 - The attached screen is the 7" TFT
3833 2 - The VGA Shield is attached (1024x768)
3837 b - Enable backlight. The TFT backlight pin will be
3841 c - Enable the s3c camera interface.
3842 t - Reserved for enabling touchscreen support. The
3846 https://repo.or.cz/w/linux-2.6/mini2440.git
3851 arch-independent options, each of which is an
3852 aggregation of existing arch-specific options.
3882 ssbd=force-off [ARM64]
3896 have other ways of avoiding SMT-based attacks.
3910 supports attack-vector based controls as documented in
3911 Documentation/admin-guide/hw-vuln/attack_vector_controls.rst
3935 full - Enable mitigation on vulnerable CPUs
3937 full,nosmt - Enable mitigation and disable SMT on
3940 off - Unconditionally disable mitigation
3953 Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst
3983 module_blacklist= [KNL] Do not load a comma-separated list of
4008 movable_node [KNL,EARLY] Boot-time switch to make hotplugable memory
4015 Format: <name>,<region-number>,<size>,<offset>
4018 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
4057 something different and driver-specific.
4097 [NFS] enable 64-bit inode numbers.
4098 If zero, the NFS client will fake up a 32-bit inode
4100 of returning the full 64-bit number.
4101 The default is to return 64-bit inode numbers.
4136 [NFS4] Specify an additional fixed unique ident-
4167 driver. A non-zero value sets the minimum interval
4172 server-to-server copies for which this server is
4184 server-to-server copy, knfsd temporarily mounts
4191 See Documentation/admin-guide/nfs/nfsroot.rst.
4193 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
4194 See Documentation/admin-guide/nfs/nfsroot.rst.
4197 See Documentation/admin-guide/nfs/nfsroot.rst.
4201 NMI stack-backtrace request.
4210 0 - turn hardlockup detector in nmi_watchdog off
4211 1 - turn hardlockup detector in nmi_watchdog on
4212 rNNN - configure the watchdog with raw perf event 0xNNN
4225 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
4229 no4lvl [RISCV,EARLY] Disable 4-level and 5-level paging modes.
4230 Forces kernel to use 3-level paging instead.
4232 no5lvl [X86-64,RISCV,EARLY] Disable 5-level paging mode. Forces
4233 kernel to use 4-level paging instead.
4268 no_entry_flush [PPC,EARLY] Don't flush the L1-D cache when entering the kernel.
4270 noexec32 [X86-64]
4271 This affects only 32-bit executables.
4272 noexec32=on: enable non-executable mappings (default)
4274 noexec32=off: disable non-executable mappings
4285 nofxsr [BUGS=X86-32] Disables x86 floating point extended
4287 legacy floating-point registers on task switch.
4297 nohlt [ARM,ARM64,MICROBLAZE,MIPS,PPC,RISCV,SH] Forces the kernel to
4332 nointremap [X86-64,Intel-IOMMU,EARLY] Do not enable interrupt
4334 [Deprecated - use intremap=off]
4340 noirqdebug [X86-32] Disables the code which attempts to detect and
4350 no-kvmapf [X86,KVM,EARLY] Disable paravirtualized asynchronous page
4353 no-kvmclock [X86,KVM,EARLY] Disable paravirtualized KVM clock driver
4355 nolapic [X86-32,APIC,EARLY] Do not enable or use the local APIC.
4357 nolapic_timer [X86-32,APIC,EARLY] Do not use the local APIC timer.
4359 nomce [X86-32] Disable Machine Check Exception
4361 nomfgpt [X86-32] Disable Multi-Function General Purpose
4367 not load if they could possibly displace the pre-
4370 perform display-mode changes or accelerated rendering.
4383 nopcid [X86-64,EARLY] Disable the PCID cpu feature.
4388 nopti [X86-64,EARLY]
4404 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
4410 no-scroll [VGA] Disables scrollback.
4411 This is required for the Braillex ib80-piezo Braille
4414 nosgx [X86-64,SGX,EARLY] Disables Intel SGX kernel support.
4434 nosoftlockup [KNL] Disable the soft-lockup detector.
4440 nospectre_bhb [ARM64,EARLY] Disable all mitigations for Spectre-BHB (branch
4453 no-steal-acc [X86,PV_OPS,ARM64,PPC/PSERIES,RISCV,LOONGARCH,EARLY]
4460 timer IRQ sources, i.e., the IO-APIC timer. This can
4465 [PPC,EARLY] Don't flush the L1-D cache after accessing user data.
4478 no-vmw-sched-clock
4483 soft-lockup and NMI watchdog (hard-lockup).
4487 nox2apic [X86-64,APIC,EARLY] Do not enable x2APIC mode.
4495 enabling legacy floating-point and sse state.
4517 n. So during boot up some boot time memory for per-cpu
4518 variables need be pre-allocated for later physical cpu
4523 numa=off [KNL, ARM64, PPC, RISCV, SPARC, X86, EARLY]
4528 [KNL, ARM64, RISCV, X86, EARLY]
4533 [KNL, ARM64, RISCV, X86, EARLY]
4538 [KNL, ARM64, RISCV, X86, EARLY]
4545 soft-reserved memory partitioning.
4547 numa_balancing= [KNL,ARM64,PPC,RISCV,S390,X86] Enable or disable automatic
4554 See Documentation/admin-guide/sysctl/vm.rst for details.
4557 See Documentation/core-api/debugging-via-ohci1394.rst for more
4572 onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
4576 boundary - index of last SLC block on Flex-OneNAND.
4578 lock - Configure if Flex-OneNAND boundary should be locked.
4597 page_owner= [KNL,EARLY] Boot-time page_owner enabling option.
4603 page_poison= [KNL,EARLY] Boot-time parameter changing the state of
4631 See Documentation/admin-guide/tainted-kernels.rst for
4703 Set to non-zero to probe primary and secondary ISA
4709 Set to non-zero if a chip is present that snoops speed
4757 Set to non-zero to probe tertiary and further ISA
4773 Set to non-zero to probe QDI controllers. By default
4778 Set to non-zero to probe Winbond controllers. Use
4825 bios [X86-32] force use of PCI BIOS, don't access
4827 has a non-standard PCI host bridge.
4828 nobios [X86-32] disallow use of PCI BIOS, only direct
4834 data in IO port 0xCFC, both 32-bit).
4836 Mechanism 2 (IO port 0xCF8 is an 8-bit port for
4837 the function, IO port 0xCFA, also 8-bit, sets
4839 through ports 0xC000-0xCFFF).
4846 root domains (aka PCI segments, in ACPI-speak).
4854 disable the use of MSI interrupts system-wide.
4859 primary IO-APIC for bridges that cannot disable
4866 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
4890 F0000h-100000h range.
4895 assign-busses [X86] Always assign all PCI bus
4916 <linux-pci@vger.kernel.org>.
4920 a bug to <linux-pci@vger.kernel.org>.
4932 bfsort Sort PCI devices into breadth-first order.
4935 nobfsort Don't sort PCI devices into breadth-first order.
4937 tuning and use the BIOS-configured MPS defaults.
4947 configuration allows peer-to-peer DMA between
4950 that hot-added devices will work.
4965 A PCI-PCI bridge can be specified if resource
4971 for 4096-byte alignment.
4973 end-to-end CRC checking). Only effective if
5004 noats [PCIE, Intel-IOMMU, AMD-IOMMU]
5035 bit-0 : ACS Source Validation
5036 bit-1 : ACS Translation Blocking
5037 bit-2 : ACS P2P Request Redirect
5038 bit-3 : ACS P2P Completion Redirect
5039 bit-4 : ACS Upstream Forwarding
5040 bit-5 : ACS P2P Egress Control
5041 bit-6 : ACS Direct Translated P2P
5051 Validation unchanged from whatever power-up
5063 system-wide.
5077 dpc-native Use native PCIe service for DPC only. May
5094 Keep all power-domains already enabled by bootloader on,
5112 pirq= [SMP,APIC] Manual mp-table setup
5113 See Documentation/arch/x86/i386/IO-APIC.rst.
5117 See also Documentation/admin-guide/parport.rst.
5136 resume of devices during system-wide power transitions.
5138 dependencies are not well-defined, or for debugging
5148 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
5157 { on | off | curr | res | no-curr | no-res }
5202 none - Limited to cond_resched() calls
5203 voluntary - Limited to cond_resched() and might_sleep() calls
5204 full - Any section that isn't explicitly preempt disabled
5208 lazy - Scheduler controlled. Similar to full but instead
5214 print-fatal-signals=
5220 coredump - etc.
5223 you might want to try "ulimit -i unlimited".
5235 or lockdep-detected issues (only if lock debug is on).
5243 Allows storing messages from non-panic CPUs into
5245 flushed to consoles by the panic-CPU on
5246 a best-effort basis.
5252 on - unlimited logging to /dev/kmsg from userspace
5253 off - logging to /dev/kmsg disabled
5254 ratelimit - ratelimit the logging
5265 - 'always': traditional behavior always allows mem overrides.
5266 - 'ptrace': only allow mem overrides for active ptracers.
5267 - 'never': never allow mem overrides.
5271 Limit processor to maximum C-state
5275 Ignore the _CST method to determine C-states,
5282 Param: "schedule" - profile schedule points.
5283 Param: "kvm" - profile VM exits.
5284 Param: <number> - step/bucket size as a power of 2 for
5315 pti= [X86-64] Control Page Table Isolation of user and
5320 on - unconditionally enable
5321 off - unconditionally disable
5322 auto - kernel detects whether your CPU model is
5328 [KNL] Number of legacy pty's. Overwrites compiled-in
5340 See Documentation/admin-guide/md.rst.
5343 See Documentation/admin-guide/blockdev/ramdisk.rst.
5362 cross-syscall address exposures. This is only
5368 ras=option[,option,...] [KNL] RAS-specific options
5374 rcu_nocbs[=cpu-list]
5379 enable the no-callback CPU mode, which prevents
5384 "p" for RCU-preempt, "s" for RCU-sched, and "g"
5388 and real-time workloads. It can also improve
5392 list of CPUs is set to no-callback mode from boot.
5396 no-callback mode from boot but the mode may be
5407 This improves the real-time response for the
5418 Do only a one-line RCU CPU stall warning when
5419 there is an ongoing too-long CSD-lock wait.
5425 If triggered before the RCU grace-period machinery
5435 RCU grace-period cleanup.
5439 RCU grace-period initialization.
5443 RCU grace-period pre-initialization, that is,
5444 the propagation of recent CPU-hotplug changes up
5448 Set delay from grace-period initialization to
5461 soliciting quiescent-state help from
5473 Set the SCHED_FIFO priority of the RCU per-CPU
5476 and for the RCU grace-period kthreads (rcu_bh,
5478 set, valid values are 1-99 and the default is 1
5479 (the least-favored priority). Otherwise, when
5480 RCU_BOOST is not set, valid values are 0-99 and
5481 the default is zero (non-realtime operation).
5486 On callback-offloaded (rcu_nocbs) CPUs,
5489 use of the ->nocb_bypass list. However, in the
5490 common non-flooded case, RCU queues directly to
5491 the main ->cblist in order to avoid the extra
5492 overhead of the ->nocb_bypass list and its lock.
5494 a single jiffy, RCU pre-queues the callbacks into
5495 the ->nocb_bypass queue. The definition of "too
5499 On callback-offloaded (rcu_nocbs) CPUs, avoid
5512 batch limiting is re-enabled.
5516 RCU's force-quiescent-state scan will aggressively
5524 Set the page-cache refill delay (in milliseconds)
5525 in response to low-memory conditions. The range
5529 Set the shift-right count to use to compute
5530 the callback-invocation batch limit bl from
5537 Please note that this callback-invocation batch
5538 limit applies only to non-offloaded callback
5547 cache-to-cache transfer latencies.
5553 and for NUMA systems with large remote-access
5569 the wakeup overhead on the global grace-period
5571 each group's NOCB grace-period kthread.
5574 Cause the grace-period kthread to get an extra
5576 it should at force-quiescent-state time.
5589 this specifies an rcu_read_unlock()-time delay
5593 of RCU-protected pointers after the relevant
5603 per-CPU rcuc kthreads. Defaults to a non-zero
5633 grace-period primitives such as call_rcu().
5644 grace-period primitives.
5647 Set test-start holdoff period. The purpose of
5665 Test the double-argument variant of kfree_rcu().
5667 rcuscale.kfree_rcu_test_single, both the single-
5668 and double-argument variants are tested.
5671 Test the single-argument variant of kfree_rcu().
5673 rcuscale.kfree_rcu_test_double, both the single-
5674 and double-argument variants are tested.
5688 does not affect the data-collection interval,
5693 Set number of RCU readers. The value -1 selects
5695 "n" less than -1 selects N-n+1, where N is again
5696 the number of CPUs. For example, -2 selects N
5697 (the number of CPUs), -3 selects N+1, and so on.
5698 A value of "n" less than or equal to -N selects
5711 complete. This is useful for hands-off automated
5718 Write-side holdoff between grace periods,
5723 Additional write-side holdoff between grace
5741 for RCU grace-period forward-progress testing
5748 Specify the fraction of a CPU-stall-warning
5749 period to do tight-loop forward-progress testing.
5753 forward-progress tests.
5757 need_resched() during tight-loop forward-progress
5761 Use conditional/asynchronous update-side
5762 normal-grace-period primitives, if available.
5765 Use conditional/asynchronous update-side
5766 expedited-grace-period primitives, if available.
5769 Use conditional/asynchronous update-side
5770 normal-grace-period primitives that also take
5775 Use conditional/asynchronous update-side
5776 expedited-grace-period primitives that also take
5800 Use expedited update-side primitives, if available.
5803 Use normal (non-expedited) asynchronous
5804 update-side primitives, if available.
5807 Use polled update-side normal-grace-period
5811 Use polled update-side expedited-grace-period
5815 Use polled update-side normal-grace-period
5820 Use polled update-side expedited-grace-period
5844 Use normal (non-expedited) synchronous
5845 update-side primitives, if available. If all
5849 they are all non-zero.
5852 Enable grace-period wrap lag testing. Setting
5857 Set the value for grace-period wrap lag during
5872 the grace-period wrap lag will be set to the
5882 Leak an RCU-protected pointer out of the reader.
5897 Set number of RCU callback-offload togglers.
5902 callback-offload toggling attempts.
5905 Set number of RCU readers. The value -1 selects
5906 N-1, where N is the number of CPUs. A value
5907 "n" less than -1 selects N-n-2, where N is again
5908 the number of CPUs. For example, -2 selects N
5909 (the number of CPUs), -3 selects N+1, and so on.
5912 Enable debug-object double-call_rcu() testing.
5915 Set time (s) after boot for CPU-hotplug testing.
5918 Set time (jiffies) between CPU-hotplug operations,
5919 or zero to disable CPU-hotplug testing.
5923 by a high-priority FIFO real-time task. Set to
5932 second) between preemptions by a high-priority
5933 FIFO real-time task. This delay is mediated
5938 The number of times in a given read-then-exit
5939 episode that a set of read-then-exit kthreads
5944 read-then-exit testing episodes.
5949 are entered from low-order bit up, and are
5951 0x1 bit is normal readers, 0x2 NMI-safe readers,
5952 and 0x4 light-weight readers.
5955 Set task-shuffle interval (s). Shuffling tasks
5956 allows some CPUs to go into dyntick-idle mode
5961 is useful for hands-off automated testing.
5970 any other stall-related activity. Note that
5976 in scheduling-while-atomic splats.
5995 grace-period kthread to test RCU CPU stall
6019 of RCU priority-boost testing. Defaults to zero,
6026 Test RCU's dyntick-idle handling. See also the
6081 Use expedited grace-period primitives, for
6085 real-time latency, and degrade energy efficiency.
6089 Use only normal grace-period primitives,
6092 real-time latency, CPU utilization, and
6094 increased grace-period latency. This parameter
6101 only normal grace-period primitives. No effect
6107 post-boot attempt at an expedited RCU grace
6108 period to instead use normal non-expedited
6109 grace-period processing.
6117 set to the default value of -1.
6120 Set the minimum number of callback-queuing-time
6121 lock-contention events per jiffy required to
6122 cause the RCU Tasks flavors to switch to per-CPU
6125 the default value of -1.
6130 of -1 allows this to be automatically (and
6138 number avoids disturbing real-time workloads,
6143 cancel laziness on that CPU. Use -1 to disable
6153 only printed prior to the stall-warning message
6201 force - Override the decision by the kernel to hide the
6234 Use the CPU reboot vector for warm reset
6240 There are some built-in platform specific "quirks"
6241 - you may see: "reboot: <name> series board detected.
6245 built-in quirk table, and use the generic default
6278 Set test-start holdoff period. The purpose of
6293 but the default has already reduced the per-pass
6298 Set number of readers. The default value of -1
6307 Set the read-side critical-section duration,
6311 Specify the read-protection implementation to test.
6337 See Documentation/admin-guide/cgroup-v1/cpusets.rst.
6367 reservetop= [X86-32,EARLY]
6384 See Documentation/power/swsusp-and-swap-files.rst
6400 AMD-based UNRET and IBPB mitigations alone do not stop
6402 sibling threads. For that reason, STIBP is used on pro-
6406 off - no mitigation
6407 auto - automatically select a migitation
6408 auto,nosmt - automatically select a mitigation,
6412 ibpb - On AMD, mitigate short speculation
6417 ibpb,nosmt - Like "ibpb" above but will disable SMT
6421 unret - Force enable untrained return thunks,
6422 only effective on AMD f15h-f17h based
6424 unret,nosmt - Like unret, but will disable SMT when STIBP
6449 riscv_isa_fallback [RISCV,EARLY]
6452 "riscv,isa" property on devicetree systems when the
6456 ro [KNL] Mount root device read-only on boot
6459 on Mark read-only kernel memory as read-only (default).
6460 off Leave read-only kernel memory writable for debugging.
6461 noalias Mark read-only kernel memory as read-only but retain
6469 debug-uart get routed to the D+ and D- pins of the usb
6475 block/early-lookup.c for details.
6508 rw [KNL] Mount root device read-write on boot
6537 solution to mutex-based priority inversion.
6567 to 10 seconds for built-in smp_call_function()
6574 that requesting even small non-zero numbers of
6581 The default of -1 specifies a number of kthreads
6586 test before initiating CPU-hotplug operations.
6590 CPU-hotplug operations. Specifying zero (which
6591 is the default) disables CPU-hotplug operations.
6597 Non-zero values are useful for automated tests.
6620 "wait" parameter. A value of -1 selects the
6621 default if all other weights are -1. However,
6623 value of -1 will instead select a weight of zero.
6628 non-zero "wait" parameter. See weight_single.
6641 non-zero "wait" parameter. See weight_single
6653 non-zero "wait" parameter. See weight_single
6664 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
6665 1 -- enable.
6676 0 -- disable.
6677 1 -- enable.
6680 serialnumber [BUGS=X86-32]
6682 sev=option[,option...] [X86-64]
6688 Do not enable SEV-SNP (applies to host/hypervisor
6691 SEV-SNP guests.
6699 to set it to "all" by meaning -- no limit here.
6711 Documentation/admin-guide/mm/slab.rst.
6722 Documentation/admin-guide/mm/slab.rst.
6738 Documentation/admin-guide/mm/slab.rst.
6744 Documentation/admin-guide/mm/slab.rst.
6759 Documentation/admin-guide/mm/slab.rst.
6786 using the csdlock_debug- kernel parameter.
6791 system. By default, let CSD-lock acquisition
6793 for this value provides a 5-minute timeout.
6795 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
6796 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
6797 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
6798 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
6799 smsc-ircc2.ircc_irq= [HW] IRQ line
6800 smsc-ircc2.ircc_dma= [HW] DMA channel
6801 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
6811 Default: -1 (no limit)
6814 [KNL] Should the soft-lockup detector generate panics.
6817 A value of 1 instructs the soft-lockup detector
6818 to panic the machine when a soft-lockup occurs. It is
6821 respective build-time switch to that functionality.
6824 [KNL] Should the soft-lockup detector generate
6829 See Documentation/admin-guide/laptops/sonypi.rst
6836 on - (default) Enable the HW or SW mitigation as
6839 vmexit - On systems which don't have the HW mitigation
6842 protected from VM-originated BHI attacks, but
6844 off - Disable the mitigation.
6851 on - unconditionally enable, implies
6853 off - unconditionally disable, implies
6855 auto - kernel detects whether your CPU model is
6874 retpoline - replace indirect branches
6875 retpoline,generic - Retpolines
6876 retpoline,lfence - LFENCE; indirect branch
6877 retpoline,amd - alias for retpoline,lfence
6878 eibrs - Enhanced/Auto IBRS
6879 eibrs,retpoline - Enhanced/Auto IBRS + Retpolines
6880 eibrs,lfence - Enhanced/Auto IBRS + LFENCE
6881 ibrs - use IBRS to protect kernel
6891 on - Unconditionally enable mitigations. Is
6894 off - Unconditionally disable mitigations. Is
6897 prctl - Indirect branch speculation is enabled,
6903 - Like "prctl" above, but only STIBP is
6909 - Same as "prctl" above, but all seccomp
6914 - Like "seccomp" above, but only STIBP is
6919 auto - Kernel selects the mitigation depending on
6930 off - Disable mitigation
6931 microcode - Enable microcode mitigation only
6932 safe-ret - Enable sw-only safe RET mitigation (default)
6933 ibpb - Enable mitigation by issuing IBPB on
6935 ibpb-vmexit - Issue IBPB only on VMEXIT
6936 (cloud-specific mitigation)
6961 on - Unconditionally disable Speculative Store Bypass
6962 off - Unconditionally enable Speculative Store Bypass
6963 auto - Kernel detects whether the CPU model contains an
6969 prctl - Control Speculative Store Bypass per thread
6973 seccomp - Same as "prctl" above, but all seccomp threads
6981 on,auto - On Power8 and Power9 insert a store-forwarding
6985 off - No action.
6999 off - not enabled
7001 warn - the kernel will emit rate-limited warnings
7009 fatal - the kernel will send SIGBUS to applications
7014 ratelimit:N -
7034 Certain CPUs are vulnerable to an MDS-like
7054 This kernel-boot parameter defaults to 128,
7055 but takes effect only when the low-order four
7072 instead of the compile-time CONFIG_NR_CPUS.
7076 grace-period sequence counter wrap for the
7077 srcu_data structure's ->srcu_gp_seq_needed field.
7092 Specifies the number of no-delay instances
7099 Specifies the per-grace-period phase, number of
7100 non-sleeping polls of readers. Beyond this limit,
7106 Specifies number of microseconds of non-sleeping
7107 delay between each non-sleeping poll of readers.
7110 Specifies the number of update-side contention
7115 set for contention-based conversions to occur.
7125 force-on: Unconditionally enable mitigation for
7127 force-off: Unconditionally disable mitigation for
7149 stack traces. Pools are allocated on-demand up to this
7155 stacktrace_filter=[function-list]
7157 will trace at boot up. function-list is a comma-separated
7165 Set the STI (builtin display/keyboard on the HP-PARISC
7167 as the initial boot-console.
7227 to global on non-NUMA machines)
7252 <int> -- Number of I/O TLB slabs
7253 <int> -- Second integer after comma. Number of swiotlb
7256 force -- force using of bounce buffers even if they
7258 noforce -- Never use bounce buffers (for debugging)
7273 Ignore sysrq setting - this boot parameter will
7281 cache size. See Documentation/networking/ip-sysctl.rst
7288 Specify "mem" (for Suspend-to-RAM) or "standby" (for
7293 wakeup-capable RTC alarm.
7299 -1: disable all active trip points in all thermal zones
7303 -1: disable all critical trip points in all thermal zones
7310 -1: disable all passive trip points
7316 <deci-seconds>: poll all this frequency
7320 Format: <size>[KMG],<size>[KMG]:<state>;<size>[KMG]-<size>[KMG]:<state>
7325 See Documentation/admin-guide/mm/transhuge.rst for more
7333 Format: <size>[KMG],<size>[KMG]:<policy>;<size>[KMG]-<size>[KMG]:<policy>
7339 See Documentation/admin-guide/mm/transhuge.rst for more
7351 Prevent the CPU-hotplug component of torturing
7355 Dump the ftrace buffer at torture-test shutdown,
7359 with rotating-rust storage.
7364 disables verbose-printk() sleeping.
7367 Duration of each verbose-printk() sleep in jiffies.
7400 https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/
7438 local - Use the per CPU time stamp counter
7442 global - Event time stamps are synchronized across
7445 counter - Simple counting of events (1, 2, ..)
7449 uptime - Use jiffies as the time stamp.
7450 perf - Use the same clock that perf uses.
7451 mono - Use ktime_get_mono_fast_ns() for time stamps.
7452 mono_raw - Use ktime_get_raw_fast_ns() for time
7454 boot - Use ktime_get_boot_fast_ns() for time stamps.
7458 trace_event=[event-list]
7460 to facilitate early boot debugging. The event-list is a
7461 comma-separated list of trace events to enable. See
7472 trace_instance=[instance-info]
7497 traceoff - Have the tracing instance tracing disabled after it is created.
7498 traceprintk - Have trace_printk() write into this trace instance
7545 trace_options=[option-list]
7547 The option-list is a comma delimited list of options
7561 trace_trigger=[trigger-list]
7607 See Documentation/admin-guide/mm/transhuge.rst
7614 See Documentation/admin-guide/mm/transhuge.rst
7621 See Documentation/admin-guide/mm/transhuge.rst
7629 - "tpm"
7630 - "tee"
7631 - "caam"
7632 - "dcp"
7642 - "kernel"
7643 - the same value as trusted.source: "tpm" or "tee"
7644 - "default"
7667 off - disable the mitigation
7668 on - enable the mitigation (default)
7669 user - mitigate only user/kernel transitions
7670 vm - mitigate only guest/host transitions
7678 high-resolution timer mode on older hardware, and in
7714 on - Enable TSX on the system. Although there are
7717 several previous speculation-related CVEs, and
7721 off - Disable TSX on the system. (Note that this
7729 auto - Disable TSX if X86_BUG_TAA is present,
7734 See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
7740 Similar to Micro-architectural Data Sampling (MDS)
7755 full - Enable TAA mitigation on vulnerable CPUs
7758 full,nosmt - Enable TAA mitigation and disable SMT on
7761 vulnerable to cross-thread TAA attacks.
7762 off - Unconditionally disable TAA mitigation
7764 On MDS-affected machines, tsx_async_abort=off can be
7776 Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
7782 See also Documentation/input/devices/joystick-parport.rst
7784 udbg-immortal [PPC] When debugging early kernel crashes that
7790 Set number of hash buckets for UDP/UDP-Lite connections
7792 uhci-hcd.ignore_oc=
7794 Some badly-designed motherboards generate lots of
7801 [RISCV]
7809 [RISCV]
7811 Allow skipping vector unaligned access speed tests. This
7814 CPUs must have the same vector unaligned access speed.
7819 unwind_debug [X86-64,EARLY]
7827 (default -1 = authorized (same as 1),
7833 for newly-detected USB devices (default 2). This
7861 [USB] Specifies timeout for the initial 64-byte
7868 [USB] A list of quirk entries to augment the built-in
7871 VendorID:ProductID:Flags. The IDs are 4-digit hex
7873 will change the built-in quirk; setting it if it is
7878 a 255-byte read);
7882 Set-Interface requests);
7897 endpoints, the USB 2.0 and USB 3.0 spec
7901 (bInterval-1).
7939 usb-storage.delay_use=
7946 usb-storage.quirks=
7948 override the built-in unusual_devs list. List
7951 and Product ID values (4-digit hex numbers) and
7953 to a common usb-storage quirk flag as follows:
7995 medium is write-protected).
8004 1 - undefined instruction events
8005 2 - system calls
8006 4 - invalid data aborts
8007 8 - SIGSEGV faults
8008 16 - SIGBUS faults
8017 vdso32= [X86] Control the 32-bit vDSO
8018 vdso32=1: enable 32-bit VDSO
8019 vdso32=0 or vdso32=2: disable 32-bit VDSO
8029 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
8060 vga= [BOOT,X86-32] Select a particular video mode
8062 Documentation/admin-guide/svga.rst.
8077 - Disable all of the above options
8086 parisc, m64k, powerpc, riscv, sh, um, xtensa, s390, sparc).
8103 hypervisor to a guest via speculative side-channels.
8105 off - disable the mitigation
8106 ibpb - use Indirect Branch Prediction Barrier
8108 force - force vulnerability detection even on
8111 vsyscall= [X86-64,EARLY]
8114 code). Most statically-linked binaries and older
8138 see vga-softcursor.rst. Default: 2 = underline.
8143 This is a 16-member array composed of values
8144 ranging from 0-255.
8149 This is a 16-member array composed of values
8150 ranging from 0-255.
8155 This is a 16-member array composed of values
8156 ranging from 0-255.
8161 Set system-wide default UTF-8 mode for all tty's.
8162 Default is 1, i.e. UTF-8 mode is enabled for all
8167 Format=<-1|0|1>
8168 Set system-wide default for whether a cursor
8169 is shown on new VTs. Default is -1,
8174 vt.italic= [VT] Default color for italic text; 0-15.
8177 vt.underline= [VT] Default color for underlined text; 0-15.
8181 see Documentation/watchdog/watchdog-parameters.rst
8182 or other driver-specific files in the
8196 Format: <cpu-list>
8217 Per-cpu work items which run for longer than this
8220 them from noticeably delaying other per-cpu work
8238 Per-cpu workqueues are generally preferred because
8240 locality; unfortunately, per-cpu workqueues tend to
8243 Enabling this makes the per-cpu workqueues which
8257 Documentation/core-api/workqueue.rst.
8270 forces round-robin CPU selection to flush out
8278 on - Enable writecombine, use WUC for ioremap_wc()
8279 off - Disable writecombine, use SUC for ioremap_wc()
8281 x2apic_phys [X86-64,APIC,EARLY] Use x2apic physical mode instead of
8285 xen_512gb_limit [KNL,X86-64,XEN]
8295 ide-disks -- unplug primary master IDE devices
8296 aux-ide-disks -- unplug non-primary-master IDE devices
8297 nics -- unplug network devices
8298 all -- unplug all emulated devices (NICs and IDE disks)
8299 unnecessary -- unplugging emulated devices is
8302 never -- do not unplug even if version check succeeds
8316 Select whether to always use non-faulting (safe) MSR
8327 [KNL,X86,XEN,EARLY] Disable the vector callback for Xen
8336 xen_timer_slop= [X86-64,XEN,EARLY]
8361 preferred over the 2-level event handling, as it is
8378 xive.store-eoi=off [PPC]
8384 xhci-hcd.quirks [USB,KNL]