Lines Matching +full:assigned +full:- +full:resolution +full:- +full:bits
39 Documentation/arch/m68k/kernel-options.rst.
49 PARISC The PA-RISC architecture is enabled.
64 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
143 If set to vendor, prefer vendor-specific driver
168 debug output. Bits in debug_layer correspond to a
171 Bits in debug_level correspond to a level in
175 Documentation/firmware-guide/acpi/debug.rst for more information about
233 Format: <byte> or <bitmap-list>
236 Disable auto-serialization of AML methods
239 auto-serialization feature.
257 Ignore the ACPI-based watchdog interface (WDAT) and let
278 acpi_osi=! # disable all built-in OS vendor
280 acpi_osi=!! # enable all built-in OS vendor
342 For broken nForce2 BIOS resulting in XT-PIC timer.
351 as soon as the kernel's real-mode entry point is called.
389 See Documentation/sound/alsa-configuration.rst
396 align_va_addr= [X86-64]
401 CPU-intensive style benchmark, and it can vary highly in
404 32: only for 32-bit processes
405 64: only for 64-bit processes
406 on: enable for both 32- and 64-bit processes
407 off: disable for both 32- and 64-bit processes
417 Allow execve() of 32-bit applications and setting of the
419 subset of the CPUs support 32-bit EL0. When this
420 parameter is present, the set of CPUs supporting 32-bit
422 and hot-unplug operations may be restricted.
424 See Documentation/arch/arm64/asymmetric-32bit.rst for more
427 amd_iommu= [HW,X86-64]
430 fullflush - Deprecated, equivalent to iommu.strict=1
431 off - do not initialize any AMD IOMMU found in
433 force_isolation - Force device isolation for all
438 force_enable - Force enable the IOMMU on platforms known
441 pgtbl_v1 - Use v1 page table for DMA-API (Default).
442 pgtbl_v2 - Use v2 page table for DMA-API.
443 irtcachedis - Disable Interrupt Remapping Table (IRT) caching.
444 nohugepages - Limit page-sizes used for v1 page-tables
446 v2_pgsizes_only - Limit page-sizes used for v1 page-tables
450 amd_iommu_dump= [HW,X86-64]
456 amd_iommu_intr= [HW,X86-64]
459 legacy - Use legacy interrupt remapping mode.
460 vapic - Use virtual APIC mode, which allows IOMMU
462 This mode requires kvm-amd.avic=1.
491 Disable amd-pstate preferred core.
504 Power management functions (SPARCstation-4/5 + deriv.)
506 Disable APC CPU standby support. SPARCstation-Fox does
507 not play well with APC CPU idle - disable it if you have
510 apic [APIC,X86-64] Use IO-APIC. Default.
516 when initialising the APIC and IO-APIC components.
540 0 -- disable.
541 1 -- enable.
544 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
595 audit= [KNL] Enable the audit sub-system
597 0 | off - kernel audit is disabled and can not be
599 unset - kernel audit is initialized but disabled and
601 1 | on - kernel audit is initialized and partially
614 0 - Disable the BAU.
615 1 - Enable the BAU.
616 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
808 some critical bits.
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)
948 bits, and "f" is flow control ("r" for RTS or
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
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
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
1396 Control how the dt_cpu_ftrs device-tree binding is
1406 what data is available or for reverse-engineering.
1411 Documentation/admin-guide/dynamic-debug-howto.rst
1422 determined by stdout-path property in device tree's
1427 Start an early, polled-mode console on a Cadence
1438 Start an early, polled-mode console on the 8250/16550
1440 MMIO inter-register address stride is either 8-bit
1441 (mmio) or 32-bit (mmio32 or mmio32be).
1451 Start an early, polled-mode console on a pl011 serial
1455 the driver will use only 32-bit accessors to read/write
1464 Start an early, polled-mode console on a meson serial
1470 Start an early, polled-mode console on an msm serial
1476 Start an early, polled-mode console on an msm serial
1482 Start an early, polled-mode console on a serial port
1488 Start an early, polled-mode console on a serial port
1494 Use RISC-V SBI (Supervisor Binary Interface) for early
1512 Start an early, polled-mode console on a lantiq serial
1526 Start an early, polled-mode, output-only console on the
1531 Start an early, polled-mode console on the
1537 Start an early, polled-mode console on a Qualcomm
1545 coherent non-x86 systems that use system memory for
1648 Documentation/admin-guide/acpi/ssdt-overlays.rst for details.
1665 elanfreq= [X86-32]
1673 See Documentation/admin-guide/kdump/kdump.rst for details.
1689 0 -- permissive (log only, no denials).
1690 1 -- enforcing (deny and log).
1723 See also Documentation/fault-injection/.
1727 See Documentation/admin-guide/sysctl/net.rst for
1731 See Documentation/admin-guide/blockdev/floppy.rst.
1733 forcepae [X86-32]
1740 fred= [X86-64]
1791 ftrace_filter=[function-list]
1793 tracer at boot up. function-list is a comma-separated
1798 ftrace_notrace=[function-list]
1800 function-list. This list can be changed at run time
1804 ftrace_graph_filter=[function-list]
1807 function-list is a comma-separated list of functions
1811 ftrace_graph_notrace=[function-list]
1813 function-list. This list is a comma-separated list of
1833 off -- Don't create device links from firmware info.
1834 permissive -- Create device links from firmware info
1837 on -- Create device links from firmware info and use it
1839 rpm -- Like "on", but also use to order runtime PM.
1852 strict -- Default. Continue waiting on consumers to
1854 timeout -- Give up waiting on consumers and call
1864 See also Documentation/input/devices/joystick-parport.rst
1868 gart_fix_e820= [X86-64,EARLY] disable the fix e820 for K8 GART
1894 gcov_persist= [GCOV] When non-zero (default), profiling data for
1904 gpio-mockup.gpio_mockup_ranges
1907 gpio-mockup.gpio_mockup_named_lines
1939 against bounds-checking flaws in the kernel's
1947 [KNL] Should the hard-lockup detector generate
1963 auto - Hash pointers unless slab_debug is enabled.
1964 always - Always hash pointers (even if slab_debug is
1966 never - Never hash pointers. This option should only
1974 for 64-bit NUMA, off otherwise.
1982 corresponding firmware-first mode error processing
1992 during restoration read-only).
2027 highres= [KNL] Enable/disable high resolution timer mode.
2046 hpet= [X86-32,HPET] option to control HPET usage
2063 number of pages to allocate per-node can be specified.
2064 See also Documentation/admin-guide/mm/hugetlbpage.rst.
2075 Documentation/admin-guide/mm/hugetlbpage.rst.
2085 Note that this parameter only applies to non-gigantic huge pages.
2095 boot-time allocation of gigantic hugepages is skipped.
2128 When set to a non-zero value, a kernel panic will be triggered if
2136 CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time option. The value
2142 hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
2164 Set device-properties for ACPI-enumerated I2C-attached
2165 touchscreen, to e.g. fix coordinates of upside-down
2173 Omit "=<val>" entirely Set a boolean device-property
2174 Unsigned number Set a u32 device-property
2175 Anything else Set a string device-property
2178 i2c_touchscreen_props=GDIX1001:touchscreen-inverted-x:
2179 touchscreen-inverted-y
2181 i2c_touchscreen_props=MSSL1680:touchscreen-size-x=1920:
2182 touchscreen-size-y=1080:touchscreen-inverted-y:
2183 firmware-name=gsl1680-vendor-model.fw:silead,home-button
2188 (disabled by default, and as a pre-condition
2190 i8042.direct [HW] Put keyboard port into non-translated mode
2204 suspend-to-ram transitions, only during s2r
2228 -1 -- never invert brightness
2229 0 -- machine default
2230 1 -- force brightness inversion
2232 ia32_emulation= [X86-64]
2234 When true, allows loading 32-bit programs and executing 32-bit
2259 idle=nomwait: Disable mwait for CPU C-states
2287 legacy only accept legacy-NaN binaries, if supported
2289 2008 only accept 2008-NaN binaries, if supported
2300 'relaxed' straps the emulator for both legacy-NaN and
2301 2008-NaN, whereas 'strict' enables legacy-NaN only on
2310 Ignore loglevel setting - this will print /all/
2377 Formats: { "ima" | "ima-ng" | "ima-ngv2" | "ima-sig" |
2378 "ima-sigv2" }
2379 Default: "ima-ng"
2417 stuff: Deploy RSB-fill mitigation when retpoline is
2422 Documentation/admin-guide/hw-vuln/indirect-target-selection.rst
2433 initcall_blacklist= [KNL] Do not execute a comma-separated list of
2434 initcall functions. Useful for debugging built-in
2479 0 -- basic integrity auditing messages. (Default)
2480 1 -- additional integrity auditing messages.
2508 could harm performance of some high-throughput
2517 1 to 9 specify maximum depth of C-state.
2526 algorithms for p-state selection. There are two
2527 P-state selection algorithms provided by
2530 on whether or not the hardware managed P-states
2537 used along with the hardware-managed P-states (HWP)
2541 in favor of acpi-cpufreq. Forcing the intel_pstate driver
2542 instead of acpi-cpufreq may disable platform features, such
2544 P-States information being indicated to OSPM and therefore
2547 or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
2560 Allow per-logical-CPU P-State performance control limits using
2563 Do not enable capacity-aware scheduling (CAS) on
2566 intremap= [X86-64,Intel-IOMMU,EARLY]
2571 BIOS x2APIC opt-out request will be ignored
2614 AMD Gart HW IOMMU-specific options:
2633 Do scatter-gather (SG) merging. Implies "force"
2637 Don't do scatter-gather (SG) merging.
2650 0 - Try to allocate a 32-bit DMA address first, before
2652 1 - Allocate directly from the full usable range,
2654 greater than 32-bit addressing.
2658 0 - Lazy mode.
2664 1 - Strict mode.
2667 unset - Use value of CONFIG_IOMMU_DEFAULT_DMA_{LAZY,STRICT}.
2669 legacy driver-specific options takes precedence.
2674 0 - Use IOMMU translation for DMA.
2675 1 - Bypass the IOMMU for DMA.
2676 unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
2678 io7= [HW] IO7 for Marvel-based Alpha systems
2693 See Documentation/admin-guide/nfs/nfsroot.rst.
2729 Enables support for pseudo-NMIs in the kernel. This
2734 [RISC-V,EARLY]
2736 as IPIs. Intended for system where IMSIC is trap-n-emulated,
2748 long-running IRQs in the system.
2760 [Deprecated - use cpusets instead]
2761 Format: [flag-list,]<cpu-list>
2794 "number of CPUs in system - 1".
2805 if the automatically assigned interrupt mask of a
2820 The format of <cpu-list> is described above.
2824 ivrs_ioapic [HW,X86-64]
2825 Provide an override to the IOAPIC-ID<->DEVICE-ID
2829 For example, to map IOAPIC-ID decimal 10 to
2835 * To map IOAPIC-ID decimal 10 to PCI device 00:14.0
2838 * To map IOAPIC-ID decimal 10 to PCI segment 0x1 and
2842 ivrs_hpet [HW,X86-64]
2843 Provide an override to the HPET-ID<->DEVICE-ID
2847 For example, to map HPET-ID decimal 10 to
2853 * To map HPET-ID decimal 0 to PCI device 00:14.0
2856 * To map HPET-ID decimal 10 to PCI segment 0x1 and
2860 ivrs_acpihid [HW,X86-64]
2861 Provide an override to the ACPI-HID:UID<->DEVICE-ID
2865 For example, to map UART-HID:UID AMD0020:0 to
2871 * To map UART-HID:UID AMD0020:0 to PCI segment is 0,
2874 * To map UART-HID:UID AMD0020:0 to PCI segment 0x1 and
2898 the kernel for non-movable allocations. The requested
2908 subsystem. Note that allocations like PTEs-from-HighMem
2916 for non-movable allocations and remaining memory is used
2927 gdb or control-c on the dbgp connection. When
2928 not using this parameter you use sysrq-g to break into
2933 or a supported polling keyboard driver (non-usb).
2962 "0" | "off" | "n" - kexec handover is disabled
2963 "1" | "on" | "y" - kexec handover is enabled
2969 ranges that can only be used for non-kernel
2980 parameter defines the size of additional per-node
2985 Configure the RouterBoard 532 series on-chip
2988 kmemleak= [KNL,EARLY] Boot-time kmemleak enable/disable
2994 kprobe_event=[probe-list]
2996 The probe-list is a semicolon delimited list of probe
3026 execution by eliminating the write-protection faults
3053 virtualization on-demand when creating and destroying
3061 is that doing so may interfere with using out-of-tree
3088 back to huge pages. If the value is a non-zero N, KVM will
3093 kvm-amd.nested= [KVM,AMD] Control nested virtualization feature in
3096 kvm-amd.npt= [KVM,AMD] Control KVM's use of Nested Page Tables,
3097 a.k.a. Two-Dimensional Page Tables. Default is 1
3101 kvm-amd.ciphertext_hiding_asids=
3106 If ciphertext hiding is enabled, the joint SEV-ES and
3107 SEV-SNP ASID space is partitioned into separate SEV-ES
3108 and SEV-SNP ASID ranges, with the SEV-SNP range being
3109 [1..max_snp_asid] and the SEV-ES range being
3113 A non-zero value enables SEV-SNP ciphertext hiding and
3114 adjusts the ASID ranges for SEV-ES and SEV-SNP guests.
3115 KVM caps the number of SEV-SNP ASIDs at the maximum
3116 possible value, e.g. specifying -1u will assign all
3117 joint SEV-ES and SEV-SNP ASIDs to SEV-SNP. Note,
3118 assigning all joint ASIDs to SEV-SNP, i.e. configuring
3119 max_snp_asid == min_sev_asid-1, will effectively make
3120 SEV-ES unusable.
3122 kvm-arm.mode=
3128 nvhe: Standard nVHE-based mode, without support for
3135 nested: VHE-based mode with support for nested
3143 command-line.
3147 kvm-arm.vgic_v3_group0_trap=
3148 [KVM,ARM,EARLY] Trap guest accesses to GICv3 group-0
3151 kvm-arm.vgic_v3_group1_trap=
3152 [KVM,ARM,EARLY] Trap guest accesses to GICv3 group-1
3155 kvm-arm.vgic_v3_common_trap=
3159 kvm-arm.vgic_v4_enable=
3163 kvm-arm.wfe_trap_policy=
3172 kvm-arm.wfi_trap_policy=
3189 kvm-intel.ept= [KVM,Intel] Control KVM's use of Extended Page Tables,
3190 a.k.a. Two-Dimensional Page Tables. Default is 1
3194 kvm-intel.emulate_invalid_guest_state=
3196 state. Ignored if kvm-intel.enable_unrestricted_guest=1,
3202 kvm-intel.flexpriority=
3207 kvm-intel.nested=
3211 kvm-intel.unrestricted_guest=
3217 kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
3218 CVE-2018-3620.
3229 kvm-intel.vpid= [KVM,Intel] Control KVM's use of Virtual Processor
3249 on - enable the interface for the mitigation
3314 For details see: Documentation/admin-guide/hw-vuln/l1tf.rst
3320 lapic [X86-32,APIC,EARLY] Enable the local APIC even if BIOS
3324 value for LAPIC timer one-shot implementation. Default
3347 libata.force= [LIBATA] Force configurations. The format is a comma-
3359 first fan-out link behind PMP device. It does not
3373 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
3380 * rstonce: only attempt one reset during hot-unplug
3423 * external: Mark port as external (hotplug-capable).
3477 Specify the number of self-propagating call_rcu()
3485 occasional long-duration lock hold time. Defaults
3496 Set the number of locking read-acquisition kthreads.
3501 Set the number of locking write-acquisition kthreads.
3504 Set time (s) after boot for CPU-hotplug testing.
3507 Set time (s) between CPU-hotplug operations, or
3508 zero to disable CPU-hotplug testing.
3511 Do periodic testing of real-time lock priority
3516 non-real-time spinlocks, due to their disabling
3517 of preemption. Note that non-realtime mutexes
3530 Set task-shuffle interval (jiffies). Shuffling
3531 tasks allows some CPUs to go into dyntick-idle
3536 is useful for hands-off automated testing.
3555 Run the write-side locktorture kthreads at
3556 sched_set_fifo() real-time priority.
3574 7 (KERN_DEBUG) debug-level messages
3586 logo.nologo [FB] Disables display of the built-in Linux logo.
3604 an IEEE 1284-compliant printer is attached; if
3610 time-consuming boot-time autodetection (up to 250 ms per
3630 Example: machtype=lemote-yeeloong-2f-7inch
3642 (loop.max_loop) unconditionally pre-created at init time. The default
3645 devices can be requested on-demand with the
3646 /dev/loop-control interface.
3648 mce= [X86-{32,64}]
3685 do not opt-in to Local MCE delivery. Use legacy method
3706 don't overwrite the bios-set CMCI threshold. This boot
3715 force-enable recoverable machine check code paths
3721 See Documentation/admin-guide/md.rst.
3728 Control mitigation for the Micro-architectural Data
3743 full - Enable MDS mitigation on vulnerable CPUs
3744 full,nosmt - Enable MDS mitigation and disable
3746 off - Unconditionally disable MDS mitigation
3748 On TAA-affected machines, mds=off can be prevented by
3757 For details see: Documentation/admin-guide/hw-vuln/mds.rst
3769 the hypervisor, then assigned to KVM guests.
3772 [ARC,MICROBLAZE] - the limit applies only to low memory,
3775 [ARM64] - only limits memory covered by the linear
3788 [ARM,MIPS,EARLY] - override the memory layout
3795 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
3802 per-device physically contiguous DMA buffers.
3810 See Documentation/admin-guide/mm/memory-hotplug.rst.
3835 Example: Exclude memory from 0x18690000-0x1869ffff
3849 memmap=<size>%<offset>-<oldtype>+<newtype>
3851 from <oldtype> to <newtype>. If "-<oldtype>" is left
3866 repeatable BIOS-originated corruption always
3910 mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control
3916 Refer to Documentation/virt/kvm/x86/amd-memory-encryption.rst
3920 s2idle - Suspend-To-Idle
3921 shallow - Power-On Suspend or equivalent (if supported)
3922 deep - Suspend-To-RAM or equivalent (if supported)
3923 See Documentation/admin-guide/pm/sleep-states.rst.
3925 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
3935 base_rev=X - with <X> with format: <u32>
3949 0 - The attached screen is the 3.5" TFT
3950 1 - The attached screen is the 7" TFT
3951 2 - The VGA Shield is attached (1024x768)
3955 b - Enable backlight. The TFT backlight pin will be
3959 c - Enable the s3c camera interface.
3960 t - Reserved for enabling touchscreen support. The
3964 https://repo.or.cz/w/linux-2.6/mini2440.git
3969 arch-independent options, each of which is an
3970 aggregation of existing arch-specific options.
4000 ssbd=force-off [ARM64]
4014 have other ways of avoiding SMT-based attacks.
4028 supports attack-vector based controls as documented in
4029 Documentation/admin-guide/hw-vuln/attack_vector_controls.rst
4053 full - Enable mitigation on vulnerable CPUs
4055 full,nosmt - Enable mitigation and disable SMT on
4058 off - Unconditionally disable mitigation
4071 Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst
4101 module_blacklist= [KNL] Do not load a comma-separated list of
4110 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
4112 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
4126 movable_node [KNL,EARLY] Boot-time switch to make hotplugable memory
4133 Format: <name>,<region-number>,<size>,<offset>
4136 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
4175 something different and driver-specific.
4215 [NFS] enable 64-bit inode numbers.
4216 If zero, the NFS client will fake up a 32-bit inode
4218 of returning the full 64-bit number.
4219 The default is to return 64-bit inode numbers.
4254 [NFS4] Specify an additional fixed unique ident-
4285 driver. A non-zero value sets the minimum interval
4290 server-to-server copies for which this server is
4302 server-to-server copy, knfsd temporarily mounts
4309 See Documentation/admin-guide/nfs/nfsroot.rst.
4311 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
4312 See Documentation/admin-guide/nfs/nfsroot.rst.
4315 See Documentation/admin-guide/nfs/nfsroot.rst.
4319 NMI stack-backtrace request.
4328 0 - turn hardlockup detector in nmi_watchdog off
4329 1 - turn hardlockup detector in nmi_watchdog on
4330 rNNN - configure the watchdog with raw perf event 0xNNN
4343 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
4347 no4lvl [RISCV,EARLY] Disable 4-level and 5-level paging modes.
4348 Forces kernel to use 3-level paging instead.
4350 no5lvl [X86-64,RISCV,EARLY] Disable 5-level paging mode. Forces
4351 kernel to use 4-level paging instead.
4386 no_entry_flush [PPC,EARLY] Don't flush the L1-D cache when entering the kernel.
4388 noexec32 [X86-64]
4389 This affects only 32-bit executables.
4390 noexec32=on: enable non-executable mappings (default)
4392 noexec32=off: disable non-executable mappings
4403 nofxsr [BUGS=X86-32] Disables x86 floating point extended
4405 legacy floating-point registers on task switch.
4450 nointremap [X86-64,Intel-IOMMU,EARLY] Do not enable interrupt
4452 [Deprecated - use intremap=off]
4458 noirqdebug [X86-32] Disables the code which attempts to detect and
4468 no-kvmapf [X86,KVM,EARLY] Disable paravirtualized asynchronous page
4471 no-kvmclock [X86,KVM,EARLY] Disable paravirtualized KVM clock driver
4473 nolapic [X86-32,APIC,EARLY] Do not enable or use the local APIC.
4475 nolapic_timer [X86-32,APIC,EARLY] Do not use the local APIC timer.
4477 nomce [X86-32] Disable Machine Check Exception
4479 nomfgpt [X86-32] Disable Multi-Function General Purpose
4485 not load if they could possibly displace the pre-
4488 perform display-mode changes or accelerated rendering.
4501 nopcid [X86-64,EARLY] Disable the PCID cpu feature.
4506 nopti [X86-64,EARLY]
4522 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
4528 no-scroll [VGA] Disables scrollback.
4529 This is required for the Braillex ib80-piezo Braille
4532 nosgx [X86-64,SGX,EARLY] Disables Intel SGX kernel support.
4552 nosoftlockup [KNL] Disable the soft-lockup detector.
4558 nospectre_bhb [ARM64,EARLY] Disable all mitigations for Spectre-BHB (branch
4571 no-steal-acc [X86,PV_OPS,ARM64,PPC/PSERIES,RISCV,LOONGARCH,EARLY]
4578 timer IRQ sources, i.e., the IO-APIC timer. This can
4583 [PPC,EARLY] Don't flush the L1-D cache after accessing user data.
4596 no-vmw-sched-clock
4601 soft-lockup and NMI watchdog (hard-lockup).
4605 nox2apic [X86-64,APIC,EARLY] Do not enable x2APIC mode.
4613 enabling legacy floating-point and sse state.
4635 n. So during boot up some boot time memory for per-cpu
4636 variables need be pre-allocated for later physical cpu
4663 soft-reserved memory partitioning.
4672 See Documentation/admin-guide/sysctl/vm.rst for details.
4675 See Documentation/core-api/debugging-via-ohci1394.rst for more
4690 onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
4694 boundary - index of last SLC block on Flex-OneNAND.
4696 lock - Configure if Flex-OneNAND boundary should be locked.
4715 page_owner= [KNL,EARLY] Boot-time page_owner enabling option.
4721 page_poison= [KNL,EARLY] Boot-time parameter changing the state of
4749 See Documentation/admin-guide/tainted-kernels.rst for
4757 User can chose combination of the following bits:
4807 Parallel ports are assigned in the order they
4821 Set to non-zero to probe primary and secondary ISA
4827 Set to non-zero if a chip is present that snoops speed
4844 IORDY enable mask. Set individual bits to allow IORDY
4869 bits to allow the use of the respective PIO modes.
4875 Set to non-zero to probe tertiary and further ISA
4885 corresponding bits in the mask to 1. Bit 0 is for
4891 Set to non-zero to probe QDI controllers. By default
4896 Set to non-zero to probe Winbond controllers. Use
4904 Supported PIO mode mask. Set individual bits to allow
4943 bios [X86-32] force use of PCI BIOS, don't access
4945 has a non-standard PCI host bridge.
4946 nobios [X86-32] disallow use of PCI BIOS, only direct
4952 data in IO port 0xCFC, both 32-bit).
4954 Mechanism 2 (IO port 0xCF8 is an 8-bit port for
4955 the function, IO port 0xCFA, also 8-bit, sets
4957 through ports 0xC000-0xCFFF).
4964 root domains (aka PCI segments, in ACPI-speak).
4972 disable the use of MSI interrupts system-wide.
4977 primary IO-APIC for bridges that cannot disable
4984 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
4998 BIOS assigned address ranges.
5000 BARs that weren't assigned by the BIOS.
5002 assigned automatically to PCI devices. You can
5008 F0000h-100000h range.
5013 assign-busses [X86] Always assign all PCI bus
5034 <linux-pci@vger.kernel.org>.
5038 a bug to <linux-pci@vger.kernel.org>.
5050 bfsort Sort PCI devices into breadth-first order.
5053 nobfsort Don't sort PCI devices into breadth-first order.
5055 tuning and use the BIOS-configured MPS defaults.
5065 configuration allows peer-to-peer DMA between
5068 that hot-added devices will work.
5083 A PCI-PCI bridge can be specified if resource
5089 for 4096-byte alignment.
5091 end-to-end CRC checking). Only effective if
5122 noats [PCIE, Intel-IOMMU, AMD-IOMMU]
5153 bit-0 : ACS Source Validation
5154 bit-1 : ACS Translation Blocking
5155 bit-2 : ACS P2P Request Redirect
5156 bit-3 : ACS P2P Completion Redirect
5157 bit-4 : ACS Upstream Forwarding
5158 bit-5 : ACS P2P Egress Control
5159 bit-6 : ACS Direct Translated P2P
5169 Validation unchanged from whatever power-up
5181 system-wide.
5195 dpc-native Use native PCIe service for DPC only. May
5212 Keep all power-domains already enabled by bootloader on,
5230 pirq= [SMP,APIC] Manual mp-table setup
5231 See Documentation/arch/x86/i386/IO-APIC.rst.
5235 See also Documentation/admin-guide/parport.rst.
5254 resume of devices during system-wide power transitions.
5256 dependencies are not well-defined, or for debugging
5266 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
5275 { on | off | curr | res | no-curr | no-res }
5320 none - Limited to cond_resched() calls
5321 voluntary - Limited to cond_resched() and might_sleep() calls
5322 full - Any section that isn't explicitly preempt disabled
5326 lazy - Scheduler controlled. Similar to full but instead
5332 print-fatal-signals=
5338 coredump - etc.
5341 you might want to try "ulimit -i unlimited".
5353 or lockdep-detected issues (only if lock debug is on).
5361 Allows storing messages from non-panic CPUs into
5363 flushed to consoles by the panic-CPU on
5364 a best-effort basis.
5370 on - unlimited logging to /dev/kmsg from userspace
5371 off - logging to /dev/kmsg disabled
5372 ratelimit - ratelimit the logging
5383 - 'always': traditional behavior always allows mem overrides.
5384 - 'ptrace': only allow mem overrides for active ptracers.
5385 - 'never': never allow mem overrides.
5389 Limit processor to maximum C-state
5393 Ignore the _CST method to determine C-states,
5400 Param: "schedule" - profile schedule points.
5401 Param: "kvm" - profile VM exits.
5402 Param: <number> - step/bucket size as a power of 2 for
5425 psmouse.resolution=
5426 [HW,MOUSE] Set desired mouse resolution, in dpi.
5433 pti= [X86-64] Control Page Table Isolation of user and
5438 on - unconditionally enable
5439 off - unconditionally disable
5440 auto - kernel detects whether your CPU model is
5446 [KNL] Number of legacy pty's. Overwrites compiled-in
5458 See Documentation/admin-guide/md.rst.
5461 See Documentation/admin-guide/blockdev/ramdisk.rst.
5477 randomization, which provides roughly 5 bits of
5480 cross-syscall address exposures. This is only
5486 ras=option[,option,...] [KNL] RAS-specific options
5492 rcu_nocbs[=cpu-list]
5497 enable the no-callback CPU mode, which prevents
5502 "p" for RCU-preempt, "s" for RCU-sched, and "g"
5506 and real-time workloads. It can also improve
5510 list of CPUs is set to no-callback mode from boot.
5514 no-callback mode from boot but the mode may be
5525 This improves the real-time response for the
5536 Do only a one-line RCU CPU stall warning when
5537 there is an ongoing too-long CSD-lock wait.
5543 If triggered before the RCU grace-period machinery
5553 RCU grace-period cleanup.
5557 RCU grace-period initialization.
5561 RCU grace-period pre-initialization, that is,
5562 the propagation of recent CPU-hotplug changes up
5566 Set delay from grace-period initialization to
5579 soliciting quiescent-state help from
5591 Set the SCHED_FIFO priority of the RCU per-CPU
5594 and for the RCU grace-period kthreads (rcu_bh,
5596 set, valid values are 1-99 and the default is 1
5597 (the least-favored priority). Otherwise, when
5598 RCU_BOOST is not set, valid values are 0-99 and
5599 the default is zero (non-realtime operation).
5604 On callback-offloaded (rcu_nocbs) CPUs,
5607 use of the ->nocb_bypass list. However, in the
5608 common non-flooded case, RCU queues directly to
5609 the main ->cblist in order to avoid the extra
5610 overhead of the ->nocb_bypass list and its lock.
5612 a single jiffy, RCU pre-queues the callbacks into
5613 the ->nocb_bypass queue. The definition of "too
5617 On callback-offloaded (rcu_nocbs) CPUs, avoid
5630 batch limiting is re-enabled.
5634 RCU's force-quiescent-state scan will aggressively
5642 Set the page-cache refill delay (in milliseconds)
5643 in response to low-memory conditions. The range
5647 Set the shift-right count to use to compute
5648 the callback-invocation batch limit bl from
5655 Please note that this callback-invocation batch
5656 limit applies only to non-offloaded callback
5665 cache-to-cache transfer latencies.
5668 Change the number of CPUs assigned to each
5671 and for NUMA systems with large remote-access
5687 the wakeup overhead on the global grace-period
5689 each group's NOCB grace-period kthread.
5692 Cause the grace-period kthread to get an extra
5694 it should at force-quiescent-state time.
5707 this specifies an rcu_read_unlock()-time delay
5711 of RCU-protected pointers after the relevant
5721 per-CPU rcuc kthreads. Defaults to a non-zero
5751 grace-period primitives such as call_rcu().
5762 grace-period primitives.
5765 Set test-start holdoff period. The purpose of
5783 Test the double-argument variant of kfree_rcu().
5785 rcuscale.kfree_rcu_test_single, both the single-
5786 and double-argument variants are tested.
5789 Test the single-argument variant of kfree_rcu().
5791 rcuscale.kfree_rcu_test_double, both the single-
5792 and double-argument variants are tested.
5806 does not affect the data-collection interval,
5811 Set number of RCU readers. The value -1 selects
5813 "n" less than -1 selects N-n+1, where N is again
5814 the number of CPUs. For example, -2 selects N
5815 (the number of CPUs), -3 selects N+1, and so on.
5816 A value of "n" less than or equal to -N selects
5829 complete. This is useful for hands-off automated
5836 Write-side holdoff between grace periods,
5841 Additional write-side holdoff between grace
5859 for RCU grace-period forward-progress testing
5866 Specify the fraction of a CPU-stall-warning
5867 period to do tight-loop forward-progress testing.
5871 forward-progress tests.
5875 need_resched() during tight-loop forward-progress
5879 Use conditional/asynchronous update-side
5880 normal-grace-period primitives, if available.
5883 Use conditional/asynchronous update-side
5884 expedited-grace-period primitives, if available.
5887 Use conditional/asynchronous update-side
5888 normal-grace-period primitives that also take
5893 Use conditional/asynchronous update-side
5894 expedited-grace-period primitives that also take
5918 Use expedited update-side primitives, if available.
5921 Use normal (non-expedited) asynchronous
5922 update-side primitives, if available.
5925 Use polled update-side normal-grace-period
5929 Use polled update-side expedited-grace-period
5933 Use polled update-side normal-grace-period
5938 Use polled update-side expedited-grace-period
5962 Use normal (non-expedited) synchronous
5963 update-side primitives, if available. If all
5967 they are all non-zero.
5970 Enable grace-period wrap lag testing. Setting
5975 Set the value for grace-period wrap lag during
5990 the grace-period wrap lag will be set to the
6000 Leak an RCU-protected pointer out of the reader.
6015 Set number of RCU callback-offload togglers.
6020 callback-offload toggling attempts.
6023 Set number of RCU readers. The value -1 selects
6024 N-1, where N is the number of CPUs. A value
6025 "n" less than -1 selects N-n-2, where N is again
6026 the number of CPUs. For example, -2 selects N
6027 (the number of CPUs), -3 selects N+1, and so on.
6030 Enable debug-object double-call_rcu() testing.
6033 Set time (s) after boot for CPU-hotplug testing.
6036 Set time (jiffies) between CPU-hotplug operations,
6037 or zero to disable CPU-hotplug testing.
6041 by a high-priority FIFO real-time task. Set to
6050 second) between preemptions by a high-priority
6051 FIFO real-time task. This delay is mediated
6056 The number of times in a given read-then-exit
6057 episode that a set of read-then-exit kthreads
6062 read-then-exit testing episodes.
6067 are entered from low-order bit up, and are
6069 0x1 bit is normal readers, 0x2 NMI-safe readers,
6070 and 0x4 light-weight readers.
6073 Set task-shuffle interval (s). Shuffling tasks
6074 allows some CPUs to go into dyntick-idle mode
6079 is useful for hands-off automated testing.
6088 any other stall-related activity. Note that
6094 in scheduling-while-atomic splats.
6113 grace-period kthread to test RCU CPU stall
6137 of RCU priority-boost testing. Defaults to zero,
6144 Test RCU's dyntick-idle handling. See also the
6182 adjusted to an arch timer tick resolution.
6199 Use expedited grace-period primitives, for
6203 real-time latency, and degrade energy efficiency.
6207 Use only normal grace-period primitives,
6210 real-time latency, CPU utilization, and
6212 increased grace-period latency. This parameter
6219 only normal grace-period primitives. No effect
6225 post-boot attempt at an expedited RCU grace
6226 period to instead use normal non-expedited
6227 grace-period processing.
6235 set to the default value of -1.
6238 Set the minimum number of callback-queuing-time
6239 lock-contention events per jiffy required to
6240 cause the RCU Tasks flavors to switch to per-CPU
6243 the default value of -1.
6248 of -1 allows this to be automatically (and
6256 number avoids disturbing real-time workloads,
6261 cancel laziness on that CPU. Use -1 to disable
6271 only printed prior to the stall-warning message
6319 force - Override the decision by the kernel to hide the
6358 There are some built-in platform specific "quirks"
6359 - you may see: "reboot: <name> series board detected.
6363 built-in quirk table, and use the generic default
6396 Set test-start holdoff period. The purpose of
6411 but the default has already reduced the per-pass
6416 Set number of readers. The default value of -1
6425 Set the read-side critical-section duration,
6429 Specify the read-protection implementation to test.
6455 See Documentation/admin-guide/cgroup-v1/cpusets.rst.
6485 reservetop= [X86-32,EARLY]
6502 See Documentation/power/swsusp-and-swap-files.rst
6518 AMD-based UNRET and IBPB mitigations alone do not stop
6520 sibling threads. For that reason, STIBP is used on pro-
6524 off - no mitigation
6525 auto - automatically select a mitigation
6526 auto,nosmt - automatically select a mitigation,
6530 ibpb - On AMD, mitigate short speculation
6535 ibpb,nosmt - Like "ibpb" above but will disable SMT
6539 unret - Force enable untrained return thunks,
6540 only effective on AMD f15h-f17h based
6542 unret,nosmt - Like unret, but will disable SMT when STIBP
6574 ro [KNL] Mount root device read-only on boot
6577 on Mark read-only kernel memory as read-only (default).
6578 off Leave read-only kernel memory writable for debugging.
6579 noalias Mark read-only kernel memory as read-only but retain
6587 debug-uart get routed to the D+ and D- pins of the usb
6593 block/early-lookup.c for details.
6630 rw [KNL] Mount root device read-write on boot
6659 solution to mutex-based priority inversion.
6689 to 10 seconds for built-in smp_call_function()
6696 that requesting even small non-zero numbers of
6703 The default of -1 specifies a number of kthreads
6708 test before initiating CPU-hotplug operations.
6712 CPU-hotplug operations. Specifying zero (which
6713 is the default) disables CPU-hotplug operations.
6719 Non-zero values are useful for automated tests.
6742 "wait" parameter. A value of -1 selects the
6743 default if all other weights are -1. However,
6745 value of -1 will instead select a weight of zero.
6750 non-zero "wait" parameter. See weight_single.
6763 non-zero "wait" parameter. See weight_single
6775 non-zero "wait" parameter. See weight_single
6786 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
6787 1 -- enable.
6798 0 -- disable.
6799 1 -- enable.
6802 serialnumber [BUGS=X86-32]
6804 sev=option[,option...] [X86-64]
6810 Do not enable SEV-SNP (applies to host/hypervisor
6813 SEV-SNP guests.
6821 to set it to "all" by meaning -- no limit here.
6833 Documentation/admin-guide/mm/slab.rst.
6844 Documentation/admin-guide/mm/slab.rst.
6860 Documentation/admin-guide/mm/slab.rst.
6866 Documentation/admin-guide/mm/slab.rst.
6881 Documentation/admin-guide/mm/slab.rst.
6908 using the csdlock_debug- kernel parameter.
6913 system. By default, let CSD-lock acquisition
6915 for this value provides a 5-minute timeout.
6917 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
6918 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
6919 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
6920 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
6921 smsc-ircc2.ircc_irq= [HW] IRQ line
6922 smsc-ircc2.ircc_dma= [HW] DMA channel
6923 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
6933 Default: -1 (no limit)
6936 [KNL] Should the soft-lockup detector generate panics.
6939 A value of 1 instructs the soft-lockup detector
6940 to panic the machine when a soft-lockup occurs. It is
6943 respective build-time switch to that functionality.
6946 [KNL] Should the soft-lockup detector generate
6951 See Documentation/admin-guide/laptops/sonypi.rst
6958 on - (default) Enable the HW or SW mitigation as
6961 vmexit - On systems which don't have the HW mitigation
6964 protected from VM-originated BHI attacks, but
6966 off - Disable the mitigation.
6973 on - unconditionally enable, implies
6975 off - unconditionally disable, implies
6977 auto - kernel detects whether your CPU model is
6996 retpoline - replace indirect branches
6997 retpoline,generic - Retpolines
6998 retpoline,lfence - LFENCE; indirect branch
6999 retpoline,amd - alias for retpoline,lfence
7000 eibrs - Enhanced/Auto IBRS
7001 eibrs,retpoline - Enhanced/Auto IBRS + Retpolines
7002 eibrs,lfence - Enhanced/Auto IBRS + LFENCE
7003 ibrs - use IBRS to protect kernel
7013 on - Unconditionally enable mitigations. Is
7016 off - Unconditionally disable mitigations. Is
7019 prctl - Indirect branch speculation is enabled,
7025 - Like "prctl" above, but only STIBP is
7031 - Same as "prctl" above, but all seccomp
7036 - Like "seccomp" above, but only STIBP is
7041 auto - Kernel selects the mitigation depending on
7052 off - Disable mitigation
7053 microcode - Enable microcode mitigation only
7054 safe-ret - Enable sw-only safe RET mitigation (default)
7055 ibpb - Enable mitigation by issuing IBPB on
7057 ibpb-vmexit - Issue IBPB only on VMEXIT
7058 (cloud-specific mitigation)
7083 on - Unconditionally disable Speculative Store Bypass
7084 off - Unconditionally enable Speculative Store Bypass
7085 auto - Kernel detects whether the CPU model contains an
7091 prctl - Control Speculative Store Bypass per thread
7095 seccomp - Same as "prctl" above, but all seccomp threads
7103 on,auto - On Power8 and Power9 insert a store-forwarding
7107 off - No action.
7121 off - not enabled
7123 warn - the kernel will emit rate-limited warnings
7131 fatal - the kernel will send SIGBUS to applications
7136 ratelimit:N -
7156 Certain CPUs are vulnerable to an MDS-like
7157 exploit which can leak bits from the random
7176 This kernel-boot parameter defaults to 128,
7177 but takes effect only when the low-order four
7178 bits of srcutree.convert_to_big is equal to 3
7194 instead of the compile-time CONFIG_NR_CPUS.
7198 grace-period sequence counter wrap for the
7199 srcu_data structure's ->srcu_gp_seq_needed field.
7200 The greater the number of bits set in this kernel
7202 be checked for. Note that the bottom two bits
7214 Specifies the number of no-delay instances
7221 Specifies the per-grace-period phase, number of
7222 non-sleeping polls of readers. Beyond this limit,
7228 Specifies number of microseconds of non-sleeping
7229 delay between each non-sleeping poll of readers.
7232 Specifies the number of update-side contention
7237 set for contention-based conversions to occur.
7247 force-on: Unconditionally enable mitigation for
7249 force-off: Unconditionally disable mitigation for
7271 stack traces. Pools are allocated on-demand up to this
7277 stacktrace_filter=[function-list]
7279 will trace at boot up. function-list is a comma-separated
7287 Set the STI (builtin display/keyboard on the HP-PARISC
7289 as the initial boot-console.
7352 to global on non-NUMA machines)
7377 <int> -- Number of I/O TLB slabs
7378 <int> -- Second integer after comma. Number of swiotlb
7381 force -- force using of bounce buffers even if they
7383 noforce -- Never use bounce buffers (for debugging)
7398 Ignore sysrq setting - this boot parameter will
7406 cache size. See Documentation/networking/ip-sysctl.rst
7413 Specify "mem" (for Suspend-to-RAM) or "standby" (for
7418 wakeup-capable RTC alarm.
7424 -1: disable all active trip points in all thermal zones
7428 -1: disable all critical trip points in all thermal zones
7435 -1: disable all passive trip points
7441 <deci-seconds>: poll all this frequency
7445 Format: <size>[KMG],<size>[KMG]:<state>;<size>[KMG]-<size>[KMG]:<state>
7450 See Documentation/admin-guide/mm/transhuge.rst for more
7458 Format: <size>[KMG],<size>[KMG]:<policy>;<size>[KMG]-<size>[KMG]:<policy>
7464 See Documentation/admin-guide/mm/transhuge.rst for more
7476 Prevent the CPU-hotplug component of torturing
7480 Dump the ftrace buffer at torture-test shutdown,
7484 with rotating-rust storage.
7489 disables verbose-printk() sleeping.
7492 Duration of each verbose-printk() sleep in jiffies.
7525 https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/
7563 local - Use the per CPU time stamp counter
7567 global - Event time stamps are synchronized across
7570 counter - Simple counting of events (1, 2, ..)
7574 uptime - Use jiffies as the time stamp.
7575 perf - Use the same clock that perf uses.
7576 mono - Use ktime_get_mono_fast_ns() for time stamps.
7577 mono_raw - Use ktime_get_raw_fast_ns() for time
7579 boot - Use ktime_get_boot_fast_ns() for time stamps.
7583 trace_event=[event-list]
7585 to facilitate early boot debugging. The event-list is a
7586 comma-separated list of trace events to enable. See
7597 trace_instance=[instance-info]
7622 traceoff - Have the tracing instance tracing disabled after it is created.
7623 traceprintk - Have trace_printk() write into this trace instance
7670 trace_options=[option-list]
7672 The option-list is a comma delimited list of options
7686 trace_trigger=[trigger-list]
7732 See Documentation/admin-guide/mm/transhuge.rst
7739 See Documentation/admin-guide/mm/transhuge.rst
7746 See Documentation/admin-guide/mm/transhuge.rst
7754 - "tpm"
7755 - "tee"
7756 - "caam"
7757 - "dcp"
7767 - "kernel"
7768 - the same value as trusted.source: "tpm" or "tee"
7769 - "default"
7792 off - disable the mitigation
7793 on - enable the mitigation (default)
7794 user - mitigate only user/kernel transitions
7795 vm - mitigate only guest/host transitions
7803 high-resolution timer mode on older hardware, and in
7839 on - Enable TSX on the system. Although there are
7842 several previous speculation-related CVEs, and
7846 off - Disable TSX on the system. (Note that this
7854 auto - Disable TSX if X86_BUG_TAA is present,
7859 See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
7865 Similar to Micro-architectural Data Sampling (MDS)
7880 full - Enable TAA mitigation on vulnerable CPUs
7883 full,nosmt - Enable TAA mitigation and disable SMT on
7886 vulnerable to cross-thread TAA attacks.
7887 off - Unconditionally disable TAA mitigation
7889 On MDS-affected machines, tsx_async_abort=off can be
7901 Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
7907 See also Documentation/input/devices/joystick-parport.rst
7909 udbg-immortal [PPC] When debugging early kernel crashes that
7915 Set number of hash buckets for UDP/UDP-Lite connections
7917 uhci-hcd.ignore_oc=
7919 Some badly-designed motherboards generate lots of
7944 unwind_debug [X86-64,EARLY]
7952 (default -1 = authorized (same as 1),
7958 for newly-detected USB devices (default 2). This
7986 [USB] Specifies timeout for the initial 64-byte
7993 [USB] A list of quirk entries to augment the built-in
7996 VendorID:ProductID:Flags. The IDs are 4-digit hex
7998 will change the built-in quirk; setting it if it is
8003 a 255-byte read);
8007 Set-Interface requests);
8026 (bInterval-1).
8064 usb-storage.delay_use=
8071 usb-storage.quirks=
8073 override the built-in unusual_devs list. List
8076 and Product ID values (4-digit hex numbers) and
8078 to a common usb-storage quirk flag as follows:
8120 medium is write-protected).
8129 1 - undefined instruction events
8130 2 - system calls
8131 4 - invalid data aborts
8132 8 - SIGSEGV faults
8133 16 - SIGBUS faults
8142 vdso32= [X86] Control the 32-bit vDSO
8143 vdso32=1: enable 32-bit VDSO
8144 vdso32=0 or vdso32=2: disable 32-bit VDSO
8154 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
8185 vga= [BOOT,X86-32] Select a particular video mode
8187 Documentation/admin-guide/svga.rst.
8202 - Disable all of the above options
8228 hypervisor to a guest via speculative side-channels.
8230 off - disable the mitigation
8231 ibpb - use Indirect Branch Prediction Barrier
8233 force - force vulnerability detection even on
8236 vsyscall= [X86-64,EARLY]
8239 code). Most statically-linked binaries and older
8263 see vga-softcursor.rst. Default: 2 = underline.
8268 This is a 16-member array composed of values
8269 ranging from 0-255.
8274 This is a 16-member array composed of values
8275 ranging from 0-255.
8280 This is a 16-member array composed of values
8281 ranging from 0-255.
8286 Set system-wide default UTF-8 mode for all tty's.
8287 Default is 1, i.e. UTF-8 mode is enabled for all
8292 Format=<-1|0|1>
8293 Set system-wide default for whether a cursor
8294 is shown on new VTs. Default is -1,
8299 vt.italic= [VT] Default color for italic text; 0-15.
8302 vt.underline= [VT] Default color for underlined text; 0-15.
8306 see Documentation/watchdog/watchdog-parameters.rst
8307 or other driver-specific files in the
8321 Format: <cpu-list>
8342 Per-cpu work items which run for longer than this
8345 them from noticeably delaying other per-cpu work
8363 Per-cpu workqueues are generally preferred because
8365 locality; unfortunately, per-cpu workqueues tend to
8368 Enabling this makes the per-cpu workqueues which
8382 Documentation/core-api/workqueue.rst.
8395 forces round-robin CPU selection to flush out
8403 on - Enable writecombine, use WUC for ioremap_wc()
8404 off - Disable writecombine, use SUC for ioremap_wc()
8406 x2apic_phys [X86-64,APIC,EARLY] Use x2apic physical mode instead of
8410 xen_512gb_limit [KNL,X86-64,XEN]
8420 ide-disks -- unplug primary master IDE devices
8421 aux-ide-disks -- unplug non-primary-master IDE devices
8422 nics -- unplug network devices
8423 all -- unplug all emulated devices (NICs and IDE disks)
8424 unnecessary -- unplugging emulated devices is
8427 never -- do not unplug even if version check succeeds
8441 Select whether to always use non-faulting (safe) MSR
8461 xen_timer_slop= [X86-64,XEN,EARLY]
8465 improve timer resolution at the expense of processing
8486 preferred over the 2-level event handling, as it is
8503 xive.store-eoi=off [PPC]
8509 xhci-hcd.quirks [USB,KNL]