Lines Matching +full:uefi +full:- +full:rtc +full:- +full:info
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
174 The debug_level mask defaults to "info". See
175 Documentation/firmware-guide/acpi/debug.rst for more information about
178 Enable processor driver info messages:
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
816 force such clocks to be always-on nor does it reserve
820 information, see Documentation/driver-api/clk.rst.
822 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
839 [X86-32] pit,hpet,tsc;
846 [X86-64] hpet,tsc
852 architected timer so that code using WFE-based polling
866 clocksource-wdtest.holdoff= [KNL]
872 cma=nn[MG]@[start[MG][-end[MG]]]
883 Sets the size of kernel per-numa memory area for
885 per-numa CMA altogether. And If this option is not
887 With per-numa CMA enabled, DMA users on node nid will
914 com20020= [HW,NET] ARCnet - COM20020 chipset
918 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
922 ARCnet - COM90xx chipset (memory-mapped buffers)
951 See Documentation/admin-guide/serial-console.rst for more
966 $ ls -d /sys/bus/serial-base/devices/*:*.*/tty/*
967 /sys/bus/serial-base/devices/00:04:0.0/tty/ttyS0
980 Start an early, polled-mode console on the 8250/16550
983 MMIO inter-register address stride is either 8-bit
984 (mmio), 16-bit (mmio16), or 32-bit (mmio32).
988 the h/w is not re-initialized.
1015 syscall, or to executing "dmesg -S --raw" or to reading
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
1183 Print debugging info while doing the locking API
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
1641 you are really sure that your UEFI does sane gc and
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).
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".
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
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
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.
4588 specified debug info. Drivers can append the 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
4676 info.
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
4756 panic_print= Bitmask for printing system info when panic happens.
4758 bit 0: print all tasks info
4759 bit 1: print system memory info
4760 bit 2: print timer info
4761 bit 3: print locks info if CONFIG_LOCKDEP is on
4776 tasks: print all tasks info
4777 mem: print system memory info
4778 timers: print timers info
4779 locks: print locks info if CONFIG_LOCKDEP is on
4821 Set to non-zero to probe primary and secondary ISA
4827 Set to non-zero if a chip is present that snoops speed
4875 Set to non-zero to probe tertiary and further ISA
4891 Set to non-zero to probe QDI controllers. By default
4896 Set to non-zero to probe Winbond controllers. Use
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).
4958 See http://wiki.osdev.org/PCI for more info
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
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
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.
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.
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
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
7176 This kernel-boot parameter defaults to 128,
7177 but takes effect only when the low-order four
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.
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]
8486 preferred over the 2-level event handling, as it is
8503 xive.store-eoi=off [PPC]
8509 xhci-hcd.quirks [USB,KNL]