Lines Matching +full:meson +full:- +full:rng
16 force -- enable ACPI if default was off
17 on -- enable ACPI but allow fallback to DT [arm64,riscv64]
18 off -- disable ACPI if default was on
19 noirq -- do not use ACPI for IRQ routing
20 strict -- Be less tolerant of platforms that are not
22 rsdt -- prefer RSDT over (default) XSDT
23 copy_dsdt -- copy DSDT to memory
24 nospcr -- disable console in ACPI SPCR table as
41 If set to vendor, prefer vendor-specific driver
73 Documentation/firmware-guide/acpi/debug.rst for more information about
131 Format: <byte> or <bitmap-list>
134 Disable auto-serialization of AML methods
137 auto-serialization feature.
155 Ignore the ACPI-based watchdog interface (WDAT) and let
176 acpi_osi=! # disable all built-in OS vendor
178 acpi_osi=!! # enable all built-in OS vendor
240 For broken nForce2 BIOS resulting in XT-PIC timer.
249 as soon as the kernel's real-mode entry point is called.
287 See Documentation/sound/alsa-configuration.rst
294 align_va_addr= [X86-64]
299 CPU-intensive style benchmark, and it can vary highly in
302 32: only for 32-bit processes
303 64: only for 64-bit processes
304 on: enable for both 32- and 64-bit processes
305 off: disable for both 32- and 64-bit processes
315 Allow execve() of 32-bit applications and setting of the
317 subset of the CPUs support 32-bit EL0. When this
318 parameter is present, the set of CPUs supporting 32-bit
320 and hot-unplug operations may be restricted.
322 See Documentation/arch/arm64/asymmetric-32bit.rst for more
325 amd_iommu= [HW,X86-64]
328 fullflush - Deprecated, equivalent to iommu.strict=1
329 off - do not initialize any AMD IOMMU found in
331 force_isolation - Force device isolation for all
336 force_enable - Force enable the IOMMU on platforms known
339 pgtbl_v1 - Use v1 page table for DMA-API (Default).
340 pgtbl_v2 - Use v2 page table for DMA-API.
341 irtcachedis - Disable Interrupt Remapping Table (IRT) caching.
342 nohugepages - Limit page-sizes used for v1 page-tables
344 v2_pgsizes_only - Limit page-sizes used for v1 page-tables
348 amd_iommu_dump= [HW,X86-64]
354 amd_iommu_intr= [HW,X86-64]
357 legacy - Use legacy interrupt remapping mode.
358 vapic - Use virtual APIC mode, which allows IOMMU
360 This mode requires kvm-amd.avic=1.
389 Disable amd-pstate preferred core.
402 Power management functions (SPARCstation-4/5 + deriv.)
404 Disable APC CPU standby support. SPARCstation-Fox does
405 not play well with APC CPU idle - disable it if you have
412 when initialising the APIC and IO-APIC components.
413 For X86-32, this can also be used to specify an APIC
436 0 -- disable.
437 1 -- enable.
440 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
485 audit= [KNL] Enable the audit sub-system
487 0 | off - kernel audit is disabled and can not be
489 unset - kernel audit is initialized but disabled and
491 1 | on - kernel audit is initialized and partially
504 0 - Disable the BAU.
505 1 - Enable the BAU.
506 unset - Disable the BAU.
545 See Documentation/block/cmdline-partition.rst
559 See Documentation/admin-guide/bootconfig.rst
564 bttv.pll= See Documentation/admin-guide/media/bttv.rst
573 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
592 inclusive. See arch/mips/include/asm/pgtable-bits.h
602 - foo isn't auto-mounted if you mount all cgroups in
604 - foo isn't visible as an individually mountable
606 - if foo is an optional feature then the feature is
612 Specifying "pressure" disables per-cgroup pressure
630 nosocket -- Disable socket memory accounting.
631 nokmem -- Disable kernel memory accounting.
632 nobpf -- Disable BPF memory accounting.
637 0 -- check protection applied by kernel (includes
639 1 -- check protection requested by application.
651 numbers X. Note the Linux-specific bits are not necessarily
652 stable over kernel options, but the vendor-specific
672 force such clocks to be always-on nor does it reserve
676 information, see Documentation/driver-api/clk.rst.
678 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
695 [X86-32] pit,hpet,tsc;
702 [X86-64] hpet,tsc
708 architected timer so that code using WFE-based polling
722 clocksource-wdtest.holdoff= [KNL]
728 cma=nn[MG]@[start[MG][-end[MG]]]
739 Sets the size of kernel per-numa memory area for
741 per-numa CMA altogether. And If this option is not
743 With per-numa CMA enabled, DMA users on node nid will
770 com20020= [HW,NET] ARCnet - COM20020 chipset
774 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
778 ARCnet - COM90xx chipset (memory-mapped buffers)
807 See Documentation/admin-guide/serial-console.rst for more
822 $ ls -d /sys/bus/serial-base/devices/*:*.*/tty/*
823 /sys/bus/serial-base/devices/00:04:0.0/tty/ttyS0
836 Start an early, polled-mode console on the 8250/16550
839 MMIO inter-register address stride is either 8-bit
840 (mmio), 16-bit (mmio16), or 32-bit (mmio32).
844 the h/w is not re-initialized.
871 syscall, or to executing "dmesg -S --raw" or to reading
895 disable the cpuidle sub-system
901 disable the cpufreq sub-system
909 [X86,EARLY] Delay for N microsec between assert and de-assert
921 Run kdump after running panic-notifiers and dumping
934 [KNL, X86-64, ARM64, RISCV, LoongArch] Select a region
937 See Documentation/admin-guide/kdump/kdump.rst for further details.
942 start-[end] where start and end are both
944 Documentation/admin-guide/kdump/kdump.rst for an example.
947 [KNL, X86-64, ARM64, RISCV, LoongArch] range could be
955 [KNL, X86-64, ARM64, RISCV, LoongArch] range under 4G.
961 for 32-bit devices won't run out. Kernel would try to allocate
964 --> x86: max(swiotlb_size_or_default() + 8MiB, 256MiB)
965 --> arm64: 128MiB
966 --> riscv: 128MiB
967 --> loongarch: 128MiB
975 [KNL] Disable crypto self-tests
983 csdlock_debug= [KNL] Enable or disable debug add-ons of cross-CPU
998 See also Documentation/input/devices/joystick-parport.rst
1011 [KNL] verbose locking self-tests
1014 self-tests.
1016 (no extra messages), setting it to -1 (all bits set)
1017 will print _a_lot_ more information - normally only
1052 Format: { on, no-mount, off }
1054 no-mount:
1059 get a -EPERM as result when trying to register files
1063 Default value is set in build-time with a kernel configuration.
1075 Documentation/admin-guide/mm/hugetlbpage.rst.
1089 delayacct [KNL] Enable per-task delay accounting
1175 entries for DMA-API debugging code. One entry is
1176 required per DMA-API allocation. Use this if the
1177 DMA-API debugging code disables itself because the
1181 With this option the DMA-API debugging driver
1205 Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst
1230 Control how the dt_cpu_ftrs device-tree binding is
1240 what data is available or for reverse-engineering.
1245 Documentation/admin-guide/dynamic-debug-howto.rst
1256 determined by stdout-path property in device tree's
1261 Start an early, polled-mode console on a Cadence
1272 Start an early, polled-mode console on the 8250/16550
1274 MMIO inter-register address stride is either 8-bit
1275 (mmio) or 32-bit (mmio32 or mmio32be).
1285 Start an early, polled-mode console on a pl011 serial
1289 the driver will use only 32-bit accessors to read/write
1297 meson,<addr>
1298 Start an early, polled-mode console on a meson serial
1304 Start an early, polled-mode console on an msm serial
1310 Start an early, polled-mode console on an msm serial
1316 Start an early, polled-mode console on a serial port
1322 Start an early, polled-mode console on a serial port
1328 Use RISC-V SBI (Supervisor Binary Interface) for early
1346 Start an early, polled-mode console on a lantiq serial
1360 Start an early, polled-mode, output-only console on the
1365 Start an early, polled-mode console on the
1371 Start an early, polled-mode console on a Qualcomm
1379 coherent non-x86 systems that use system memory for
1478 Documentation/admin-guide/acpi/ssdt-overlays.rst for details.
1495 elanfreq= [X86-32]
1503 See Documentation/admin-guide/kdump/kdump.rst for details.
1519 0 -- permissive (log only, no denials).
1520 1 -- enforcing (deny and log).
1552 See also Documentation/fault-injection/.
1556 See Documentation/admin-guide/sysctl/net.rst for
1560 See Documentation/admin-guide/blockdev/floppy.rst.
1562 forcepae [X86-32]
1569 fred= [X86-64]
1620 ftrace_filter=[function-list]
1622 tracer at boot up. function-list is a comma-separated
1627 ftrace_notrace=[function-list]
1629 function-list. This list can be changed at run time
1633 ftrace_graph_filter=[function-list]
1636 function-list is a comma-separated list of functions
1640 ftrace_graph_notrace=[function-list]
1642 function-list. This list is a comma-separated list of
1662 off -- Don't create device links from firmware info.
1663 permissive -- Create device links from firmware info
1666 on -- Create device links from firmware info and use it
1668 rpm -- Like "on", but also use to order runtime PM.
1681 strict -- Default. Continue waiting on consumers to
1683 timeout -- Give up waiting on consumers and call
1693 See also Documentation/input/devices/joystick-parport.rst
1697 gart_fix_e820= [X86-64,EARLY] disable the fix e820 for K8 GART
1721 gcov_persist= [GCOV] When non-zero (default), profiling data for
1731 gpio-mockup.gpio_mockup_ranges
1734 gpio-mockup.gpio_mockup_named_lines
1766 against bounds-checking flaws in the kernel's
1772 [KNL] Should the hard-lockup detector generate
1778 for 64-bit NUMA, off otherwise.
1786 corresponding firmware-first mode error processing
1796 during restoration read-only).
1833 hpet= [X86-32,HPET] option to control HPET usage
1850 number of pages to allocate per-node can be specified.
1851 See also Documentation/admin-guide/mm/hugetlbpage.rst.
1862 Documentation/admin-guide/mm/hugetlbpage.rst.
1873 boot-time allocation of gigantic hugepages is skipped.
1901 by the CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time
1907 hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
1923 Set device-properties for ACPI-enumerated I2C-attached
1924 touchscreen, to e.g. fix coordinates of upside-down
1932 Omit "=<val>" entirely Set a boolean device-property
1933 Unsigned number Set a u32 device-property
1934 Anything else Set a string device-property
1937 i2c_touchscreen_props=GDIX1001:touchscreen-inverted-x:
1938 touchscreen-inverted-y
1940 i2c_touchscreen_props=MSSL1680:touchscreen-size-x=1920:
1941 touchscreen-size-y=1080:touchscreen-inverted-y:
1942 firmware-name=gsl1680-vendor-model.fw:silead,home-button
1947 (disabled by default, and as a pre-condition
1949 i8042.direct [HW] Put keyboard port into non-translated mode
1963 suspend-to-ram transitions, only during s2r
1987 -1 -- never invert brightness
1988 0 -- machine default
1989 1 -- force brightness inversion
1991 ia32_emulation= [X86-64]
1993 When true, allows loading 32-bit programs and executing 32-bit
2009 idle=nomwait: Disable mwait for CPU C-states
2037 legacy only accept legacy-NaN binaries, if supported
2039 2008 only accept 2008-NaN binaries, if supported
2050 'relaxed' straps the emulator for both legacy-NaN and
2051 2008-NaN, whereas 'strict' enables legacy-NaN only on
2060 Ignore loglevel setting - this will print /all/
2127 Formats: { "ima" | "ima-ng" | "ima-ngv2" | "ima-sig" |
2128 "ima-sigv2" }
2129 Default: "ima-ng"
2161 initcall_blacklist= [KNL] Do not execute a comma-separated list of
2162 initcall functions. Useful for debugging built-in
2207 0 -- basic integrity auditing messages. (Default)
2208 1 -- additional integrity auditing messages.
2236 could harm performance of some high-throughput
2245 1 to 9 specify maximum depth of C-state.
2254 algorithms for p-state selection. There are two
2255 P-state selection algorithms provided by
2258 on whether or not the hardware managed P-states
2265 used along with the hardware-managed P-states (HWP)
2269 in favor of acpi-cpufreq. Forcing the intel_pstate driver
2270 instead of acpi-cpufreq may disable platform features, such
2272 P-States information being indicated to OSPM and therefore
2275 or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
2288 Allow per-logical-CPU P-State performance control limits using
2291 intremap= [X86-64,Intel-IOMMU,EARLY]
2296 BIOS x2APIC opt-out request will be ignored
2322 0 - Try to allocate a 32-bit DMA address first, before
2324 1 - Allocate directly from the full usable range,
2326 greater than 32-bit addressing.
2330 0 - Lazy mode.
2336 1 - Strict mode.
2339 unset - Use value of CONFIG_IOMMU_DEFAULT_DMA_{LAZY,STRICT}.
2341 legacy driver-specific options takes precedence.
2346 0 - Use IOMMU translation for DMA.
2347 1 - Bypass the IOMMU for DMA.
2348 unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
2350 io7= [HW] IO7 for Marvel-based Alpha systems
2365 See Documentation/admin-guide/nfs/nfsroot.rst.
2401 Enables support for pseudo-NMIs in the kernel. This
2420 [Deprecated - use cpusets instead]
2421 Format: [flag-list,]<cpu-list>
2452 "number of CPUs in system - 1".
2478 The format of <cpu-list> is described above.
2482 ivrs_ioapic [HW,X86-64]
2483 Provide an override to the IOAPIC-ID<->DEVICE-ID
2487 For example, to map IOAPIC-ID decimal 10 to
2493 * To map IOAPIC-ID decimal 10 to PCI device 00:14.0
2496 * To map IOAPIC-ID decimal 10 to PCI segment 0x1 and
2500 ivrs_hpet [HW,X86-64]
2501 Provide an override to the HPET-ID<->DEVICE-ID
2505 For example, to map HPET-ID decimal 10 to
2511 * To map HPET-ID decimal 0 to PCI device 00:14.0
2514 * To map HPET-ID decimal 10 to PCI segment 0x1 and
2518 ivrs_acpihid [HW,X86-64]
2519 Provide an override to the ACPI-HID:UID<->DEVICE-ID
2523 For example, to map UART-HID:UID AMD0020:0 to
2529 * To map UART-HID:UID AMD0020:0 to PCI segment is 0,
2532 * To map UART-HID:UID AMD0020:0 to PCI segment 0x1 and
2556 the kernel for non-movable allocations. The requested
2566 subsystem. Note that allocations like PTEs-from-HighMem
2574 for non-movable allocations and remaining memory is used
2585 gdb or control-c on the dbgp connection. When
2586 not using this parameter you use sysrq-g to break into
2591 or a supported polling keyboard driver (non-usb).
2618 Configure the RouterBoard 532 series on-chip
2621 kmemleak= [KNL,EARLY] Boot-time kmemleak enable/disable
2627 kprobe_event=[probe-list]
2629 The probe-list is a semicolon delimited list of probe
2659 execution by eliminating the write-protection faults
2686 virtualization on-demand when creating and destroying
2694 is that doing so may interfere with using out-of-tree
2721 back to huge pages. If the value is a non-zero N, KVM will
2726 kvm-amd.nested= [KVM,AMD] Control nested virtualization feature in
2729 kvm-amd.npt= [KVM,AMD] Control KVM's use of Nested Page Tables,
2730 a.k.a. Two-Dimensional Page Tables. Default is 1
2734 kvm-arm.mode=
2740 nvhe: Standard nVHE-based mode, without support for
2743 protected: nVHE-based mode with support for guests whose
2746 nested: VHE-based mode with support for nested
2755 kvm-arm.vgic_v3_group0_trap=
2756 [KVM,ARM,EARLY] Trap guest accesses to GICv3 group-0
2759 kvm-arm.vgic_v3_group1_trap=
2760 [KVM,ARM,EARLY] Trap guest accesses to GICv3 group-1
2763 kvm-arm.vgic_v3_common_trap=
2767 kvm-arm.vgic_v4_enable=
2771 kvm-arm.wfe_trap_policy=
2780 kvm-arm.wfi_trap_policy=
2797 kvm-intel.ept= [KVM,Intel] Control KVM's use of Extended Page Tables,
2798 a.k.a. Two-Dimensional Page Tables. Default is 1
2802 kvm-intel.emulate_invalid_guest_state=
2804 state. Ignored if kvm-intel.enable_unrestricted_guest=1,
2810 kvm-intel.flexpriority=
2815 kvm-intel.nested=
2819 kvm-intel.unrestricted_guest=
2825 kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
2826 CVE-2018-3620.
2837 kvm-intel.vpid= [KVM,Intel] Control KVM's use of Virtual Processor
2857 on - enable the interface for the mitigation
2922 For details see: Documentation/admin-guide/hw-vuln/l1tf.rst
2928 lapic [X86-32,APIC,EARLY] Enable the local APIC even if BIOS
2932 value for LAPIC timer one-shot implementation. Default
2955 libata.force= [LIBATA] Force configurations. The format is a comma-
2967 first fan-out link behind PMP device. It does not
2981 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
2988 * rstonce: only attempt one reset during hot-unplug
3083 Specify the number of self-propagating call_rcu()
3091 occasional long-duration lock hold time. Defaults
3102 Set the number of locking read-acquisition kthreads.
3107 Set the number of locking write-acquisition kthreads.
3110 Set time (s) after boot for CPU-hotplug testing.
3113 Set time (s) between CPU-hotplug operations, or
3114 zero to disable CPU-hotplug testing.
3117 Do periodic testing of real-time lock priority
3122 non-real-time spinlocks, due to their disabling
3123 of preemption. Note that non-realtime mutexes
3136 Set task-shuffle interval (jiffies). Shuffling
3137 tasks allows some CPUs to go into dyntick-idle
3142 is useful for hands-off automated testing.
3161 Run the write-side locktorture kthreads at
3162 sched_set_fifo() real-time priority.
3180 7 (KERN_DEBUG) debug-level messages
3192 logo.nologo [FB] Disables display of the built-in Linux logo.
3210 an IEEE 1284-compliant printer is attached; if
3216 time-consuming boot-time autodetection (up to 250 ms per
3236 Example: machtype=lemote-yeeloong-2f-7inch
3248 (loop.max_loop) unconditionally pre-created at init time. The default
3251 devices can be requested on-demand with the
3252 /dev/loop-control interface.
3254 mce [X86-32] Machine Check Exception
3256 mce=option [X86-64] See Documentation/arch/x86/x86_64/boot-options.rst
3259 See Documentation/admin-guide/md.rst.
3266 Control mitigation for the Micro-architectural Data
3281 full - Enable MDS mitigation on vulnerable CPUs
3282 full,nosmt - Enable MDS mitigation and disable
3284 off - Unconditionally disable MDS mitigation
3286 On TAA-affected machines, mds=off can be prevented by
3295 For details see: Documentation/admin-guide/hw-vuln/mds.rst
3310 [ARC,MICROBLAZE] - the limit applies only to low memory,
3313 [ARM64] - only limits memory covered by the linear
3326 [ARM,MIPS,EARLY] - override the memory layout
3333 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
3340 per-device physically contiguous DMA buffers.
3348 See Documentation/admin-guide/mm/memory-hotplug.rst.
3373 Example: Exclude memory from 0x18690000-0x1869ffff
3387 memmap=<size>%<offset>-<oldtype>+<newtype>
3389 from <oldtype> to <newtype>. If "-<oldtype>" is left
3404 repeatable BIOS-originated corruption always
3448 mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control
3454 Refer to Documentation/virt/kvm/x86/amd-memory-encryption.rst
3458 s2idle - Suspend-To-Idle
3459 shallow - Power-On Suspend or equivalent (if supported)
3460 deep - Suspend-To-RAM or equivalent (if supported)
3461 See Documentation/admin-guide/pm/sleep-states.rst.
3463 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
3479 0 - The attached screen is the 3.5" TFT
3480 1 - The attached screen is the 7" TFT
3481 2 - The VGA Shield is attached (1024x768)
3485 b - Enable backlight. The TFT backlight pin will be
3489 c - Enable the s3c camera interface.
3490 t - Reserved for enabling touchscreen support. The
3494 https://repo.or.cz/w/linux-2.6/mini2440.git
3499 arch-independent options, each of which is an
3500 aggregation of existing arch-specific options.
3529 ssbd=force-off [ARM64]
3542 have other ways of avoiding SMT-based attacks.
3577 full - Enable mitigation on vulnerable CPUs
3579 full,nosmt - Enable mitigation and disable SMT on
3582 off - Unconditionally disable mitigation
3595 Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst
3625 module_blacklist= [KNL] Do not load a comma-separated list of
3650 movable_node [KNL,EARLY] Boot-time switch to make hotplugable memory
3657 Format: <name>,<region-number>,<size>,<offset>
3660 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
3699 something different and driver-specific.
3739 [NFS] enable 64-bit inode numbers.
3740 If zero, the NFS client will fake up a 32-bit inode
3742 of returning the full 64-bit number.
3743 The default is to return 64-bit inode numbers.
3778 [NFS4] Specify an additional fixed unique ident-
3809 driver. A non-zero value sets the minimum interval
3814 server-to-server copies for which this server is
3826 server-to-server copy, knfsd temporarily mounts
3833 See Documentation/admin-guide/nfs/nfsroot.rst.
3835 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
3836 See Documentation/admin-guide/nfs/nfsroot.rst.
3839 See Documentation/admin-guide/nfs/nfsroot.rst.
3843 NMI stack-backtrace request.
3852 0 - turn hardlockup detector in nmi_watchdog off
3853 1 - turn hardlockup detector in nmi_watchdog on
3854 rNNN - configure the watchdog with raw perf event 0xNNN
3867 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
3871 no4lvl [RISCV,EARLY] Disable 4-level and 5-level paging modes.
3872 Forces kernel to use 3-level paging instead.
3874 no5lvl [X86-64,RISCV,EARLY] Disable 5-level paging mode. Forces
3875 kernel to use 4-level paging instead.
3908 no_entry_flush [PPC,EARLY] Don't flush the L1-D cache when entering the kernel.
3910 noexec32 [X86-64]
3911 This affects only 32-bit executables.
3912 noexec32=on: enable non-executable mappings (default)
3914 noexec32=off: disable non-executable mappings
3925 nofxsr [BUGS=X86-32] Disables x86 floating point extended
3927 legacy floating-point registers on task switch.
3938 compared. However, if this command-line option is
3979 nointremap [X86-64,Intel-IOMMU,EARLY] Do not enable interrupt
3981 [Deprecated - use intremap=off]
3987 noirqdebug [X86-32] Disables the code which attempts to detect and
3997 no-kvmapf [X86,KVM,EARLY] Disable paravirtualized asynchronous page
4000 no-kvmclock [X86,KVM,EARLY] Disable paravirtualized KVM clock driver
4002 nolapic [X86-32,APIC,EARLY] Do not enable or use the local APIC.
4004 nolapic_timer [X86-32,APIC,EARLY] Do not use the local APIC timer.
4006 nomce [X86-32] Disable Machine Check Exception
4008 nomfgpt [X86-32] Disable Multi-Function General Purpose
4014 not load if they could possibly displace the pre-
4017 perform display-mode changes or accelerated rendering.
4030 nopcid [X86-64,EARLY] Disable the PCID cpu feature.
4035 nopti [X86-64,EARLY]
4051 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
4057 no-scroll [VGA] Disables scrollback.
4058 This is required for the Braillex ib80-piezo Braille
4061 nosgx [X86-64,SGX,EARLY] Disables Intel SGX kernel support.
4081 nosoftlockup [KNL] Disable the soft-lockup detector.
4087 nospectre_bhb [ARM64,EARLY] Disable all mitigations for Spectre-BHB (branch
4100 no-steal-acc [X86,PV_OPS,ARM64,PPC/PSERIES,RISCV,LOONGARCH,EARLY]
4110 [PPC,EARLY] Don't flush the L1-D cache after accessing user data.
4123 no-vmw-sched-clock
4128 soft-lockup and NMI watchdog (hard-lockup).
4132 nox2apic [X86-64,APIC,EARLY] Do not enable x2APIC mode.
4140 enabling legacy floating-point and sse state.
4162 n. So during boot up some boot time memory for per-cpu
4163 variables need be pre-allocated for later physical cpu
4194 See Documentation/admin-guide/sysctl/vm.rst for details.
4197 See Documentation/core-api/debugging-via-ohci1394.rst for more
4212 onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
4216 boundary - index of last SLC block on Flex-OneNAND.
4218 lock - Configure if Flex-OneNAND boundary should be locked.
4237 page_owner= [KNL,EARLY] Boot-time page_owner enabling option.
4243 page_poison= [KNL,EARLY] Boot-time parameter changing the state of
4271 See Documentation/admin-guide/tainted-kernels.rst for
4324 Set to non-zero to probe primary and secondary ISA
4330 Set to non-zero if a chip is present that snoops speed
4378 Set to non-zero to probe tertiary and further ISA
4394 Set to non-zero to probe QDI controllers. By default
4399 Set to non-zero to probe Winbond controllers. Use
4446 bios [X86-32] force use of PCI BIOS, don't access
4448 has a non-standard PCI host bridge.
4449 nobios [X86-32] disallow use of PCI BIOS, only direct
4455 data in IO port 0xCFC, both 32-bit).
4457 Mechanism 2 (IO port 0xCF8 is an 8-bit port for
4458 the function, IO port 0xCFA, also 8-bit, sets
4460 through ports 0xC000-0xCFFF).
4467 root domains (aka PCI segments, in ACPI-speak).
4475 disable the use of MSI interrupts system-wide.
4480 primary IO-APIC for bridges that cannot disable
4487 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
4511 F0000h-100000h range.
4516 assign-busses [X86] Always assign all PCI bus
4537 <linux-pci@vger.kernel.org>.
4541 a bug to <linux-pci@vger.kernel.org>.
4553 bfsort Sort PCI devices into breadth-first order.
4556 nobfsort Don't sort PCI devices into breadth-first order.
4558 tuning and use the BIOS-configured MPS defaults.
4568 configuration allows peer-to-peer DMA between
4571 that hot-added devices will work.
4586 A PCI-PCI bridge can be specified if resource
4592 for 4096-byte alignment.
4594 end-to-end CRC checking). Only effective if
4625 noats [PCIE, Intel-IOMMU, AMD-IOMMU]
4656 bit-0 : ACS Source Validation
4657 bit-1 : ACS Translation Blocking
4658 bit-2 : ACS P2P Request Redirect
4659 bit-3 : ACS P2P Completion Redirect
4660 bit-4 : ACS Upstream Forwarding
4661 bit-5 : ACS P2P Egress Control
4662 bit-6 : ACS Direct Translated P2P
4672 Validation unchanged from whatever power-up
4694 dpc-native Use native PCIe service for DPC only. May
4711 Keep all power-domains already enabled by bootloader on,
4729 pirq= [SMP,APIC] Manual mp-table setup
4730 See Documentation/arch/x86/i386/IO-APIC.rst.
4734 See also Documentation/admin-guide/parport.rst.
4753 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
4762 { on | off | curr | res | no-curr | no-res }
4807 none - Limited to cond_resched() calls
4808 voluntary - Limited to cond_resched() and might_sleep() calls
4809 full - Any section that isn't explicitly preempt disabled
4814 print-fatal-signals=
4820 coredump - etc.
4823 you might want to try "ulimit -i unlimited".
4835 or lockdep-detected issues (only if lock debug is on).
4844 on - unlimited logging to /dev/kmsg from userspace
4845 off - logging to /dev/kmsg disabled
4846 ratelimit - ratelimit the logging
4857 - 'always': traditional behavior always allows mem overrides.
4858 - 'ptrace': only allow mem overrides for active ptracers.
4859 - 'never': never allow mem overrides.
4863 Limit processor to maximum C-state
4867 Ignore the _CST method to determine C-states,
4874 Param: "schedule" - profile schedule points.
4875 Param: "kvm" - profile VM exits.
4876 Param: <number> - step/bucket size as a power of 2 for
4907 pti= [X86-64] Control Page Table Isolation of user and
4912 on - unconditionally enable
4913 off - unconditionally disable
4914 auto - kernel detects whether your CPU model is
4920 [KNL] Number of legacy pty's. Overwrites compiled-in
4932 See Documentation/admin-guide/md.rst.
4935 See Documentation/admin-guide/blockdev/ramdisk.rst.
4942 initialize the kernel's RNG.
4947 initialize the kernel's RNG.
4954 cross-syscall address exposures. This is only
4960 ras=option[,option,...] [KNL] RAS-specific options
4966 rcu_nocbs[=cpu-list]
4971 enable the no-callback CPU mode, which prevents
4976 "p" for RCU-preempt, "s" for RCU-sched, and "g"
4980 and real-time workloads. It can also improve
4984 list of CPUs is set to no-callback mode from boot.
4988 no-callback mode from boot but the mode may be
4999 This improves the real-time response for the
5010 Do only a one-line RCU CPU stall warning when
5011 there is an ongoing too-long CSD-lock wait.
5017 If triggered before the RCU grace-period machinery
5027 RCU grace-period cleanup.
5031 RCU grace-period initialization.
5035 RCU grace-period pre-initialization, that is,
5036 the propagation of recent CPU-hotplug changes up
5040 Set delay from grace-period initialization to
5053 soliciting quiescent-state help from
5065 Set the SCHED_FIFO priority of the RCU per-CPU
5068 and for the RCU grace-period kthreads (rcu_bh,
5070 set, valid values are 1-99 and the default is 1
5071 (the least-favored priority). Otherwise, when
5072 RCU_BOOST is not set, valid values are 0-99 and
5073 the default is zero (non-realtime operation).
5078 On callback-offloaded (rcu_nocbs) CPUs,
5081 use of the ->nocb_bypass list. However, in the
5082 common non-flooded case, RCU queues directly to
5083 the main ->cblist in order to avoid the extra
5084 overhead of the ->nocb_bypass list and its lock.
5086 a single jiffy, RCU pre-queues the callbacks into
5087 the ->nocb_bypass queue. The definition of "too
5091 On callback-offloaded (rcu_nocbs) CPUs, avoid
5104 batch limiting is re-enabled.
5108 RCU's force-quiescent-state scan will aggressively
5116 Set the page-cache refill delay (in milliseconds)
5117 in response to low-memory conditions. The range
5121 Set the shift-right count to use to compute
5122 the callback-invocation batch limit bl from
5129 Please note that this callback-invocation batch
5130 limit applies only to non-offloaded callback
5139 cache-to-cache transfer latencies.
5145 and for NUMA systems with large remote-access
5161 the wakeup overhead on the global grace-period
5163 each group's NOCB grace-period kthread.
5166 Cause the grace-period kthread to get an extra
5168 it should at force-quiescent-state time.
5181 this specifies an rcu_read_unlock()-time delay
5185 of RCU-protected pointers after the relevant
5195 per-CPU rcuc kthreads. Defaults to a non-zero
5224 grace-period primitives such as call_rcu().
5235 grace-period primitives.
5238 Set test-start holdoff period. The purpose of
5256 Test the double-argument variant of kfree_rcu().
5258 rcuscale.kfree_rcu_test_single, both the single-
5259 and double-argument variants are tested.
5262 Test the single-argument variant of kfree_rcu().
5264 rcuscale.kfree_rcu_test_double, both the single-
5265 and double-argument variants are tested.
5279 does not affect the data-collection interval,
5284 Set number of RCU readers. The value -1 selects
5286 "n" less than -1 selects N-n+1, where N is again
5287 the number of CPUs. For example, -2 selects N
5288 (the number of CPUs), -3 selects N+1, and so on.
5289 A value of "n" less than or equal to -N selects
5302 complete. This is useful for hands-off automated
5309 Write-side holdoff between grace periods,
5314 Additional write-side holdoff between grace
5332 for RCU grace-period forward-progress testing
5339 Specify the fraction of a CPU-stall-warning
5340 period to do tight-loop forward-progress testing.
5344 forward-progress tests.
5348 need_resched() during tight-loop forward-progress
5352 Use conditional/asynchronous update-side
5356 Use expedited update-side primitives, if available.
5359 Use normal (non-expedited) asynchronous
5360 update-side primitives, if available.
5363 Use normal (non-expedited) synchronous
5364 update-side primitives, if available. If all
5368 they are all non-zero.
5376 Leak an RCU-protected pointer out of the reader.
5391 Set number of RCU callback-offload togglers.
5396 callback-offload toggling attempts.
5399 Set number of RCU readers. The value -1 selects
5400 N-1, where N is the number of CPUs. A value
5401 "n" less than -1 selects N-n-2, where N is again
5402 the number of CPUs. For example, -2 selects N
5403 (the number of CPUs), -3 selects N+1, and so on.
5406 Enable debug-object double-call_rcu() testing.
5409 Set time (s) after boot for CPU-hotplug testing.
5412 Set time (jiffies) between CPU-hotplug operations,
5413 or zero to disable CPU-hotplug testing.
5416 Set the number of read-then-exit kthreads used
5418 task-exit processing.
5421 The number of times in a given read-then-exit
5422 episode that a set of read-then-exit kthreads
5427 read-then-exit testing episodes.
5430 Set task-shuffle interval (s). Shuffling tasks
5431 allows some CPUs to go into dyntick-idle mode
5436 is useful for hands-off automated testing.
5445 any other stall-related activity. Note that
5451 in scheduling-while-atomic splats.
5470 grace-period kthread to test RCU CPU stall
5496 Test RCU's dyntick-idle handling. See also the
5551 Use expedited grace-period primitives, for
5555 real-time latency, and degrade energy efficiency.
5559 Use only normal grace-period primitives,
5562 real-time latency, CPU utilization, and
5564 increased grace-period latency. This parameter
5571 only normal grace-period primitives. No effect
5577 post-boot attempt at an expedited RCU grace
5578 period to instead use normal non-expedited
5579 grace-period processing.
5587 set to the default value of -1.
5590 Set the minimum number of callback-queuing-time
5591 lock-contention events per jiffy required to
5592 cause the RCU Tasks flavors to switch to per-CPU
5595 the default value of -1.
5600 of -1 allows this to be automatically (and
5608 number avoids disturbing real-time workloads,
5613 cancel laziness on that CPU. Use -1 to disable
5623 only printed prior to the stall-warning message
5671 force - Override the decision by the kernel to hide the
5699 Set test-start holdoff period. The purpose of
5714 but the default has already reduced the per-pass
5719 Set number of readers. The default value of -1
5728 Set the read-side critical-section duration,
5732 Specify the read-protection implementation to test.
5758 See Documentation/admin-guide/cgroup-v1/cpusets.rst.
5788 reservetop= [X86-32,EARLY]
5805 See Documentation/power/swsusp-and-swap-files.rst
5821 AMD-based UNRET and IBPB mitigations alone do not stop
5823 sibling threads. For that reason, STIBP is used on pro-
5827 off - no mitigation
5828 auto - automatically select a migitation
5829 auto,nosmt - automatically select a mitigation,
5833 ibpb - On AMD, mitigate short speculation
5838 ibpb,nosmt - Like "ibpb" above but will disable SMT
5842 unret - Force enable untrained return thunks,
5843 only effective on AMD f15h-f17h based
5845 unret,nosmt - Like unret, but will disable SMT when STIBP
5877 ro [KNL] Mount root device read-only on boot
5880 on Mark read-only kernel memory as read-only (default).
5881 off Leave read-only kernel memory writable for debugging.
5882 full Mark read-only kernel memory and aliases as read-only
5889 debug-uart get routed to the D+ and D- pins of the usb
5895 block/early-lookup.c for details.
5920 rw [KNL] Mount root device read-write on boot
5974 to 10 seconds for built-in smp_call_function()
5981 that requesting even small non-zero numbers of
5988 The default of -1 specifies a number of kthreads
5993 test before initiating CPU-hotplug operations.
5997 CPU-hotplug operations. Specifying zero (which
5998 is the default) disables CPU-hotplug operations.
6004 Non-zero values are useful for automated tests.
6027 "wait" parameter. A value of -1 selects the
6028 default if all other weights are -1. However,
6030 value of -1 will instead select a weight of zero.
6035 non-zero "wait" parameter. See weight_single.
6048 non-zero "wait" parameter. See weight_single
6060 non-zero "wait" parameter. See weight_single
6067 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
6068 1 -- enable.
6079 0 -- disable.
6080 1 -- enable.
6083 serialnumber [BUGS=X86-32]
6085 sev=option[,option...] [X86-64] See Documentation/arch/x86/x86_64/boot-options.rst
6093 to set it to "all" by meaning -- no limit here.
6164 using the csdlock_debug- kernel parameter.
6169 system. By default, let CSD-lock acquisition
6171 for this value provides a 5-minute timeout.
6173 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
6174 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
6175 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
6176 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
6177 smsc-ircc2.ircc_irq= [HW] IRQ line
6178 smsc-ircc2.ircc_dma= [HW] DMA channel
6179 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
6189 Default: -1 (no limit)
6192 [KNL] Should the soft-lockup detector generate panics.
6195 A value of 1 instructs the soft-lockup detector
6196 to panic the machine when a soft-lockup occurs. It is
6199 respective build-time switch to that functionality.
6202 [KNL] Should the soft-lockup detector generate
6207 See Documentation/admin-guide/laptops/sonypi.rst
6214 on - (default) Enable the HW or SW mitigation as
6217 vmexit - On systems which don't have the HW mitigation
6220 protected from VM-originated BHI attacks, but
6222 off - Disable the mitigation.
6229 on - unconditionally enable, implies
6231 off - unconditionally disable, implies
6233 auto - kernel detects whether your CPU model is
6250 retpoline - replace indirect branches
6251 retpoline,generic - Retpolines
6252 retpoline,lfence - LFENCE; indirect branch
6253 retpoline,amd - alias for retpoline,lfence
6254 eibrs - Enhanced/Auto IBRS
6255 eibrs,retpoline - Enhanced/Auto IBRS + Retpolines
6256 eibrs,lfence - Enhanced/Auto IBRS + LFENCE
6257 ibrs - use IBRS to protect kernel
6267 on - Unconditionally enable mitigations. Is
6270 off - Unconditionally disable mitigations. Is
6273 prctl - Indirect branch speculation is enabled,
6279 - Like "prctl" above, but only STIBP is
6285 - Same as "prctl" above, but all seccomp
6290 - Like "seccomp" above, but only STIBP is
6295 auto - Kernel selects the mitigation depending on
6306 off - Disable mitigation
6307 microcode - Enable microcode mitigation only
6308 safe-ret - Enable sw-only safe RET mitigation (default)
6309 ibpb - Enable mitigation by issuing IBPB on
6311 ibpb-vmexit - Issue IBPB only on VMEXIT
6312 (cloud-specific mitigation)
6337 on - Unconditionally disable Speculative Store Bypass
6338 off - Unconditionally enable Speculative Store Bypass
6339 auto - Kernel detects whether the CPU model contains an
6345 prctl - Control Speculative Store Bypass per thread
6349 seccomp - Same as "prctl" above, but all seccomp threads
6357 on,auto - On Power8 and Power9 insert a store-forwarding
6361 off - No action.
6375 off - not enabled
6377 warn - the kernel will emit rate-limited warnings
6385 fatal - the kernel will send SIGBUS to applications
6390 ratelimit:N -
6410 Certain CPUs are vulnerable to an MDS-like
6430 This kernel-boot parameter defaults to 128,
6431 but takes effect only when the low-order four
6448 instead of the compile-time CONFIG_NR_CPUS.
6452 grace-period sequence counter wrap for the
6453 srcu_data structure's ->srcu_gp_seq_needed field.
6468 Specifies the number of no-delay instances
6475 Specifies the per-grace-period phase, number of
6476 non-sleeping polls of readers. Beyond this limit,
6482 Specifies number of microseconds of non-sleeping
6483 delay between each non-sleeping poll of readers.
6486 Specifies the number of update-side contention
6491 set for contention-based conversions to occur.
6501 force-on: Unconditionally enable mitigation for
6503 force-off: Unconditionally disable mitigation for
6526 stacktrace_filter=[function-list]
6528 will trace at boot up. function-list is a comma-separated
6536 Set the STI (builtin display/keyboard on the HP-PARISC
6538 as the initial boot-console.
6598 to global on non-NUMA machines)
6623 <int> -- Number of I/O TLB slabs
6624 <int> -- Second integer after comma. Number of swiotlb
6627 force -- force using of bounce buffers even if they
6629 noforce -- Never use bounce buffers (for debugging)
6644 Ignore sysrq setting - this boot parameter will
6652 cache size. See Documentation/networking/ip-sysctl.rst
6659 Specify "mem" (for Suspend-to-RAM) or "standby" (for
6664 wakeup-capable RTC alarm.
6670 -1: disable all active trip points in all thermal zones
6674 -1: disable all critical trip points in all thermal zones
6681 -1: disable all passive trip points
6687 <deci-seconds>: poll all this frequency
6691 Format: <size>[KMG],<size>[KMG]:<state>;<size>[KMG]-<size>[KMG]:<state>
6696 See Documentation/admin-guide/mm/transhuge.rst for more
6712 Prevent the CPU-hotplug component of torturing
6716 Dump the ftrace buffer at torture-test shutdown,
6720 with rotating-rust storage.
6725 disables verbose-printk() sleeping.
6728 Duration of each verbose-printk() sleep in jiffies.
6753 https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/
6791 local - Use the per CPU time stamp counter
6795 global - Event time stamps are synchronize across
6798 counter - Simple counting of events (1, 2, ..)
6802 uptime - Use jiffies as the time stamp.
6803 perf - Use the same clock that perf uses.
6804 mono - Use ktime_get_mono_fast_ns() for time stamps.
6805 mono_raw - Use ktime_get_raw_fast_ns() for time
6807 boot - Use ktime_get_boot_fast_ns() for time stamps.
6811 trace_event=[event-list]
6813 to facilitate early boot debugging. The event-list is a
6814 comma-separated list of trace events to enable. See
6817 trace_instance=[instance-info]
6842 traceoff - Have the tracing instance tracing disabled after it is created.
6843 traceprintk - Have trace_printk() write into this trace instance
6882 trace_options=[option-list]
6884 The option-list is a comma delimited list of options
6898 trace_trigger=[trigger-list]
6935 See Documentation/admin-guide/mm/transhuge.rst
6943 - "tpm"
6944 - "tee"
6945 - "caam"
6946 - "dcp"
6952 trusted.rng= [KEYS]
6954 The RNG used to generate key material for trusted keys.
6956 - "kernel"
6957 - the same value as trusted.source: "tpm" or "tee"
6958 - "default"
6960 the RNG's choice is left to each individual trust source.
6979 high-resolution timer mode on older hardware, and in
7015 on - Enable TSX on the system. Although there are
7018 several previous speculation-related CVEs, and
7022 off - Disable TSX on the system. (Note that this
7030 auto - Disable TSX if X86_BUG_TAA is present,
7035 See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
7041 Similar to Micro-architectural Data Sampling (MDS)
7056 full - Enable TAA mitigation on vulnerable CPUs
7059 full,nosmt - Enable TAA mitigation and disable SMT on
7062 vulnerable to cross-thread TAA attacks.
7063 off - Unconditionally disable TAA mitigation
7065 On MDS-affected machines, tsx_async_abort=off can be
7077 Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
7083 See also Documentation/input/devices/joystick-parport.rst
7085 udbg-immortal [PPC] When debugging early kernel crashes that
7091 Set number of hash buckets for UDP/UDP-Lite connections
7093 uhci-hcd.ignore_oc=
7095 Some badly-designed motherboards generate lots of
7104 unwind_debug [X86-64,EARLY]
7112 (default -1 = authorized (same as 1),
7118 for newly-detected USB devices (default 2). This
7146 [USB] Specifies timeout for the initial 64-byte
7153 [USB] A list of quirk entries to augment the built-in
7156 VendorID:ProductID:Flags. The IDs are 4-digit hex
7158 will change the built-in quirk; setting it if it is
7163 a 255-byte read);
7167 Set-Interface requests);
7186 (bInterval-1).
7224 usb-storage.delay_use=
7231 usb-storage.quirks=
7233 override the built-in unusual_devs list. List
7236 and Product ID values (4-digit hex numbers) and
7238 to a common usb-storage quirk flag as follows:
7280 medium is write-protected).
7289 1 - undefined instruction events
7290 2 - system calls
7291 4 - invalid data aborts
7292 8 - SIGSEGV faults
7293 16 - SIGBUS faults
7309 vdso32= [X86] Control the 32-bit vDSO
7310 vdso32=1: enable 32-bit VDSO
7311 vdso32=0 or vdso32=2: disable 32-bit VDSO
7321 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
7352 vga= [BOOT,X86-32] Select a particular video mode
7354 Documentation/admin-guide/svga.rst.
7369 - Disable all of the above options
7393 vsyscall= [X86-64,EARLY]
7396 code). Most statically-linked binaries and older
7420 see VGA-softcursor.txt. Default: 2 = underline.
7425 This is a 16-member array composed of values
7426 ranging from 0-255.
7431 This is a 16-member array composed of values
7432 ranging from 0-255.
7437 This is a 16-member array composed of values
7438 ranging from 0-255.
7443 Set system-wide default UTF-8 mode for all tty's.
7444 Default is 1, i.e. UTF-8 mode is enabled for all
7449 Format=<-1|0|1>
7450 Set system-wide default for whether a cursor
7451 is shown on new VTs. Default is -1,
7456 vt.italic= [VT] Default color for italic text; 0-15.
7459 vt.underline= [VT] Default color for underlined text; 0-15.
7463 see Documentation/watchdog/watchdog-parameters.rst
7464 or other driver-specific files in the
7478 Format: <cpu-list>
7499 Per-cpu work items which run for longer than this
7502 them from noticeably delaying other per-cpu work
7520 Per-cpu workqueues are generally preferred because
7522 locality; unfortunately, per-cpu workqueues tend to
7525 Enabling this makes the per-cpu workqueues which
7539 Documentation/core-api/workqueue.rst.
7552 forces round-robin CPU selection to flush out
7560 on - Enable writecombine, use WUC for ioremap_wc()
7561 off - Disable writecombine, use SUC for ioremap_wc()
7563 x2apic_phys [X86-64,APIC,EARLY] Use x2apic physical mode instead of
7567 xen_512gb_limit [KNL,X86-64,XEN]
7577 ide-disks -- unplug primary master IDE devices
7578 aux-ide-disks -- unplug non-primary-master IDE devices
7579 nics -- unplug network devices
7580 all -- unplug all emulated devices (NICs and IDE disks)
7581 unnecessary -- unplugging emulated devices is
7584 never -- do not unplug even if version check succeeds
7598 Select whether to always use non-faulting (safe) MSR
7618 xen_timer_slop= [X86-64,XEN,EARLY]
7643 preferred over the 2-level event handling, as it is
7660 xive.store-eoi=off [PPC]
7666 xhci-hcd.quirks [USB,KNL]