Lines Matching +full:no +full:- +full:dump +full:- +full:oops
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
89 { strict | lax | no }
101 no: ACPI OperationRegions are not marked as reserved,
102 no further checks are performed.
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]
349 Enable AMD IOMMU driver option to dump the ACPI table
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
424 useful so that a dump capture kernel won't be
436 0 -- disable.
437 1 -- enable.
440 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
488 audit= [KNL] Enable the audit sub-system
490 0 | off - kernel audit is disabled and can not be
492 unset - kernel audit is initialized but disabled and
494 1 | on - kernel audit is initialized and partially
507 0 - Disable the BAU.
508 1 - Enable the BAU.
509 unset - Disable the BAU.
548 See Documentation/block/cmdline-partition.rst
562 See Documentation/admin-guide/bootconfig.rst
567 bttv.pll= See Documentation/admin-guide/media/bttv.rst
576 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
595 inclusive. See arch/mips/include/asm/pgtable-bits.h
605 - foo isn't auto-mounted if you mount all cgroups in
607 - foo isn't visible as an individually mountable
609 - if foo is an optional feature then the feature is
615 Specifying "pressure" disables per-cgroup pressure
633 nosocket -- Disable socket memory accounting.
634 nokmem -- Disable kernel memory accounting.
635 nobpf -- Disable BPF memory accounting.
640 0 -- check protection applied by kernel (includes
642 1 -- check protection requested by application.
654 numbers X. Note the Linux-specific bits are not necessarily
655 stable over kernel options, but the vendor-specific
675 force such clocks to be always-on nor does it reserve
679 information, see Documentation/driver-api/clk.rst.
681 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
698 [X86-32] pit,hpet,tsc;
705 [X86-64] hpet,tsc
711 architected timer so that code using WFE-based polling
723 no replacement if the same CPU is chosen twice.
725 clocksource-wdtest.holdoff= [KNL]
731 cma=nn[MG]@[start[MG][-end[MG]]]
742 Sets the size of kernel per-numa memory area for
744 per-numa CMA altogether. And If this option is not
746 With per-numa CMA enabled, DMA users on node nid will
762 cmo_free_hint= [PPC] Format: { yes | no }
773 com20020= [HW,NET] ARCnet - COM20020 chipset
777 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
781 ARCnet - COM90xx chipset (memory-mapped buffers)
795 terminal emulator is active. If no 3270 terminal
796 emulator is used, this parameter has no effect.
810 See Documentation/admin-guide/serial-console.rst for more
825 $ ls -d /sys/bus/serial-base/devices/*:*.*/tty/*
826 /sys/bus/serial-base/devices/00:04:0.0/tty/ttyS0
839 Start an early, polled-mode console on the 8250/16550
842 MMIO inter-register address stride is either 8-bit
843 (mmio), 16-bit (mmio16), or 32-bit (mmio32).
847 the h/w is not re-initialized.
874 syscall, or to executing "dmesg -S --raw" or to reading
898 disable the cpuidle sub-system
904 disable the cpufreq sub-system
912 [X86,EARLY] Delay for N microsec between assert and de-assert
921 the parameter has no effect.
933 like Hyper-V, PowerPC (fadump) and AMD SEV-SNP.
941 [KNL, X86-64, ARM64, RISCV, LoongArch] Select a region
944 See Documentation/admin-guide/kdump/kdump.rst for further details.
949 start-[end] where start and end are both
951 Documentation/admin-guide/kdump/kdump.rst for an example.
954 [KNL, X86-64, ARM64, RISCV, LoongArch] range could be
962 [KNL, X86-64, ARM64, RISCV, LoongArch] range under 4G.
968 for 32-bit devices won't run out. Kernel would try to allocate
971 --> x86: max(swiotlb_size_or_default() + 8MiB, 256MiB)
972 --> arm64: 128MiB
973 --> riscv: 128MiB
974 --> loongarch: 128MiB
982 [KNL] Disable crypto self-tests
990 csdlock_debug= [KNL] Enable or disable debug add-ons of cross-CPU
1005 See also Documentation/input/devices/joystick-parport.rst
1018 [KNL] verbose locking self-tests
1021 self-tests.
1023 (no extra messages), setting it to -1 (all bits set)
1024 will print _a_lot_ more information - normally only
1059 Format: { on, no-mount, off }
1061 no-mount:
1066 get a -EPERM as result when trying to register files
1070 Default value is set in build-time with a kernel configuration.
1082 Documentation/admin-guide/mm/hugetlbpage.rst.
1093 dump out devices still on the deferred probe list after
1096 delayacct [KNL] Enable per-task delay accounting
1126 off: No s390 zlib hardware support
1182 entries for DMA-API debugging code. One entry is
1183 required per DMA-API allocation. Use this if the
1184 DMA-API debugging code disables itself because the
1188 With this option the DMA-API debugging driver
1212 Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst
1223 panels may send no or incorrect EDID data sets.
1230 data set with no connector name will be used for
1237 Control how the dt_cpu_ftrs device-tree binding is
1245 Dump name and content of EFI device properties on
1247 what data is available or for reverse-engineering.
1252 Documentation/admin-guide/dynamic-debug-howto.rst
1262 When used with no options, the early console is
1263 determined by stdout-path property in device tree's
1268 Start an early, polled-mode console on a Cadence
1279 Start an early, polled-mode console on the 8250/16550
1281 MMIO inter-register address stride is either 8-bit
1282 (mmio) or 32-bit (mmio32 or mmio32be).
1292 Start an early, polled-mode console on a pl011 serial
1296 the driver will use only 32-bit accessors to read/write
1305 Start an early, polled-mode console on a meson serial
1311 Start an early, polled-mode console on an msm serial
1317 Start an early, polled-mode console on an msm serial
1323 Start an early, polled-mode console on a serial port
1329 Start an early, polled-mode console on a serial port
1335 Use RISC-V SBI (Supervisor Binary Interface) for early
1353 Start an early, polled-mode console on a lantiq serial
1367 Start an early, polled-mode, output-only console on the
1372 Start an early, polled-mode console on the
1378 Start an early, polled-mode console on a Qualcomm
1386 coherent non-x86 systems that use system memory for
1485 Documentation/admin-guide/acpi/ssdt-overlays.rst for details.
1502 elanfreq= [X86-32]
1510 See Documentation/admin-guide/kdump/kdump.rst for details.
1526 0 -- permissive (log only, no denials).
1527 1 -- enforcing (deny and log).
1560 See also Documentation/fault-injection/.
1564 See Documentation/admin-guide/sysctl/net.rst for
1568 See Documentation/admin-guide/blockdev/floppy.rst.
1570 forcepae [X86-32]
1577 fred= [X86-64]
1607 [FTRACE] will dump the trace buffers on oops.
1608 If no parameter is passed, ftrace will dump global
1610 will dump only the buffer of the CPU that triggered
1611 the oops, or the specific instance will be dumped if
1612 its name is passed. Multiple instance dump is also
1614 instance supports only dump on CPU that triggered the
1615 oops by passing 2 or orig_cpu to it.
1619 The above will dump only the buffer of "foo" instance
1620 on CPU that triggered the oops.
1624 The above will dump global buffer on all CPUs, the
1626 of "bar" instance on CPU that triggered the oops.
1628 ftrace_filter=[function-list]
1630 tracer at boot up. function-list is a comma-separated
1635 ftrace_notrace=[function-list]
1637 function-list. This list can be changed at run time
1641 ftrace_graph_filter=[function-list]
1644 function-list is a comma-separated list of functions
1648 ftrace_graph_notrace=[function-list]
1650 function-list. This list is a comma-separated list of
1658 in the tracefs tracing directory. default: 0 (no limit)
1670 off -- Don't create device links from firmware info.
1671 permissive -- Create device links from firmware info
1674 on -- Create device links from firmware info and use it
1676 rpm -- Like "on", but also use to order runtime PM.
1689 strict -- Default. Continue waiting on consumers to
1691 timeout -- Give up waiting on consumers and call
1701 See also Documentation/input/devices/joystick-parport.rst
1705 gart_fix_e820= [X86-64,EARLY] disable the fix e820 for K8 GART
1723 microcode mitigation. No effect if the microcode
1729 gcov_persist= [GCOV] When non-zero (default), profiling data for
1739 gpio-mockup.gpio_mockup_ranges
1742 gpio-mockup.gpio_mockup_named_lines
1774 against bounds-checking flaws in the kernel's
1780 [KNL] Should the hard-lockup detector generate
1786 for 64-bit NUMA, off otherwise.
1794 corresponding firmware-first mode error processing
1801 no Disable hibernation and resume.
1804 during restoration read-only).
1818 size of <nn>. This works even on boxes that have no
1841 hpet= [X86-32,HPET] option to control HPET usage
1858 number of pages to allocate per-node can be specified.
1859 See also Documentation/admin-guide/mm/hugetlbpage.rst.
1870 Documentation/admin-guide/mm/hugetlbpage.rst.
1881 boot-time allocation of gigantic hugepages is skipped.
1909 by the CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time
1915 hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
1931 Set device-properties for ACPI-enumerated I2C-attached
1932 touchscreen, to e.g. fix coordinates of upside-down
1940 Omit "=<val>" entirely Set a boolean device-property
1941 Unsigned number Set a u32 device-property
1942 Anything else Set a string device-property
1945 i2c_touchscreen_props=GDIX1001:touchscreen-inverted-x:
1946 touchscreen-inverted-y
1948 i2c_touchscreen_props=MSSL1680:touchscreen-size-x=1920:
1949 touchscreen-size-y=1080:touchscreen-inverted-y:
1950 firmware-name=gsl1680-vendor-model.fw:silead,home-button
1955 (disabled by default, and as a pre-condition
1957 i8042.direct [HW] Put keyboard port into non-translated mode
1971 suspend-to-ram transitions, only during s2r
1995 -1 -- never invert brightness
1996 0 -- machine default
1997 1 -- force brightness inversion
1999 ia32_emulation= [X86-64]
2001 When true, allows loading 32-bit programs and executing 32-bit
2017 idle=nomwait: Disable mwait for CPU C-states
2045 legacy only accept legacy-NaN binaries, if supported
2047 2008 only accept 2008-NaN binaries, if supported
2055 encodings, so if no FPU hardware is present or it has
2058 'relaxed' straps the emulator for both legacy-NaN and
2059 2008-NaN, whereas 'strict' enables legacy-NaN only on
2068 Ignore loglevel setting - this will print /all/
2135 Formats: { "ima" | "ima-ng" | "ima-ngv2" | "ima-sig" |
2136 "ima-sigv2" }
2137 Default: "ima-ng"
2169 initcall_blacklist= [KNL] Do not execute a comma-separated list of
2170 initcall functions. Useful for debugging built-in
2215 0 -- basic integrity auditing messages. (Default)
2216 1 -- additional integrity auditing messages.
2244 could harm performance of some high-throughput
2253 1 to 9 specify maximum depth of C-state.
2262 algorithms for p-state selection. There are two
2263 P-state selection algorithms provided by
2266 on whether or not the hardware managed P-states
2273 used along with the hardware-managed P-states (HWP)
2277 in favor of acpi-cpufreq. Forcing the intel_pstate driver
2278 instead of acpi-cpufreq may disable platform features, such
2280 P-States information being indicated to OSPM and therefore
2283 or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
2296 Allow per-logical-CPU P-State performance control limits using
2299 intremap= [X86-64,Intel-IOMMU,EARLY]
2304 BIOS x2APIC opt-out request will be ignored
2330 0 - Try to allocate a 32-bit DMA address first, before
2332 1 - Allocate directly from the full usable range,
2334 greater than 32-bit addressing.
2338 0 - Lazy mode.
2344 1 - Strict mode.
2347 unset - Use value of CONFIG_IOMMU_DEFAULT_DMA_{LAZY,STRICT}.
2349 legacy driver-specific options takes precedence.
2354 0 - Use IOMMU translation for DMA.
2355 1 - Bypass the IOMMU for DMA.
2356 unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
2358 io7= [HW] IO7 for Marvel-based Alpha systems
2370 No delay
2373 See Documentation/admin-guide/nfs/nfsroot.rst.
2409 Enables support for pseudo-NMIs in the kernel. This
2428 [Deprecated - use cpusets instead]
2429 Format: [flag-list,]<cpu-list>
2460 "number of CPUs in system - 1".
2479 CPUs then this parameter has no effect on the
2483 housekeeping CPUs has no influence on those
2486 The format of <cpu-list> is described above.
2490 ivrs_ioapic [HW,X86-64]
2491 Provide an override to the IOAPIC-ID<->DEVICE-ID
2495 For example, to map IOAPIC-ID decimal 10 to
2501 * To map IOAPIC-ID decimal 10 to PCI device 00:14.0
2504 * To map IOAPIC-ID decimal 10 to PCI segment 0x1 and
2508 ivrs_hpet [HW,X86-64]
2509 Provide an override to the HPET-ID<->DEVICE-ID
2513 For example, to map HPET-ID decimal 10 to
2519 * To map HPET-ID decimal 0 to PCI device 00:14.0
2522 * To map HPET-ID decimal 10 to PCI segment 0x1 and
2526 ivrs_acpihid [HW,X86-64]
2527 Provide an override to the ACPI-HID:UID<->DEVICE-ID
2531 For example, to map UART-HID:UID AMD0020:0 to
2537 * To map UART-HID:UID AMD0020:0 to PCI segment is 0,
2540 * To map UART-HID:UID AMD0020:0 to PCI segment 0x1 and
2564 the kernel for non-movable allocations. The requested
2574 subsystem. Note that allocations like PTEs-from-HighMem
2582 for non-movable allocations and remaining memory is used
2593 gdb or control-c on the dbgp connection. When
2594 not using this parameter you use sysrq-g to break into
2599 or a supported polling keyboard driver (non-usb).
2626 Configure the RouterBoard 532 series on-chip
2629 kmemleak= [KNL,EARLY] Boot-time kmemleak enable/disable
2635 kprobe_event=[probe-list]
2637 The probe-list is a semicolon delimited list of probe
2667 execution by eliminating the write-protection faults
2694 virtualization on-demand when creating and destroying
2702 is that doing so may interfere with using out-of-tree
2729 back to huge pages. If the value is a non-zero N, KVM will
2734 kvm-amd.nested= [KVM,AMD] Control nested virtualization feature in
2737 kvm-amd.npt= [KVM,AMD] Control KVM's use of Nested Page Tables,
2738 a.k.a. Two-Dimensional Page Tables. Default is 1
2742 kvm-arm.mode=
2748 nvhe: Standard nVHE-based mode, without support for
2751 protected: nVHE-based mode with support for guests whose
2754 nested: VHE-based mode with support for nested
2763 kvm-arm.vgic_v3_group0_trap=
2764 [KVM,ARM,EARLY] Trap guest accesses to GICv3 group-0
2767 kvm-arm.vgic_v3_group1_trap=
2768 [KVM,ARM,EARLY] Trap guest accesses to GICv3 group-1
2771 kvm-arm.vgic_v3_common_trap=
2775 kvm-arm.vgic_v4_enable=
2779 kvm-arm.wfe_trap_policy=
2788 kvm-arm.wfi_trap_policy=
2805 kvm-intel.ept= [KVM,Intel] Control KVM's use of Extended Page Tables,
2806 a.k.a. Two-Dimensional Page Tables. Default is 1
2810 kvm-intel.emulate_invalid_guest_state=
2812 state. Ignored if kvm-intel.enable_unrestricted_guest=1,
2818 kvm-intel.flexpriority=
2823 kvm-intel.nested=
2827 kvm-intel.unrestricted_guest=
2833 kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
2834 CVE-2018-3620.
2845 kvm-intel.vpid= [KVM,Intel] Control KVM's use of Virtual Processor
2865 on - enable the interface for the mitigation
2930 For details see: Documentation/admin-guide/hw-vuln/l1tf.rst
2936 lapic [X86-32,APIC,EARLY] Enable the local APIC even if BIOS
2940 value for LAPIC timer one-shot implementation. Default
2963 libata.force= [LIBATA] Force configurations. The format is a comma-
2975 first fan-out link behind PMP device. It does not
2980 as there is no ambiguity, shortcut notation is allowed.
2989 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
2996 * rstonce: only attempt one reset during hot-unplug
2999 * [no]dbdelay: Enable or disable the extra 200ms delay
3003 * [no]ncq: Turn on or off NCQ.
3005 * [no]ncqtrim: Enable or disable queued DSM TRIM.
3007 * [no]ncqati: Enable or disable NCQ trim on ATI chipset.
3009 * [no]trim: Enable or disable (unqueued) TRIM.
3015 * [no]dma: Turn on or off DMA transfers.
3022 * [no]dmalog: Enable or disable the use of the
3025 * [no]iddevlog: Enable or disable access to the
3028 * [no]logdir: Enable or disable access to the general
3039 * [no]lpm: Enable or disable link power management.
3041 * [no]setxfer: Indicate if transfer speed mode setting
3044 * [no]fua: Disable or enable FUA (Force Unit Access)
3047 * dump_id: Dump IDENTIFY data.
3091 Specify the number of self-propagating call_rcu()
3099 occasional long-duration lock hold time. Defaults
3110 Set the number of locking read-acquisition kthreads.
3115 Set the number of locking write-acquisition kthreads.
3118 Set time (s) after boot for CPU-hotplug testing.
3121 Set time (s) between CPU-hotplug operations, or
3122 zero to disable CPU-hotplug testing.
3125 Do periodic testing of real-time lock priority
3130 non-real-time spinlocks, due to their disabling
3131 of preemption. Note that non-realtime mutexes
3144 Set task-shuffle interval (jiffies). Shuffling
3145 tasks allows some CPUs to go into dyntick-idle
3150 is useful for hands-off automated testing.
3169 Run the write-side locktorture kthreads at
3170 sched_set_fifo() real-time priority.
3188 7 (KERN_DEBUG) debug-level messages
3200 logo.nologo [FB] Disables display of the built-in Linux logo.
3218 an IEEE 1284-compliant printer is attached; if
3224 time-consuming boot-time autodetection (up to 250 ms per
3244 Example: machtype=lemote-yeeloong-2f-7inch
3256 (loop.max_loop) unconditionally pre-created at init time. The default
3259 devices can be requested on-demand with the
3260 /dev/loop-control interface.
3262 mce [X86-32] Machine Check Exception
3264 mce=option [X86-64] See Documentation/arch/x86/x86_64/boot-options.rst
3267 See Documentation/admin-guide/md.rst.
3274 Control mitigation for the Micro-architectural Data
3289 full - Enable MDS mitigation on vulnerable CPUs
3290 full,nosmt - Enable MDS mitigation and disable
3292 off - Unconditionally disable MDS mitigation
3294 On TAA-affected machines, mds=off can be prevented by
3303 For details see: Documentation/admin-guide/hw-vuln/mds.rst
3318 [ARC,MICROBLAZE] - the limit applies only to low memory,
3321 [ARM64] - only limits memory covered by the linear
3334 [ARM,MIPS,EARLY] - override the memory layout
3341 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
3348 per-device physically contiguous DMA buffers.
3356 See Documentation/admin-guide/mm/memory-hotplug.rst.
3381 Example: Exclude memory from 0x18690000-0x1869ffff
3395 memmap=<size>%<offset>-<oldtype>+<newtype>
3397 from <oldtype> to <newtype>. If "-<oldtype>" is left
3412 repeatable BIOS-originated corruption always
3456 mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control
3462 Refer to Documentation/virt/kvm/x86/amd-memory-encryption.rst
3466 s2idle - Suspend-To-Idle
3467 shallow - Power-On Suspend or equivalent (if supported)
3468 deep - Suspend-To-RAM or equivalent (if supported)
3469 See Documentation/admin-guide/pm/sleep-states.rst.
3471 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
3487 0 - The attached screen is the 3.5" TFT
3488 1 - The attached screen is the 7" TFT
3489 2 - The VGA Shield is attached (1024x768)
3493 b - Enable backlight. The TFT backlight pin will be
3497 c - Enable the s3c camera interface.
3498 t - Reserved for enabling touchscreen support. The
3502 https://repo.or.cz/w/linux-2.6/mini2440.git
3507 arch-independent options, each of which is an
3508 aggregation of existing arch-specific options.
3537 ssbd=force-off [ARM64]
3550 have other ways of avoiding SMT-based attacks.
3585 full - Enable mitigation on vulnerable CPUs
3587 full,nosmt - Enable mitigation and disable SMT on
3590 off - Unconditionally disable mitigation
3603 Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst
3606 If no <bool> value is specified or if the value
3633 module_blacklist= [KNL] Do not load a comma-separated list of
3658 movable_node [KNL,EARLY] Boot-time switch to make hotplugable memory
3665 Format: <name>,<region-number>,<size>,<offset>
3668 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
3707 something different and driver-specific.
3747 [NFS] enable 64-bit inode numbers.
3748 If zero, the NFS client will fake up a 32-bit inode
3750 of returning the full 64-bit number.
3751 The default is to return 64-bit inode numbers.
3786 [NFS4] Specify an additional fixed unique ident-
3795 no guarantees that the file will remain unchanged
3806 If zero, no implementation identification information
3817 driver. A non-zero value sets the minimum interval
3822 server-to-server copies for which this server is
3834 server-to-server copy, knfsd temporarily mounts
3841 See Documentation/admin-guide/nfs/nfsroot.rst.
3843 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
3844 See Documentation/admin-guide/nfs/nfsroot.rst.
3847 See Documentation/admin-guide/nfs/nfsroot.rst.
3850 Dump stacks even of idle CPUs in response to an
3851 NMI stack-backtrace request.
3860 0 - turn hardlockup detector in nmi_watchdog off
3861 1 - turn hardlockup detector in nmi_watchdog on
3862 rNNN - configure the watchdog with raw perf event 0xNNN
3875 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
3879 no4lvl [RISCV,EARLY] Disable 4-level and 5-level paging modes.
3880 Forces kernel to use 3-level paging instead.
3882 no5lvl [X86-64,RISCV,EARLY] Disable 5-level paging mode. Forces
3883 kernel to use 4-level paging instead.
3916 no_entry_flush [PPC,EARLY] Don't flush the L1-D cache when entering the kernel.
3918 noexec32 [X86-64]
3919 This affects only 32-bit executables.
3920 noexec32=on: enable non-executable mappings (default)
3922 noexec32=off: disable non-executable mappings
3933 nofxsr [BUGS=X86-32] Disables x86 floating point extended
3935 legacy floating-point registers on task switch.
3945 difficult since unequal pointers can no longer be
3946 compared. However, if this command-line option is
3987 nointremap [X86-64,Intel-IOMMU,EARLY] Do not enable interrupt
3989 [Deprecated - use intremap=off]
3995 noirqdebug [X86-32] Disables the code which attempts to detect and
4005 no-kvmapf [X86,KVM,EARLY] Disable paravirtualized asynchronous page
4008 no-kvmclock [X86,KVM,EARLY] Disable paravirtualized KVM clock driver
4010 nolapic [X86-32,APIC,EARLY] Do not enable or use the local APIC.
4012 nolapic_timer [X86-32,APIC,EARLY] Do not use the local APIC timer.
4014 nomce [X86-32] Disable Machine Check Exception
4016 nomfgpt [X86-32] Disable Multi-Function General Purpose
4022 not load if they could possibly displace the pre-
4025 perform display-mode changes or accelerated rendering.
4038 nopcid [X86-64,EARLY] Disable the PCID cpu feature.
4043 nopti [X86-64,EARLY]
4048 as generic guest with no PV drivers. Currently support
4059 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
4065 no-scroll [VGA] Disables scrollback.
4066 This is required for the Braillex ib80-piezo Braille
4069 nosgx [X86-64,SGX,EARLY] Disables Intel SGX kernel support.
4089 nosoftlockup [KNL] Disable the soft-lockup detector.
4095 nospectre_bhb [ARM64,EARLY] Disable all mitigations for Spectre-BHB (branch
4108 no-steal-acc [X86,PV_OPS,ARM64,PPC/PSERIES,RISCV,LOONGARCH,EARLY]
4118 [PPC,EARLY] Don't flush the L1-D cache after accessing user data.
4121 Disable device dump. Device dump allows drivers to
4122 append dump data to vmcore so you can collect driver
4126 device dump can help save memory but the driver debug
4127 data will be no longer available. This parameter
4131 no-vmw-sched-clock
4136 soft-lockup and NMI watchdog (hard-lockup).
4140 nox2apic [X86-64,APIC,EARLY] Do not enable x2APIC mode.
4148 enabling legacy floating-point and sse state.
4170 n. So during boot up some boot time memory for per-cpu
4171 variables need be pre-allocated for later physical cpu
4202 See Documentation/admin-guide/sysctl/vm.rst for details.
4205 See Documentation/core-api/debugging-via-ohci1394.rst for more
4220 onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
4224 boundary - index of last SLC block on Flex-OneNAND.
4226 lock - Configure if Flex-OneNAND boundary should be locked.
4230 oops=panic [KNL,EARLY]
4245 page_owner= [KNL,EARLY] Boot-time page_owner enabling option.
4251 page_poison= [KNL,EARLY] Boot-time parameter changing the state of
4279 See Documentation/admin-guide/tainted-kernels.rst for
4325 computer where firmware has no options for setting
4332 Set to non-zero to probe primary and secondary ISA
4333 port ranges on PCI systems where no PCI PATA device
4338 Set to non-zero if a chip is present that snoops speed
4386 Set to non-zero to probe tertiary and further ISA
4402 Set to non-zero to probe QDI controllers. By default
4407 Set to non-zero to probe Winbond controllers. Use
4421 Halt all CPUs after the first oops has been printed for
4451 earlydump dump PCI config space before the kernel
4454 bios [X86-32] force use of PCI BIOS, don't access
4456 has a non-standard PCI host bridge.
4457 nobios [X86-32] disallow use of PCI BIOS, only direct
4463 data in IO port 0xCFC, both 32-bit).
4465 Mechanism 2 (IO port 0xCF8 is an 8-bit port for
4466 the function, IO port 0xCFA, also 8-bit, sets
4468 through ports 0xC000-0xCFFF).
4475 root domains (aka PCI segments, in ACPI-speak).
4483 disable the use of MSI interrupts system-wide.
4488 primary IO-APIC for bridges that cannot disable
4495 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
4519 F0000h-100000h range.
4524 assign-busses [X86] Always assign all PCI bus
4531 notebooks. This will have no effect if ACPI
4545 <linux-pci@vger.kernel.org>.
4549 a bug to <linux-pci@vger.kernel.org>.
4561 bfsort Sort PCI devices into breadth-first order.
4564 nobfsort Don't sort PCI devices into breadth-first order.
4566 tuning and use the BIOS-configured MPS defaults.
4572 value (no larger than the MPS that the device
4576 configuration allows peer-to-peer DMA between
4579 that hot-added devices will work.
4594 A PCI-PCI bridge can be specified if resource
4600 for 4096-byte alignment.
4602 end-to-end CRC checking). Only effective if
4633 noats [PCIE, Intel-IOMMU, AMD-IOMMU]
4664 bit-0 : ACS Source Validation
4665 bit-1 : ACS Translation Blocking
4666 bit-2 : ACS P2P Request Redirect
4667 bit-3 : ACS P2P Completion Redirect
4668 bit-4 : ACS Upstream Forwarding
4669 bit-5 : ACS P2P Egress Control
4670 bit-6 : ACS Direct Translated P2P
4680 Validation unchanged from whatever power-up
4692 system-wide.
4706 dpc-native Use native PCIe service for DPC only. May
4723 Keep all power-domains already enabled by bootloader on,
4724 even if no driver has claimed them. This is useful
4741 pirq= [SMP,APIC] Manual mp-table setup
4742 See Documentation/arch/x86/i386/IO-APIC.rst.
4746 See also Documentation/admin-guide/parport.rst.
4753 This option takes over the PMU facility, so it is no
4765 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
4774 { on | off | curr | res | no-curr | no-res }
4819 none - Limited to cond_resched() calls
4820 voluntary - Limited to cond_resched() and might_sleep() calls
4821 full - Any section that isn't explicitly preempt disabled
4825 lazy - Scheduler controlled. Similar to full but instead
4831 print-fatal-signals=
4837 coredump - etc.
4840 you might want to try "ulimit -i unlimited".
4845 Trigger kmsg_dump for cases other than kernel oops or
4851 Disable console loglevel raise on oops, panic
4852 or lockdep-detected issues (only if lock debug is on).
4861 on - unlimited logging to /dev/kmsg from userspace
4862 off - logging to /dev/kmsg disabled
4863 ratelimit - ratelimit the logging
4874 - 'always': traditional behavior always allows mem overrides.
4875 - 'ptrace': only allow mem overrides for active ptracers.
4876 - 'never': never allow mem overrides.
4880 Limit processor to maximum C-state
4884 Ignore the _CST method to determine C-states,
4891 Param: "schedule" - profile schedule points.
4892 Param: "kvm" - profile VM exits.
4893 Param: <number> - step/bucket size as a power of 2 for
4924 pti= [X86-64] Control Page Table Isolation of user and
4929 on - unconditionally enable
4930 off - unconditionally disable
4931 auto - kernel detects whether your CPU model is
4937 [KNL] Number of legacy pty's. Overwrites compiled-in
4949 See Documentation/admin-guide/md.rst.
4952 See Documentation/admin-guide/blockdev/ramdisk.rst.
4971 cross-syscall address exposures. This is only
4977 ras=option[,option,...] [KNL] RAS-specific options
4983 rcu_nocbs[=cpu-list]
4988 enable the no-callback CPU mode, which prevents
4993 "p" for RCU-preempt, "s" for RCU-sched, and "g"
4997 and real-time workloads. It can also improve
5001 list of CPUs is set to no-callback mode from boot.
5004 arguments are omitted, no CPU will be set to
5005 no-callback mode from boot but the mode may be
5016 This improves the real-time response for the
5027 Do only a one-line RCU CPU stall warning when
5028 there is an ongoing too-long CSD-lock wait.
5034 If triggered before the RCU grace-period machinery
5038 Dump the structure of the rcu_node combining tree
5044 RCU grace-period cleanup.
5048 RCU grace-period initialization.
5052 RCU grace-period pre-initialization, that is,
5053 the propagation of recent CPU-hotplug changes up
5057 Set delay from grace-period initialization to
5070 soliciting quiescent-state help from
5082 Set the SCHED_FIFO priority of the RCU per-CPU
5085 and for the RCU grace-period kthreads (rcu_bh,
5087 set, valid values are 1-99 and the default is 1
5088 (the least-favored priority). Otherwise, when
5089 RCU_BOOST is not set, valid values are 0-99 and
5090 the default is zero (non-realtime operation).
5095 On callback-offloaded (rcu_nocbs) CPUs,
5098 use of the ->nocb_bypass list. However, in the
5099 common non-flooded case, RCU queues directly to
5100 the main ->cblist in order to avoid the extra
5101 overhead of the ->nocb_bypass list and its lock.
5103 a single jiffy, RCU pre-queues the callbacks into
5104 the ->nocb_bypass queue. The definition of "too
5108 On callback-offloaded (rcu_nocbs) CPUs, avoid
5121 batch limiting is re-enabled.
5125 RCU's force-quiescent-state scan will aggressively
5133 Set the page-cache refill delay (in milliseconds)
5134 in response to low-memory conditions. The range
5138 Set the shift-right count to use to compute
5139 the callback-invocation batch limit bl from
5146 Please note that this callback-invocation batch
5147 limit applies only to non-offloaded callback
5156 cache-to-cache transfer latencies.
5162 and for NUMA systems with large remote-access
5178 the wakeup overhead on the global grace-period
5180 each group's NOCB grace-period kthread.
5183 Cause the grace-period kthread to get an extra
5185 it should at force-quiescent-state time.
5198 this specifies an rcu_read_unlock()-time delay
5202 of RCU-protected pointers after the relevant
5206 Commandeer a sysrq key to dump out Tree RCU's
5212 per-CPU rcuc kthreads. Defaults to a non-zero
5241 grace-period primitives such as call_rcu().
5252 grace-period primitives.
5255 Set test-start holdoff period. The purpose of
5273 Test the double-argument variant of kfree_rcu().
5275 rcuscale.kfree_rcu_test_single, both the single-
5276 and double-argument variants are tested.
5279 Test the single-argument variant of kfree_rcu().
5281 rcuscale.kfree_rcu_test_double, both the single-
5282 and double-argument variants are tested.
5296 does not affect the data-collection interval,
5301 Set number of RCU readers. The value -1 selects
5303 "n" less than -1 selects N-n+1, where N is again
5304 the number of CPUs. For example, -2 selects N
5305 (the number of CPUs), -3 selects N+1, and so on.
5306 A value of "n" less than or equal to -N selects
5319 complete. This is useful for hands-off automated
5326 Write-side holdoff between grace periods,
5328 no holdoff.
5331 Additional write-side holdoff between grace
5333 says no holdoff.
5349 for RCU grace-period forward-progress testing
5356 Specify the fraction of a CPU-stall-warning
5357 period to do tight-loop forward-progress testing.
5361 forward-progress tests.
5365 need_resched() during tight-loop forward-progress
5369 Use conditional/asynchronous update-side
5373 Use expedited update-side primitives, if available.
5376 Use normal (non-expedited) asynchronous
5377 update-side primitives, if available.
5380 Use normal (non-expedited) synchronous
5381 update-side primitives, if available. If all
5385 they are all non-zero.
5393 Leak an RCU-protected pointer out of the reader.
5408 Set number of RCU callback-offload togglers.
5413 callback-offload toggling attempts.
5416 Set number of RCU readers. The value -1 selects
5417 N-1, where N is the number of CPUs. A value
5418 "n" less than -1 selects N-n-2, where N is again
5419 the number of CPUs. For example, -2 selects N
5420 (the number of CPUs), -3 selects N+1, and so on.
5423 Enable debug-object double-call_rcu() testing.
5426 Set time (s) after boot for CPU-hotplug testing.
5429 Set time (jiffies) between CPU-hotplug operations,
5430 or zero to disable CPU-hotplug testing.
5433 The number of times in a given read-then-exit
5434 episode that a set of read-then-exit kthreads
5439 read-then-exit testing episodes.
5444 are entered from low-order bit up, and are
5446 0x1 bit is normal readers, 0x2 NMI-safe readers,
5447 and 0x4 light-weight readers.
5450 Set task-shuffle interval (s). Shuffling tasks
5451 allows some CPUs to go into dyntick-idle mode
5456 is useful for hands-off automated testing.
5465 any other stall-related activity. Note that
5471 in scheduling-while-atomic splats.
5490 grace-period kthread to test RCU CPU stall
5505 Test RCU priority boosting? 0=no, 1=maybe, 2=yes.
5516 Test RCU's dyntick-idle handling. See also the
5526 Dump ftrace buffer after reporting RCU CPU
5571 Use expedited grace-period primitives, for
5575 real-time latency, and degrade energy efficiency.
5576 No effect on CONFIG_TINY_RCU kernels.
5579 Use only normal grace-period primitives,
5582 real-time latency, CPU utilization, and
5584 increased grace-period latency. This parameter
5585 overrides rcupdate.rcu_expedited. No effect on
5591 only normal grace-period primitives. No effect
5597 post-boot attempt at an expedited RCU grace
5598 period to instead use normal non-expedited
5599 grace-period processing.
5607 set to the default value of -1.
5610 Set the minimum number of callback-queuing-time
5611 lock-contention events per jiffy required to
5612 cause the RCU Tasks flavors to switch to per-CPU
5615 the default value of -1.
5620 of -1 allows this to be automatically (and
5628 number avoids disturbing real-time workloads,
5633 cancel laziness on that CPU. Use -1 to disable
5643 only printed prior to the stall-warning message
5691 force - Override the decision by the kernel to hide the
5719 Set test-start holdoff period. The purpose of
5734 but the default has already reduced the per-pass
5739 Set number of readers. The default value of -1
5748 Set the read-side critical-section duration,
5752 Specify the read-protection implementation to test.
5772 that are unused, due no driver claiming them. This may
5778 See Documentation/admin-guide/cgroup-v1/cpusets.rst.
5806 reserve_mem=12M:4096:oops ramoops.mem_name=oops
5808 reservetop= [X86-32,EARLY]
5825 See Documentation/power/swsusp-and-swap-files.rst
5841 AMD-based UNRET and IBPB mitigations alone do not stop
5843 sibling threads. For that reason, STIBP is used on pro-
5847 off - no mitigation
5848 auto - automatically select a migitation
5849 auto,nosmt - automatically select a mitigation,
5853 ibpb - On AMD, mitigate short speculation
5858 ibpb,nosmt - Like "ibpb" above but will disable SMT
5862 unret - Force enable untrained return thunks,
5863 only effective on AMD f15h-f17h based
5865 unret,nosmt - Like unret, but will disable SMT when STIBP
5897 ro [KNL] Mount root device read-only on boot
5900 on Mark read-only kernel memory as read-only (default).
5901 off Leave read-only kernel memory writable for debugging.
5902 full Mark read-only kernel memory and aliases as read-only
5909 debug-uart get routed to the D+ and D- pins of the usb
5915 block/early-lookup.c for details.
5940 rw [KNL] Mount root device read-write on boot
5960 and so on. As a special case a factor of 0 imposes no
5994 to 10 seconds for built-in smp_call_function()
6001 that requesting even small non-zero numbers of
6008 The default of -1 specifies a number of kthreads
6013 test before initiating CPU-hotplug operations.
6017 CPU-hotplug operations. Specifying zero (which
6018 is the default) disables CPU-hotplug operations.
6024 Non-zero values are useful for automated tests.
6047 "wait" parameter. A value of -1 selects the
6048 default if all other weights are -1. However,
6050 value of -1 will instead select a weight of zero.
6055 non-zero "wait" parameter. See weight_single.
6068 non-zero "wait" parameter. See weight_single
6080 non-zero "wait" parameter. See weight_single
6091 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
6092 1 -- enable.
6103 0 -- disable.
6104 1 -- enable.
6107 serialnumber [BUGS=X86-32]
6109 sev=option[,option...] [X86-64] See Documentation/arch/x86/x86_64/boot-options.rst
6117 to set it to "all" by meaning -- no limit here.
6198 using the csdlock_debug- kernel parameter.
6203 system. By default, let CSD-lock acquisition
6205 for this value provides a 5-minute timeout.
6207 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
6208 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
6209 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
6210 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
6211 smsc-ircc2.ircc_irq= [HW] IRQ line
6212 smsc-ircc2.ircc_dma= [HW] DMA channel
6213 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
6223 Default: -1 (no limit)
6226 [KNL] Should the soft-lockup detector generate panics.
6229 A value of 1 instructs the soft-lockup detector
6230 to panic the machine when a soft-lockup occurs. It is
6233 respective build-time switch to that functionality.
6236 [KNL] Should the soft-lockup detector generate
6241 See Documentation/admin-guide/laptops/sonypi.rst
6248 on - (default) Enable the HW or SW mitigation as
6251 vmexit - On systems which don't have the HW mitigation
6254 protected from VM-originated BHI attacks, but
6256 off - Disable the mitigation.
6263 on - unconditionally enable, implies
6265 off - unconditionally disable, implies
6267 auto - kernel detects whether your CPU model is
6284 retpoline - replace indirect branches
6285 retpoline,generic - Retpolines
6286 retpoline,lfence - LFENCE; indirect branch
6287 retpoline,amd - alias for retpoline,lfence
6288 eibrs - Enhanced/Auto IBRS
6289 eibrs,retpoline - Enhanced/Auto IBRS + Retpolines
6290 eibrs,lfence - Enhanced/Auto IBRS + LFENCE
6291 ibrs - use IBRS to protect kernel
6301 on - Unconditionally enable mitigations. Is
6304 off - Unconditionally disable mitigations. Is
6307 prctl - Indirect branch speculation is enabled,
6313 - Like "prctl" above, but only STIBP is
6319 - Same as "prctl" above, but all seccomp
6324 - Like "seccomp" above, but only STIBP is
6329 auto - Kernel selects the mitigation depending on
6340 off - Disable mitigation
6341 microcode - Enable microcode mitigation only
6342 safe-ret - Enable sw-only safe RET mitigation (default)
6343 ibpb - Enable mitigation by issuing IBPB on
6345 ibpb-vmexit - Issue IBPB only on VMEXIT
6346 (cloud-specific mitigation)
6371 on - Unconditionally disable Speculative Store Bypass
6372 off - Unconditionally enable Speculative Store Bypass
6373 auto - Kernel detects whether the CPU model contains an
6379 prctl - Control Speculative Store Bypass per thread
6383 seccomp - Same as "prctl" above, but all seccomp threads
6391 on,auto - On Power8 and Power9 insert a store-forwarding
6395 off - No action.
6409 off - not enabled
6411 warn - the kernel will emit rate-limited warnings
6419 fatal - the kernel will send SIGBUS to applications
6424 ratelimit:N -
6434 the kernel will oops in either "warn" or "fatal"
6444 Certain CPUs are vulnerable to an MDS-like
6464 This kernel-boot parameter defaults to 128,
6465 but takes effect only when the low-order four
6482 instead of the compile-time CONFIG_NR_CPUS.
6486 grace-period sequence counter wrap for the
6487 srcu_data structure's ->srcu_gp_seq_needed field.
6502 Specifies the number of no-delay instances
6509 Specifies the per-grace-period phase, number of
6510 non-sleeping polls of readers. Beyond this limit,
6516 Specifies number of microseconds of non-sleeping
6517 delay between each non-sleeping poll of readers.
6520 Specifies the number of update-side contention
6525 set for contention-based conversions to occur.
6535 force-on: Unconditionally enable mitigation for
6537 force-off: Unconditionally disable mitigation for
6548 growing up) the main stack are reserved for no other
6560 stacktrace_filter=[function-list]
6562 will trace at boot up. function-list is a comma-separated
6570 Set the STI (builtin display/keyboard on the HP-PARISC
6572 as the initial boot-console.
6616 The default value is 0 (no limit).
6632 to global on non-NUMA machines)
6657 <int> -- Number of I/O TLB slabs
6658 <int> -- Second integer after comma. Number of swiotlb
6661 force -- force using of bounce buffers even if they
6663 noforce -- Never use bounce buffers (for debugging)
6678 Ignore sysrq setting - this boot parameter will
6686 cache size. See Documentation/networking/ip-sysctl.rst
6693 Specify "mem" (for Suspend-to-RAM) or "standby" (for
6698 wakeup-capable RTC alarm.
6704 -1: disable all active trip points in all thermal zones
6708 -1: disable all critical trip points in all thermal zones
6715 -1: disable all passive trip points
6721 <deci-seconds>: poll all this frequency
6722 0: no polling (default)
6725 Format: <size>[KMG],<size>[KMG]:<state>;<size>[KMG]-<size>[KMG]:<state>
6730 See Documentation/admin-guide/mm/transhuge.rst for more
6738 Format: <size>[KMG],<size>[KMG]:<policy>;<size>[KMG]-<size>[KMG]:<policy>
6744 See Documentation/admin-guide/mm/transhuge.rst for more
6756 Prevent the CPU-hotplug component of torturing
6760 Dump the ftrace buffer at torture-test shutdown,
6761 even if there were no errors. This can be a
6764 with rotating-rust storage.
6769 disables verbose-printk() sleeping.
6772 Duration of each verbose-printk() sleep in jiffies.
6797 https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/
6809 tp_printk kernel cmdline option has no effect.
6835 local - Use the per CPU time stamp counter
6839 global - Event time stamps are synchronize across
6842 counter - Simple counting of events (1, 2, ..)
6846 uptime - Use jiffies as the time stamp.
6847 perf - Use the same clock that perf uses.
6848 mono - Use ktime_get_mono_fast_ns() for time stamps.
6849 mono_raw - Use ktime_get_raw_fast_ns() for time
6851 boot - Use ktime_get_boot_fast_ns() for time stamps.
6855 trace_event=[event-list]
6857 to facilitate early boot debugging. The event-list is a
6858 comma-separated list of trace events to enable. See
6861 trace_instance=[instance-info]
6886 traceoff - Have the tracing instance tracing disabled after it is created.
6887 traceprintk - Have trace_printk() write into this trace instance
6932 trace_options=[option-list]
6934 The option-list is a comma delimited list of options
6940 For example, to enable stacktrace option (to dump the
6948 trace_trigger=[trigger-list]
6974 the WARNING dump is called, which prevents the trace to
6985 See Documentation/admin-guide/mm/transhuge.rst
6992 See Documentation/admin-guide/mm/transhuge.rst
7000 - "tpm"
7001 - "tee"
7002 - "caam"
7003 - "dcp"
7013 - "kernel"
7014 - the same value as trusted.source: "tpm" or "tee"
7015 - "default"
7036 high-resolution timer mode on older hardware, and in
7072 on - Enable TSX on the system. Although there are
7075 several previous speculation-related CVEs, and
7079 off - Disable TSX on the system. (Note that this
7087 auto - Disable TSX if X86_BUG_TAA is present,
7092 See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
7098 Similar to Micro-architectural Data Sampling (MDS)
7113 full - Enable TAA mitigation on vulnerable CPUs
7116 full,nosmt - Enable TAA mitigation and disable SMT on
7119 vulnerable to cross-thread TAA attacks.
7120 off - Unconditionally disable TAA mitigation
7122 On MDS-affected machines, tsx_async_abort=off can be
7134 Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
7140 See also Documentation/input/devices/joystick-parport.rst
7142 udbg-immortal [PPC] When debugging early kernel crashes that
7148 Set number of hash buckets for UDP/UDP-Lite connections
7150 uhci-hcd.ignore_oc=
7152 Some badly-designed motherboards generate lots of
7161 unwind_debug [X86-64,EARLY]
7169 (default -1 = authorized (same as 1),
7175 for newly-detected USB devices (default 2). This
7203 [USB] Specifies timeout for the initial 64-byte
7210 [USB] A list of quirk entries to augment the built-in
7213 VendorID:ProductID:Flags. The IDs are 4-digit hex
7215 will change the built-in quirk; setting it if it is
7220 a 255-byte read);
7224 Set-Interface requests);
7243 (bInterval-1).
7281 usb-storage.delay_use=
7288 usb-storage.quirks=
7290 override the built-in unusual_devs list. List
7293 and Product ID values (4-digit hex numbers) and
7295 to a common usb-storage quirk flag as follows:
7337 medium is write-protected).
7339 even if the device claims no cache,
7346 1 - undefined instruction events
7347 2 - system calls
7348 4 - invalid data aborts
7349 8 - SIGSEGV faults
7350 16 - SIGBUS faults
7366 vdso32= [X86] Control the 32-bit vDSO
7367 vdso32=1: enable 32-bit VDSO
7368 vdso32=0 or vdso32=2: disable 32-bit VDSO
7378 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
7409 vga= [BOOT,X86-32] Select a particular video mode
7411 Documentation/admin-guide/svga.rst.
7426 - Disable all of the above options
7450 vsyscall= [X86-64,EARLY]
7453 code). Most statically-linked binaries and older
7477 see VGA-softcursor.txt. Default: 2 = underline.
7482 This is a 16-member array composed of values
7483 ranging from 0-255.
7488 This is a 16-member array composed of values
7489 ranging from 0-255.
7494 This is a 16-member array composed of values
7495 ranging from 0-255.
7500 Set system-wide default UTF-8 mode for all tty's.
7501 Default is 1, i.e. UTF-8 mode is enabled for all
7506 Format=<-1|0|1>
7507 Set system-wide default for whether a cursor
7508 is shown on new VTs. Default is -1,
7513 vt.italic= [VT] Default color for italic text; 0-15.
7516 vt.underline= [VT] Default color for underlined text; 0-15.
7520 see Documentation/watchdog/watchdog-parameters.rst
7521 or other driver-specific files in the
7535 Format: <cpu-list>
7541 warn stall conditions and dump internal state to
7556 Per-cpu work items which run for longer than this
7559 them from noticeably delaying other per-cpu work
7577 Per-cpu workqueues are generally preferred because
7579 locality; unfortunately, per-cpu workqueues tend to
7582 Enabling this makes the per-cpu workqueues which
7596 Documentation/core-api/workqueue.rst.
7606 on the local CPU. This guarantee is no longer true
7609 forces round-robin CPU selection to flush out
7617 on - Enable writecombine, use WUC for ioremap_wc()
7618 off - Disable writecombine, use SUC for ioremap_wc()
7620 x2apic_phys [X86-64,APIC,EARLY] Use x2apic physical mode instead of
7624 xen_512gb_limit [KNL,X86-64,XEN]
7634 ide-disks -- unplug primary master IDE devices
7635 aux-ide-disks -- unplug non-primary-master IDE devices
7636 nics -- unplug network devices
7637 all -- unplug all emulated devices (NICs and IDE disks)
7638 unnecessary -- unplugging emulated devices is
7641 never -- do not unplug even if version check succeeds
7655 Select whether to always use non-faulting (safe) MSR
7661 run as generic HVM guest with no PV drivers.
7675 xen_timer_slop= [X86-64,XEN,EARLY]
7700 preferred over the 2-level event handling, as it is
7717 xive.store-eoi=off [PPC]
7723 xhci-hcd.quirks [USB,KNL]