Lines Matching +full:can +full:- +full:disable
5 force -- enable ACPI if default was off
6 on -- enable ACPI but allow fallback to DT [arm64]
7 off -- disable ACPI if default was on
8 noirq -- do not use ACPI for IRQ routing
9 strict -- Be less tolerant of platforms that are not
11 rsdt -- prefer RSDT over (default) XSDT
12 copy_dsdt -- copy DSDT to memory
26 If set to vendor, prefer vendor-specific driver
31 If set to none, disable the ACPI backlight interface.
40 Disable AML predefined validation mechanism
41 This mechanism can repair the evaluation result to make
58 Documentation/firmware-guide/acpi/debug.rst for more information about
81 can interfere with legacy drivers.
113 by unsupported hardware/firmware features can result in
116 This facility can be used to prevent such uncontrolled
121 Disable auto-serialization of AML methods
124 auto-serialization feature.
128 acpi_no_memhotplug [ACPI] Disable memory hotplug. Useful for kdump
132 Disable installation of static SSDTs at early boot time
142 Ignore the ACPI-based watchdog interface (WDAT) and let
163 acpi_osi=! # disable all built-in OS vendor
165 acpi_osi=!! # enable all built-in OS vendor
167 acpi_osi= # disable all strings
169 'acpi_osi=!' can be used in combination with single or
171 vendor string(s). Note that such command can only
182 can make '_OSI("Windows 2000")' TRUE.
186 exist in the ACPI namespace. NOTE that such command can
191 1. 'acpi_osi=' can make 'CondRefOf(_OSI, Local1)'
194 'acpi_osi=!*' can be used in combination with single or
196 string(s). Note that such command can affect the
206 1. 'acpi_osi="Module Device" acpi_osi=!*' can make
208 2. 'acpi_osi=!* acpi_osi="Module Device"' can make
227 For broken nForce2 BIOS resulting in XT-PIC timer.
235 as soon as the kernel's real-mode entry point is called.
260 off: disable AGP support
265 See Documentation/sound/alsa-configuration.rst
272 align_va_addr= [X86-64]
277 CPU-intensive style benchmark, and it can vary highly in
280 32: only for 32-bit processes
281 64: only for 64-bit processes
282 on: enable for both 32- and 64-bit processes
283 off: disable for both 32- and 64-bit processes
292 amd_iommu= [HW,X86-64]
295 fullflush - enable flushing of IO/TLB entries when
299 off - do not initialize any AMD IOMMU found in
301 force_isolation - Force device isolation for all
307 amd_iommu_dump= [HW,X86-64]
313 amd_iommu_intr= [HW,X86-64]
316 legacy - Use legacy interrupt remapping mode.
317 vapic - Use virtual APIC mode, which allows IOMMU
319 This mode requires kvm-amd.avic=1.
333 Power management functions (SPARCstation-4/5 + deriv.)
335 Disable APC CPU standby support. SPARCstation-Fox does
336 not play well with APC CPU idle - disable it if you have
343 when initialising the APIC and IO-APIC components.
344 For X86-32, this can also be used to specify an APIC
364 to set it to "all" by meaning -- no limit here.
373 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
397 audit= [KNL] Enable the audit sub-system
399 0 | off - kernel audit is disabled and can not be
401 unset - kernel audit is initialized but disabled and
403 1 | on - kernel audit is initialized and partially
414 behavior is to disable the BAU (i.e. bau=0).
416 0 - Disable the BAU.
417 1 - Enable the BAU.
418 unset - Disable the BAU.
439 See Documentation/block/cmdline-partition.rst
447 Extended command line options can be added to an initrd
450 See Documentation/admin-guide/bootconfig.rst
453 Disable BERT OS support on buggy BIOSes.
456 Disable BGRT to avoid flickering OEM logo.
461 bttv.pll= See Documentation/admin-guide/media/bttv.rst
470 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
489 inclusive. See arch/mips/include/asm/pgtable-bits.h
496 cgroup_disable= [KNL] Disable a particular controller
497 Format: {name of the controller(s) to disable}
499 - foo isn't auto-mounted if you mount all cgroups in
501 - foo isn't visible as an individually mountable
504 cut the overhead, others just disable the usage. So
507 cgroup_no_v1= [KNL] Disable cgroup controllers and named hierarchies in v1
518 nosocket -- Disable socket memory accounting.
519 nokmem -- Disable kernel memory accounting.
520 kmem -- Enable kernel memory accounting.
525 0 -- check protection applied by kernel (includes
527 1 -- check protection requested by application.
529 Value can be changed at runtime via
541 force such clocks to be always-on nor does it reserve
545 information, see Documentation/driver-api/clk.rst.
547 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
564 [X86-32] pit,hpet,tsc;
571 [X86-64] hpet,tsc
576 Enable/disable the eventstream feature of the ARM
577 architected timer so that code using WFE-based polling
578 loops can be debugged more effectively on production
588 Disable CPUID feature X for the kernel. See
597 Also note the kernel might malfunction if you disable
600 cma=nn[MG]@[start[MG][-end[MG]]]
611 Sets the size of kernel per-numa memory area for
613 per-numa CMA altogether. And If this option is not
615 With per-numa CMA enabled, DMA users on node nid will
631 com20020= [HW,NET] ARCnet - COM20020 chipset
635 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
639 ARCnet - COM90xx chipset (memory-mapped buffers)
657 See Documentation/admin-guide/serial-console.rst for more
667 Start an early, polled-mode console on the 8250/16550
670 MMIO inter-register address stride is either 8-bit
671 (mmio), 16-bit (mmio16), or 32-bit (mmio32).
675 the h/w is not re-initialized.
696 syscall, or to executing "dmesg -S --raw" or to reading
711 Enable/disable the CPU sampling based debugging.
712 0: default value, disable debugging
716 disable the cpuidle sub-system
722 disable the cpufreq sub-system
730 [X86] Delay for N microsec between assert and de-assert
740 [KNL] Using kexec, Linux can switch to a 'crash kernel'
745 [KNL, X86-64] Select a region under 4G first, and
748 See Documentation/admin-guide/kdump/kdump.rst for further details.
753 start-[end] where start and end are both
755 Documentation/admin-guide/kdump/kdump.rst for an example.
758 [KNL, X86-64] range could be above 4G. Allow kernel
765 [KNL, X86-64] range under 4G. When crashkernel=X,high
770 low memory is needed to make sure DMA buffers for 32-bit
775 0: to disable low allocation.
780 [KNL] Disable crypto self-tests
794 See also Documentation/input/devices/joystick-parport.rst
798 Documentation/admin-guide/dynamic-debug-howto.rst for
812 [KNL] verbose self-tests
815 self-tests.
817 1 will print _a lot_ more information - normally
823 [KNL] Disable object debugging
855 Format: { on, no-mount, off }
857 no-mount:
858 Filesystem is not registered but kernel clients can
859 access APIs and a crashkernel can be used to read
862 get a -EPERM as result when trying to register files
866 Default value is set in build-time with a kernel configuration.
882 Documentation/admin-guide/mm/hugetlbpage.rst.
912 can be useful when debugging issues that require an SLB
920 disable= [IPV6]
929 against bounds-checking flaws in the kernel's
932 off Disable hardened usercopy checks.
935 Disable RADIX MMU mode on POWER9
938 Disable RADIX GTSE feature and use hcall for TLB
942 Disable TLBIE instruction. Currently does not work
950 disable BSP to wake up multiple CPUs without
956 Disable Intel PMU counter freezing feature.
961 Disable Dynamic DMA Window support. Use this
979 Disable PIN 1 of APIC timer
980 Can be useful to work around chipset bugs.
982 dis_ucode_ldr [X86] Disable the microcode loader.
989 entries for DMA-API debugging code. One entry is
990 required per DMA-API allocation. Use this if the
991 DMA-API debugging code disables itself because the
995 With this option the DMA-API debugging driver
996 filter feature can be enabled at boot time. Just
998 The filter can be disabled or changed to another
1010 Generic built-in EDID data sets are used, if one of
1015 available in Documentation/admin-guide/edid.rst. An EDID
1027 Control how the dt_cpu_ftrs device-tree binding is
1037 what data is available or for reverse-engineering.
1042 Documentation/admin-guide/dynamic-debug-howto.rst
1045 nopku [X86] Disable Memory Protection Keys CPU feature found
1059 determined by stdout-path property in device tree's
1064 Start an early, polled-mode console on a Cadence
1075 Start an early, polled-mode console on the 8250/16550
1077 MMIO inter-register address stride is either 8-bit
1078 (mmio) or 32-bit (mmio32 or mmio32be).
1086 Start an early, polled-mode console on a pl011 serial
1090 the driver will use only 32-bit accessors to read/write
1094 Start an early, polled-mode console on a meson serial
1100 Start an early, polled-mode console on an msm serial
1106 Start an early, polled-mode console on an msm serial
1112 Start an early, polled-mode console on a serial port
1118 Start an early, polled-mode console on a serial port
1124 Use RISC-V SBI (Supervisor Binary Interface) for early
1142 Start an early, polled-mode console on a lantiq serial
1156 Start an early, polled-mode, output-only console on the
1161 Start an early, polled-mode console on the
1167 Start an early, polled-mode console on a Qualcomm
1175 coherent non-x86 systems that use system memory for
1200 Append ",keep" to not disable it when the real console
1203 Only one of vga, efi, serial, or usb debug port can
1211 You can find the port for a given device in
1221 The xen output can only be used by Xen PV guests.
1223 The sclp output can only be used on s390.
1233 off: disable H/W event reporting through EDAC.
1244 but can only be used if the backing tty is available
1256 disable_early_pci_dma: disable the busmaster bit on all
1258 nochunk: disable reading files in "chunks" in the EFI
1259 boot stub, as chunking can cause problems with some
1261 noruntime : disable EFI runtime services support
1265 claim. Specify efi=nosoftreserve to disable this
1273 Using this parameter you can use more than 50% of
1286 attribute is added to range 0x100000000-0x180000000 and
1287 0x10a0000000-0x1120000000.
1291 range 0x240000000-0x43fffffff.
1293 Using this parameter you can do debugging of EFI memmap
1294 related features. For example, you can do debugging of
1303 Documentation/admin-guide/acpi/ssdt-overlays.rst for details.
1309 elanfreq= [X86-32]
1317 See Documentation/admin-guide/kdump/kdump.rst for details.
1326 Can be useful to work around chipset bugs
1333 0 -- permissive (log only, no denials).
1334 1 -- enforcing (deny and log).
1336 Value can be changed at runtime via
1340 Disable Error Record Serialization Table (ERST)
1358 See also Documentation/fault-injection/.
1362 See Documentation/admin-guide/sysctl/net.rst for
1366 See Documentation/admin-guide/blockdev/floppy.rst.
1369 [IA-64] Avoid check_sal_cache_flush which may hang on
1374 forcepae [X86-32]
1376 Many Pentium M systems disable PAE but may have a
1393 ftrace_filter=[function-list]
1395 tracer at boot up. function-list is a comma separated
1396 list of functions. This list can be changed at run
1400 ftrace_notrace=[function-list]
1402 function-list. This list can be changed at run time
1406 ftrace_graph_filter=[function-list]
1409 function-list is a comma separated list of functions
1410 that can be changed at run time by the
1413 ftrace_graph_notrace=[function-list]
1415 function-list. This list is a comma separated list of
1416 functions that can be changed at run time by the
1422 can be changed at run time by the max_graph_depth file
1435 off -- Don't create device links from firmware info.
1436 permissive -- Create device links from firmware info
1439 on -- Create device links from firmware info and use it
1441 rpm -- Like "on", but also use to order runtime PM.
1447 See also Documentation/input/devices/joystick-parport.rst
1451 gart_fix_e820= [X86-64] disable the fix e820 for K8 GART
1455 gcov_persist= [GCOV] When non-zero (default), profiling data for
1488 gpio-mockup.gpio_mockup_ranges
1493 [KNL] Should the hard-lockup detector generate
1499 for 64-bit NUMA, off otherwise.
1502 hcl= [IA-64] SGI's Hardware Graph compatibility layer
1508 Disable Hardware Error Source Table (HEST) support;
1509 corresponding firmware-first mode error processing
1517 highres= [KNL] Enable/disable high resolution timer mode.
1523 hpet= [X86-32,HPET] option to control HPET usage
1524 Format: { enable (default) | disable | force |
1526 disable: disable HPET and use PIT instead
1540 boot-time allocation of gigantic hugepages is skipped.
1548 Documentation/admin-guide/mm/hugetlbpage.rst.
1555 hugepagesz=X hugepages=Y can be specified once for
1558 Documentation/admin-guide/mm/hugetlbpage.rst.
1567 by the CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time
1568 option. The value selected by this boot parameter can
1573 hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
1596 (disabled by default, and as a pre-condition
1598 i8042.direct [HW] Put keyboard port into non-translated mode
1599 i8042.dumbkbd [HW] Pretend that controller can only read data from
1604 i8042.noloop [HW] Disable the AUX Loopback command while probing
1612 suspend-to-ram transitions, only during s2r
1645 -1 -- never invert brightness
1646 0 -- machine default
1647 1 -- force brightness inversion
1652 ide-core.nodma= [HW] (E)IDE subsystem
1658 ide-generic.probe-mask= [HW] (E)IDE subsystem
1670 ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
1675 Poll forces a polling idle loop that can slightly
1681 idle=nomwait: Disable mwait for CPU C-states
1698 legacy only accept legacy-NaN binaries, if supported
1700 2008 only accept 2008-NaN binaries, if supported
1709 'relaxed' straps the emulator for both legacy-NaN and
1710 2008-NaN, whereas 'strict' enables legacy-NaN only on
1719 Ignore loglevel setting - this will print /all/
1727 print warning at first misuse. Can be changed via
1783 Formats: { "ima" | "ima-ng" | "ima-sig" }
1784 Default: "ima-ng"
1796 different crypto accelerators. This option can be used
1804 different crypto accelerators. This option can be used
1816 initcall_blacklist= [KNL] Do not execute a comma-separated list of
1817 initcall functions. Useful for debugging built-in
1840 default (disallow access to all but pkey 0). Can
1850 0 -- basic integrity auditing messages. (Default)
1851 1 -- additional integrity auditing messages.
1857 Disable intel iommu driver.
1864 forcedac [X86-64]
1866 for io virtual address below 32-bit forcing dual
1868 than 32-bit addressing. The default is to look
1869 for translation below 32-bit and if not available
1887 could harm performance of some high-throughput
1894 Disable bounce buffer for untrusted devices such as
1901 1 to 9 specify maximum depth of C-state.
1904 disable
1911 used along with the hardware-managed P-states (HWP)
1915 in favor of acpi-cpufreq. Forcing the intel_pstate driver
1916 instead of acpi-cpufreq may disable platform features, such
1918 P-States information being indicated to OSPM and therefore
1921 or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
1934 Allow per-logical-CPU P-State performance control limits using
1937 intremap= [X86-64, Intel-IOMMU]
1939 off disable Interrupt Remapping
1940 nosid disable Source ID checking
1942 BIOS x2APIC opt-out request will be ignored
1943 nopost disable Interrupt Posting
1945 iomem= Disable strict checking of access to MMIO memory
1962 Disable IOMMU bypass, using IOMMU for PCI devices.
1966 0 - Lazy mode.
1972 1 - Strict mode (default).
1979 0 - Use IOMMU translation for DMA.
1980 1 - Bypass the IOMMU for DMA.
1981 unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
1983 io7= [HW] IO7 for Marvel-based Alpha systems
1998 See Documentation/admin-guide/nfs/nfsroot.rst.
2022 Enables support for pseudo-NMIs in the kernel. This
2041 [Deprecated - use cpusets instead]
2042 Format: [flag-list,]<cpu-list>
2048 Disable the tick when a single task runs.
2065 advised to use cpusets instead to disable scheduler load
2067 It offers a much more flexible interface where CPUs can
2070 You can move a process onto or off an "isolated" CPU via
2073 "number of CPUs in system - 1".
2099 The format of <cpu-list> is described above.
2103 ivrs_ioapic [HW,X86-64]
2104 Provide an override to the IOAPIC-ID<->DEVICE-ID
2106 example, to map IOAPIC-ID decimal 10 to
2110 ivrs_hpet [HW,X86-64]
2111 Provide an override to the HPET-ID<->DEVICE-ID
2113 example, to map HPET-ID decimal 0 to
2117 ivrs_acpihid [HW,X86-64]
2118 Provide an override to the ACPI-HID:UID<->DEVICE-ID
2120 example, to map UART-HID:UID AMD0020:0 to
2140 kernelcore= [KNL,X86,IA-64,PPC]
2143 the kernel for non-movable allocations. The requested
2153 subsystem. Note that allocations like PTEs-from-HighMem
2161 for non-movable allocations and remaining memory is used
2172 gdb or control-c on the dbgp connection. When
2173 not using this parameter you use sysrq-g to break into
2178 or a supported polling keyboard driver (non-usb).
2188 characters and can work in polling mode, you can use
2205 Configure the RouterBoard 532 series on-chip
2208 kmemleak= [KNL] Boot-time kmemleak enable/disable
2214 kprobe_event=[probe-list]
2216 The probe-list is a semicolon delimited list of probe
2262 kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM.
2265 kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
2267 Default is 1 (enabled) if in 64-bit or 32-bit PAE mode.
2269 kvm-arm.vgic_v3_group0_trap=
2270 [KVM,ARM] Trap guest accesses to GICv3 group-0
2273 kvm-arm.vgic_v3_group1_trap=
2274 [KVM,ARM] Trap guest accesses to GICv3 group-1
2277 kvm-arm.vgic_v3_common_trap=
2281 kvm-arm.vgic_v4_enable=
2293 kvm-intel.ept= [KVM,Intel] Disable extended page tables
2297 kvm-intel.emulate_invalid_guest_state=
2301 kvm-intel.flexpriority=
2302 [KVM,Intel] Disable FlexPriority feature (TPR shadow).
2305 kvm-intel.nested=
2309 kvm-intel.unrestricted_guest=
2310 [KVM,Intel] Disable unrestricted guest feature
2314 kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
2315 CVE-2018-3620.
2321 VMEXIT and VMENTER can leak host memory.
2326 kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification
2393 For details see: Documentation/admin-guide/hw-vuln/l1tf.rst
2399 lapic [X86-32,APIC] Enable the local APIC even if BIOS
2403 value for LAPIC timer one-shot implementation. Default
2411 libata.dma=0 Disable all PATA and SATA DMA
2438 first fan-out link behind PMP device. It does not
2445 The following configurations can be forced.
2452 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
2464 hot-unplug link recovery
2470 * disable: Disable this device.
2501 Set the number of locking read-acquisition kthreads.
2506 Set the number of locking write-acquisition kthreads.
2509 Set time (s) after boot for CPU-hotplug testing.
2512 Set time (s) between CPU-hotplug operations, or
2513 zero to disable CPU-hotplug testing.
2516 Set task-shuffle interval (jiffies). Shuffling
2517 tasks allows some CPUs to go into dyntick-idle
2522 is useful for hands-off automated testing.
2544 console loglevel will be printed to the console. It can
2555 7 (KERN_DEBUG) debug-level messages
2565 logo.nologo [FB] Disables display of the built-in Linux logo.
2573 lp=auto printer driver. 'lp=reset' (which can be
2583 an IEEE 1284-compliant printer is attached; if
2589 time-consuming boot-time autodetection (up to 250 ms per
2610 machvec= [IA-64] Force the use of a particular machine-vector
2616 Example: machtype=lemote-yeeloong-2f-7inch
2624 bootup you can bring up the other plugged cpu by executing
2631 (loop.max_loop) unconditionally pre-created at init time. The default
2634 devices can be requested on-demand with the
2635 /dev/loop-control interface.
2637 mce [X86-32] Machine Check Exception
2639 mce=option [X86-64] See Documentation/x86/x86_64/boot-options.rst
2642 See Documentation/admin-guide/md.rst.
2649 Control mitigation for the Micro-architectural Data
2653 internal buffers which can forward information to a
2657 forwarded data can be used in a cache side channel
2664 full - Enable MDS mitigation on vulnerable CPUs
2665 full,nosmt - Enable MDS mitigation and disable
2667 off - Unconditionally disable MDS mitigation
2669 On TAA-affected machines, mds=off can be prevented by
2671 mitigated with the same mechanism so in order to disable
2678 For details see: Documentation/admin-guide/hw-vuln/mds.rst
2697 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
2702 per-device physically contiguous DMA buffers.
2710 See Documentation/admin-guide/mm/memory-hotplug.rst.
2714 Such memmap=exactmap lines can be constructed based on
2723 Multiple different regions can be specified,
2735 Example: Exclude memory from 0x18690000-0x1869ffff
2749 memmap=<size>%<offset>-<oldtype>+<newtype>
2751 from <oldtype> to <newtype>. If "-<oldtype>" is left
2766 repeatable BIOS-originated corruption always
2767 affects the same memory, you can use memmap=
2783 default : 0 <disable>
2791 mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control
2799 Refer to Documentation/virt/kvm/amd-memory-encryption.rst
2800 for details on when memory encryption can be activated.
2803 s2idle - Suspend-To-Idle
2804 shallow - Power-On Suspend or equivalent (if supported)
2805 deep - Suspend-To-RAM or equivalent (if supported)
2806 See Documentation/admin-guide/pm/sleep-states.rst.
2809 See Documentation/admin-guide/media/meye.rst.
2811 mfgpt_irq= [IA-32] Specify the IRQ to use for the
2812 Multi-Function General Purpose Timers on AMD Geode
2815 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
2818 problem by letting the user disable the workaround.
2829 0 - The attached screen is the 3.5" TFT
2830 1 - The attached screen is the 7" TFT
2831 2 - The VGA Shield is attached (1024x768)
2835 b - Enable backlight. The TFT backlight pin will be
2839 c - Enable the s3c camera interface.
2840 t - Reserved for enabling touchscreen support. The
2842 kernel as of 2.6.30, a preliminary port can be found
2844 https://repo.or.cz/w/linux-2.6/mini2440.git
2849 arch-independent options, each of which is an
2850 aggregation of existing arch-specific options.
2853 Disable all optional CPU mitigations. This
2863 ssbd=force-off [ARM64]
2882 have other ways of avoiding SMT-based attacks.
2916 full - Enable mitigation on vulnerable CPUs
2918 full,nosmt - Enable mitigation and disable SMT on
2921 off - Unconditionally disable mitigation
2924 mmio_stale_data=off can be prevented by an active
2927 disable this mitigation, you need to specify
2934 Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst
2942 module_blacklist= [KNL] Do not load a comma-separated list of
2956 movablecore= [KNL,X86,IA-64,PPC]
2967 movable_node [KNL] Boot-time switch to make hotplugable memory
2974 Format: <name>,<region-number>,<size>,<offset>
2977 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
2986 onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
2990 boundary - index of last SLC block on Flex-OneNAND.
2992 lock - Configure if Flex-OneNAND boundary should be locked.
2999 See arch/arm/mach-s3c2412/mach-jive.c
3027 something different and driver-specific.
3033 0 to disable accounting
3038 See Documentation/admin-guide/nfs/nfsroot.rst.
3040 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
3041 See Documentation/admin-guide/nfs/nfsroot.rst.
3044 See Documentation/admin-guide/nfs/nfsroot.rst.
3068 [NFS] enable 64-bit inode numbers.
3069 If zero, the NFS client will fake up a 32-bit inode
3071 of returning the full 64-bit number.
3072 The default is to return 64-bit inode numbers.
3085 that the client can send to the NFSv4.1 server.
3095 disabling idmapping, which can make migration from
3102 [NFS4] Specify an additional fixed unique ident-
3103 ification string that NFSv4 clients can insert into
3133 driver. A non-zero value sets the minimum interval
3145 NMI stack-backtrace request.
3154 0 - turn hardlockup detector in nmi_watchdog off
3155 1 - turn hardlockup detector in nmi_watchdog on
3159 To disable both hard and soft lockup detectors,
3164 These settings can be accessed at runtime via
3172 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
3176 no5lvl [X86-64] Disable 5-level paging mode. Forces
3177 kernel to use 4-level paging instead.
3183 Disable suspending of consoles during suspend and
3185 messages can reach various consoles while the rest
3197 Disable device dump. Device dump allows drivers to
3198 append dump data to vmcore so you can collect driver
3199 specified debug info. Drivers can append the data
3202 device dump can help save memory but the driver debug
3208 caches in the slab allocator. Saves per-node memory,
3219 noautogroup Disable scheduler automatic task group creation.
3228 nodelayacct [KNL] Disable per-task delay accounting
3230 nodsp [SH] Disable hardware DSP at boot time.
3232 noefi Disable EFI runtime services support.
3234 no_entry_flush [PPC] Don't flush the L1-D cache when entering the kernel.
3236 noexec [IA-64]
3239 On X86-32 available only on PAE configured kernels.
3240 noexec=on: enable non-executable mappings (default)
3241 noexec=off: disable non-executable mappings
3244 Disable SMAP (Supervisor Mode Access Prevention)
3248 Disable SMEP (Supervisor Mode Execution Prevention)
3251 noexec32 [X86-64]
3252 This affects only 32-bit executables.
3253 noexec32=on: enable non-executable mappings (default)
3255 noexec32=off: disable non-executable mappings
3258 nofpu [MIPS,SH] Disable hardware FPU at boot time.
3260 nofxsr [BUGS=X86-32] Disables x86 floating point extended
3262 legacy floating-point registers on task switch.
3264 nohugeiomap [KNL,X86,PPC,ARM64] Disable kernel huge I/O mappings.
3266 nosmt [KNL,S390] Disable symmetric multithreading (SMT).
3269 [KNL,X86] Disable symmetric multithreading (SMT).
3270 nosmt=force: Force disable SMT, cannot be undone
3273 nospectre_v1 [X86,PPC] Disable mitigations for Spectre Variant 1
3277 nospectre_v2 [X86,PPC_FSL_BOOK3E,ARM64] Disable all mitigations for
3283 [HW] Disable all mitigations for the Speculative Store Bypass vulnerability
3286 [PPC] Don't flush the L1-D cache after accessing user data.
3290 enabling legacy floating-point and sse state.
3315 nohalt [IA-64] Tells the kernel not to use the power saving
3317 power-consumption. On the positive side, it reduces
3318 interrupt wake-up latency, which may improve performance
3320 real-time systems.
3322 nohibernate [HIBERNATION] Disable hibernation and resume.
3324 nohz= [KNL] Boottime enable/disable dynamic ticks
3340 noirqdebug [X86-32] Disables the code which attempts to detect and
3341 disable unhandled interrupt sources.
3351 nointremap [X86-64, Intel-IOMMU] Do not enable interrupt
3353 [Deprecated - use intremap=off]
3355 nointroute [IA-64]
3357 noinvpcid [X86] Disable the INVPCID cpu feature.
3359 nojitter [IA-64] Disables jitter checking for ITC timers.
3361 no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
3363 no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page
3366 no-vmw-sched-clock
3367 [X86,PV_OPS] Disable paravirtualized VMware scheduler
3370 no-steal-acc [X86,PV_OPS,ARM64] Disable paravirtualized steal time
3374 nolapic [X86-32,APIC] Do not enable or use the local APIC.
3376 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
3381 nomca [IA-64] Disable machine check abort handling
3383 nomce [X86-32] Disable Machine Check Exception
3385 nomfgpt [X86-32] Disable Multi-Function General Purpose
3388 nonmi_ipi [X86] Disable using NMI IPIs during panic/reboot to
3392 nomodule Disable module load
3394 nopat [X86] Disable PAT (page attribute table extension of
3397 nopcid [X86-64] Disable the PCID cpu feature.
3402 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
3405 nordrand [X86] Disable kernel use of the RDRAND and
3413 no-scroll [VGA] Disables scrollback.
3414 This is required for the Braillex ib80-piezo Braille
3417 nosbagart [IA-64]
3419 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
3422 and disable the IO APIC. legacy for "maxcpus=0".
3424 nosoftlockup [KNL] Disable the soft-lockup detector.
3428 nowatchdog [KNL] Disable both lockup detectors, i.e.
3429 soft-lockup and NMI watchdog (hard-lockup).
3433 nox2apic [X86-64,APIC] Do not enable x2APIC mode.
3441 2. PIC interrupts also depend on CPU0. CPU0 can't be
3446 If the dependencies are under your control, you can
3451 cycles, each HW thread of the CTOP can run
3458 nptcg= [IA-64] Override max number of concurrent global TLB
3466 runtime you can physically add extra cpu until it reaches
3467 n. So during boot up some boot time memory for per-cpu
3468 variables need be pre-allocated for later physical cpu
3473 numa_balancing= [KNL,X86] Enable or disable automatic NUMA balancing.
3474 Allowed values are enable and disable
3477 'node', 'default' can be specified
3478 This can be set from sysctl after boot.
3479 See Documentation/admin-guide/sysctl/vm.rst for details.
3482 See Documentation/core-api/debugging-via-ohci1394.rst for more
3521 running on a platform with a direct-mapped memory-side
3522 cache, and this parameter can be used to
3523 override/disable that behavior. The state of the flag
3524 can be read from sysfs at:
3527 page_owner= [KNL] Boot-time page_owner enabling option.
3530 we can turn it on.
3533 page_poison= [KNL] Boot-time parameter changing the state of
3546 User can chose combination of the following bits:
3559 The optional switch "nousertaint" can be utilized to
3563 See Documentation/admin-guide/tainted-kernels.rst for
3564 extra details on the taint flags that users can pick
3571 Run kdump after running panic-notifiers and dumping
3575 because some panic notifiers can make the crashed
3590 possible conflicts). You can specify the base
3616 See also Documentation/admin-guide/blockdev/paride.rst.
3635 addresses can be specified after the base
3645 bios [X86-32] force use of PCI BIOS, don't access
3647 has a non-standard PCI host bridge.
3648 nobios [X86-32] disallow use of PCI BIOS, only direct
3654 data in IO port 0xCFC, both 32-bit).
3656 Mechanism 2 (IO port 0xCF8 is an 8-bit port for
3657 the function, IO port 0xCFA, also 8-bit, sets
3659 through ports 0xC000-0xCFFF).
3663 enabled, this kernel boot option can be used to
3664 disable the use of PCIE advanced error reporting.
3665 nodomains [PCI] Disable support for multiple PCI
3666 root domains (aka PCI segments, in ACPI-speak).
3667 nommconf [X86] Disable use of MMCONFIG for PCI
3673 enabled, this kernel boot option can be used to
3674 disable the use of MSI interrupts system-wide.
3675 noioapicquirk [APIC] Disable all boot interrupt quirks.
3679 primary IO-APIC for bridges that cannot disable
3682 noioapicreroute [APIC] Disable workaround that uses the
3686 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
3704 assigned automatically to PCI devices. You can
3710 F0000h-100000h range.
3711 lastbus=N [X86] Scan all buses thru bus #N. Can be
3715 assign-busses [X86] Always assign all PCI bus
3736 skip_isa_align [X86] do not align io start addr, so can
3743 bfsort Sort PCI devices into breadth-first order.
3746 nobfsort Don't sort PCI devices into breadth-first order.
3747 pcie_bus_tune_off Disable PCIe MPS (Max Payload Size)
3748 tuning and use the BIOS-configured MPS defaults.
3755 or bus can support) for best performance.
3758 configuration allows peer-to-peer DMA between
3761 that hot-added devices will work.
3776 A PCI-PCI bridge can be specified if resource
3782 for 4096-byte alignment.
3783 ecrc= Enable/disable PCIe ECRC (transaction layer
3784 end-to-end CRC checking).
3805 realloc= Enable/disable reallocating PCI bridge resources
3813 noats [PCIE, Intel-IOMMU, AMD-IOMMU]
3820 can resize a BAR to allow access to all VRAM.
3838 pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
3840 off Disable ASPM.
3849 dpc-native Use native PCIe service for DPC only. May
3851 compat Disable native PCIe services (PME, AER, DPC, PCIe
3855 off Disable power management of all PCIe ports
3866 Keep all power-domains already enabled by bootloader on,
3872 See Documentation/admin-guide/blockdev/paride.rst.
3874 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
3887 See Documentation/admin-guide/blockdev/paride.rst.
3890 See Documentation/admin-guide/blockdev/paride.rst.
3892 pirq= [SMP,APIC] Manual mp-table setup
3893 See Documentation/x86/i386/IO-APIC.rst.
3897 See also Documentation/admin-guide/parport.rst.
3908 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
3917 { on | off | curr | res | no-curr | no-res }
3953 Disable Hardware Transactional Memory
3955 print-fatal-signals=
3961 coredump - etc.
3964 you might want to try "ulimit -i unlimited".
3971 Format: <bool> (1/Y/y=enable, 0/N/n=disable)
3976 on - unlimited logging to /dev/kmsg from userspace
3977 off - logging to /dev/kmsg disabled
3978 ratelimit - ratelimit the logging
3982 Format: <bool> (1/Y/y=enable, 0/N/n=disable)
3985 Limit processor to maximum C-state
3989 Ignore the _CST method to determine C-states,
3996 Param: "schedule" - profile schedule points.
3997 Param: "sleep" - profile D-state sleeping (millisecs).
3999 Param: "kvm" - profile VM exits.
4000 Param: <number> - step/bucket size as a power of 2 for
4010 psi= [KNL] Enable or disable pressure stall information
4030 See Documentation/admin-guide/blockdev/paride.rst.
4032 pti= [X86-64] Control Page Table Isolation of user and
4037 on - unconditionally enable
4038 off - unconditionally disable
4039 auto - kernel detects whether your CPU model is
4044 nopti [X86-64]
4048 [KNL] Number of legacy pty's. Overwrites compiled-in
4051 quiet [KNL] Disable most log messages
4056 See Documentation/admin-guide/md.rst.
4059 See Documentation/admin-guide/blockdev/ramdisk.rst.
4064 [KNL] Enable or disable trusting the use of the
4069 ras=option[,option,...] [KNL] RAS-specific options
4072 Disable the Correctable Errors Collector,
4077 except that the string "all" can be used to
4081 the specified list of CPUs to be no-callback CPUs.
4084 purpose, where "x" is "p" for RCU-preempt, and
4085 "s" for RCU-sched, and "N" is the CPU number.
4087 which can be useful for HPC and real-time
4088 workloads. It can also improve energy efficiency
4096 This improves the real-time response for the
4113 RCU grace-period cleanup.
4117 RCU grace-period initialization.
4121 RCU grace-period pre-initialization, that is,
4122 the propagation of recent CPU-hotplug changes up
4127 per-CPU rcuc kthreads. Defaults to a non-zero
4132 Disable autobalancing of the rcu_node combining
4135 cache-to-cache transfer latencies.
4141 and for NUMA systems with large remote-access
4154 Set delay from grace-period initialization to
4167 soliciting quiescent-state help from
4179 Set the SCHED_FIFO priority of the RCU per-CPU
4182 and for the RCU grace-period kthreads (rcu_bh,
4184 set, valid values are 1-99 and the default is 1
4185 (the least-favored priority). Otherwise, when
4186 RCU_BOOST is not set, valid values are 0-99 and
4187 the default is zero (non-realtime operation).
4193 the wakeup overhead on the global grace-period
4195 each group's NOCB grace-period kthread.
4203 batch limiting is re-enabled.
4207 RCU's force-quiescent-state scan will aggressively
4212 disable more aggressive help enlistment.
4221 Lazy RCU callbacks are those which RCU can
4225 Cause the grace-period kthread to get an extra
4227 it should at force-quiescent-state time.
4233 this specifies an rcu_read_unlock()-time delay
4237 of RCU-protected pointers after the relevant
4247 grace-period primitives such as call_rcu().
4258 grace-period primitives.
4261 Set test-start holdoff period. The purpose of
4280 Set number of RCU readers. The value -1 selects
4282 "n" less than -1 selects N-n+1, where N is again
4283 the number of CPUs. For example, -2 selects N
4284 (the number of CPUs), -3 selects N+1, and so on.
4285 A value of "n" less than or equal to -N selects
4298 complete. This is useful for hands-off automated
4305 Write-side holdoff between grace periods,
4322 Enable RCU grace-period forward-progress testing
4326 Specify the fraction of a CPU-stall-warning
4327 period to do tight-loop forward-progress testing.
4331 forward-progress tests.
4335 need_resched() during tight-loop forward-progress
4339 Use conditional/asynchronous update-side
4343 Use expedited update-side primitives, if available.
4346 Use normal (non-expedited) asynchronous
4347 update-side primitives, if available.
4350 Use normal (non-expedited) synchronous
4351 update-side primitives, if available. If all
4355 they are all non-zero.
4363 Leak an RCU-protected pointer out of the reader.
4364 This can of course result in splats, and is
4378 Set number of RCU readers. The value -1 selects
4379 N-1, where N is the number of CPUs. A value
4380 "n" less than -1 selects N-n-2, where N is again
4381 the number of CPUs. For example, -2 selects N
4382 (the number of CPUs), -3 selects N+1, and so on.
4385 Enable debug-object double-call_rcu() testing.
4388 Set time (s) after boot for CPU-hotplug testing.
4391 Set time (jiffies) between CPU-hotplug operations,
4392 or zero to disable CPU-hotplug testing.
4395 Set the number of read-then-exit kthreads used
4397 task-exit processing.
4400 The number of times in a given read-then-exit
4401 episode that a set of read-then-exit kthreads
4406 read-then-exit testing episodes.
4409 Set task-shuffle interval (s). Shuffling tasks
4410 allows some CPUs to go into dyntick-idle mode
4415 is useful for hands-off automated testing.
4419 warnings, zero to disable.
4424 to any other stall-related activity.
4430 Disable interrupts while stalling if set.
4434 grace-period kthread to test RCU CPU stall
4435 warnings, zero to disable. If both stall_cpu
4460 Test RCU's dyntick-idle handling. See also the
4486 Use expedited grace-period primitives, for
4489 but can increase CPU utilization, degrade
4490 real-time latency, and degrade energy efficiency.
4494 Use only normal grace-period primitives,
4497 real-time latency, CPU utilization, and
4498 energy efficiency, but can expose users to
4499 increased grace-period latency. This parameter
4506 only normal grace-period primitives. No effect
4513 number avoids disturbing real-time workloads,
4518 messages. Disable with a value less than or equal
4530 force - Override the decision by the kernel to hide the
4558 Set test-start holdoff period. The purpose of
4567 but the default has already reduced the per-pass
4572 Set number of readers. The default value of -1
4581 Set the read-side critical-section duration,
4585 Specify the read-protection implementation to test.
4598 See Documentation/admin-guide/cgroup-v1/cpusets.rst.
4606 reservetop= [X86-32]
4628 See Documentation/power/swsusp-and-swap-files.rst
4641 no Disable hibernation and resume.
4644 during restoration read-only).
4652 off - no mitigation
4653 auto - automatically select a migitation
4654 auto,nosmt - automatically select a mitigation,
4658 ibpb - mitigate short speculation windows on
4661 unret - force enable untrained return thunks,
4662 only effective on AMD f15h-f17h
4664 unret,nosmt - like unret, will disable SMT when STIBP
4687 ring3mwait=disable
4688 [KNL] Disable ring 3 MONITOR/MWAIT feature on supported
4691 ro [KNL] Mount root device read-only on boot
4694 on Mark read-only kernel memory as read-only (default).
4695 off Leave read-only kernel memory writable for debugging.
4700 debug-uart get routed to the D+ and D- pins of the usb
4722 rw [KNL] Mount root device read-write on boot
4740 schedstats= [KNL,X86] Enable or disable scheduled statistics.
4741 Allowed values are enable and disable. This feature
4764 to 10 seconds for built-in smp_call_function()
4771 that requesting even small non-zero numbers of
4772 seconds can result in RCU CPU stall warnings,
4778 The default of -1 specifies a number of kthreads
4783 test before initiating CPU-hotplug operations.
4787 CPU-hotplug operations. Specifying zero (which
4788 is the default) disables CPU-hotplug operations.
4794 Non-zero values are useful for automated tests.
4807 preempt_disable() to disable CPU hotplug
4817 "wait" parameter. A value of -1 selects the
4818 default if all other weights are -1. However,
4820 value of -1 will instead select a weight of zero.
4825 non-zero "wait" parameter. See weight_single.
4832 this weighting can place serious IPI load
4838 non-zero "wait" parameter. See weight_single
4850 non-zero "wait" parameter. See weight_single
4857 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
4858 1 -- enable.
4866 selinux= [SELINUX] Disable or enable SELinux at boot time.
4869 0 -- disable.
4870 1 -- enable.
4873 apparmor= [APPARMOR] Disable or enable AppArmor at boot time
4876 0 -- disable.
4877 1 -- enable.
4880 serialnumber [BUGS=X86-32]
4885 simeth= [IA-64]
4891 Disable merging of slabs with similar size. May be
4895 layout control by attackers can usually be
4899 unchanged). Debug options disable merging on their
4912 slub_debug can create guard zones around objects and
4919 memory cgroup sub-caches. 1 to enable, 0 to disable.
4921 Enabling this can lead to a very high number of debug
4952 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
4953 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
4954 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
4955 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
4956 smsc-ircc2.ircc_irq= [HW] IRQ line
4957 smsc-ircc2.ircc_dma= [HW] DMA channel
4958 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
4968 Default: -1 (no limit)
4971 [KNL] Should the soft-lockup detector generate panics.
4974 A value of 1 instructs the soft-lockup detector
4975 to panic the machine when a soft-lockup occurs. It is
4978 respective build-time switch to that functionality.
4981 [KNL] Should the soft-lockup detector generate
4986 See Documentation/admin-guide/laptops/sonypi.rst
4993 on - unconditionally enable, implies
4995 off - unconditionally disable, implies
4997 auto - kernel detects whether your CPU model is
5009 Selecting 'off' will disable both the kernel and
5012 Specific mitigations can also be selected manually:
5014 retpoline - replace indirect branches
5015 retpoline,generic - Retpolines
5016 retpoline,lfence - LFENCE; indirect branch
5017 retpoline,amd - alias for retpoline,lfence
5018 eibrs - enhanced IBRS
5019 eibrs,retpoline - enhanced IBRS + Retpolines
5020 eibrs,lfence - enhanced IBRS + LFENCE
5021 ibrs - use IBRS to protect kernel
5031 on - Unconditionally enable mitigations. Is
5034 off - Unconditionally disable mitigations. Is
5037 prctl - Indirect branch speculation is enabled,
5038 but mitigation can be enabled via prctl
5043 - Like "prctl" above, but only STIBP is
5049 - Same as "prctl" above, but all seccomp
5054 - Like "seccomp" above, but only STIBP is
5059 auto - Kernel selects the mitigation depending on
5069 [HW] Control Speculative Store Bypass (SSB) Disable mitigation
5077 is that such stores are unlikely and that they can
5082 store can be used in a cache side channel attack, for
5091 on - Unconditionally disable Speculative Store Bypass
5092 off - Unconditionally enable Speculative Store Bypass
5093 auto - Kernel detects whether the CPU model contains an
5099 prctl - Control Speculative Store Bypass per thread
5103 seccomp - Same as "prctl" above, but all seccomp threads
5104 will disable SSB unless they explicitly opt out.
5111 on,auto - On Power8 and Power9 insert a store-forwarding
5115 off - No action.
5132 off - not enabled
5134 warn - the kernel will emit rate limited warnings
5139 fatal - the kernel will send SIGBUS to applications
5151 Certain CPUs are vulnerable to an MDS-like
5152 exploit which can leak bits from the random
5156 microcode. However, the microcode fix can cause
5161 The microcode mitigation can be disabled with
5164 off: Disable mitigation and remove
5169 grace-period sequence counter wrap for the
5170 srcu_data structure's ->srcu_gp_seq_needed field.
5181 expediting. Set to zero to disable automatic
5185 Speculative Store Bypass Disable control
5192 force-on: Unconditionally enable mitigation for
5194 force-off: Unconditionally disable mitigation for
5211 stacktrace_filter=[function-list]
5213 will trace at boot up. function-list is a comma separated
5214 list of functions. This list can be changed at run
5221 Set the STI (builtin display/keyboard on the HP-PARISC
5223 as the initial boot-console.
5264 to global on non-NUMA machines)
5270 RPC calls that can be sent from the client to a
5289 controller if no parameter or 1 is given or disable
5290 it if 0 is given (See Documentation/admin-guide/cgroup-v1/memory.rst)
5292 swiotlb= [ARM,IA-64,PPC,MIPS,X86]
5294 <int> -- Number of I/O TLB slabs
5295 force -- force using of bounce buffers even if they
5297 noforce -- Never use bounce buffers (for debugging)
5311 Enable/disable old style sysfs layout for old udev
5321 Ignore sysrq setting - this boot parameter will
5329 cache size. See Documentation/networking/ip-sysctl.rst
5335 Specify "mem" (for Suspend-to-RAM) or "standby" (for
5340 wakeup-capable RTC alarm.
5346 -1: disable all active trip points in all thermal zones
5350 -1: disable all critical trip points in all thermal zones
5354 Set to disable actions on ACPI thermal zone
5358 1: disable ACPI thermal control
5361 -1: disable all passive trip points
5367 <deci-seconds>: poll all this frequency
5389 Prevent the CPU-hotplug component of torturing
5393 Dump the ftrace buffer at torture-test shutdown,
5394 even if there were no errors. This can be a
5397 with rotating-rust storage.
5413 trace_event=[event-list]
5415 to facilitate early boot debugging. The event-list is a
5419 trace_options=[option-list]
5420 [FTRACE] Enable or disable tracer options at boot.
5421 The option-list is a comma delimited list of options
5422 that can be enabled or disabled just as if you were
5450 frequency tracepoints such as irq or sched, can cause
5454 [FTRACE] enable this option to disable tracing when a
5455 warning is hit. This turns off "tracing_on". Tracing can
5463 This option can also be set at run time via the sysctl
5469 Can be used to control the default behavior of the system
5471 See Documentation/admin-guide/mm/transhuge.rst
5474 tsc= Disable clocksource stability checks for TSC.
5479 high-resolution timer mode on older hardware, and in
5482 Used to run time disable IRQ_TIME_ACCOUNTING on any
5484 can add overhead.
5488 [x86] nowatchdog: disable clocksource watchdog. Used
5505 on - Enable TSX on the system. Although there are
5508 several previous speculation-related CVEs, and
5512 off - Disable TSX on the system. (Note that this
5520 auto - Disable TSX if X86_BUG_TAA is present,
5525 See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
5531 Similar to Micro-architectural Data Sampling (MDS)
5534 exploit against CPU internal buffers which can forward
5539 data can be used in a cache side channel attack, to
5546 full - Enable TAA mitigation on vulnerable CPUs
5549 full,nosmt - Enable TAA mitigation and disable SMT on
5552 vulnerable to cross-thread TAA attacks.
5553 off - Unconditionally disable TAA mitigation
5555 On MDS-affected machines, tsx_async_abort=off can be
5557 are mitigated with the same mechanism so in order to disable
5567 Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
5573 See also Documentation/input/devices/joystick-parport.rst
5575 udbg-immortal [PPC] When debugging early kernel crashes that
5581 Set number of hash buckets for UDP/UDP-Lite connections
5583 uhci-hcd.ignore_oc=
5585 Some badly-designed motherboards generate lots of
5596 (default -1 = authorized except for wireless USB,
5602 for newly-detected USB devices (default 2). This
5630 [USB] Specifies timeout for the initial 64-byte
5634 usbcore.nousb [USB] Disable the USB subsystem
5637 [USB] A list of quirk entries to augment the built-in
5640 VendorID:ProductID:Flags. The IDs are 4-digit hex
5642 will change the built-in quirk; setting it if it is
5647 a 255-byte read);
5648 b = USB_QUIRK_RESET_RESUME (device can't resume
5650 c = USB_QUIRK_NO_SET_INTF (device can't handle
5651 Set-Interface requests);
5652 d = USB_QUIRK_CONFIG_INTF_STRINGS (device can't
5655 e = USB_QUIRK_RESET (device can't be reset
5659 bNumInterfaces count, and can't handle
5670 (bInterval-1).
5675 i = USB_QUIRK_DEVICE_QUALIFIER (device can't
5681 k = USB_QUIRK_NO_LPM (device can't handle Link
5705 usb-storage.delay_use=
5709 usb-storage.quirks=
5711 override the built-in unusual_devs list. List
5714 and Product ID values (4-digit hex numbers) and
5716 to a common usb-storage quirk flag as follows:
5758 medium is write-protected).
5767 1 - undefined instruction events
5768 2 - system calls
5769 4 - invalid data aborts
5770 8 - SIGSEGV faults
5771 16 - SIGBUS faults
5785 vdso=0: disable VDSO mapping
5787 vdso32= [X86] Control the 32-bit vDSO
5788 vdso32=1: enable 32-bit VDSO
5789 vdso32=0 or vdso32=2: disable 32-bit VDSO
5799 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
5801 vector= [IA-64,SMP]
5821 <size> := size (can use standard suffixes
5830 Can be used multiple times for multiple devices.
5832 vga= [BOOT,X86-32] Select a particular video mode
5834 Documentation/admin-guide/svga.rst.
5849 - Disable all of the above options
5852 size of <nn>. This can be used to increase the
5853 minimum size (128MB on x86). It can also be used to
5870 vsyscall= [X86-64]
5873 code). Most statically-linked binaries and older
5876 targets for exploits that can control RIP.
5897 see VGA-softcursor.txt. Default: 2 = underline.
5902 This is a 16-member array composed of values
5903 ranging from 0-255.
5908 This is a 16-member array composed of values
5909 ranging from 0-255.
5914 This is a 16-member array composed of values
5915 ranging from 0-255.
5920 Set system-wide default UTF-8 mode for all tty's.
5921 Default is 1, i.e. UTF-8 mode is enabled for all
5926 Format=<-1|0|1>
5927 Set system-wide default for whether a cursor
5928 is shown on new VTs. Default is -1,
5933 vt.italic= [VT] Default color for italic text; 0-15.
5936 vt.underline= [VT] Default color for underlined text; 0-15.
5940 see Documentation/watchdog/watchdog-parameters.rst
5941 or other driver-specific files in the
5953 If CONFIG_WQ_WATCHDOG is configured, workqueue can
5958 it can be updated at runtime by writing to the
5966 whatever reason, this option can be used. Note
5967 that this also can be controlled per-workqueue for
5971 Per-cpu workqueues are generally preferred because
5973 locality; unfortunately, per-cpu workqueues tend to
5976 Enabling this makes the per-cpu workqueues which
5991 forces round-robin CPU selection to flush out
5996 x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
6000 x86_intel_mid_timer= [X86-32,APBT]
6006 xen_512gb_limit [KNL,X86-64,XEN]
6016 ide-disks -- unplug primary master IDE devices
6017 aux-ide-disks -- unplug non-primary-master IDE devices
6018 nics -- unplug network devices
6019 all -- unplug all emulated devices (NICs and IDE disks)
6020 unnecessary -- unplugging emulated devices is
6023 never -- do not unplug even if version check succeeds
6041 [KNL,X86,XEN] Disable the vector callback for Xen
6046 to Xen, for use by other domains. Can be also changed at runtime
6050 xen_timer_slop= [X86-64,XEN]
6066 Boolean parameter to disable using fifo event handling
6068 preferred over the 2-level event handling, as it is
6095 xhci-hcd.quirks [USB,KNL]
6097 host controller quirks. Meaning of each bit can be
6113 can be written using xmon commands.
6115 memory, and other data can't be written using