Lines Matching +full:ether +full:- +full:link +full:- +full:active +full:- +full:low
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
58 Documentation/firmware-guide/acpi/debug.rst for more information about
97 ACPI will balance active IRQs
101 ACPI will not move active IRQs (default)
121 Disable auto-serialization of AML methods
124 auto-serialization feature.
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
223 Format: { level | edge | high | low }
227 For broken nForce2 BIOS resulting in XT-PIC timer.
235 as soon as the kernel's real-mode entry point is called.
240 low power states, to be enforced (the ACPI 2.0 ordering
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
416 0 - Disable the BAU.
417 1 - Enable the BAU.
418 unset - Disable the BAU.
439 See Documentation/block/cmdline-partition.rst
450 See Documentation/admin-guide/bootconfig.rst
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
499 - foo isn't auto-mounted if you mount all cgroups in
501 - foo isn't visible as an individually mountable
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.
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
577 architected timer so that code using WFE-based polling
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
716 disable the cpuidle sub-system
722 disable the cpufreq sub-system
730 [X86] Delay for N microsec between assert and de-assert
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
764 crashkernel=size[KMG],low
765 [KNL, X86-64] range under 4G. When crashkernel=X,high
768 that require some amount of low memory, e.g. swiotlb
769 requires at least 64M+32K low memory, also enough extra
770 low memory is needed to make sure DMA buffers for 32-bit
773 This one let user to specify own low range under 4G
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
855 Format: { on, no-mount, off }
857 no-mount:
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.
929 against bounds-checking flaws in the kernel's
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
992 architectural default is too low.
995 With this option the DMA-API debugging driver
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
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
1286 attribute is added to range 0x100000000-0x180000000 and
1287 0x10a0000000-0x1120000000.
1291 range 0x240000000-0x43fffffff.
1303 Documentation/admin-guide/acpi/ssdt-overlays.rst for details.
1309 elanfreq= [X86-32]
1317 See Documentation/admin-guide/kdump/kdump.rst for details.
1333 0 -- permissive (log only, no denials).
1334 1 -- enforcing (deny and log).
1343 ether= [HW,NET] Ethernet cards parameters
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]
1393 ftrace_filter=[function-list]
1395 tracer at boot up. function-list is a comma separated
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
1413 ftrace_graph_notrace=[function-list]
1415 function-list. This list is a comma separated list of
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
1509 corresponding firmware-first mode error processing
1523 hpet= [X86-32,HPET] option to control HPET usage
1540 boot-time allocation of gigantic hugepages is skipped.
1548 Documentation/admin-guide/mm/hugetlbpage.rst.
1558 Documentation/admin-guide/mm/hugetlbpage.rst.
1567 by the CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time
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
1606 i8042.nomux [HW] Don't check presence of an active multiplexing
1612 suspend-to-ram transitions, only during s2r
1647 -1 -- never invert brightness
1648 0 -- machine default
1649 1 -- force brightness inversion
1654 ide-core.nodma= [HW] (E)IDE subsystem
1660 ide-generic.probe-mask= [HW] (E)IDE subsystem
1672 ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
1683 idle=nomwait: Disable mwait for CPU C-states
1700 legacy only accept legacy-NaN binaries, if supported
1702 2008 only accept 2008-NaN binaries, if supported
1711 'relaxed' straps the emulator for both legacy-NaN and
1712 2008-NaN, whereas 'strict' enables legacy-NaN only on
1721 Ignore loglevel setting - this will print /all/
1785 Formats: { "ima" | "ima-ng" | "ima-sig" }
1786 Default: "ima-ng"
1818 initcall_blacklist= [KNL] Do not execute a comma-separated list of
1819 initcall functions. Useful for debugging built-in
1852 0 -- basic integrity auditing messages. (Default)
1853 1 -- additional integrity auditing messages.
1866 forcedac [X86-64]
1868 for io virtual address below 32-bit forcing dual
1870 than 32-bit addressing. The default is to look
1871 for translation below 32-bit and if not available
1889 could harm performance of some high-throughput
1903 1 to 9 specify maximum depth of C-state.
1913 used along with the hardware-managed P-states (HWP)
1917 in favor of acpi-cpufreq. Forcing the intel_pstate driver
1918 instead of acpi-cpufreq may disable platform features, such
1920 P-States information being indicated to OSPM and therefore
1923 or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
1936 Allow per-logical-CPU P-State performance control limits using
1939 intremap= [X86-64, Intel-IOMMU]
1944 BIOS x2APIC opt-out request will be ignored
1968 0 - Lazy mode.
1974 1 - Strict mode (default).
1981 0 - Use IOMMU translation for DMA.
1982 1 - Bypass the IOMMU for DMA.
1983 unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
1985 io7= [HW] IO7 for Marvel-based Alpha systems
2000 See Documentation/admin-guide/nfs/nfsroot.rst.
2024 Enables support for pseudo-NMIs in the kernel. This
2043 [Deprecated - use cpusets instead]
2044 Format: [flag-list,]<cpu-list>
2075 "number of CPUs in system - 1".
2101 The format of <cpu-list> is described above.
2105 ivrs_ioapic [HW,X86-64]
2106 Provide an override to the IOAPIC-ID<->DEVICE-ID
2110 For example, to map IOAPIC-ID decimal 10 to
2116 * To map IOAPIC-ID decimal 10 to PCI device 00:14.0
2119 * To map IOAPIC-ID decimal 10 to PCI segment 0x1 and
2123 ivrs_hpet [HW,X86-64]
2124 Provide an override to the HPET-ID<->DEVICE-ID
2128 For example, to map HPET-ID decimal 10 to
2134 * To map HPET-ID decimal 0 to PCI device 00:14.0
2137 * To map HPET-ID decimal 10 to PCI segment 0x1 and
2141 ivrs_acpihid [HW,X86-64]
2142 Provide an override to the ACPI-HID:UID<->DEVICE-ID
2146 For example, to map UART-HID:UID AMD0020:0 to
2152 * To map UART-HID:UID AMD0020:0 to PCI segment is 0,
2155 * To map UART-HID:UID AMD0020:0 to PCI segment 0x1 and
2175 kernelcore= [KNL,X86,IA-64,PPC]
2178 the kernel for non-movable allocations. The requested
2188 subsystem. Note that allocations like PTEs-from-HighMem
2196 for non-movable allocations and remaining memory is used
2207 gdb or control-c on the dbgp connection. When
2208 not using this parameter you use sysrq-g to break into
2213 or a supported polling keyboard driver (non-usb).
2240 Configure the RouterBoard 532 series on-chip
2243 kmemleak= [KNL] Boot-time kmemleak enable/disable
2249 kprobe_event=[probe-list]
2251 The probe-list is a semicolon delimited list of probe
2297 kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM.
2300 kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
2302 Default is 1 (enabled) if in 64-bit or 32-bit PAE mode.
2304 kvm-arm.vgic_v3_group0_trap=
2305 [KVM,ARM] Trap guest accesses to GICv3 group-0
2308 kvm-arm.vgic_v3_group1_trap=
2309 [KVM,ARM] Trap guest accesses to GICv3 group-1
2312 kvm-arm.vgic_v3_common_trap=
2316 kvm-arm.vgic_v4_enable=
2328 kvm-intel.ept= [KVM,Intel] Disable extended page tables
2332 kvm-intel.emulate_invalid_guest_state=
2334 Ignored if kvm-intel.enable_unrestricted_guest=1, as
2340 kvm-intel.flexpriority=
2344 kvm-intel.nested=
2348 kvm-intel.unrestricted_guest=
2353 kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
2354 CVE-2018-3620.
2365 kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification
2432 For details see: Documentation/admin-guide/hw-vuln/l1tf.rst
2438 lapic [X86-32,APIC] Enable the local APIC even if BIOS
2442 value for LAPIC timer one-shot implementation. Default
2468 matching port, link or device. Basically, it matches
2477 first fan-out link behind PMP device. It does not
2478 select the host link. DEVICE number of 15 selects the
2479 host link and device attached to it.
2489 * SATA link speed limit: 1.5Gbps or 3.0Gbps.
2491 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
2503 hot-unplug link recovery
2540 Set the number of locking read-acquisition kthreads.
2545 Set the number of locking write-acquisition kthreads.
2548 Set time (s) after boot for CPU-hotplug testing.
2551 Set time (s) between CPU-hotplug operations, or
2552 zero to disable CPU-hotplug testing.
2555 Set task-shuffle interval (jiffies). Shuffling
2556 tasks allows some CPUs to go into dyntick-idle
2561 is useful for hands-off automated testing.
2594 7 (KERN_DEBUG) debug-level messages
2604 logo.nologo [FB] Disables display of the built-in Linux logo.
2622 an IEEE 1284-compliant printer is attached; if
2628 time-consuming boot-time autodetection (up to 250 ms per
2649 machvec= [IA-64] Force the use of a particular machine-vector
2655 Example: machtype=lemote-yeeloong-2f-7inch
2670 (loop.max_loop) unconditionally pre-created at init time. The default
2673 devices can be requested on-demand with the
2674 /dev/loop-control interface.
2676 mce [X86-32] Machine Check Exception
2678 mce=option [X86-64] See Documentation/x86/x86_64/boot-options.rst
2681 See Documentation/admin-guide/md.rst.
2688 Control mitigation for the Micro-architectural Data
2703 full - Enable MDS mitigation on vulnerable CPUs
2704 full,nosmt - Enable MDS mitigation and disable
2706 off - Unconditionally disable MDS mitigation
2708 On TAA-affected machines, mds=off can be prevented by
2709 an active TAA mitigation as both vulnerabilities are
2717 For details see: Documentation/admin-guide/hw-vuln/mds.rst
2736 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
2741 per-device physically contiguous DMA buffers.
2749 See Documentation/admin-guide/mm/memory-hotplug.rst.
2774 Example: Exclude memory from 0x18690000-0x1869ffff
2788 memmap=<size>%<offset>-<oldtype>+<newtype>
2790 from <oldtype> to <newtype>. If "-<oldtype>" is left
2805 repeatable BIOS-originated corruption always
2810 By default it checks for corruption in the low
2830 mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control
2838 Refer to Documentation/virt/kvm/amd-memory-encryption.rst
2842 s2idle - Suspend-To-Idle
2843 shallow - Power-On Suspend or equivalent (if supported)
2844 deep - Suspend-To-RAM or equivalent (if supported)
2845 See Documentation/admin-guide/pm/sleep-states.rst.
2848 See Documentation/admin-guide/media/meye.rst.
2850 mfgpt_irq= [IA-32] Specify the IRQ to use for the
2851 Multi-Function General Purpose Timers on AMD Geode
2854 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
2868 0 - The attached screen is the 3.5" TFT
2869 1 - The attached screen is the 7" TFT
2870 2 - The VGA Shield is attached (1024x768)
2874 b - Enable backlight. The TFT backlight pin will be
2878 c - Enable the s3c camera interface.
2879 t - Reserved for enabling touchscreen support. The
2883 https://repo.or.cz/w/linux-2.6/mini2440.git
2888 arch-independent options, each of which is an
2889 aggregation of existing arch-specific options.
2902 ssbd=force-off [ARM64]
2922 have other ways of avoiding SMT-based attacks.
2957 full - Enable mitigation on vulnerable CPUs
2959 full,nosmt - Enable mitigation and disable SMT on
2962 off - Unconditionally disable mitigation
2965 mmio_stale_data=off can be prevented by an active
2975 Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst
2983 module_blacklist= [KNL] Do not load a comma-separated list of
2997 movablecore= [KNL,X86,IA-64,PPC]
3008 movable_node [KNL] Boot-time switch to make hotplugable memory
3015 Format: <name>,<region-number>,<size>,<offset>
3018 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
3027 onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
3031 boundary - index of last SLC block on Flex-OneNAND.
3033 lock - Configure if Flex-OneNAND boundary should be locked.
3040 See arch/arm/mach-s3c2412/mach-jive.c
3068 something different and driver-specific.
3079 See Documentation/admin-guide/nfs/nfsroot.rst.
3081 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
3082 See Documentation/admin-guide/nfs/nfsroot.rst.
3085 See Documentation/admin-guide/nfs/nfsroot.rst.
3109 [NFS] enable 64-bit inode numbers.
3110 If zero, the NFS client will fake up a 32-bit inode
3112 of returning the full 64-bit number.
3113 The default is to return 64-bit inode numbers.
3143 [NFS4] Specify an additional fixed unique ident-
3174 driver. A non-zero value sets the minimum interval
3186 NMI stack-backtrace request.
3195 0 - turn hardlockup detector in nmi_watchdog off
3196 1 - turn hardlockup detector in nmi_watchdog on
3213 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
3217 no5lvl [X86-64] Disable 5-level paging mode. Forces
3218 kernel to use 4-level paging instead.
3249 caches in the slab allocator. Saves per-node memory,
3269 nodelayacct [KNL] Disable per-task delay accounting
3275 no_entry_flush [PPC] Don't flush the L1-D cache when entering the kernel.
3277 noexec [IA-64]
3280 On X86-32 available only on PAE configured kernels.
3281 noexec=on: enable non-executable mappings (default)
3282 noexec=off: disable non-executable mappings
3292 noexec32 [X86-64]
3293 This affects only 32-bit executables.
3294 noexec32=on: enable non-executable mappings (default)
3296 noexec32=off: disable non-executable mappings
3301 nofxsr [BUGS=X86-32] Disables x86 floating point extended
3303 legacy floating-point registers on task switch.
3327 [PPC] Don't flush the L1-D cache after accessing user data.
3331 enabling legacy floating-point and sse state.
3356 nohalt [IA-64] Tells the kernel not to use the power saving
3358 power-consumption. On the positive side, it reduces
3359 interrupt wake-up latency, which may improve performance
3361 real-time systems.
3381 noirqdebug [X86-32] Disables the code which attempts to detect and
3392 nointremap [X86-64, Intel-IOMMU] Do not enable interrupt
3394 [Deprecated - use intremap=off]
3396 nointroute [IA-64]
3400 nojitter [IA-64] Disables jitter checking for ITC timers.
3402 no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
3404 no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page
3407 no-vmw-sched-clock
3411 no-steal-acc [X86,PV_OPS,ARM64] Disable paravirtualized steal time
3415 nolapic [X86-32,APIC] Do not enable or use the local APIC.
3417 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
3422 nomca [IA-64] Disable machine check abort handling
3424 nomce [X86-32] Disable Machine Check Exception
3426 nomfgpt [X86-32] Disable Multi-Function General Purpose
3438 nopcid [X86-64] Disable the PCID cpu feature.
3443 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
3454 no-scroll [VGA] Disables scrollback.
3455 This is required for the Braillex ib80-piezo Braille
3458 nosbagart [IA-64]
3460 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
3465 nosoftlockup [KNL] Disable the soft-lockup detector.
3470 soft-lockup and NMI watchdog (hard-lockup).
3474 nox2apic [X86-64,APIC] Do not enable x2APIC mode.
3499 nptcg= [IA-64] Override max number of concurrent global TLB
3508 n. So during boot up some boot time memory for per-cpu
3509 variables need be pre-allocated for later physical cpu
3520 See Documentation/admin-guide/sysctl/vm.rst for details.
3523 See Documentation/core-api/debugging-via-ohci1394.rst for more
3562 running on a platform with a direct-mapped memory-side
3568 page_owner= [KNL] Boot-time page_owner enabling option.
3574 page_poison= [KNL] Boot-time parameter changing the state of
3604 See Documentation/admin-guide/tainted-kernels.rst for
3612 Run kdump after running panic-notifiers and dumping
3657 See also Documentation/admin-guide/blockdev/paride.rst.
3686 bios [X86-32] force use of PCI BIOS, don't access
3688 has a non-standard PCI host bridge.
3689 nobios [X86-32] disallow use of PCI BIOS, only direct
3695 data in IO port 0xCFC, both 32-bit).
3697 Mechanism 2 (IO port 0xCF8 is an 8-bit port for
3698 the function, IO port 0xCFA, also 8-bit, sets
3700 through ports 0xC000-0xCFFF).
3707 root domains (aka PCI segments, in ACPI-speak).
3715 disable the use of MSI interrupts system-wide.
3720 primary IO-APIC for bridges that cannot disable
3727 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
3751 F0000h-100000h range.
3756 assign-busses [X86] Always assign all PCI bus
3784 bfsort Sort PCI devices into breadth-first order.
3787 nobfsort Don't sort PCI devices into breadth-first order.
3789 tuning and use the BIOS-configured MPS defaults.
3799 configuration allows peer-to-peer DMA between
3802 that hot-added devices will work.
3817 A PCI-PCI bridge can be specified if resource
3823 for 4096-byte alignment.
3825 end-to-end CRC checking).
3854 noats [PCIE, Intel-IOMMU, AMD-IOMMU]
3879 pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
3890 dpc-native Use native PCIe service for DPC only. May
3907 Keep all power-domains already enabled by bootloader on,
3913 See Documentation/admin-guide/blockdev/paride.rst.
3928 See Documentation/admin-guide/blockdev/paride.rst.
3931 See Documentation/admin-guide/blockdev/paride.rst.
3933 pirq= [SMP,APIC] Manual mp-table setup
3934 See Documentation/x86/i386/IO-APIC.rst.
3936 plip= [PPT,NET] Parallel port network link
3938 See also Documentation/admin-guide/parport.rst.
3949 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
3958 { on | off | curr | res | no-curr | no-res }
3996 print-fatal-signals=
4002 coredump - etc.
4005 you might want to try "ulimit -i unlimited".
4017 on - unlimited logging to /dev/kmsg from userspace
4018 off - logging to /dev/kmsg disabled
4019 ratelimit - ratelimit the logging
4026 Limit processor to maximum C-state
4030 Ignore the _CST method to determine C-states,
4037 Param: "schedule" - profile schedule points.
4038 Param: "sleep" - profile D-state sleeping (millisecs).
4040 Param: "kvm" - profile VM exits.
4041 Param: <number> - step/bucket size as a power of 2 for
4071 See Documentation/admin-guide/blockdev/paride.rst.
4073 pti= [X86-64] Control Page Table Isolation of user and
4078 on - unconditionally enable
4079 off - unconditionally disable
4080 auto - kernel detects whether your CPU model is
4085 nopti [X86-64]
4089 [KNL] Number of legacy pty's. Overwrites compiled-in
4097 See Documentation/admin-guide/md.rst.
4100 See Documentation/admin-guide/blockdev/ramdisk.rst.
4116 ras=option[,option,...] [KNL] RAS-specific options
4128 the specified list of CPUs to be no-callback CPUs.
4131 purpose, where "x" is "p" for RCU-preempt, and
4132 "s" for RCU-sched, and "N" is the CPU number.
4134 which can be useful for HPC and real-time
4143 This improves the real-time response for the
4160 RCU grace-period cleanup.
4164 RCU grace-period initialization.
4168 RCU grace-period pre-initialization, that is,
4169 the propagation of recent CPU-hotplug changes up
4174 per-CPU rcuc kthreads. Defaults to a non-zero
4182 cache-to-cache transfer latencies.
4188 and for NUMA systems with large remote-access
4197 whole algorithm to behave better in low memory
4201 Set delay from grace-period initialization to
4214 soliciting quiescent-state help from
4226 Set the SCHED_FIFO priority of the RCU per-CPU
4229 and for the RCU grace-period kthreads (rcu_bh,
4231 set, valid values are 1-99 and the default is 1
4232 (the least-favored priority). Otherwise, when
4233 RCU_BOOST is not set, valid values are 0-99 and
4234 the default is zero (non-realtime operation).
4240 the wakeup overhead on the global grace-period
4242 each group's NOCB grace-period kthread.
4250 batch limiting is re-enabled.
4254 RCU's force-quiescent-state scan will aggressively
4272 Cause the grace-period kthread to get an extra
4274 it should at force-quiescent-state time.
4280 this specifies an rcu_read_unlock()-time delay
4284 of RCU-protected pointers after the relevant
4294 grace-period primitives such as call_rcu().
4305 grace-period primitives.
4308 Set test-start holdoff period. The purpose of
4327 Set number of RCU readers. The value -1 selects
4329 "n" less than -1 selects N-n+1, where N is again
4330 the number of CPUs. For example, -2 selects N
4331 (the number of CPUs), -3 selects N+1, and so on.
4332 A value of "n" less than or equal to -N selects
4345 complete. This is useful for hands-off automated
4352 Write-side holdoff between grace periods,
4369 Enable RCU grace-period forward-progress testing
4373 Specify the fraction of a CPU-stall-warning
4374 period to do tight-loop forward-progress testing.
4378 forward-progress tests.
4382 need_resched() during tight-loop forward-progress
4386 Use conditional/asynchronous update-side
4390 Use expedited update-side primitives, if available.
4393 Use normal (non-expedited) asynchronous
4394 update-side primitives, if available.
4397 Use normal (non-expedited) synchronous
4398 update-side primitives, if available. If all
4402 they are all non-zero.
4410 Leak an RCU-protected pointer out of the reader.
4425 Set number of RCU readers. The value -1 selects
4426 N-1, where N is the number of CPUs. A value
4427 "n" less than -1 selects N-n-2, where N is again
4428 the number of CPUs. For example, -2 selects N
4429 (the number of CPUs), -3 selects N+1, and so on.
4432 Enable debug-object double-call_rcu() testing.
4435 Set time (s) after boot for CPU-hotplug testing.
4438 Set time (jiffies) between CPU-hotplug operations,
4439 or zero to disable CPU-hotplug testing.
4442 Set the number of read-then-exit kthreads used
4444 task-exit processing.
4447 The number of times in a given read-then-exit
4448 episode that a set of read-then-exit kthreads
4453 read-then-exit testing episodes.
4456 Set task-shuffle interval (s). Shuffling tasks
4457 allows some CPUs to go into dyntick-idle mode
4462 is useful for hands-off automated testing.
4471 to any other stall-related activity.
4481 grace-period kthread to test RCU CPU stall
4507 Test RCU's dyntick-idle handling. See also the
4533 Use expedited grace-period primitives, for
4537 real-time latency, and degrade energy efficiency.
4541 Use only normal grace-period primitives,
4544 real-time latency, CPU utilization, and
4546 increased grace-period latency. This parameter
4553 only normal grace-period primitives. No effect
4560 number avoids disturbing real-time workloads,
4577 force - Override the decision by the kernel to hide the
4605 Set test-start holdoff period. The purpose of
4614 but the default has already reduced the per-pass
4619 Set number of readers. The default value of -1
4628 Set the read-side critical-section duration,
4632 Specify the read-protection implementation to test.
4645 See Documentation/admin-guide/cgroup-v1/cpusets.rst.
4653 reservetop= [X86-32]
4675 See Documentation/power/swsusp-and-swap-files.rst
4691 during restoration read-only).
4699 AMD-based UNRET and IBPB mitigations alone do not stop
4701 sibling threads. For that reason, STIBP is used on pro-
4705 off - no mitigation
4706 auto - automatically select a migitation
4707 auto,nosmt - automatically select a mitigation,
4711 ibpb - On AMD, mitigate short speculation
4716 ibpb,nosmt - Like "ibpb" above but will disable SMT
4720 unret - Force enable untrained return thunks,
4721 only effective on AMD f15h-f17h based
4723 unret,nosmt - Like unret, but will disable SMT when STIBP
4751 ro [KNL] Mount root device read-only on boot
4754 on Mark read-only kernel memory as read-only (default).
4755 off Leave read-only kernel memory writable for debugging.
4759 on Rockchip SoCs. When active, the signals of the
4760 debug-uart get routed to the D+ and D- pins of the usb
4782 rw [KNL] Mount root device read-write on boot
4824 to 10 seconds for built-in smp_call_function()
4831 that requesting even small non-zero numbers of
4838 The default of -1 specifies a number of kthreads
4843 test before initiating CPU-hotplug operations.
4847 CPU-hotplug operations. Specifying zero (which
4848 is the default) disables CPU-hotplug operations.
4854 Non-zero values are useful for automated tests.
4877 "wait" parameter. A value of -1 selects the
4878 default if all other weights are -1. However,
4880 value of -1 will instead select a weight of zero.
4885 non-zero "wait" parameter. See weight_single.
4898 non-zero "wait" parameter. See weight_single
4910 non-zero "wait" parameter. See weight_single
4917 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
4918 1 -- enable.
4929 0 -- disable.
4930 1 -- enable.
4936 0 -- disable.
4937 1 -- enable.
4940 serialnumber [BUGS=X86-32]
4945 simeth= [IA-64]
4979 memory cgroup sub-caches. 1 to enable, 0 to disable.
5012 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
5013 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
5014 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
5015 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
5016 smsc-ircc2.ircc_irq= [HW] IRQ line
5017 smsc-ircc2.ircc_dma= [HW] DMA channel
5018 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
5028 Default: -1 (no limit)
5031 [KNL] Should the soft-lockup detector generate panics.
5034 A value of 1 instructs the soft-lockup detector
5035 to panic the machine when a soft-lockup occurs. It is
5038 respective build-time switch to that functionality.
5041 [KNL] Should the soft-lockup detector generate
5046 See Documentation/admin-guide/laptops/sonypi.rst
5053 on - unconditionally enable, implies
5055 off - unconditionally disable, implies
5057 auto - kernel detects whether your CPU model is
5074 retpoline - replace indirect branches
5075 retpoline,generic - Retpolines
5076 retpoline,lfence - LFENCE; indirect branch
5077 retpoline,amd - alias for retpoline,lfence
5078 eibrs - enhanced IBRS
5079 eibrs,retpoline - enhanced IBRS + Retpolines
5080 eibrs,lfence - enhanced IBRS + LFENCE
5081 ibrs - use IBRS to protect kernel
5091 on - Unconditionally enable mitigations. Is
5094 off - Unconditionally disable mitigations. Is
5097 prctl - Indirect branch speculation is enabled,
5103 - Like "prctl" above, but only STIBP is
5109 - Same as "prctl" above, but all seccomp
5114 - Like "seccomp" above, but only STIBP is
5119 auto - Kernel selects the mitigation depending on
5151 on - Unconditionally disable Speculative Store Bypass
5152 off - Unconditionally enable Speculative Store Bypass
5153 auto - Kernel detects whether the CPU model contains an
5159 prctl - Control Speculative Store Bypass per thread
5163 seccomp - Same as "prctl" above, but all seccomp threads
5171 on,auto - On Power8 and Power9 insert a store-forwarding
5175 off - No action.
5192 off - not enabled
5194 warn - the kernel will emit rate limited warnings
5199 fatal - the kernel will send SIGBUS to applications
5211 Certain CPUs are vulnerable to an MDS-like
5229 grace-period sequence counter wrap for the
5230 srcu_data structure's ->srcu_gp_seq_needed field.
5252 force-on: Unconditionally enable mitigation for
5254 force-off: Unconditionally disable mitigation for
5271 stacktrace_filter=[function-list]
5273 will trace at boot up. function-list is a comma separated
5281 Set the STI (builtin display/keyboard on the HP-PARISC
5283 as the initial boot-console.
5324 to global on non-NUMA machines)
5350 it if 0 is given (See Documentation/admin-guide/cgroup-v1/memory.rst)
5352 swiotlb= [ARM,IA-64,PPC,MIPS,X86]
5354 <int> -- Number of I/O TLB slabs
5355 force -- force using of bounce buffers even if they
5357 noforce -- Never use bounce buffers (for debugging)
5381 Ignore sysrq setting - this boot parameter will
5389 cache size. See Documentation/networking/ip-sysctl.rst
5395 Specify "mem" (for Suspend-to-RAM) or "standby" (for
5400 wakeup-capable RTC alarm.
5406 -1: disable all active trip points in all thermal zones
5407 <degrees C>: override all lowest active trip points
5410 -1: disable all critical trip points in all thermal zones
5421 -1: disable all passive trip points
5427 <deci-seconds>: poll all this frequency
5449 Prevent the CPU-hotplug component of torturing
5453 Dump the ftrace buffer at torture-test shutdown,
5457 with rotating-rust storage.
5473 trace_event=[event-list]
5475 to facilitate early boot debugging. The event-list is a
5479 trace_options=[option-list]
5481 The option-list is a comma delimited list of options
5531 See Documentation/admin-guide/mm/transhuge.rst
5539 high-resolution timer mode on older hardware, and in
5565 on - Enable TSX on the system. Although there are
5568 several previous speculation-related CVEs, and
5572 off - Disable TSX on the system. (Note that this
5580 auto - Disable TSX if X86_BUG_TAA is present,
5585 See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
5591 Similar to Micro-architectural Data Sampling (MDS)
5606 full - Enable TAA mitigation on vulnerable CPUs
5609 full,nosmt - Enable TAA mitigation and disable SMT on
5612 vulnerable to cross-thread TAA attacks.
5613 off - Unconditionally disable TAA mitigation
5615 On MDS-affected machines, tsx_async_abort=off can be
5616 prevented by an active MDS mitigation as both vulnerabilities
5627 Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
5633 See also Documentation/input/devices/joystick-parport.rst
5635 udbg-immortal [PPC] When debugging early kernel crashes that
5641 Set number of hash buckets for UDP/UDP-Lite connections
5643 uhci-hcd.ignore_oc=
5645 Some badly-designed motherboards generate lots of
5656 (default -1 = authorized except for wireless USB,
5662 for newly-detected USB devices (default 2). This
5690 [USB] Specifies timeout for the initial 64-byte
5697 [USB] A list of quirk entries to augment the built-in
5700 VendorID:ProductID:Flags. The IDs are 4-digit hex
5702 will change the built-in quirk; setting it if it is
5707 a 255-byte read);
5711 Set-Interface requests);
5730 (bInterval-1).
5741 k = USB_QUIRK_NO_LPM (device can't handle Link
5765 usb-storage.delay_use=
5769 usb-storage.quirks=
5771 override the built-in unusual_devs list. List
5774 and Product ID values (4-digit hex numbers) and
5776 to a common usb-storage quirk flag as follows:
5818 medium is write-protected).
5827 1 - undefined instruction events
5828 2 - system calls
5829 4 - invalid data aborts
5830 8 - SIGSEGV faults
5831 16 - SIGBUS faults
5847 vdso32= [X86] Control the 32-bit vDSO
5848 vdso32=1: enable 32-bit VDSO
5849 vdso32=0 or vdso32=2: disable 32-bit VDSO
5859 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
5861 vector= [IA-64,SMP]
5892 vga= [BOOT,X86-32] Select a particular video mode
5894 Documentation/admin-guide/svga.rst.
5909 - Disable all of the above options
5930 vsyscall= [X86-64]
5933 code). Most statically-linked binaries and older
5957 see VGA-softcursor.txt. Default: 2 = underline.
5962 This is a 16-member array composed of values
5963 ranging from 0-255.
5968 This is a 16-member array composed of values
5969 ranging from 0-255.
5974 This is a 16-member array composed of values
5975 ranging from 0-255.
5980 Set system-wide default UTF-8 mode for all tty's.
5981 Default is 1, i.e. UTF-8 mode is enabled for all
5986 Format=<-1|0|1>
5987 Set system-wide default for whether a cursor
5988 is shown on new VTs. Default is -1,
5993 vt.italic= [VT] Default color for italic text; 0-15.
5996 vt.underline= [VT] Default color for underlined text; 0-15.
6000 see Documentation/watchdog/watchdog-parameters.rst
6001 or other driver-specific files in the
6027 that this also can be controlled per-workqueue for
6031 Per-cpu workqueues are generally preferred because
6033 locality; unfortunately, per-cpu workqueues tend to
6036 Enabling this makes the per-cpu workqueues which
6051 forces round-robin CPU selection to flush out
6056 x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
6060 x86_intel_mid_timer= [X86-32,APBT]
6066 xen_512gb_limit [KNL,X86-64,XEN]
6076 ide-disks -- unplug primary master IDE devices
6077 aux-ide-disks -- unplug non-primary-master IDE devices
6078 nics -- unplug network devices
6079 all -- unplug all emulated devices (NICs and IDE disks)
6080 unnecessary -- unplugging emulated devices is
6083 never -- do not unplug even if version check succeeds
6110 xen_timer_slop= [X86-64,XEN]
6135 preferred over the 2-level event handling, as it is
6162 xhci-hcd.quirks [USB,KNL]