Lines Matching +full:auto +full:- +full:boot
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
121 Disable auto-serialization of AML methods
124 auto-serialization feature.
132 Disable installation of static SSDTs at early boot time
142 Ignore the ACPI-based watchdog interface (WDAT) and let
147 on machines running EFI runtime service to boot the
163 acpi_osi=! # disable all built-in OS vendor
165 acpi_osi=!! # enable all built-in OS vendor
227 For broken nForce2 BIOS resulting in XT-PIC timer.
235 as soon as the kernel's real-mode entry point is called.
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
286 Allocate the ftrace snapshot buffer on boot up when the
288 and you need to use tracing_snapshot() on boot up, and
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
441 boot_delay= Milliseconds to delay each printk during boot.
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.
524 0 -- check protection applied by kernel (includes
526 1 -- check protection requested by application.
540 force such clocks to be always-on nor does it reserve
544 information, see Documentation/driver-api/clk.rst.
546 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
563 [X86-32] pit,hpet,tsc;
570 [X86-64] hpet,tsc
576 architected timer so that code using WFE-based polling
593 cma=nn[MG]@[start[MG][-end[MG]]]
604 Sets the size of kernel per-numa memory area for
606 per-numa CMA altogether. And If this option is not
608 With per-numa CMA enabled, DMA users on node nid will
624 com20020= [HW,NET] ARCnet - COM20020 chipset
628 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
632 ARCnet - COM90xx chipset (memory-mapped buffers)
650 See Documentation/admin-guide/serial-console.rst for more
660 Start an early, polled-mode console on the 8250/16550
663 MMIO inter-register address stride is either 8-bit
664 (mmio), 16-bit (mmio16), or 32-bit (mmio32).
668 the h/w is not re-initialized.
689 syscall, or to executing "dmesg -S --raw" or to reading
706 1: enable debugging at boot time
709 disable the cpuidle sub-system
715 disable the cpufreq sub-system
723 [X86] Delay for N microsec between assert and de-assert
725 on every CPU online, such as boot, and resume from suspend.
738 [KNL, X86-64] Select a region under 4G first, and
741 See Documentation/admin-guide/kdump/kdump.rst for further details.
746 start-[end] where start and end are both
748 Documentation/admin-guide/kdump/kdump.rst for an example.
751 [KNL, X86-64] range could be above 4G. Allow kernel
758 [KNL, X86-64] range under 4G. When crashkernel=X,high
763 low memory is needed to make sure DMA buffers for 32-bit
773 [KNL] Disable crypto self-tests
787 See also Documentation/input/devices/joystick-parport.rst
789 ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot
791 Documentation/admin-guide/dynamic-debug-howto.rst for
798 boot sequence. If enabled, we use a weak hash instead
805 [KNL] verbose self-tests
808 self-tests.
810 1 will print _a lot_ more information - normally
839 enables the feature at boot time. By default, it is
848 Format: { on, no-mount, off }
850 no-mount:
855 get a -EPERM as result when trying to register files
859 Default value is set in build-time with a kernel configuration.
875 Documentation/admin-guide/mm/hugetlbpage.rst.
918 hardening is enabled for this boot. Hardened
922 against bounds-checking flaws in the kernel's
941 corresponding CPU to be disabled at boot,
978 this option disables the debugging code at boot.
982 entries for DMA-API debugging code. One entry is
983 required per DMA-API allocation. Use this if the
984 DMA-API debugging code disables itself because the
988 With this option the DMA-API debugging driver
989 filter feature can be enabled at boot time. Just
1003 Generic built-in EDID data sets are used, if one of
1008 available in Documentation/admin-guide/edid.rst. An EDID
1020 Control how the dt_cpu_ftrs device-tree binding is
1030 what data is available or for reverse-engineering.
1034 Enable debug messages at boot time. See
1035 Documentation/admin-guide/dynamic-debug-howto.rst
1052 determined by stdout-path property in device tree's
1057 Start an early, polled-mode console on a Cadence
1068 Start an early, polled-mode console on the 8250/16550
1070 MMIO inter-register address stride is either 8-bit
1071 (mmio) or 32-bit (mmio32 or mmio32be).
1079 Start an early, polled-mode console on a pl011 serial
1083 the driver will use only 32-bit accessors to read/write
1087 Start an early, polled-mode console on a meson serial
1093 Start an early, polled-mode console on an msm serial
1099 Start an early, polled-mode console on an msm serial
1105 Start an early, polled-mode console on a serial port
1111 Start an early, polled-mode console on a serial port
1117 Use RISC-V SBI (Supervisor Binary Interface) for early
1135 Start an early, polled-mode console on a lantiq serial
1149 Start an early, polled-mode, output-only console on the
1154 Start an early, polled-mode console on the
1160 Start an early, polled-mode console on a Qualcomm
1168 coherent non-x86 systems that use system memory for
1234 the boot argument: earlyprintk=vga
1238 very early in the boot process. For early debugging
1250 PCI bridges while in the EFI boot stub.
1252 boot stub, as chunking can cause problems with some
1263 on all PCI bridges while in the EFI boot stub
1279 attribute is added to range 0x100000000-0x180000000 and
1280 0x10a0000000-0x1120000000.
1284 range 0x240000000-0x43fffffff.
1296 Documentation/admin-guide/acpi/ssdt-overlays.rst for details.
1302 elanfreq= [X86-32]
1310 See Documentation/admin-guide/kdump/kdump.rst for details.
1326 0 -- permissive (log only, no denials).
1327 1 -- enforcing (deny and log).
1351 See also Documentation/fault-injection/.
1355 See Documentation/admin-guide/sysctl/net.rst for
1359 See Documentation/admin-guide/blockdev/floppy.rst.
1362 [IA-64] Avoid check_sal_cache_flush which may hang on
1367 forcepae [X86-32]
1377 boot debugging.
1386 ftrace_filter=[function-list]
1388 tracer at boot up. function-list is a comma separated
1393 ftrace_notrace=[function-list]
1395 function-list. This list can be changed at run time
1399 ftrace_graph_filter=[function-list]
1401 by the function graph tracer at boot up.
1402 function-list is a comma separated list of functions
1406 ftrace_graph_notrace=[function-list]
1408 function-list. This list is a comma separated list of
1423 (suppliers first, then consumers), supplier boot state
1428 off -- Don't create device links from firmware info.
1429 permissive -- Create device links from firmware info
1430 but use it only for ordering boot state clean
1432 on -- Create device links from firmware info and use it
1434 rpm -- Like "on", but also use to order runtime PM.
1440 See also Documentation/input/devices/joystick-parport.rst
1444 gart_fix_e820= [X86-64] disable the fix e820 for K8 GART
1448 gcov_persist= [GCOV] When non-zero (default), profiling data for
1481 gpio-mockup.gpio_mockup_ranges
1486 [KNL] Should the hard-lockup detector generate
1490 hashdist= [KNL,NUMA] Large hashes allocated during boot
1492 for 64-bit NUMA, off otherwise.
1495 hcl= [IA-64] SGI's Hardware Graph compatibility layer
1502 corresponding firmware-first mode error processing
1505 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
1516 hpet= [X86-32,HPET] option to control HPET usage
1533 boot-time allocation of gigantic hugepages is skipped.
1535 hugepages= [HW] Number of HugeTLB pages to allocate at boot.
1541 Documentation/admin-guide/mm/hugetlbpage.rst.
1547 pages of a specific size at boot. The pair
1551 Documentation/admin-guide/mm/hugetlbpage.rst.
1560 by the CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time
1561 option. The value selected by this boot parameter can
1566 hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
1575 Do not unregister boot console at start. This is only
1577 between unregistering the boot console and initializing
1589 (disabled by default, and as a pre-condition
1591 i8042.direct [HW] Put keyboard port into non-translated mode
1605 suspend-to-ram transitions, only during s2r
1638 -1 -- never invert brightness
1639 0 -- machine default
1640 1 -- force brightness inversion
1645 ide-core.nodma= [HW] (E)IDE subsystem
1651 ide-generic.probe-mask= [HW] (E)IDE subsystem
1663 ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
1674 idle=nomwait: Disable mwait for CPU C-states
1691 legacy only accept legacy-NaN binaries, if supported
1693 2008 only accept 2008-NaN binaries, if supported
1702 'relaxed' straps the emulator for both legacy-NaN and
1703 2008-NaN, whereas 'strict' enables legacy-NaN only on
1712 Ignore loglevel setting - this will print /all/
1776 Formats: { "ima" | "ima-ng" | "ima-sig" }
1777 Default: "ima-ng"
1809 initcall_blacklist= [KNL] Do not execute a comma-separated list of
1810 initcall functions. Useful for debugging built-in
1813 initrd= [BOOT] Specify the location of the initial ramdisk
1834 override in debugfs after boot.
1843 0 -- basic integrity auditing messages. (Default)
1844 1 -- additional integrity auditing messages.
1857 forcedac [X86-64]
1859 for io virtual address below 32-bit forcing dual
1861 than 32-bit addressing. The default is to look
1862 for translation below 32-bit and if not available
1880 could harm performance of some high-throughput
1894 1 to 9 specify maximum depth of C-state.
1904 used along with the hardware-managed P-states (HWP)
1908 in favor of acpi-cpufreq. Forcing the intel_pstate driver
1909 instead of acpi-cpufreq may disable platform features, such
1911 P-States information being indicated to OSPM and therefore
1914 or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
1927 Allow per-logical-CPU P-State performance control limits using
1930 intremap= [X86-64, Intel-IOMMU]
1935 BIOS x2APIC opt-out request will be ignored
1959 0 - Lazy mode.
1965 1 - Strict mode (default).
1972 0 - Use IOMMU translation for DMA.
1973 1 - Bypass the IOMMU for DMA.
1974 unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
1976 io7= [HW] IO7 for Marvel-based Alpha systems
1991 See Documentation/admin-guide/nfs/nfsroot.rst.
2015 Enables support for pseudo-NMIs in the kernel. This
2034 [Deprecated - use cpusets instead]
2035 Format: [flag-list,]<cpu-list>
2066 "number of CPUs in system - 1".
2092 The format of <cpu-list> is described above.
2096 ivrs_ioapic [HW,X86-64]
2097 Provide an override to the IOAPIC-ID<->DEVICE-ID
2099 example, to map IOAPIC-ID decimal 10 to
2103 ivrs_hpet [HW,X86-64]
2104 Provide an override to the HPET-ID<->DEVICE-ID
2106 example, to map HPET-ID decimal 0 to
2110 ivrs_acpihid [HW,X86-64]
2111 Provide an override to the ACPI-HID:UID<->DEVICE-ID
2113 example, to map UART-HID:UID AMD0020:0 to
2133 kernelcore= [KNL,X86,IA-64,PPC]
2136 the kernel for non-movable allocations. The requested
2146 subsystem. Note that allocations like PTEs-from-HighMem
2154 for non-movable allocations and remaining memory is used
2165 gdb or control-c on the dbgp connection. When
2166 not using this parameter you use sysrq-g to break into
2171 or a supported polling keyboard driver (non-usb).
2180 If the boot console provides the ability to read
2191 blank and the first boot console that implements
2198 Configure the RouterBoard 532 series on-chip
2201 kmemleak= [KNL] Boot-time kmemleak enable/disable
2207 kprobe_event=[probe-list]
2208 [FTRACE] Add kprobe events and enable at boot time.
2209 The probe-list is a semicolon delimited list of probe
2218 Boot Parameter" section.
2241 auto : Deploy workaround based on the presence of
2244 Default is 'auto'.
2255 kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM.
2258 kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
2260 Default is 1 (enabled) if in 64-bit or 32-bit PAE mode.
2262 kvm-arm.vgic_v3_group0_trap=
2263 [KVM,ARM] Trap guest accesses to GICv3 group-0
2266 kvm-arm.vgic_v3_group1_trap=
2267 [KVM,ARM] Trap guest accesses to GICv3 group-1
2270 kvm-arm.vgic_v3_common_trap=
2274 kvm-arm.vgic_v4_enable=
2286 kvm-intel.ept= [KVM,Intel] Disable extended page tables
2290 kvm-intel.emulate_invalid_guest_state=
2294 kvm-intel.flexpriority=
2298 kvm-intel.nested=
2302 kvm-intel.unrestricted_guest=
2307 kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
2308 CVE-2018-3620.
2319 kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification
2337 boot. Hypervisors will issue a warning
2355 boot. Hypervisors will issue a warning
2367 boot. Hypervisors will issue a warning
2386 For details see: Documentation/admin-guide/hw-vuln/l1tf.rst
2392 lapic [X86-32,APIC] Enable the local APIC even if BIOS
2396 value for LAPIC timer one-shot implementation. Default
2431 first fan-out link behind PMP device. It does not
2445 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
2457 hot-unplug link recovery
2494 Set the number of locking read-acquisition kthreads.
2499 Set the number of locking write-acquisition kthreads.
2502 Set time (s) after boot for CPU-hotplug testing.
2505 Set time (s) between CPU-hotplug operations, or
2506 zero to disable CPU-hotplug testing.
2509 Set task-shuffle interval (jiffies). Shuffling
2510 tasks allows some CPUs to go into dyntick-idle
2514 Set time (s) after boot system shutdown. This
2515 is useful for hands-off automated testing.
2548 7 (KERN_DEBUG) debug-level messages
2558 logo.nologo [FB] Disables display of the built-in Linux logo.
2561 kernel boot problems.
2566 lp=auto printer driver. 'lp=reset' (which can be
2573 'parport0'. Specifying 'lp=auto' instead of a
2576 an IEEE 1284-compliant printer is attached; if
2582 time-consuming boot-time autodetection (up to 250 ms per
2584 the correct value for your kernel, boot with normal
2603 machvec= [IA-64] Force the use of a particular machine-vector
2609 Example: machtype=lemote-yeeloong-2f-7inch
2611 max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater
2624 (loop.max_loop) unconditionally pre-created at init time. The default
2627 devices can be requested on-demand with the
2628 /dev/loop-control interface.
2630 mce [X86-32] Machine Check Exception
2632 mce=option [X86-64] See Documentation/x86/x86_64/boot-options.rst
2635 See Documentation/admin-guide/md.rst.
2642 Control mitigation for the Micro-architectural Data
2657 full - Enable MDS mitigation on vulnerable CPUs
2658 full,nosmt - Enable MDS mitigation and disable
2660 off - Unconditionally disable MDS mitigation
2662 On TAA-affected machines, mds=off can be prevented by
2671 For details see: Documentation/admin-guide/hw-vuln/mds.rst
2673 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
2686 Note that this only takes effects during boot time since
2687 in above case 3, memory may need be hot added after boot
2690 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
2695 per-device physically contiguous DMA buffers.
2703 See Documentation/admin-guide/mm/memory-hotplug.rst.
2728 Example: Exclude memory from 0x18690000-0x1869ffff
2742 memmap=<size>%<offset>-<oldtype>+<newtype>
2744 from <oldtype> to <newtype>. If "-<oldtype>" is left
2759 repeatable BIOS-originated corruption always
2784 mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control
2792 Refer to Documentation/virt/kvm/amd-memory-encryption.rst
2796 s2idle - Suspend-To-Idle
2797 shallow - Power-On Suspend or equivalent (if supported)
2798 deep - Suspend-To-RAM or equivalent (if supported)
2799 See Documentation/admin-guide/pm/sleep-states.rst.
2802 See Documentation/admin-guide/media/meye.rst.
2804 mfgpt_irq= [IA-32] Specify the IRQ to use for the
2805 Multi-Function General Purpose Timers on AMD Geode
2808 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
2815 min_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory below this
2822 0 - The attached screen is the 3.5" TFT
2823 1 - The attached screen is the 7" TFT
2824 2 - The VGA Shield is attached (1024x768)
2828 b - Enable backlight. The TFT backlight pin will be
2832 c - Enable the s3c camera interface.
2833 t - Reserved for enabling touchscreen support. The
2837 https://repo.or.cz/w/linux-2.6/mini2440.git
2842 arch-independent options, each of which is an
2843 aggregation of existing arch-specific options.
2856 ssbd=force-off [ARM64]
2869 auto (default)
2874 have other ways of avoiding SMT-based attacks.
2877 auto,nosmt
2899 module_blacklist= [KNL] Do not load a comma-separated list of
2913 movablecore= [KNL,X86,IA-64,PPC]
2924 movable_node [KNL] Boot-time switch to make hotplugable memory
2931 Format: <name>,<region-number>,<size>,<offset>
2934 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
2943 onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
2947 boundary - index of last SLC block on Flex-OneNAND.
2949 lock - Configure if Flex-OneNAND boundary should be locked.
2954 ARM/S3C2412 JIVE boot control
2956 See arch/arm/mach-s3c2412/mach-jive.c
2984 something different and driver-specific.
2995 See Documentation/admin-guide/nfs/nfsroot.rst.
2997 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
2998 See Documentation/admin-guide/nfs/nfsroot.rst.
3001 See Documentation/admin-guide/nfs/nfsroot.rst.
3025 [NFS] enable 64-bit inode numbers.
3026 If zero, the NFS client will fake up a 32-bit inode
3028 of returning the full 64-bit number.
3029 The default is to return 64-bit inode numbers.
3059 [NFS4] Specify an additional fixed unique ident-
3090 driver. A non-zero value sets the minimum interval
3102 NMI stack-backtrace request.
3111 0 - turn hardlockup detector in nmi_watchdog off
3112 1 - turn hardlockup detector in nmi_watchdog on
3129 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
3133 no5lvl [X86-64] Disable 5-level paging mode. Forces
3134 kernel to use 4-level paging instead.
3165 caches in the slab allocator. Saves per-node memory,
3185 nodelayacct [KNL] Disable per-task delay accounting
3187 nodsp [SH] Disable hardware DSP at boot time.
3191 no_entry_flush [PPC] Don't flush the L1-D cache when entering the kernel.
3193 noexec [IA-64]
3196 On X86-32 available only on PAE configured kernels.
3197 noexec=on: enable non-executable mappings (default)
3198 noexec=off: disable non-executable mappings
3208 noexec32 [X86-64]
3209 This affects only 32-bit executables.
3210 noexec32=on: enable non-executable mappings (default)
3212 noexec32=off: disable non-executable mappings
3215 nofpu [MIPS,SH] Disable hardware FPU at boot time.
3217 nofxsr [BUGS=X86-32] Disables x86 floating point extended
3219 legacy floating-point registers on task switch.
3243 [PPC] Don't flush the L1-D cache after accessing user data.
3247 enabling legacy floating-point and sse state.
3272 nohalt [IA-64] Tells the kernel not to use the power saving
3274 power-consumption. On the positive side, it reduces
3275 interrupt wake-up latency, which may improve performance
3277 real-time systems.
3285 nohz_full= [KNL,BOOT,SMP,ISOL]
3289 whenever possible. The boot CPU will be forced outside
3293 rcu_nocbs= boot parameter.
3297 noirqdebug [X86-32] Disables the code which attempts to detect and
3308 nointremap [X86-64, Intel-IOMMU] Do not enable interrupt
3310 [Deprecated - use intremap=off]
3312 nointroute [IA-64]
3316 nojitter [IA-64] Disables jitter checking for ITC timers.
3318 no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
3320 no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page
3323 no-vmw-sched-clock
3327 no-steal-acc [X86,PV_OPS,ARM64] Disable paravirtualized steal time
3331 nolapic [X86-32,APIC] Do not enable or use the local APIC.
3333 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
3338 nomca [IA-64] Disable machine check abort handling
3340 nomce [X86-32] Disable Machine Check Exception
3342 nomfgpt [X86-32] Disable Multi-Function General Purpose
3354 nopcid [X86-64] Disable the PCID cpu feature.
3359 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
3370 no-scroll [VGA] Disables scrollback.
3371 This is required for the Braillex ib80-piezo Braille
3374 nosbagart [IA-64]
3376 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
3381 nosoftlockup [KNL] Disable the soft-lockup detector.
3386 soft-lockup and NMI watchdog (hard-lockup).
3390 nox2apic [X86-64,APIC] Do not enable x2APIC mode.
3415 nptcg= [IA-64] Override max number of concurrent global TLB
3424 n. So during boot up some boot time memory for per-cpu
3425 variables need be pre-allocated for later physical cpu
3433 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
3435 This can be set from sysctl after boot.
3436 See Documentation/admin-guide/sysctl/vm.rst for details.
3439 See Documentation/core-api/debugging-via-ohci1394.rst for more
3478 running on a platform with a direct-mapped memory-side
3484 page_owner= [KNL] Boot-time page_owner enabling option.
3490 page_poison= [KNL] Boot-time parameter changing the state of
3520 See Documentation/admin-guide/tainted-kernels.rst for
3528 Run kdump after running panic-notifiers and dumping
3543 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
3544 Use 'auto' to force the driver to use any
3549 should be numbers, or 'auto' (for using detected
3573 See also Documentation/admin-guide/blockdev/paride.rst.
3602 bios [X86-32] force use of PCI BIOS, don't access
3604 has a non-standard PCI host bridge.
3605 nobios [X86-32] disallow use of PCI BIOS, only direct
3611 data in IO port 0xCFC, both 32-bit).
3613 Mechanism 2 (IO port 0xCF8 is an 8-bit port for
3614 the function, IO port 0xCFA, also 8-bit, sets
3616 through ports 0xC000-0xCFFF).
3620 enabled, this kernel boot option can be used to
3623 root domains (aka PCI segments, in ACPI-speak).
3630 enabled, this kernel boot option can be used to
3631 disable the use of MSI interrupts system-wide.
3632 noioapicquirk [APIC] Disable all boot interrupt quirks.
3633 Safety option to keep boot IRQs enabled. This
3635 ioapicreroute [APIC] Enable rerouting of boot IRQs to the
3636 primary IO-APIC for bridges that cannot disable
3637 boot IRQs. This fixes a source of spurious IRQs
3640 boot IRQ equivalent of an IRQ that connects to
3641 a chipset where boot IRQs cannot be disabled.
3643 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
3667 F0000h-100000h range.
3672 assign-busses [X86] Always assign all PCI bus
3700 bfsort Sort PCI devices into breadth-first order.
3703 nobfsort Don't sort PCI devices into breadth-first order.
3705 tuning and use the BIOS-configured MPS defaults.
3715 configuration allows peer-to-peer DMA between
3718 that hot-added devices will work.
3733 A PCI-PCI bridge can be specified if resource
3739 for 4096-byte alignment.
3741 end-to-end CRC checking).
3770 noats [PCIE, Intel-IOMMU, AMD-IOMMU]
3806 dpc-native Use native PCIe service for DPC only. May
3823 Keep all power-domains already enabled by bootloader on,
3829 See Documentation/admin-guide/blockdev/paride.rst.
3832 boot time.
3844 See Documentation/admin-guide/blockdev/paride.rst.
3847 See Documentation/admin-guide/blockdev/paride.rst.
3849 pirq= [SMP,APIC] Manual mp-table setup
3850 See Documentation/x86/i386/IO-APIC.rst.
3854 See also Documentation/admin-guide/parport.rst.
3861 Enable suspend/resume debug messages during boot up.
3865 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
3874 { on | off | curr | res | no-curr | no-res }
3912 print-fatal-signals=
3918 coredump - etc.
3921 you might want to try "ulimit -i unlimited".
3933 on - unlimited logging to /dev/kmsg from userspace
3934 off - logging to /dev/kmsg disabled
3935 ratelimit - ratelimit the logging
3942 Limit processor to maximum C-state
3946 Ignore the _CST method to determine C-states,
3953 Param: "schedule" - profile schedule points.
3954 Param: "sleep" - profile D-state sleeping (millisecs).
3956 Param: "kvm" - profile VM exits.
3957 Param: <number> - step/bucket size as a power of 2 for
3987 See Documentation/admin-guide/blockdev/paride.rst.
3989 pti= [X86-64] Control Page Table Isolation of user and
3994 on - unconditionally enable
3995 off - unconditionally disable
3996 auto - kernel detects whether your CPU model is
3999 Not specifying this option is equivalent to pti=auto.
4001 nopti [X86-64]
4005 [KNL] Number of legacy pty's. Overwrites compiled-in
4013 See Documentation/admin-guide/md.rst.
4016 See Documentation/admin-guide/blockdev/ramdisk.rst.
4026 ras=option[,option,...] [KNL] RAS-specific options
4038 the specified list of CPUs to be no-callback CPUs.
4041 purpose, where "x" is "p" for RCU-preempt, and
4042 "s" for RCU-sched, and "N" is the CPU number.
4044 which can be useful for HPC and real-time
4053 This improves the real-time response for the
4065 out at early boot. This is used for diagnostic
4070 RCU grace-period cleanup.
4074 RCU grace-period initialization.
4078 RCU grace-period pre-initialization, that is,
4079 the propagation of recent CPU-hotplug changes up
4084 per-CPU rcuc kthreads. Defaults to a non-zero
4092 cache-to-cache transfer latencies.
4098 and for NUMA systems with large remote-access
4111 Set delay from grace-period initialization to
4124 soliciting quiescent-state help from
4135 rcutree.kthread_prio= [KNL,BOOT]
4136 Set the SCHED_FIFO priority of the RCU per-CPU
4139 and for the RCU grace-period kthreads (rcu_bh,
4141 set, valid values are 1-99 and the default is 1
4142 (the least-favored priority). Otherwise, when
4143 RCU_BOOST is not set, valid values are 0-99 and
4144 the default is zero (non-realtime operation).
4150 the wakeup overhead on the global grace-period
4152 each group's NOCB grace-period kthread.
4160 batch limiting is re-enabled.
4164 RCU's force-quiescent-state scan will aggressively
4168 on rcutree.qhimark at boot time and to zero to
4182 Cause the grace-period kthread to get an extra
4184 it should at force-quiescent-state time.
4190 this specifies an rcu_read_unlock()-time delay
4194 of RCU-protected pointers after the relevant
4204 grace-period primitives such as call_rcu().
4215 grace-period primitives.
4218 Set test-start holdoff period. The purpose of
4220 test until boot completes in order to avoid
4237 Set number of RCU readers. The value -1 selects
4239 "n" less than -1 selects N-n+1, where N is again
4240 the number of CPUs. For example, -2 selects N
4241 (the number of CPUs), -3 selects N+1, and so on.
4242 A value of "n" less than or equal to -N selects
4255 complete. This is useful for hands-off automated
4262 Write-side holdoff between grace periods,
4279 Enable RCU grace-period forward-progress testing
4283 Specify the fraction of a CPU-stall-warning
4284 period to do tight-loop forward-progress testing.
4288 forward-progress tests.
4292 need_resched() during tight-loop forward-progress
4296 Use conditional/asynchronous update-side
4300 Use expedited update-side primitives, if available.
4303 Use normal (non-expedited) asynchronous
4304 update-side primitives, if available.
4307 Use normal (non-expedited) synchronous
4308 update-side primitives, if available. If all
4312 they are all non-zero.
4320 Leak an RCU-protected pointer out of the reader.
4335 Set number of RCU readers. The value -1 selects
4336 N-1, where N is the number of CPUs. A value
4337 "n" less than -1 selects N-n-2, where N is again
4338 the number of CPUs. For example, -2 selects N
4339 (the number of CPUs), -3 selects N+1, and so on.
4342 Enable debug-object double-call_rcu() testing.
4345 Set time (s) after boot for CPU-hotplug testing.
4348 Set time (jiffies) between CPU-hotplug operations,
4349 or zero to disable CPU-hotplug testing.
4352 Set the number of read-then-exit kthreads used
4354 task-exit processing.
4357 The number of times in a given read-then-exit
4358 episode that a set of read-then-exit kthreads
4363 read-then-exit testing episodes.
4366 Set task-shuffle interval (s). Shuffling tasks
4367 allows some CPUs to go into dyntick-idle mode
4371 Set time (s) after boot system shutdown. This
4372 is useful for hands-off automated testing.
4381 to any other stall-related activity.
4384 Time to wait (s) after boot before inducing stall.
4391 grace-period kthread to test RCU CPU stall
4417 Test RCU's dyntick-idle handling. See also the
4436 during early boot, that is, during the time
4443 Use expedited grace-period primitives, for
4447 real-time latency, and degrade energy efficiency.
4451 Use only normal grace-period primitives,
4454 real-time latency, CPU utilization, and
4456 increased grace-period latency. This parameter
4461 Once boot has completed (that is, after
4463 only normal grace-period primitives. No effect
4470 number avoids disturbing real-time workloads,
4479 Run the RCU early boot self tests
4487 force - Override the decision by the kernel to hide the
4515 Set test-start holdoff period. The purpose of
4517 test until boot completes in order to avoid
4524 but the default has already reduced the per-pass
4529 Set number of readers. The default value of -1
4538 Set the read-side critical-section duration,
4542 Specify the read-protection implementation to test.
4555 See Documentation/admin-guide/cgroup-v1/cpusets.rst.
4563 reservetop= [X86-32]
4585 See Documentation/power/swsusp-and-swap-files.rst
4596 present during boot.
4601 during restoration read-only).
4624 ro [KNL] Mount root device read-only on boot
4627 on Mark read-only kernel memory as read-only (default).
4628 off Leave read-only kernel memory writable for debugging.
4633 debug-uart get routed to the D+ and D- pins of the usb
4655 rw [KNL] Mount root device read-write on boot
4697 to 10 seconds for built-in smp_call_function()
4704 that requesting even small non-zero numbers of
4711 The default of -1 specifies a number of kthreads
4716 test before initiating CPU-hotplug operations.
4720 CPU-hotplug operations. Specifying zero (which
4721 is the default) disables CPU-hotplug operations.
4727 Non-zero values are useful for automated tests.
4750 "wait" parameter. A value of -1 selects the
4751 default if all other weights are -1. However,
4753 value of -1 will instead select a weight of zero.
4758 non-zero "wait" parameter. See weight_single.
4771 non-zero "wait" parameter. See weight_single
4783 non-zero "wait" parameter. See weight_single
4790 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
4791 1 -- enable.
4796 enable at boot. This has been deprecated by the
4799 selinux= [SELINUX] Disable or enable SELinux at boot time.
4802 0 -- disable.
4803 1 -- enable.
4806 apparmor= [APPARMOR] Disable or enable AppArmor at boot time
4809 0 -- disable.
4810 1 -- enable.
4813 serialnumber [BUGS=X86-32]
4818 simeth= [IA-64]
4852 memory cgroup sub-caches. 1 to enable, 0 to disable.
4885 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
4886 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
4887 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
4888 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
4889 smsc-ircc2.ircc_irq= [HW] IRQ line
4890 smsc-ircc2.ircc_dma= [HW] DMA channel
4891 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
4901 Default: -1 (no limit)
4904 [KNL] Should the soft-lockup detector generate panics.
4907 A value of 1 instructs the soft-lockup detector
4908 to panic the machine when a soft-lockup occurs. It is
4911 respective build-time switch to that functionality.
4914 [KNL] Should the soft-lockup detector generate
4919 See Documentation/admin-guide/laptops/sonypi.rst
4926 on - unconditionally enable, implies
4928 off - unconditionally disable, implies
4930 auto - kernel detects whether your CPU model is
4933 Selecting 'on' will, and 'auto' may, choose a
4947 retpoline - replace indirect branches
4948 retpoline,generic - google's original retpoline
4949 retpoline,amd - AMD-specific minimal thunk
4952 spectre_v2=auto.
4959 on - Unconditionally enable mitigations. Is
4962 off - Unconditionally disable mitigations. Is
4965 prctl - Indirect branch speculation is enabled,
4971 - Like "prctl" above, but only STIBP is
4977 - Same as "prctl" above, but all seccomp
4982 - Like "seccomp" above, but only STIBP is
4987 auto - Kernel selects the mitigation depending on
4994 spectre_v2_user=auto.
5019 on - Unconditionally disable Speculative Store Bypass
5020 off - Unconditionally enable Speculative Store Bypass
5021 auto - Kernel detects whether the CPU model contains an
5027 prctl - Control Speculative Store Bypass per thread
5031 seccomp - Same as "prctl" above, but all seccomp threads
5039 on,auto - On Power8 and Power9 insert a store-forwarding
5043 off - No action.
5046 spec_store_bypass_disable=auto.
5060 off - not enabled
5062 warn - the kernel will emit rate limited warnings
5067 fatal - the kernel will send SIGBUS to applications
5079 Certain CPUs are vulnerable to an MDS-like
5097 grace-period sequence counter wrap for the
5098 srcu_data structure's ->srcu_gp_seq_needed field.
5120 force-on: Unconditionally enable mitigation for
5122 force-off: Unconditionally disable mitigation for
5137 Enabled the stack tracer on boot up.
5139 stacktrace_filter=[function-list]
5141 will trace at boot up. function-list is a comma separated
5149 Set the STI (builtin display/keyboard on the HP-PARISC
5151 as the initial boot-console.
5187 auto the server chooses an appropriate mode
5192 to global on non-NUMA machines)
5218 it if 0 is given (See Documentation/admin-guide/cgroup-v1/memory.rst)
5220 swiotlb= [ARM,IA-64,PPC,MIPS,X86]
5222 <int> -- Number of I/O TLB slabs
5223 force -- force using of bounce buffers even if they
5225 noforce -- Never use bounce buffers (for debugging)
5249 Ignore sysrq setting - this boot parameter will
5257 cache size. See Documentation/networking/ip-sysctl.rst
5263 Specify "mem" (for Suspend-to-RAM) or "standby" (for
5268 wakeup-capable RTC alarm.
5274 -1: disable all active trip points in all thermal zones
5278 -1: disable all critical trip points in all thermal zones
5289 -1: disable all passive trip points
5295 <deci-seconds>: poll all this frequency
5317 Prevent the CPU-hotplug component of torturing
5321 Dump the ftrace buffer at torture-test shutdown,
5325 with rotating-rust storage.
5341 trace_event=[event-list]
5343 to facilitate early boot debugging. The event-list is a
5347 trace_options=[option-list]
5348 [FTRACE] Enable or disable tracer options at boot.
5349 The option-list is a comma delimited list of options
5365 tracing ring buffer. This is useful for early boot up
5399 See Documentation/admin-guide/mm/transhuge.rst
5407 high-resolution timer mode on older hardware, and in
5433 on - Enable TSX on the system. Although there are
5436 several previous speculation-related CVEs, and
5440 off - Disable TSX on the system. (Note that this
5448 auto - Disable TSX if X86_BUG_TAA is present,
5453 See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
5459 Similar to Micro-architectural Data Sampling (MDS)
5474 full - Enable TAA mitigation on vulnerable CPUs
5477 full,nosmt - Enable TAA mitigation and disable SMT on
5480 vulnerable to cross-thread TAA attacks.
5481 off - Unconditionally disable TAA mitigation
5483 On MDS-affected machines, tsx_async_abort=off can be
5495 Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
5501 See also Documentation/input/devices/joystick-parport.rst
5503 udbg-immortal [PPC] When debugging early kernel crashes that
5505 console driver takes over, this boot options might
5509 Set number of hash buckets for UDP/UDP-Lite connections
5511 uhci-hcd.ignore_oc=
5513 Some badly-designed motherboards generate lots of
5524 (default -1 = authorized except for wireless USB,
5530 for newly-detected USB devices (default 2). This
5558 [USB] Specifies timeout for the initial 64-byte
5565 [USB] A list of quirk entries to augment the built-in
5568 VendorID:ProductID:Flags. The IDs are 4-digit hex
5570 will change the built-in quirk; setting it if it is
5575 a 255-byte read);
5579 Set-Interface requests);
5598 (bInterval-1).
5633 usb-storage.delay_use=
5637 usb-storage.quirks=
5639 override the built-in unusual_devs list. List
5642 and Product ID values (4-digit hex numbers) and
5644 to a common usb-storage quirk flag as follows:
5685 medium is write-protected).
5694 1 - undefined instruction events
5695 2 - system calls
5696 4 - invalid data aborts
5697 8 - SIGSEGV faults
5698 16 - SIGBUS faults
5714 vdso32= [X86] Control the 32-bit vDSO
5715 vdso32=1: enable 32-bit VDSO
5716 vdso32=0 or vdso32=2: disable 32-bit VDSO
5726 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
5728 vector= [IA-64,SMP]
5759 vga= [BOOT,X86-32] Select a particular video mode
5760 See Documentation/x86/boot.rst and
5761 Documentation/admin-guide/svga.rst.
5763 This is actually a boot loader parameter; the value is
5767 May slow down system boot speed, especially when
5776 - Disable all of the above options
5778 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
5797 vsyscall= [X86-64]
5800 code). Most statically-linked binaries and older
5824 see VGA-softcursor.txt. Default: 2 = underline.
5829 This is a 16-member array composed of values
5830 ranging from 0-255.
5835 This is a 16-member array composed of values
5836 ranging from 0-255.
5841 This is a 16-member array composed of values
5842 ranging from 0-255.
5847 Set system-wide default UTF-8 mode for all tty's.
5848 Default is 1, i.e. UTF-8 mode is enabled for all
5853 Format=<-1|0|1>
5854 Set system-wide default for whether a cursor
5855 is shown on new VTs. Default is -1,
5860 vt.italic= [VT] Default color for italic text; 0-15.
5863 vt.underline= [VT] Default color for underlined text; 0-15.
5867 see Documentation/watchdog/watchdog-parameters.rst
5868 or other driver-specific files in the
5894 that this also can be controlled per-workqueue for
5898 Per-cpu workqueues are generally preferred because
5900 locality; unfortunately, per-cpu workqueues tend to
5903 Enabling this makes the per-cpu workqueues which
5918 forces round-robin CPU selection to flush out
5923 x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
5927 x86_intel_mid_timer= [X86-32,APBT]
5933 xen_512gb_limit [KNL,X86-64,XEN]
5943 ide-disks -- unplug primary master IDE devices
5944 aux-ide-disks -- unplug non-primary-master IDE devices
5945 nics -- unplug network devices
5946 all -- unplug all emulated devices (NICs and IDE disks)
5947 unnecessary -- unplugging emulated devices is
5950 never -- do not unplug even if version check succeeds
5973 xen_timer_slop= [X86-64,XEN]
5991 preferred over the 2-level event handling, as it is
6018 xhci-hcd.quirks [USB,KNL]
6027 early Call xmon as early as possible on boot; xmon