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,riscv64]
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
116 Format: <byte> or <bitmap-list>
119 Disable auto-serialization of AML methods
122 auto-serialization feature.
130 Disable installation of static SSDTs at early boot time
140 Ignore the ACPI-based watchdog interface (WDAT) and let
145 on machines running EFI runtime service to boot the
161 acpi_osi=! # disable all built-in OS vendor
163 acpi_osi=!! # enable all built-in OS vendor
225 For broken nForce2 BIOS resulting in XT-PIC timer.
234 as soon as the kernel's real-mode entry point is called.
272 See Documentation/sound/alsa-configuration.rst
279 align_va_addr= [X86-64]
284 CPU-intensive style benchmark, and it can vary highly in
287 32: only for 32-bit processes
288 64: only for 64-bit processes
289 on: enable for both 32- and 64-bit processes
290 off: disable for both 32- and 64-bit processes
293 Allocate the ftrace snapshot buffer on boot up when the
295 and you need to use tracing_snapshot() on boot up, and
300 Allow execve() of 32-bit applications and setting of the
302 subset of the CPUs support 32-bit EL0. When this
303 parameter is present, the set of CPUs supporting 32-bit
305 and hot-unplug operations may be restricted.
307 See Documentation/arch/arm64/asymmetric-32bit.rst for more
310 amd_iommu= [HW,X86-64]
313 fullflush - Deprecated, equivalent to iommu.strict=1
314 off - do not initialize any AMD IOMMU found in
316 force_isolation - Force device isolation for all
321 force_enable - Force enable the IOMMU on platforms known
324 pgtbl_v1 - Use v1 page table for DMA-API (Default).
325 pgtbl_v2 - Use v2 page table for DMA-API.
326 irtcachedis - Disable Interrupt Remapping Table (IRT) caching.
328 amd_iommu_dump= [HW,X86-64]
334 amd_iommu_intr= [HW,X86-64]
337 legacy - Use legacy interrupt remapping mode.
338 vapic - Use virtual APIC mode, which allows IOMMU
340 This mode requires kvm-amd.avic=1.
377 Power management functions (SPARCstation-4/5 + deriv.)
379 Disable APC CPU standby support. SPARCstation-Fox does
380 not play well with APC CPU idle - disable it if you have
387 when initialising the APIC and IO-APIC components.
388 For X86-32, this can also be used to specify an APIC
408 apparmor= [APPARMOR] Disable or enable AppArmor at boot time
411 0 -- disable.
412 1 -- enable.
415 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
457 audit= [KNL] Enable the audit sub-system
459 0 | off - kernel audit is disabled and can not be
461 unset - kernel audit is initialized but disabled and
463 1 | on - kernel audit is initialized and partially
476 0 - Disable the BAU.
477 1 - Enable the BAU.
478 unset - Disable the BAU.
505 See Documentation/block/cmdline-partition.rst
507 boot_delay= Milliseconds to delay each printk during boot.
518 See Documentation/admin-guide/bootconfig.rst
523 bttv.pll= See Documentation/admin-guide/media/bttv.rst
532 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
551 inclusive. See arch/mips/include/asm/pgtable-bits.h
561 - foo isn't auto-mounted if you mount all cgroups in
563 - foo isn't visible as an individually mountable
565 - if foo is an optional feature then the feature is
571 Specifying "pressure" disables per-cgroup pressure
585 nosocket -- Disable socket memory accounting.
586 nokmem -- Disable kernel memory accounting.
587 nobpf -- Disable BPF memory accounting.
592 0 -- check protection applied by kernel (includes
594 1 -- check protection requested by application.
606 numbers X. Note the Linux-specific bits are not necessarily
607 stable over kernel options, but the vendor-specific
627 force such clocks to be always-on nor does it reserve
631 information, see Documentation/driver-api/clk.rst.
633 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
650 [X86-32] pit,hpet,tsc;
657 [X86-64] hpet,tsc
663 architected timer so that code using WFE-based polling
683 clocksource-wdtest.holdoff= [KNL]
689 cma=nn[MG]@[start[MG][-end[MG]]]
700 Sets the size of kernel per-numa memory area for
702 per-numa CMA altogether. And If this option is not
704 With per-numa CMA enabled, DMA users on node nid will
731 com20020= [HW,NET] ARCnet - COM20020 chipset
735 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
739 ARCnet - COM90xx chipset (memory-mapped buffers)
752 This leads to a much faster boot time when a 3270
768 See Documentation/admin-guide/serial-console.rst for more
778 Start an early, polled-mode console on the 8250/16550
781 MMIO inter-register address stride is either 8-bit
782 (mmio), 16-bit (mmio16), or 32-bit (mmio32).
786 the h/w is not re-initialized.
813 syscall, or to executing "dmesg -S --raw" or to reading
830 1: enable debugging at boot time
837 disable the cpuidle sub-system
843 disable the cpufreq sub-system
851 [X86] Delay for N microsec between assert and de-assert
853 on every CPU online, such as boot, and resume from suspend.
863 Run kdump after running panic-notifiers and dumping
876 [KNL, X86-64, ARM64, RISCV] Select a region under 4G first, and
879 See Documentation/admin-guide/kdump/kdump.rst for further details.
884 start-[end] where start and end are both
886 Documentation/admin-guide/kdump/kdump.rst for an example.
889 [KNL, X86-64, ARM64, RISCV] range could be above 4G.
896 [KNL, X86-64, ARM64, RISCV] range under 4G. When crashkernel=X,high
901 low memory is needed to make sure DMA buffers for 32-bit
905 --> x86: max(swiotlb_size_or_default() + 8MiB, 256MiB)
906 --> arm64: 128MiB
907 --> riscv: 128MiB
915 [KNL] Disable crypto self-tests
923 csdlock_debug= [KNL] Enable or disable debug add-ons of cross-CPU
938 See also Documentation/input/devices/joystick-parport.rst
944 boot sequence. If enabled, we use a weak hash instead
951 [KNL] verbose locking self-tests
954 self-tests.
956 (no extra messages), setting it to -1 (all bits set)
957 will print _a_lot_ more information - normally only
983 enables the feature at boot time. By default, it is
992 Format: { on, no-mount, off }
994 no-mount:
999 get a -EPERM as result when trying to register files
1003 Default value is set in build-time with a kernel configuration.
1015 Documentation/admin-guide/mm/hugetlbpage.rst.
1029 delayacct [KNL] Enable per-task delay accounting
1089 corresponding CPU to be disabled at boot,
1120 this option disables the debugging code at boot.
1124 entries for DMA-API debugging code. One entry is
1125 required per DMA-API allocation. Use this if the
1126 DMA-API debugging code disables itself because the
1130 With this option the DMA-API debugging driver
1131 filter feature can be enabled at boot time. Just
1154 Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst
1168 Generic built-in EDID data sets are used, if one of
1173 available in Documentation/admin-guide/edid.rst. An EDID
1185 Control how the dt_cpu_ftrs device-tree binding is
1195 what data is available or for reverse-engineering.
1199 Enable debug messages at boot time. See
1200 Documentation/admin-guide/dynamic-debug-howto.rst
1211 determined by stdout-path property in device tree's
1216 Start an early, polled-mode console on a Cadence
1227 Start an early, polled-mode console on the 8250/16550
1229 MMIO inter-register address stride is either 8-bit
1230 (mmio) or 32-bit (mmio32 or mmio32be).
1240 Start an early, polled-mode console on a pl011 serial
1244 the driver will use only 32-bit accessors to read/write
1253 Start an early, polled-mode console on a meson serial
1259 Start an early, polled-mode console on an msm serial
1265 Start an early, polled-mode console on an msm serial
1271 Start an early, polled-mode console on a serial port
1277 Start an early, polled-mode console on a serial port
1283 Use RISC-V SBI (Supervisor Binary Interface) for early
1301 Start an early, polled-mode console on a lantiq serial
1315 Start an early, polled-mode, output-only console on the
1320 Start an early, polled-mode console on the
1326 Start an early, polled-mode console on a Qualcomm
1334 coherent non-x86 systems that use system memory for
1405 PCI bridges while in the EFI boot stub.
1407 boot stub, as chunking can cause problems with some
1418 on all PCI bridges while in the EFI boot stub
1434 attribute is added to range 0x100000000-0x180000000 and
1435 0x10a0000000-0x1120000000.
1439 range 0x240000000-0x43fffffff.
1451 Documentation/admin-guide/acpi/ssdt-overlays.rst for details.
1461 the boot argument: earlyprintk=vga
1465 very early in the boot process. For early debugging
1468 elanfreq= [X86-32]
1476 See Documentation/admin-guide/kdump/kdump.rst for details.
1492 0 -- permissive (log only, no denials).
1493 1 -- enforcing (deny and log).
1512 stages so cover more early boot allocations.
1515 memory initialization is disabled) so the boot process
1525 See also Documentation/fault-injection/.
1529 See Documentation/admin-guide/sysctl/net.rst for
1533 See Documentation/admin-guide/blockdev/floppy.rst.
1536 [IA-64] Avoid check_sal_cache_flush which may hang on
1541 forcepae [X86-32]
1551 boot debugging.
1554 [FTRACE] On boot up, a snapshot will be taken of the
1558 boot up that is likely to be overridden by user space
1568 a snapshot at the end of boot up.
1577 ftrace_filter=[function-list]
1579 tracer at boot up. function-list is a comma-separated
1584 ftrace_notrace=[function-list]
1586 function-list. This list can be changed at run time
1590 ftrace_graph_filter=[function-list]
1592 by the function graph tracer at boot up.
1593 function-list is a comma-separated list of functions
1597 ftrace_graph_notrace=[function-list]
1599 function-list. This list is a comma-separated list of
1614 (suppliers first, then consumers), supplier boot state
1619 off -- Don't create device links from firmware info.
1620 permissive -- Create device links from firmware info
1621 but use it only for ordering boot state clean
1623 on -- Create device links from firmware info and use it
1625 rpm -- Like "on", but also use to order runtime PM.
1638 strict -- Default. Continue waiting on consumers to
1640 timeout -- Give up waiting on consumers and call
1650 See also Documentation/input/devices/joystick-parport.rst
1654 gart_fix_e820= [X86-64] disable the fix e820 for K8 GART
1678 gcov_persist= [GCOV] When non-zero (default), profiling data for
1688 gpio-mockup.gpio_mockup_ranges
1691 gpio-mockup.gpio_mockup_named_lines
1719 hardening is enabled for this boot. Hardened
1723 against bounds-checking flaws in the kernel's
1729 [KNL] Should the hard-lockup detector generate
1733 hashdist= [KNL,NUMA] Large hashes allocated during boot
1735 for 64-bit NUMA, off otherwise.
1738 hcl= [IA-64] SGI's Hardware Graph compatibility layer
1745 corresponding firmware-first mode error processing
1750 present during boot.
1755 during restoration read-only).
1757 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
1781 hpet= [X86-32,HPET] option to control HPET usage
1792 hugepages= [HW] Number of HugeTLB pages to allocate at boot.
1798 number of pages to allocate per-node can be specified.
1799 See also Documentation/admin-guide/mm/hugetlbpage.rst.
1806 pages of a specific size at boot. The pair
1810 Documentation/admin-guide/mm/hugetlbpage.rst.
1821 boot-time allocation of gigantic hugepages is skipped.
1849 by the CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time
1850 option. The value selected by this boot parameter can
1855 hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
1872 (disabled by default, and as a pre-condition
1874 i8042.direct [HW] Put keyboard port into non-translated mode
1888 suspend-to-ram transitions, only during s2r
1912 -1 -- never invert brightness
1913 0 -- machine default
1914 1 -- force brightness inversion
1928 idle=nomwait: Disable mwait for CPU C-states
1956 legacy only accept legacy-NaN binaries, if supported
1958 2008 only accept 2008-NaN binaries, if supported
1967 'relaxed' straps the emulator for both legacy-NaN and
1968 2008-NaN, whereas 'strict' enables legacy-NaN only on
1977 Ignore loglevel setting - this will print /all/
2044 Formats: { "ima" | "ima-ng" | "ima-ngv2" | "ima-sig" |
2045 "ima-sigv2" }
2046 Default: "ima-ng"
2078 initcall_blacklist= [KNL] Do not execute a comma-separated list of
2079 initcall functions. Useful for debugging built-in
2094 initrd= [BOOT] Specify the location of the initial ramdisk
2115 override in debugfs after boot.
2124 0 -- basic integrity auditing messages. (Default)
2125 1 -- additional integrity auditing messages.
2153 could harm performance of some high-throughput
2162 1 to 9 specify maximum depth of C-state.
2171 algorithms for p-state selection. There are two
2172 P-state selection algorithms provided by
2175 on whether or not the hardware managed P-states
2182 used along with the hardware-managed P-states (HWP)
2186 in favor of acpi-cpufreq. Forcing the intel_pstate driver
2187 instead of acpi-cpufreq may disable platform features, such
2189 P-States information being indicated to OSPM and therefore
2192 or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
2205 Allow per-logical-CPU P-State performance control limits using
2208 intremap= [X86-64, Intel-IOMMU]
2213 BIOS x2APIC opt-out request will be ignored
2237 0 - Try to allocate a 32-bit DMA address first, before
2239 1 - Allocate directly from the full usable range,
2241 greater than 32-bit addressing.
2245 0 - Lazy mode.
2251 1 - Strict mode.
2254 unset - Use value of CONFIG_IOMMU_DEFAULT_DMA_{LAZY,STRICT}.
2256 legacy driver-specific options takes precedence.
2261 0 - Use IOMMU translation for DMA.
2262 1 - Bypass the IOMMU for DMA.
2263 unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
2265 io7= [HW] IO7 for Marvel-based Alpha systems
2280 See Documentation/admin-guide/nfs/nfsroot.rst.
2304 Enables support for pseudo-NMIs in the kernel. This
2323 [Deprecated - use cpusets instead]
2324 Format: [flag-list,]<cpu-list>
2355 "number of CPUs in system - 1".
2381 The format of <cpu-list> is described above.
2385 ivrs_ioapic [HW,X86-64]
2386 Provide an override to the IOAPIC-ID<->DEVICE-ID
2390 For example, to map IOAPIC-ID decimal 10 to
2396 * To map IOAPIC-ID decimal 10 to PCI device 00:14.0
2399 * To map IOAPIC-ID decimal 10 to PCI segment 0x1 and
2403 ivrs_hpet [HW,X86-64]
2404 Provide an override to the HPET-ID<->DEVICE-ID
2408 For example, to map HPET-ID decimal 10 to
2414 * To map HPET-ID decimal 0 to PCI device 00:14.0
2417 * To map HPET-ID decimal 10 to PCI segment 0x1 and
2421 ivrs_acpihid [HW,X86-64]
2422 Provide an override to the ACPI-HID:UID<->DEVICE-ID
2426 For example, to map UART-HID:UID AMD0020:0 to
2432 * To map UART-HID:UID AMD0020:0 to PCI segment is 0,
2435 * To map UART-HID:UID AMD0020:0 to PCI segment 0x1 and
2449 Do not unregister boot console at start. This is only
2451 between unregistering the boot console and initializing
2456 kernelcore= [KNL,X86,IA-64,PPC]
2459 the kernel for non-movable allocations. The requested
2469 subsystem. Note that allocations like PTEs-from-HighMem
2477 for non-movable allocations and remaining memory is used
2488 gdb or control-c on the dbgp connection. When
2489 not using this parameter you use sysrq-g to break into
2494 or a supported polling keyboard driver (non-usb).
2503 If the boot console provides the ability to read
2514 blank and the first boot console that implements
2521 Configure the RouterBoard 532 series on-chip
2524 kmemleak= [KNL] Boot-time kmemleak enable/disable
2530 kprobe_event=[probe-list]
2531 [FTRACE] Add kprobe events and enable at boot time.
2532 The probe-list is a semicolon delimited list of probe
2541 Boot Parameter" section.
2562 execution by eliminating the write-protection faults
2591 auto : Deploy workaround based on the presence of
2594 Default is 'auto'.
2607 back to huge pages. If the value is a non-zero N, KVM will
2612 kvm-amd.nested= [KVM,AMD] Control nested virtualization feature in
2615 kvm-amd.npt= [KVM,AMD] Control KVM's use of Nested Page Tables,
2616 a.k.a. Two-Dimensional Page Tables. Default is 1
2620 kvm-arm.mode=
2625 nvhe: Standard nVHE-based mode, without support for
2628 protected: nVHE-based mode with support for guests whose
2631 nested: VHE-based mode with support for nested
2640 kvm-arm.vgic_v3_group0_trap=
2641 [KVM,ARM] Trap guest accesses to GICv3 group-0
2644 kvm-arm.vgic_v3_group1_trap=
2645 [KVM,ARM] Trap guest accesses to GICv3 group-1
2648 kvm-arm.vgic_v3_common_trap=
2652 kvm-arm.vgic_v4_enable=
2664 kvm-intel.ept= [KVM,Intel] Control KVM's use of Extended Page Tables,
2665 a.k.a. Two-Dimensional Page Tables. Default is 1
2669 kvm-intel.emulate_invalid_guest_state=
2671 state. Ignored if kvm-intel.enable_unrestricted_guest=1,
2677 kvm-intel.flexpriority=
2682 kvm-intel.nested=
2686 kvm-intel.unrestricted_guest=
2692 kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
2693 CVE-2018-3620.
2704 kvm-intel.vpid= [KVM,Intel] Control KVM's use of Virtual Processor
2724 on - enable the interface for the mitigation
2740 boot. Hypervisors will issue a warning
2758 boot. Hypervisors will issue a warning
2770 boot. Hypervisors will issue a warning
2789 For details see: Documentation/admin-guide/hw-vuln/l1tf.rst
2795 lapic [X86-32,APIC] Enable the local APIC even if BIOS
2799 value for LAPIC timer one-shot implementation. Default
2822 libata.force= [LIBATA] Force configurations. The format is a comma-
2834 first fan-out link behind PMP device. It does not
2848 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
2855 * rstonce: only attempt one reset during hot-unplug
2937 Set the number of locking read-acquisition kthreads.
2942 Set the number of locking write-acquisition kthreads.
2945 Set time (s) after boot for CPU-hotplug testing.
2948 Set time (s) between CPU-hotplug operations, or
2949 zero to disable CPU-hotplug testing.
2952 Set task-shuffle interval (jiffies). Shuffling
2953 tasks allows some CPUs to go into dyntick-idle
2957 Set time (s) after boot system shutdown. This
2958 is useful for hands-off automated testing.
2974 Run the write-side locktorture kthreads at
2975 sched_set_fifo() real-time priority.
2995 7 (KERN_DEBUG) debug-level messages
3005 logo.nologo [FB] Disables display of the built-in Linux logo.
3008 kernel boot problems.
3013 lp=auto printer driver. 'lp=reset' (which can be
3020 'parport0'. Specifying 'lp=auto' instead of a
3023 an IEEE 1284-compliant printer is attached; if
3029 time-consuming boot-time autodetection (up to 250 ms per
3031 the correct value for your kernel, boot with normal
3050 machvec= [IA-64] Force the use of a particular machine-vector
3056 Example: machtype=lemote-yeeloong-2f-7inch
3058 max_addr=nn[KMG] [KNL,BOOT,IA-64] All physical memory greater
3071 (loop.max_loop) unconditionally pre-created at init time. The default
3074 devices can be requested on-demand with the
3075 /dev/loop-control interface.
3077 mce [X86-32] Machine Check Exception
3079 mce=option [X86-64] See Documentation/arch/x86/x86_64/boot-options.rst
3082 See Documentation/admin-guide/md.rst.
3089 Control mitigation for the Micro-architectural Data
3104 full - Enable MDS mitigation on vulnerable CPUs
3105 full,nosmt - Enable MDS mitigation and disable
3107 off - Unconditionally disable MDS mitigation
3109 On TAA-affected machines, mds=off can be prevented by
3118 For details see: Documentation/admin-guide/hw-vuln/mds.rst
3123 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
3132 [ARC,MICROBLAZE] - the limit applies only to low memory,
3135 [ARM64] - only limits memory covered by the linear
3143 Note that this only takes effects during boot time since
3144 in above case 3, memory may need be hot added after boot
3148 [ARM,MIPS] - override the memory layout reported by
3155 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
3162 per-device physically contiguous DMA buffers.
3170 See Documentation/admin-guide/mm/memory-hotplug.rst.
3195 Example: Exclude memory from 0x18690000-0x1869ffff
3209 memmap=<size>%<offset>-<oldtype>+<newtype>
3211 from <oldtype> to <newtype>. If "-<oldtype>" is left
3226 repeatable BIOS-originated corruption always
3270 mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control
3278 Refer to Documentation/virt/kvm/x86/amd-memory-encryption.rst
3282 s2idle - Suspend-To-Idle
3283 shallow - Power-On Suspend or equivalent (if supported)
3284 deep - Suspend-To-RAM or equivalent (if supported)
3285 See Documentation/admin-guide/pm/sleep-states.rst.
3287 mfgpt_irq= [IA-32] Specify the IRQ to use for the
3288 Multi-Function General Purpose Timers on AMD Geode
3291 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
3298 min_addr=nn[KMG] [KNL,BOOT,IA-64] All physical memory below this
3305 0 - The attached screen is the 3.5" TFT
3306 1 - The attached screen is the 7" TFT
3307 2 - The VGA Shield is attached (1024x768)
3311 b - Enable backlight. The TFT backlight pin will be
3315 c - Enable the s3c camera interface.
3316 t - Reserved for enabling touchscreen support. The
3320 https://repo.or.cz/w/linux-2.6/mini2440.git
3325 arch-independent options, each of which is an
3326 aggregation of existing arch-specific options.
3350 ssbd=force-off [ARM64]
3358 auto (default)
3363 have other ways of avoiding SMT-based attacks.
3366 auto,nosmt
3374 retbleed=auto,nosmt [X86]
3398 full - Enable mitigation on vulnerable CPUs
3400 full,nosmt - Enable mitigation and disable SMT on
3403 off - Unconditionally disable mitigation
3416 Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst
3446 module_blacklist= [KNL] Do not load a comma-separated list of
3460 movablecore= [KNL,X86,IA-64,PPC]
3471 movable_node [KNL] Boot-time switch to make hotplugable memory
3478 Format: <name>,<region-number>,<size>,<offset>
3481 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
3487 ARM/S3C2412 JIVE boot control
3489 See arch/arm/mach-s3c/mach-jive.c
3497 registers at boot time.
3525 something different and driver-specific.
3558 [NFS] enable 64-bit inode numbers.
3559 If zero, the NFS client will fake up a 32-bit inode
3561 of returning the full 64-bit number.
3562 The default is to return 64-bit inode numbers.
3597 [NFS4] Specify an additional fixed unique ident-
3628 driver. A non-zero value sets the minimum interval
3633 server-to-server copies for which this server is
3645 server-to-server copy, knfsd temporarily mounts
3652 See Documentation/admin-guide/nfs/nfsroot.rst.
3654 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
3655 See Documentation/admin-guide/nfs/nfsroot.rst.
3658 See Documentation/admin-guide/nfs/nfsroot.rst.
3662 NMI stack-backtrace request.
3671 0 - turn hardlockup detector in nmi_watchdog off
3672 1 - turn hardlockup detector in nmi_watchdog on
3684 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
3688 no4lvl [RISCV] Disable 4-level and 5-level paging modes. Forces
3689 kernel to use 3-level paging instead.
3691 no5lvl [X86-64,RISCV] Disable 5-level paging mode. Forces
3692 kernel to use 4-level paging instead.
3695 caches in the slab allocator. Saves per-node memory,
3728 nodsp [SH] Disable hardware DSP at boot time.
3732 no_entry_flush [PPC] Don't flush the L1-D cache when entering the kernel.
3734 noexec [IA-64]
3736 noexec32 [X86-64]
3737 This affects only 32-bit executables.
3738 noexec32=on: enable non-executable mappings (default)
3740 noexec32=off: disable non-executable mappings
3747 nofpu [MIPS,SH] Disable hardware FPU at boot time.
3751 nofxsr [BUGS=X86-32] Disables x86 floating point extended
3753 legacy floating-point registers on task switch.
3755 nohalt [IA-64] Tells the kernel not to use the power saving
3757 power-consumption. On the positive side, it reduces
3758 interrupt wake-up latency, which may improve performance
3760 real-time systems.
3770 compared. However, if this command-line option is
3795 nohz_full= [KNL,BOOT,SMP,ISOL]
3799 whenever possible. The boot CPU will be forced outside
3803 rcu_nocbs= boot parameter.
3811 nointremap [X86-64, Intel-IOMMU] Do not enable interrupt
3813 [Deprecated - use intremap=off]
3815 nointroute [IA-64]
3821 noirqdebug [X86-32] Disables the code which attempts to detect and
3826 nojitter [IA-64] Disables jitter checking for ITC timers.
3833 no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page
3836 no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
3838 nolapic [X86-32,APIC] Do not enable or use the local APIC.
3840 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
3842 nomca [IA-64] Disable machine check abort handling
3844 nomce [X86-32] Disable Machine Check Exception
3846 nomfgpt [X86-32] Disable Multi-Function General Purpose
3852 not load if they could possibly displace the pre-
3855 perform display-mode changes or accelerated rendering.
3868 nopcid [X86-64] Disable the PCID cpu feature.
3873 nopti [X86-64]
3889 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
3895 nosbagart [IA-64]
3897 no-scroll [VGA] Disables scrollback.
3898 This is required for the Braillex ib80-piezo Braille
3901 nosgx [X86-64,SGX] Disables Intel SGX kernel support.
3921 nosoftlockup [KNL] Disable the soft-lockup detector.
3926 nospectre_bhb [ARM64] Disable all mitigations for Spectre-BHB (branch
3939 no-steal-acc [X86,PV_OPS,ARM64,PPC/PSERIES] Disable paravirtualized
3949 [PPC] Don't flush the L1-D cache after accessing user data.
3962 no-vmw-sched-clock
3967 soft-lockup and NMI watchdog (hard-lockup).
3971 nox2apic [X86-64,APIC] Do not enable x2APIC mode.
3979 enabling legacy floating-point and sse state.
4005 nptcg= [IA-64] Override max number of concurrent global TLB
4014 n. So during boot up some boot time memory for per-cpu
4015 variables need be pre-allocated for later physical cpu
4027 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
4029 This can be set from sysctl after boot.
4030 See Documentation/admin-guide/sysctl/vm.rst for details.
4033 See Documentation/core-api/debugging-via-ohci1394.rst for more
4048 onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
4052 boundary - index of last SLC block on Flex-OneNAND.
4054 lock - Configure if Flex-OneNAND boundary should be locked.
4068 running on a platform with a direct-mapped memory-side
4074 page_owner= [KNL] Boot-time page_owner enabling option.
4080 page_poison= [KNL] Boot-time parameter changing the state of
4107 See Documentation/admin-guide/tainted-kernels.rst for
4136 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
4137 Use 'auto' to force the driver to use any
4142 should be numbers, or 'auto' (for using detected
4159 Set to non-zero to probe primary and secondary ISA
4165 Set to non-zero if a chip is present that snoops speed
4213 Set to non-zero to probe tertiary and further ISA
4229 Set to non-zero to probe QDI controllers. By default
4234 Set to non-zero to probe Winbond controllers. Use
4281 bios [X86-32] force use of PCI BIOS, don't access
4283 has a non-standard PCI host bridge.
4284 nobios [X86-32] disallow use of PCI BIOS, only direct
4290 data in IO port 0xCFC, both 32-bit).
4292 Mechanism 2 (IO port 0xCF8 is an 8-bit port for
4293 the function, IO port 0xCFA, also 8-bit, sets
4295 through ports 0xC000-0xCFFF).
4299 enabled, this kernel boot option can be used to
4302 root domains (aka PCI segments, in ACPI-speak).
4309 enabled, this kernel boot option can be used to
4310 disable the use of MSI interrupts system-wide.
4311 noioapicquirk [APIC] Disable all boot interrupt quirks.
4312 Safety option to keep boot IRQs enabled. This
4314 ioapicreroute [APIC] Enable rerouting of boot IRQs to the
4315 primary IO-APIC for bridges that cannot disable
4316 boot IRQs. This fixes a source of spurious IRQs
4319 boot IRQ equivalent of an IRQ that connects to
4320 a chipset where boot IRQs cannot be disabled.
4322 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
4346 F0000h-100000h range.
4351 assign-busses [X86] Always assign all PCI bus
4372 <linux-pci@vger.kernel.org>.
4376 a bug to <linux-pci@vger.kernel.org>.
4388 bfsort Sort PCI devices into breadth-first order.
4391 nobfsort Don't sort PCI devices into breadth-first order.
4393 tuning and use the BIOS-configured MPS defaults.
4403 configuration allows peer-to-peer DMA between
4406 that hot-added devices will work.
4421 A PCI-PCI bridge can be specified if resource
4427 for 4096-byte alignment.
4429 end-to-end CRC checking). Only effective if
4460 noats [PCIE, Intel-IOMMU, AMD-IOMMU]
4496 dpc-native Use native PCIe service for DPC only. May
4513 Keep all power-domains already enabled by bootloader on,
4519 boot time.
4530 pirq= [SMP,APIC] Manual mp-table setup
4531 See Documentation/arch/x86/i386/IO-APIC.rst.
4535 See also Documentation/admin-guide/parport.rst.
4550 Enable suspend/resume debug messages during boot up.
4554 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
4563 { on | off | curr | res | no-curr | no-res }
4603 none - Limited to cond_resched() calls
4604 voluntary - Limited to cond_resched() and might_sleep() calls
4605 full - Any section that isn't explicitly preempt disabled
4608 print-fatal-signals=
4614 coredump - etc.
4617 you might want to try "ulimit -i unlimited".
4629 or lockdep-detected issues (only if lock debug is on).
4638 on - unlimited logging to /dev/kmsg from userspace
4639 off - logging to /dev/kmsg disabled
4640 ratelimit - ratelimit the logging
4647 Limit processor to maximum C-state
4651 Ignore the _CST method to determine C-states,
4658 Param: "schedule" - profile schedule points.
4659 Param: "sleep" - profile D-state sleeping (millisecs).
4661 Param: "kvm" - profile VM exits.
4662 Param: <number> - step/bucket size as a power of 2 for
4691 pti= [X86-64] Control Page Table Isolation of user and
4696 on - unconditionally enable
4697 off - unconditionally disable
4698 auto - kernel detects whether your CPU model is
4701 Not specifying this option is equivalent to pti=auto.
4704 [KNL] Number of legacy pty's. Overwrites compiled-in
4716 See Documentation/admin-guide/md.rst.
4719 See Documentation/admin-guide/blockdev/ramdisk.rst.
4738 cross-syscall address exposures. This is only
4744 ras=option[,option,...] [KNL] RAS-specific options
4750 rcu_nocbs[=cpu-list]
4755 enable the no-callback CPU mode, which prevents
4760 "p" for RCU-preempt, "s" for RCU-sched, and "g"
4764 and real-time workloads. It can also improve
4768 list of CPUs is set to no-callback mode from boot.
4772 no-callback mode from boot but the mode may be
4783 This improves the real-time response for the
4795 out at early boot. This is used for diagnostic
4800 RCU grace-period cleanup.
4804 RCU grace-period initialization.
4808 RCU grace-period pre-initialization, that is,
4809 the propagation of recent CPU-hotplug changes up
4813 Set delay from grace-period initialization to
4826 soliciting quiescent-state help from
4837 rcutree.kthread_prio= [KNL,BOOT]
4838 Set the SCHED_FIFO priority of the RCU per-CPU
4841 and for the RCU grace-period kthreads (rcu_bh,
4843 set, valid values are 1-99 and the default is 1
4844 (the least-favored priority). Otherwise, when
4845 RCU_BOOST is not set, valid values are 0-99 and
4846 the default is zero (non-realtime operation).
4851 On callback-offloaded (rcu_nocbs) CPUs,
4854 use of the ->nocb_bypass list. However, in the
4855 common non-flooded case, RCU queues directly to
4856 the main ->cblist in order to avoid the extra
4857 overhead of the ->nocb_bypass list and its lock.
4859 a single jiffy, RCU pre-queues the callbacks into
4860 the ->nocb_bypass queue. The definition of "too
4861 many" is supplied by this kernel boot parameter.
4869 batch limiting is re-enabled.
4873 RCU's force-quiescent-state scan will aggressively
4877 on rcutree.qhimark at boot time and to zero to
4881 Set the page-cache refill delay (in milliseconds)
4882 in response to low-memory conditions. The range
4886 Set the shift-right count to use to compute
4887 the callback-invocation batch limit bl from
4894 Please note that this callback-invocation batch
4895 limit applies only to non-offloaded callback
4904 cache-to-cache transfer latencies.
4910 and for NUMA systems with large remote-access
4926 the wakeup overhead on the global grace-period
4928 each group's NOCB grace-period kthread.
4931 Cause the grace-period kthread to get an extra
4933 it should at force-quiescent-state time.
4946 this specifies an rcu_read_unlock()-time delay
4950 of RCU-protected pointers after the relevant
4960 per-CPU rcuc kthreads. Defaults to a non-zero
4965 this kernel boot parameter, forcibly setting it
4970 grace-period primitives such as call_rcu().
4981 grace-period primitives.
4984 Set test-start holdoff period. The purpose of
4986 test until boot completes in order to avoid
5002 Test the double-argument variant of kfree_rcu().
5004 rcuscale.kfree_rcu_test_single, both the single-
5005 and double-argument variants are tested.
5008 Test the single-argument variant of kfree_rcu().
5010 rcuscale.kfree_rcu_test_double, both the single-
5011 and double-argument variants are tested.
5025 does not affect the data-collection interval,
5030 Set number of RCU readers. The value -1 selects
5032 "n" less than -1 selects N-n+1, where N is again
5033 the number of CPUs. For example, -2 selects N
5034 (the number of CPUs), -3 selects N+1, and so on.
5035 A value of "n" less than or equal to -N selects
5048 complete. This is useful for hands-off automated
5055 Write-side holdoff between grace periods,
5060 Additional write-side holdoff between grace
5078 for RCU grace-period forward-progress testing
5085 Specify the fraction of a CPU-stall-warning
5086 period to do tight-loop forward-progress testing.
5090 forward-progress tests.
5094 need_resched() during tight-loop forward-progress
5098 Use conditional/asynchronous update-side
5102 Use expedited update-side primitives, if available.
5105 Use normal (non-expedited) asynchronous
5106 update-side primitives, if available.
5109 Use normal (non-expedited) synchronous
5110 update-side primitives, if available. If all
5114 they are all non-zero.
5122 Leak an RCU-protected pointer out of the reader.
5137 Set number of RCU callback-offload togglers.
5142 callback-offload toggling attempts.
5145 Set number of RCU readers. The value -1 selects
5146 N-1, where N is the number of CPUs. A value
5147 "n" less than -1 selects N-n-2, where N is again
5148 the number of CPUs. For example, -2 selects N
5149 (the number of CPUs), -3 selects N+1, and so on.
5152 Enable debug-object double-call_rcu() testing.
5155 Set time (s) after boot for CPU-hotplug testing.
5158 Set time (jiffies) between CPU-hotplug operations,
5159 or zero to disable CPU-hotplug testing.
5162 Set the number of read-then-exit kthreads used
5164 task-exit processing.
5167 The number of times in a given read-then-exit
5168 episode that a set of read-then-exit kthreads
5173 read-then-exit testing episodes.
5176 Set task-shuffle interval (s). Shuffling tasks
5177 allows some CPUs to go into dyntick-idle mode
5181 Set time (s) after boot system shutdown. This
5182 is useful for hands-off automated testing.
5191 any other stall-related activity. Note that
5197 in scheduling-while-atomic splats.
5203 Time to wait (s) after boot before inducing stall.
5210 grace-period kthread to test RCU CPU stall
5236 Test RCU's dyntick-idle handling. See also the
5255 during early boot, that is, during the time
5285 Use expedited grace-period primitives, for
5289 real-time latency, and degrade energy efficiency.
5293 Use only normal grace-period primitives,
5296 real-time latency, CPU utilization, and
5298 increased grace-period latency. This parameter
5303 Once boot has completed (that is, after
5305 only normal grace-period primitives. No effect
5309 this kernel boot parameter, forcibly setting
5311 post-boot attempt at an expedited RCU grace
5312 period to instead use normal non-expedited
5313 grace-period processing.
5321 set to the default value of -1.
5324 Set the minimum number of callback-queuing-time
5325 lock-contention events per jiffy required to
5326 cause the RCU Tasks flavors to switch to per-CPU
5329 the default value of -1.
5334 of -1 allows this to be automatically (and
5342 number avoids disturbing real-time workloads,
5347 cancel laziness on that CPU. Use -1 to disable
5357 only printed prior to the stall-warning message
5405 Run the RCU early boot self tests
5413 force - Override the decision by the kernel to hide the
5441 Set test-start holdoff period. The purpose of
5443 test until boot completes in order to avoid
5450 but the default has already reduced the per-pass
5455 Set number of readers. The default value of -1
5464 Set the read-side critical-section duration,
5468 Specify the read-protection implementation to test.
5487 See Documentation/admin-guide/cgroup-v1/cpusets.rst.
5495 reservetop= [X86-32]
5512 See Documentation/power/swsusp-and-swap-files.rst
5527 AMD-based UNRET and IBPB mitigations alone do not stop
5529 sibling threads. For that reason, STIBP is used on pro-
5533 off - no mitigation
5534 auto - automatically select a migitation
5535 auto,nosmt - automatically select a mitigation,
5539 ibpb - On AMD, mitigate short speculation
5544 ibpb,nosmt - Like "ibpb" above but will disable SMT
5548 unret - Force enable untrained return thunks,
5549 only effective on AMD f15h-f17h based
5551 unret,nosmt - Like unret, but will disable SMT when STIBP
5555 Selecting 'auto' will choose a mitigation method at run
5558 Not specifying this option is equivalent to retbleed=auto.
5586 ro [KNL] Mount root device read-only on boot
5589 on Mark read-only kernel memory as read-only (default).
5590 off Leave read-only kernel memory writable for debugging.
5591 full Mark read-only kernel memory and aliases as read-only
5597 debug-uart get routed to the D+ and D- pins of the usb
5603 block/early-lookup.c for details.
5628 rw [KNL] Mount root device read-write on boot
5680 to 10 seconds for built-in smp_call_function()
5687 that requesting even small non-zero numbers of
5694 The default of -1 specifies a number of kthreads
5699 test before initiating CPU-hotplug operations.
5703 CPU-hotplug operations. Specifying zero (which
5704 is the default) disables CPU-hotplug operations.
5710 Non-zero values are useful for automated tests.
5733 "wait" parameter. A value of -1 selects the
5734 default if all other weights are -1. However,
5736 value of -1 will instead select a weight of zero.
5741 non-zero "wait" parameter. See weight_single.
5754 non-zero "wait" parameter. See weight_single
5766 non-zero "wait" parameter. See weight_single
5773 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
5774 1 -- enable.
5779 enable at boot. This has been deprecated by the
5782 selinux= [SELINUX] Disable or enable SELinux at boot time.
5785 0 -- disable.
5786 1 -- enable.
5789 serialnumber [BUGS=X86-32]
5791 sev=option[,option...] [X86-64] See Documentation/arch/x86/x86_64/boot-options.rst
5799 to set it to "all" by meaning -- no limit here.
5805 simeth= [IA-64]
5880 using the csdlock_debug- kernel parameter.
5885 system. By default, let CSD-lock acquisition
5887 for this value provides a 5-minute timeout.
5889 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
5890 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
5891 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
5892 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
5893 smsc-ircc2.ircc_irq= [HW] IRQ line
5894 smsc-ircc2.ircc_dma= [HW] DMA channel
5895 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
5905 Default: -1 (no limit)
5908 [KNL] Should the soft-lockup detector generate panics.
5911 A value of 1 instructs the soft-lockup detector
5912 to panic the machine when a soft-lockup occurs. It is
5915 respective build-time switch to that functionality.
5918 [KNL] Should the soft-lockup detector generate
5923 See Documentation/admin-guide/laptops/sonypi.rst
5930 on - unconditionally enable, implies
5932 off - unconditionally disable, implies
5934 auto - kernel detects whether your CPU model is
5937 Selecting 'on' will, and 'auto' may, choose a
5951 retpoline - replace indirect branches
5952 retpoline,generic - Retpolines
5953 retpoline,lfence - LFENCE; indirect branch
5954 retpoline,amd - alias for retpoline,lfence
5955 eibrs - Enhanced/Auto IBRS
5956 eibrs,retpoline - Enhanced/Auto IBRS + Retpolines
5957 eibrs,lfence - Enhanced/Auto IBRS + LFENCE
5958 ibrs - use IBRS to protect kernel
5961 spectre_v2=auto.
5968 on - Unconditionally enable mitigations. Is
5971 off - Unconditionally disable mitigations. Is
5974 prctl - Indirect branch speculation is enabled,
5980 - Like "prctl" above, but only STIBP is
5986 - Same as "prctl" above, but all seccomp
5991 - Like "seccomp" above, but only STIBP is
5996 auto - Kernel selects the mitigation depending on
6002 spectre_v2_user=auto.
6007 off - Disable mitigation
6008 microcode - Enable microcode mitigation only
6009 safe-ret - Enable sw-only safe RET mitigation (default)
6010 ibpb - Enable mitigation by issuing IBPB on
6012 ibpb-vmexit - Issue IBPB only on VMEXIT
6013 (cloud-specific mitigation)
6038 on - Unconditionally disable Speculative Store Bypass
6039 off - Unconditionally enable Speculative Store Bypass
6040 auto - Kernel detects whether the CPU model contains an
6046 prctl - Control Speculative Store Bypass per thread
6050 seccomp - Same as "prctl" above, but all seccomp threads
6058 on,auto - On Power8 and Power9 insert a store-forwarding
6062 off - No action.
6065 spec_store_bypass_disable=auto.
6081 off - not enabled
6083 warn - the kernel will emit rate-limited warnings
6091 fatal - the kernel will send SIGBUS to applications
6096 ratelimit:N -
6116 Certain CPUs are vulnerable to an MDS-like
6136 This kernel-boot parameter defaults to 128,
6137 but takes effect only when the low-order four
6139 (decide at boot).
6149 3: Decide at boot time (default).
6154 instead of the compile-time CONFIG_NR_CPUS.
6158 grace-period sequence counter wrap for the
6159 srcu_data structure's ->srcu_gp_seq_needed field.
6174 Specifies the number of no-delay instances
6181 Specifies the per-grace-period phase, number of
6182 non-sleeping polls of readers. Beyond this limit,
6188 Specifies number of microseconds of non-sleeping
6189 delay between each non-sleeping poll of readers.
6192 Specifies the number of update-side contention
6197 set for contention-based conversions to occur.
6207 force-on: Unconditionally enable mitigation for
6209 force-off: Unconditionally disable mitigation for
6230 Enabled the stack tracer on boot up.
6232 stacktrace_filter=[function-list]
6234 will trace at boot up. function-list is a comma-separated
6242 Set the STI (builtin display/keyboard on the HP-PARISC
6244 as the initial boot-console.
6299 auto the server chooses an appropriate mode
6304 to global on non-NUMA machines)
6327 swiotlb= [ARM,IA-64,PPC,MIPS,X86]
6329 <int> -- Number of I/O TLB slabs
6330 <int> -- Second integer after comma. Number of swiotlb
6333 force -- force using of bounce buffers even if they
6335 noforce -- Never use bounce buffers (for debugging)
6350 Ignore sysrq setting - this boot parameter will
6358 cache size. See Documentation/networking/ip-sysctl.rst
6365 Specify "mem" (for Suspend-to-RAM) or "standby" (for
6370 wakeup-capable RTC alarm.
6376 -1: disable all active trip points in all thermal zones
6380 -1: disable all critical trip points in all thermal zones
6387 -1: disable all passive trip points
6393 <deci-seconds>: poll all this frequency
6415 Prevent the CPU-hotplug component of torturing
6419 Dump the ftrace buffer at torture-test shutdown,
6423 with rotating-rust storage.
6428 disables verbose-printk() sleeping.
6431 Duration of each verbose-printk() sleep in jiffies.
6449 https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/
6453 tracing ring buffer. This is useful for early boot up
6476 printing of events during boot up, as user space may
6486 at boot up.
6487 local - Use the per CPU time stamp counter
6491 global - Event time stamps are synchronize across
6494 counter - Simple counting of events (1, 2, ..)
6498 uptime - Use jiffies as the time stamp.
6499 perf - Use the same clock that perf uses.
6500 mono - Use ktime_get_mono_fast_ns() for time stamps.
6501 mono_raw - Use ktime_get_raw_fast_ns() for time
6503 boot - Use ktime_get_boot_fast_ns() for time stamps.
6507 trace_event=[event-list]
6509 to facilitate early boot debugging. The event-list is a
6510 comma-separated list of trace events to enable. See
6513 trace_instance=[instance-info]
6514 [FTRACE] Create a ring buffer instance early in boot up.
6533 trace_options=[option-list]
6534 [FTRACE] Enable or disable tracer options at boot.
6535 The option-list is a comma delimited list of options
6549 trace_trigger=[trigger-list]
6586 See Documentation/admin-guide/mm/transhuge.rst
6594 - "tpm"
6595 - "tee"
6596 - "caam"
6606 - "kernel"
6607 - the same value as trusted.source: "tpm" or "tee"
6608 - "default"
6617 high-resolution timer mode on older hardware, and in
6653 on - Enable TSX on the system. Although there are
6656 several previous speculation-related CVEs, and
6660 off - Disable TSX on the system. (Note that this
6668 auto - Disable TSX if X86_BUG_TAA is present,
6673 See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
6679 Similar to Micro-architectural Data Sampling (MDS)
6694 full - Enable TAA mitigation on vulnerable CPUs
6697 full,nosmt - Enable TAA mitigation and disable SMT on
6700 vulnerable to cross-thread TAA attacks.
6701 off - Unconditionally disable TAA mitigation
6703 On MDS-affected machines, tsx_async_abort=off can be
6715 Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
6721 See also Documentation/input/devices/joystick-parport.rst
6723 udbg-immortal [PPC] When debugging early kernel crashes that
6725 console driver takes over, this boot options might
6729 Set number of hash buckets for UDP/UDP-Lite connections
6731 uhci-hcd.ignore_oc=
6733 Some badly-designed motherboards generate lots of
6742 unwind_debug [X86-64]
6750 (default -1 = authorized (same as 1),
6756 for newly-detected USB devices (default 2). This
6784 [USB] Specifies timeout for the initial 64-byte
6791 [USB] A list of quirk entries to augment the built-in
6794 VendorID:ProductID:Flags. The IDs are 4-digit hex
6796 will change the built-in quirk; setting it if it is
6801 a 255-byte read);
6805 Set-Interface requests);
6824 (bInterval-1).
6859 usb-storage.delay_use=
6863 usb-storage.quirks=
6865 override the built-in unusual_devs list. List
6868 and Product ID values (4-digit hex numbers) and
6870 to a common usb-storage quirk flag as follows:
6912 medium is write-protected).
6921 1 - undefined instruction events
6922 2 - system calls
6923 4 - invalid data aborts
6924 8 - SIGSEGV faults
6925 16 - SIGBUS faults
6941 vdso32= [X86] Control the 32-bit vDSO
6942 vdso32=1: enable 32-bit VDSO
6943 vdso32=0 or vdso32=2: disable 32-bit VDSO
6953 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
6955 vector= [IA-64,SMP]
6987 vga= [BOOT,X86-32] Select a particular video mode
6988 See Documentation/arch/x86/boot.rst and
6989 Documentation/admin-guide/svga.rst.
6991 This is actually a boot loader parameter; the value is
6995 May slow down system boot speed, especially when
7004 - Disable all of the above options
7006 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
7025 vsyscall= [X86-64]
7028 code). Most statically-linked binaries and older
7052 see VGA-softcursor.txt. Default: 2 = underline.
7057 This is a 16-member array composed of values
7058 ranging from 0-255.
7063 This is a 16-member array composed of values
7064 ranging from 0-255.
7069 This is a 16-member array composed of values
7070 ranging from 0-255.
7075 Set system-wide default UTF-8 mode for all tty's.
7076 Default is 1, i.e. UTF-8 mode is enabled for all
7081 Format=<-1|0|1>
7082 Set system-wide default for whether a cursor
7083 is shown on new VTs. Default is -1,
7088 vt.italic= [VT] Default color for italic text; 0-15.
7091 vt.underline= [VT] Default color for underlined text; 0-15.
7095 see Documentation/watchdog/watchdog-parameters.rst
7096 or other driver-specific files in the
7110 Format: <cpu-list>
7124 Per-cpu work items which run for longer than this
7127 them from noticeably delaying other per-cpu work
7136 Per-cpu workqueues are generally preferred because
7138 locality; unfortunately, per-cpu workqueues tend to
7141 Enabling this makes the per-cpu workqueues which
7155 Documentation/core-api/workqueue.rst.
7157 This can be changed after boot by writing to the
7168 forces round-robin CPU selection to flush out
7176 on - Enable writecombine, use WUC for ioremap_wc()
7177 off - Disable writecombine, use SUC for ioremap_wc()
7179 x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
7183 xen_512gb_limit [KNL,X86-64,XEN]
7193 ide-disks -- unplug primary master IDE devices
7194 aux-ide-disks -- unplug non-primary-master IDE devices
7195 nics -- unplug network devices
7196 all -- unplug all emulated devices (NICs and IDE disks)
7197 unnecessary -- unplugging emulated devices is
7200 never -- do not unplug even if version check succeeds
7208 Select whether to always use non-faulting (safe) MSR
7233 xen_timer_slop= [X86-64,XEN]
7241 The time (in seconds) to wait before giving up to boot
7258 preferred over the 2-level event handling, as it is
7275 xive.store-eoi=off [PPC]
7281 xhci-hcd.quirks [USB,KNL]
7290 early Call xmon as early as possible on boot; xmon