Lines Matching +full:use +full:- +full:advanced +full:- +full:sector +full:- +full:protection
2 Advanced Configuration and Power Interface
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
20 2: use 2nd APIC table, if available
21 1,0: use 1st APIC table
26 If set to vendor, prefer vendor-specific driver
29 If set to video, use the ACPI video.ko driver.
30 If set to native, use the device's native backlight mode.
34 force FADT to use 32 bit addresses rather than the
36 bit addresses for force ACPI ignore these and use
58 Documentation/firmware-guide/acpi/debug.rst for more information about
106 use by PCI
116 Format: <byte> or <bitmap-list>
119 Disable auto-serialization of AML methods
122 auto-serialization feature.
140 Ignore the ACPI-based watchdog interface (WDAT) and let
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.
256 suspend and resume to be ignored (use wisely).
259 Use timer override. For some broken Nvidia NF5 boards
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
295 and you need to use tracing_snapshot() on boot up, and
296 do not want to use tracing_snapshot_alloc() as it needs
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
322 to be buggy with IOMMU enabled. Use this
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.
348 Use amd_pstate with passive mode as a scaling driver.
354 Use amd_pstate_epp driver instance as the scaling driver,
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
383 apic= [APIC,X86] Advanced Programmable Interrupt Controller
387 when initialising the APIC and IO-APIC components.
388 For X86-32, this can also be used to specify an APIC
405 apm= [APM] Advanced Power Management
411 0 -- disable.
412 1 -- enable.
415 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
455 Use software keyboard repeat
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
518 See Documentation/admin-guide/bootconfig.rst
523 bttv.pll= See Documentation/admin-guide/media/bttv.rst
526 bulk_remove=off [PPC] This parameter disables the use of the pSeries
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
593 any implied execute protection).
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.
642 Override the default clocksource and use the clocksource
650 [X86-32] pit,hpet,tsc;
657 [X86-64] hpet,tsc
663 architected timer so that code using WFE-based polling
677 clocksource-wdtest.holdoff= [KNL]
683 cma=nn[MG]@[start[MG][-end[MG]]]
694 Sets the size of kernel per-numa memory area for
696 per-numa CMA altogether. And If this option is not
698 With per-numa CMA enabled, DMA users on node nid will
725 com20020= [HW,NET] ARCnet - COM20020 chipset
729 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
733 ARCnet - COM90xx chipset (memory-mapped buffers)
752 tty<n> Use the virtual console device <n>.
756 Use the specified serial port. The options are of
762 See Documentation/admin-guide/serial-console.rst for more
772 Start an early, polled-mode console on the 8250/16550
775 MMIO inter-register address stride is either 8-bit
776 (mmio), 16-bit (mmio16), or 32-bit (mmio32).
780 the h/w is not re-initialized.
782 hvc<n> Use the hypervisor console device <n>. This is for
786 Use to disable console output, i.e., to have kernel
807 syscall, or to executing "dmesg -S --raw" or to reading
831 disable the cpuidle sub-system
834 [CPU_IDLE] Name of the cpuidle governor to use.
837 disable the cpufreq sub-system
841 policy to use. This governor must be registered in the
845 [X86] Delay for N microsec between assert and de-assert
857 Run kdump after running panic-notifiers and dumping
870 [KNL, X86-64, ARM64, RISCV] Select a region under 4G first, and
873 See Documentation/admin-guide/kdump/kdump.rst for further details.
878 start-[end] where start and end are both
880 Documentation/admin-guide/kdump/kdump.rst for an example.
883 [KNL, X86-64, ARM64, RISCV] range could be above 4G.
890 [KNL, X86-64, ARM64, RISCV] range under 4G. When crashkernel=X,high
895 low memory is needed to make sure DMA buffers for 32-bit
899 --> x86: max(swiotlb_size_or_default() + 8MiB, 256MiB)
900 --> arm64: 128MiB
901 --> riscv: 128MiB
909 [KNL] Disable crypto self-tests
917 csdlock_debug= [KNL] Enable or disable debug add-ons of cross-CPU
932 See also Documentation/input/devices/joystick-parport.rst
938 boot sequence. If enabled, we use a weak hash instead
939 of siphash to hash pointers. Use this option if you are
942 insecure, please do not use on production kernels.
945 [KNL] verbose locking self-tests
948 self-tests.
950 (no extra messages), setting it to -1 (all bits set)
951 will print _a_lot_ more information - normally only
962 amount of memory for normal system use. The maximum
986 Format: { on, no-mount, off }
988 no-mount:
993 get a -EPERM as result when trying to register files
997 Default value is set in build-time with a kernel configuration.
1009 Documentation/admin-guide/mm/hugetlbpage.rst.
1023 delayacct [KNL] Enable per-task delay accounting
1065 Disables the use of 1TB hash page table segments. This
1090 Disable Dynamic DMA Window support. Use this
1118 entries for DMA-API debugging code. One entry is
1119 required per DMA-API allocation. Use this if the
1120 DMA-API debugging code disables itself because the
1124 With this option the DMA-API debugging driver
1148 Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst
1162 Generic built-in EDID data sets are used, if one of
1167 available in Documentation/admin-guide/edid.rst. An EDID
1170 name. Each connector may use a unique EDID data
1179 Control how the dt_cpu_ftrs device-tree binding is
1182 off: Do not use it, fall back to legacy cpu table.
1189 what data is available or for reverse-engineering.
1194 Documentation/admin-guide/dynamic-debug-howto.rst
1205 determined by stdout-path property in device tree's
1210 Start an early, polled-mode console on a Cadence
1221 Start an early, polled-mode console on the 8250/16550
1223 MMIO inter-register address stride is either 8-bit
1224 (mmio) or 32-bit (mmio32 or mmio32be).
1234 Start an early, polled-mode console on a pl011 serial
1238 the driver will use only 32-bit accessors to read/write
1247 Start an early, polled-mode console on a meson serial
1253 Start an early, polled-mode console on an msm serial
1259 Start an early, polled-mode console on an msm serial
1265 Start an early, polled-mode console on a serial port
1271 Start an early, polled-mode console on a serial port
1277 Use RISC-V SBI (Supervisor Binary Interface) for early
1280 smh Use ARM semihosting calls for early console.
1288 Use early console provided by serial driver available
1295 Start an early, polled-mode console on a lantiq serial
1302 Use early console provided by Freescale LP UART driver
1309 Start an early, polled-mode, output-only console on the
1314 Start an early, polled-mode console on the
1320 Start an early, polled-mode console on a Qualcomm
1328 coherent non-x86 systems that use system memory for
1333 Use early console provided by Freescale LINFlexD UART
1378 The optional "force" to "pciserial" enables use of a
1387 force: enforce the use of EDAC to report H/W event.
1415 Using this parameter you can use more than 50% of
1416 your efi variable storage. Use this parameter only if
1428 attribute is added to range 0x100000000-0x180000000 and
1429 0x10a0000000-0x1120000000.
1433 range 0x240000000-0x43fffffff.
1445 Documentation/admin-guide/acpi/ssdt-overlays.rst for details.
1462 elanfreq= [X86-32]
1470 See Documentation/admin-guide/kdump/kdump.rst for details.
1486 0 -- permissive (log only, no denials).
1487 1 -- enforcing (deny and log).
1519 See also Documentation/fault-injection/.
1523 See Documentation/admin-guide/sysctl/net.rst for
1527 See Documentation/admin-guide/blockdev/floppy.rst.
1530 [IA-64] Avoid check_sal_cache_flush which may hang on
1535 forcepae [X86-32]
1539 Warning: use of this parameter will taint the kernel
1571 ftrace_filter=[function-list]
1573 tracer at boot up. function-list is a comma-separated
1578 ftrace_notrace=[function-list]
1580 function-list. This list can be changed at run time
1584 ftrace_graph_filter=[function-list]
1587 function-list is a comma-separated list of functions
1591 ftrace_graph_notrace=[function-list]
1593 function-list. This list is a comma-separated list of
1613 off -- Don't create device links from firmware info.
1614 permissive -- Create device links from firmware info
1615 but use it only for ordering boot state clean
1617 on -- Create device links from firmware info and use it
1619 rpm -- Like "on", but also use to order runtime PM.
1632 strict -- Default. Continue waiting on consumers to
1634 timeout -- Give up waiting on consumers and call
1644 See also Documentation/input/devices/joystick-parport.rst
1648 gart_fix_e820= [X86-64] disable the fix e820 for K8 GART
1672 gcov_persist= [GCOV] When non-zero (default), profiling data for
1679 Don't use this when you are not running on the
1682 gpio-mockup.gpio_mockup_ranges
1685 gpio-mockup.gpio_mockup_named_lines
1701 grcan.select= [HW] Select which physical interface to use.
1717 against bounds-checking flaws in the kernel's
1723 [KNL] Should the hard-lockup detector generate
1729 for 64-bit NUMA, off otherwise.
1732 hcl= [IA-64] SGI's Hardware Graph compatibility layer
1739 corresponding firmware-first mode error processing
1747 protect_image Turn on image protection during restoration
1749 during restoration read-only).
1775 hpet= [X86-32,HPET] option to control HPET usage
1778 disable: disable HPET and use PIT instead
1792 number of pages to allocate per-node can be specified.
1793 See also Documentation/admin-guide/mm/hugetlbpage.rst.
1804 Documentation/admin-guide/mm/hugetlbpage.rst.
1815 boot-time allocation of gigantic hugepages is skipped.
1843 by the CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time
1849 hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
1866 (disabled by default, and as a pre-condition
1868 i8042.direct [HW] Put keyboard port into non-translated mode
1878 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
1882 suspend-to-ram transitions, only during s2r
1906 -1 -- never invert brightness
1907 0 -- machine default
1908 1 -- force brightness inversion
1918 will use a lot of power and make the system run hot.
1922 idle=nomwait: Disable mwait for CPU C-states
1950 legacy only accept legacy-NaN binaries, if supported
1952 2008 only accept 2008-NaN binaries, if supported
1961 'relaxed' straps the emulator for both legacy-NaN and
1962 2008-NaN, whereas 'strict' enables legacy-NaN only on
1971 Ignore loglevel setting - this will print /all/
1989 ima_appraise_tcb [IMA] Deprecated. Use ima_policy= instead.
1994 Use the canonical format for the binary runtime
2030 ima_tcb [IMA] Deprecated. Use ima_policy= instead.
2038 Formats: { "ima" | "ima-ng" | "ima-ngv2" | "ima-sig" |
2039 "ima-sigv2" }
2040 Default: "ima-ng"
2072 initcall_blacklist= [KNL] Do not execute a comma-separated list of
2073 initcall functions. Useful for debugging built-in
2106 init_pkru= [X86] Specify the default memory protection keys rights
2118 0 -- basic integrity auditing messages. (Default)
2119 1 -- additional integrity auditing messages.
2130 this case, gfx device will use physical address for
2143 Disallow use of the Intel IOMMU scalable mode.
2147 could harm performance of some high-throughput
2156 1 to 9 specify maximum depth of C-state.
2163 Use intel_pstate driver to bypass the scaling
2165 algorithms for p-state selection. There are two
2166 P-state selection algorithms provided by
2169 on whether or not the hardware managed P-states
2173 Use intel_pstate as a scaling driver, but configure it
2176 used along with the hardware-managed P-states (HWP)
2180 in favor of acpi-cpufreq. Forcing the intel_pstate driver
2181 instead of acpi-cpufreq may disable platform features, such
2183 P-States information being indicated to OSPM and therefore
2186 or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
2199 Allow per-logical-CPU P-State performance control limits using
2202 intremap= [X86-64, Intel-IOMMU]
2207 BIOS x2APIC opt-out request will be ignored
2231 0 - Try to allocate a 32-bit DMA address first, before
2233 1 - Allocate directly from the full usable range,
2235 greater than 32-bit addressing.
2239 0 - Lazy mode.
2240 Request that DMA unmap operations use deferred
2245 1 - Strict mode.
2248 unset - Use value of CONFIG_IOMMU_DEFAULT_DMA_{LAZY,STRICT}.
2250 legacy driver-specific options takes precedence.
2255 0 - Use IOMMU translation for DMA.
2256 1 - Bypass the IOMMU for DMA.
2257 unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
2259 io7= [HW] IO7 for Marvel-based Alpha systems
2274 See Documentation/admin-guide/nfs/nfsroot.rst.
2293 that use the kernel as a bootloader, and thus want
2298 Enables support for pseudo-NMIs in the kernel. This
2317 [Deprecated - use cpusets instead]
2318 Format: [flag-list,]<cpu-list>
2341 advised to use cpusets instead to disable scheduler load
2349 "number of CPUs in system - 1".
2375 The format of <cpu-list> is described above.
2379 ivrs_ioapic [HW,X86-64]
2380 Provide an override to the IOAPIC-ID<->DEVICE-ID
2384 For example, to map IOAPIC-ID decimal 10 to
2390 * To map IOAPIC-ID decimal 10 to PCI device 00:14.0
2393 * To map IOAPIC-ID decimal 10 to PCI segment 0x1 and
2397 ivrs_hpet [HW,X86-64]
2398 Provide an override to the HPET-ID<->DEVICE-ID
2402 For example, to map HPET-ID decimal 10 to
2408 * To map HPET-ID decimal 0 to PCI device 00:14.0
2411 * To map HPET-ID decimal 10 to PCI segment 0x1 and
2415 ivrs_acpihid [HW,X86-64]
2416 Provide an override to the ACPI-HID:UID<->DEVICE-ID
2420 For example, to map UART-HID:UID AMD0020:0 to
2426 * To map UART-HID:UID AMD0020:0 to PCI segment is 0,
2429 * To map UART-HID:UID AMD0020:0 to PCI segment 0x1 and
2450 kernelcore= [KNL,X86,IA-64,PPC]
2453 the kernel for non-movable allocations. The requested
2463 subsystem. Note that allocations like PTEs-from-HighMem
2464 still use the HighMem zone if it exists, and the Normal
2471 for non-movable allocations and remaining memory is used
2482 gdb or control-c on the dbgp connection. When
2483 not using this parameter you use sysrq-g to break into
2488 or a supported polling keyboard driver (non-usb).
2498 characters and can work in polling mode, you can use
2499 this parameter to tell kgdb to use it as a backend
2515 Configure the RouterBoard 532 series on-chip
2518 kmemleak= [KNL] Boot-time kmemleak enable/disable
2524 kprobe_event=[probe-list]
2526 The probe-list is a semicolon delimited list of probe
2556 execution by eliminating the write-protection faults
2601 back to huge pages. If the value is a non-zero N, KVM will
2606 kvm-amd.nested= [KVM,AMD] Control nested virtualization feature in
2609 kvm-amd.npt= [KVM,AMD] Control KVM's use of Nested Page Tables,
2610 a.k.a. Two-Dimensional Page Tables. Default is 1
2614 kvm-arm.mode=
2619 nvhe: Standard nVHE-based mode, without support for
2622 protected: nVHE-based mode with support for guests whose
2625 nested: VHE-based mode with support for nested
2634 kvm-arm.vgic_v3_group0_trap=
2635 [KVM,ARM] Trap guest accesses to GICv3 group-0
2638 kvm-arm.vgic_v3_group1_trap=
2639 [KVM,ARM] Trap guest accesses to GICv3 group-1
2642 kvm-arm.vgic_v3_common_trap=
2646 kvm-arm.vgic_v4_enable=
2647 [KVM,ARM] Allow use of GICv4 for direct injection of
2658 kvm-intel.ept= [KVM,Intel] Control KVM's use of Extended Page Tables,
2659 a.k.a. Two-Dimensional Page Tables. Default is 1
2663 kvm-intel.emulate_invalid_guest_state=
2665 state. Ignored if kvm-intel.enable_unrestricted_guest=1,
2671 kvm-intel.flexpriority=
2672 [KVM,Intel] Control KVM's use of FlexPriority feature
2676 kvm-intel.nested=
2680 kvm-intel.unrestricted_guest=
2681 [KVM,Intel] Control KVM's use of unrestricted guest
2686 kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
2687 CVE-2018-3620.
2698 kvm-intel.vpid= [KVM,Intel] Control KVM's use of Virtual Processor
2718 on - enable the interface for the mitigation
2723 The kernel PTE inversion protection is unconditionally
2783 For details see: Documentation/admin-guide/hw-vuln/l1tf.rst
2789 lapic [X86-32,APIC] Enable the local APIC even if BIOS
2792 lapic= [X86,APIC] Do not use TSC deadline
2793 value for LAPIC timer one-shot implementation. Default
2812 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
2816 libata.force= [LIBATA] Force configurations. The format is a comma-
2828 first fan-out link behind PMP device. It does not
2842 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
2849 * rstonce: only attempt one reset during hot-unplug
2872 * atapi_mod16_dma: Enable the use of ATAPI DMA for
2875 * [no]dmalog: Enable or disable the use of the
2931 Set the number of locking read-acquisition kthreads.
2936 Set the number of locking write-acquisition kthreads.
2939 Set time (s) after boot for CPU-hotplug testing.
2942 Set time (s) between CPU-hotplug operations, or
2943 zero to disable CPU-hotplug testing.
2946 Set task-shuffle interval (jiffies). Shuffling
2947 tasks allows some CPUs to go into dyntick-idle
2952 is useful for hands-off automated testing.
2968 Run the write-side locktorture kthreads at
2969 sched_set_fifo() real-time priority.
2989 7 (KERN_DEBUG) debug-level messages
2999 logo.nologo [FB] Disables display of the built-in Linux logo.
3004 lp=0 [LP] Specify parallel ports to use, e.g,
3017 an IEEE 1284-compliant printer is attached; if
3023 time-consuming boot-time autodetection (up to 250 ms per
3044 machvec= [IA-64] Force the use of a particular machine-vector
3050 Example: machtype=lemote-yeeloong-2f-7inch
3052 max_addr=nn[KMG] [KNL,BOOT,IA-64] All physical memory greater
3065 (loop.max_loop) unconditionally pre-created at init time. The default
3068 devices can be requested on-demand with the
3069 /dev/loop-control interface.
3071 mce [X86-32] Machine Check Exception
3073 mce=option [X86-64] See Documentation/arch/x86/x86_64/boot-options.rst
3076 See Documentation/admin-guide/md.rst.
3083 Control mitigation for the Micro-architectural Data
3098 full - Enable MDS mitigation on vulnerable CPUs
3099 full,nosmt - Enable MDS mitigation and disable
3101 off - Unconditionally disable MDS mitigation
3103 On TAA-affected machines, mds=off can be prevented by
3112 For details see: Documentation/admin-guide/hw-vuln/mds.rst
3126 [ARC,MICROBLAZE] - the limit applies only to low memory,
3129 [ARM64] - only limits memory covered by the linear
3132 [X86] Work as limiting max address. Use together
3142 [ARM,MIPS] - override the memory layout reported by
3149 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
3156 per-device physically contiguous DMA buffers.
3164 See Documentation/admin-guide/mm/memory-hotplug.rst.
3189 Example: Exclude memory from 0x18690000-0x1869ffff
3203 memmap=<size>%<offset>-<oldtype>+<newtype>
3205 from <oldtype> to <newtype>. If "-<oldtype>" is left
3220 repeatable BIOS-originated corruption always
3221 affects the same memory, you can use memmap=
3227 use. Use this parameter to scan for
3232 seconds. Use this parameter to check at some
3264 mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control
3270 Refer to Documentation/virt/kvm/x86/amd-memory-encryption.rst
3274 s2idle - Suspend-To-Idle
3275 shallow - Power-On Suspend or equivalent (if supported)
3276 deep - Suspend-To-RAM or equivalent (if supported)
3277 See Documentation/admin-guide/pm/sleep-states.rst.
3282 mfgpt_irq= [IA-32] Specify the IRQ to use for the
3283 Multi-Function General Purpose Timers on AMD Geode
3286 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
3293 min_addr=nn[KMG] [KNL,BOOT,IA-64] All physical memory below this
3300 0 - The attached screen is the 3.5" TFT
3301 1 - The attached screen is the 7" TFT
3302 2 - The VGA Shield is attached (1024x768)
3306 b - Enable backlight. The TFT backlight pin will be
3310 c - Enable the s3c camera interface.
3311 t - Reserved for enabling touchscreen support. The
3315 https://repo.or.cz/w/linux-2.6/mini2440.git
3320 arch-independent options, each of which is an
3321 aggregation of existing arch-specific options.
3349 ssbd=force-off [ARM64]
3362 have other ways of avoiding SMT-based attacks.
3397 full - Enable mitigation on vulnerable CPUs
3399 full,nosmt - Enable mitigation and disable SMT on
3402 off - Unconditionally disable mitigation
3415 Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst
3425 [KNL] When set to true, modules will use async probing
3427 specific module, use the module specific control that
3445 module_blacklist= [KNL] Do not load a comma-separated list of
3459 movablecore= [KNL,X86,IA-64,PPC]
3470 movable_node [KNL] Boot-time switch to make hotplugable memory
3474 allocations. Use with caution!
3477 Format: <name>,<region-number>,<size>,<offset>
3480 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
3488 See arch/arm/mach-s3c/mach-jive.c
3491 [HW] Make the MicroTouch USB driver use raw coordinates
3515 multitce=off [PPC] This parameter disables the use of the pSeries
3524 something different and driver-specific.
3557 [NFS] enable 64-bit inode numbers.
3558 If zero, the NFS client will fake up a 32-bit inode
3560 of returning the full 64-bit number.
3561 The default is to return 64-bit inode numbers.
3585 scheme and the NFS level operations agree to use
3596 [NFS4] Specify an additional fixed unique ident-
3625 Setting this to value to 0 causes the kernel to use
3627 driver. A non-zero value sets the minimum interval
3632 server-to-server copies for which this server is
3644 server-to-server copy, knfsd temporarily mounts
3650 nfsaddrs= [NFS] Deprecated. Use ip= instead.
3651 See Documentation/admin-guide/nfs/nfsroot.rst.
3653 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
3654 See Documentation/admin-guide/nfs/nfsroot.rst.
3657 See Documentation/admin-guide/nfs/nfsroot.rst.
3661 NMI stack-backtrace request.
3670 0 - turn hardlockup detector in nmi_watchdog off
3671 1 - turn hardlockup detector in nmi_watchdog on
3677 This is useful when you use a panic=... timeout and
3683 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
3687 no4lvl [RISCV] Disable 4-level and 5-level paging modes. Forces
3688 kernel to use 3-level paging instead.
3690 no5lvl [X86-64,RISCV] Disable 5-level paging mode. Forces
3691 kernel to use 4-level paging instead.
3694 caches in the slab allocator. Saves per-node memory,
3702 noapic [SMP,APIC] Tells the kernel to not make use of any
3720 it. Users could use console_suspend (usually
3731 no_entry_flush [PPC] Don't flush the L1-D cache when entering the kernel.
3733 noexec [IA-64]
3735 noexec32 [X86-64]
3736 This affects only 32-bit executables.
3737 noexec32=on: enable non-executable mappings (default)
3739 noexec32=off: disable non-executable mappings
3750 nofxsr [BUGS=X86-32] Disables x86 floating point extended
3752 legacy floating-point registers on task switch.
3754 nohalt [IA-64] Tells the kernel not to use the power saving
3756 power-consumption. On the positive side, it reduces
3757 interrupt wake-up latency, which may improve performance
3759 real-time systems.
3769 compared. However, if this command-line option is
3772 debugging the kernel. Please do not use on production
3778 busy wait in do_idle() and not use the arch_cpu_idle()
3810 nointremap [X86-64, Intel-IOMMU] Do not enable interrupt
3812 [Deprecated - use intremap=off]
3814 nointroute [IA-64]
3820 noirqdebug [X86-32] Disables the code which attempts to detect and
3825 nojitter [IA-64] Disables jitter checking for ITC timers.
3832 no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page
3835 no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
3837 nolapic [X86-32,APIC] Do not enable or use the local APIC.
3839 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
3841 nomca [IA-64] Disable machine check abort handling
3843 nomce [X86-32] Disable Machine Check Exception
3845 nomfgpt [X86-32] Disable Multi-Function General Purpose
3851 not load if they could possibly displace the pre-
3853 be available for use. The respective drivers will not
3854 perform display-mode changes or accelerated rendering.
3861 shutdown the other cpus. Instead use the REBOOT_VECTOR
3867 nopcid [X86-64] Disable the PCID cpu feature.
3869 nopku [X86] Disable Memory Protection Keys CPU feature found
3872 nopti [X86-64]
3885 norandmaps Don't use address space randomization. Equivalent to
3888 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
3894 nosbagart [IA-64]
3896 no-scroll [VGA] Disables scrollback.
3897 This is required for the Braillex ib80-piezo Braille
3900 nosgx [X86-64,SGX] Disables Intel SGX kernel support.
3920 nosoftlockup [KNL] Disable the soft-lockup detector.
3925 nospectre_bhb [ARM64] Disable all mitigations for Spectre-BHB (branch
3938 no-steal-acc [X86,PV_OPS,ARM64,PPC/PSERIES] Disable paravirtualized
3948 [PPC] Don't flush the L1-D cache after accessing user data.
3961 no-vmw-sched-clock
3963 clock and use the default one.
3966 soft-lockup and NMI watchdog (hard-lockup).
3970 nox2apic [X86-64,APIC] Do not enable x2APIC mode.
3978 enabling legacy floating-point and sse state.
3981 register states. The kernel will fall back to use
3989 form of xsave area. The kernel will fall back to use
4004 nptcg= [IA-64] Override max number of concurrent global TLB
4013 n. So during boot up some boot time memory for per-cpu
4014 variables need be pre-allocated for later physical cpu
4029 See Documentation/admin-guide/sysctl/vm.rst for details.
4032 See Documentation/core-api/debugging-via-ohci1394.rst for more
4047 onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
4051 boundary - index of last SLC block on Flex-OneNAND.
4053 lock - Configure if Flex-OneNAND boundary should be locked.
4067 running on a platform with a direct-mapped memory-side
4073 page_owner= [KNL] Boot-time page_owner enabling option.
4079 page_poison= [KNL] Boot-time parameter changing the state of
4106 See Documentation/admin-guide/tainted-kernels.rst for
4124 Use this option carefully, maybe worth to setup a
4136 Use 'auto' to force the driver to use any
4158 Set to non-zero to probe primary and secondary ISA
4164 Set to non-zero if a chip is present that snoops speed
4187 bus and the use of other driver options may interfere
4206 bits to allow the use of the respective PIO modes.
4212 Set to non-zero to probe tertiary and further ISA
4218 platform configuration and the use of other driver
4228 Set to non-zero to probe QDI controllers. By default
4233 Set to non-zero to probe Winbond controllers. Use
4235 value given is the I/O port to use (typically 0x1b0).
4242 the use of the respective PIO modes. Bit 0 is for
4280 bios [X86-32] force use of PCI BIOS, don't access
4281 the hardware directly. Use this if your machine
4282 has a non-standard PCI host bridge.
4283 nobios [X86-32] disallow use of PCI BIOS, only direct
4284 hardware access methods are allowed. Use this
4287 conf1 [X86] Force use of PCI Configuration Access
4289 data in IO port 0xCFC, both 32-bit).
4290 conf2 [X86] Force use of PCI Configuration Access
4291 Mechanism 2 (IO port 0xCF8 is an 8-bit port for
4292 the function, IO port 0xCFA, also 8-bit, sets
4294 through ports 0xC000-0xCFFF).
4299 disable the use of PCIE advanced error reporting.
4301 root domains (aka PCI segments, in ACPI-speak).
4302 nommconf [X86] Disable use of MMCONFIG for PCI
4309 disable the use of MSI interrupts system-wide.
4314 primary IO-APIC for bridges that cannot disable
4321 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
4330 Use with caution as certain devices share
4345 F0000h-100000h range.
4350 assign-busses [X86] Always assign all PCI bus
4359 noacpi [X86] Do not use ACPI for IRQ routing
4361 use_crs [X86] Use PCI host bridge window information
4363 is enabled by default. If you need to use this,
4366 If you need to use this, please report a bug.
4367 use_e820 [X86] Use E820 reservations to exclude parts of
4370 If you need to use this, please report a bug to
4371 <linux-pci@vger.kernel.org>.
4374 hardware. If you need to use this, please report
4375 a bug to <linux-pci@vger.kernel.org>.
4387 bfsort Sort PCI devices into breadth-first order.
4390 nobfsort Don't sort PCI devices into breadth-first order.
4392 tuning and use the BIOS-configured MPS defaults.
4402 configuration allows peer-to-peer DMA between
4405 that hot-added devices will work.
4420 A PCI-PCI bridge can be specified if resource
4426 for 4096-byte alignment.
4428 end-to-end CRC checking). Only effective if
4431 bios: Use BIOS/firmware settings. This is the
4458 noari do not use PCIe ARI.
4459 noats [PCIE, Intel-IOMMU, AMD-IOMMU]
4460 do not use PCIe ATS (and IOMMU device IOTLB).
4480 nomio [S390] Do not use MIO instructions.
4481 norid [S390] ignore the RID field and force use of
4491 native Use native PCIe services (PME, AER, DPC, PCIe hotplug)
4493 use them. This may cause conflicts if the platform
4494 also tries to use these services.
4495 dpc-native Use native PCIe service for DPC only. May
4505 nomsi Do not use MSI for native PCIe PME signaling (this makes
4506 all PCIe root ports use INTx for all services).
4512 Keep all power-domains already enabled by bootloader on,
4522 percpu_alloc= Select which percpu first chunk allocator to use.
4529 pirq= [SMP,APIC] Manual mp-table setup
4530 See Documentation/arch/x86/i386/IO-APIC.rst.
4534 See also Documentation/admin-guide/parport.rst.
4553 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
4562 { on | off | curr | res | no-curr | no-res }
4602 none - Limited to cond_resched() calls
4603 voluntary - Limited to cond_resched() and might_sleep() calls
4604 full - Any section that isn't explicitly preempt disabled
4607 print-fatal-signals=
4613 coredump - etc.
4616 you might want to try "ulimit -i unlimited".
4628 or lockdep-detected issues (only if lock debug is on).
4637 on - unlimited logging to /dev/kmsg from userspace
4638 off - logging to /dev/kmsg disabled
4639 ratelimit - ratelimit the logging
4650 - 'always': traditional behavior always allows mem overrides.
4651 - 'ptrace': only allow mem overrides for active ptracers.
4652 - 'never': never allow mem overrides.
4656 Limit processor to maximum C-state
4660 Ignore the _CST method to determine C-states,
4667 Param: "schedule" - profile schedule points.
4668 Param: "kvm" - profile VM exits.
4669 Param: <number> - step/bucket size as a power of 2 for
4696 pstore.backend= Specify the name of the pstore backend to use
4698 pti= [X86-64] Control Page Table Isolation of user and
4703 on - unconditionally enable
4704 off - unconditionally disable
4705 auto - kernel detects whether your CPU model is
4711 [KNL] Number of legacy pty's. Overwrites compiled-in
4719 Disable RADIX GTSE feature and use hcall for TLB
4723 See Documentation/admin-guide/md.rst.
4726 See Documentation/admin-guide/blockdev/ramdisk.rst.
4731 [KNL] Disable trusting the use of the CPU's
4736 [KNL] Disable trusting the use of the a seed
4745 cross-syscall address exposures. This is only
4751 ras=option[,option,...] [KNL] RAS-specific options
4757 rcu_nocbs[=cpu-list]
4762 enable the no-callback CPU mode, which prevents
4767 "p" for RCU-preempt, "s" for RCU-sched, and "g"
4771 and real-time workloads. It can also improve
4775 list of CPUs is set to no-callback mode from boot.
4779 no-callback mode from boot but the mode may be
4790 This improves the real-time response for the
4807 RCU grace-period cleanup.
4811 RCU grace-period initialization.
4815 RCU grace-period pre-initialization, that is,
4816 the propagation of recent CPU-hotplug changes up
4820 Set delay from grace-period initialization to
4833 soliciting quiescent-state help from
4845 Set the SCHED_FIFO priority of the RCU per-CPU
4848 and for the RCU grace-period kthreads (rcu_bh,
4850 set, valid values are 1-99 and the default is 1
4851 (the least-favored priority). Otherwise, when
4852 RCU_BOOST is not set, valid values are 0-99 and
4853 the default is zero (non-realtime operation).
4858 On callback-offloaded (rcu_nocbs) CPUs,
4861 use of the ->nocb_bypass list. However, in the
4862 common non-flooded case, RCU queues directly to
4863 the main ->cblist in order to avoid the extra
4864 overhead of the ->nocb_bypass list and its lock.
4866 a single jiffy, RCU pre-queues the callbacks into
4867 the ->nocb_bypass queue. The definition of "too
4876 batch limiting is re-enabled.
4880 RCU's force-quiescent-state scan will aggressively
4888 Set the page-cache refill delay (in milliseconds)
4889 in response to low-memory conditions. The range
4893 Set the shift-right count to use to compute
4894 the callback-invocation batch limit bl from
4901 Please note that this callback-invocation batch
4902 limit applies only to non-offloaded callback
4911 cache-to-cache transfer latencies.
4917 and for NUMA systems with large remote-access
4933 the wakeup overhead on the global grace-period
4935 each group's NOCB grace-period kthread.
4938 Cause the grace-period kthread to get an extra
4940 it should at force-quiescent-state time.
4953 this specifies an rcu_read_unlock()-time delay
4956 catching RCU pointer leaks, that is, buggy use
4957 of RCU-protected pointers after the relevant
4967 per-CPU rcuc kthreads. Defaults to a non-zero
4969 Specify rcutree.use_softirq=0 to use rcuc kthreads.
4977 grace-period primitives such as call_rcu().
4988 grace-period primitives.
4991 Set test-start holdoff period. The purpose of
5009 Test the double-argument variant of kfree_rcu().
5011 rcuscale.kfree_rcu_test_single, both the single-
5012 and double-argument variants are tested.
5015 Test the single-argument variant of kfree_rcu().
5017 rcuscale.kfree_rcu_test_double, both the single-
5018 and double-argument variants are tested.
5032 does not affect the data-collection interval,
5037 Set number of RCU readers. The value -1 selects
5039 "n" less than -1 selects N-n+1, where N is again
5040 the number of CPUs. For example, -2 selects N
5041 (the number of CPUs), -3 selects N+1, and so on.
5042 A value of "n" less than or equal to -N selects
5055 complete. This is useful for hands-off automated
5062 Write-side holdoff between grace periods,
5067 Additional write-side holdoff between grace
5085 for RCU grace-period forward-progress testing
5092 Specify the fraction of a CPU-stall-warning
5093 period to do tight-loop forward-progress testing.
5097 forward-progress tests.
5101 need_resched() during tight-loop forward-progress
5105 Use conditional/asynchronous update-side
5109 Use expedited update-side primitives, if available.
5112 Use normal (non-expedited) asynchronous
5113 update-side primitives, if available.
5116 Use normal (non-expedited) synchronous
5117 update-side primitives, if available. If all
5121 they are all non-zero.
5129 Leak an RCU-protected pointer out of the reader.
5144 Set number of RCU callback-offload togglers.
5149 callback-offload toggling attempts.
5152 Set number of RCU readers. The value -1 selects
5153 N-1, where N is the number of CPUs. A value
5154 "n" less than -1 selects N-n-2, where N is again
5155 the number of CPUs. For example, -2 selects N
5156 (the number of CPUs), -3 selects N+1, and so on.
5159 Enable debug-object double-call_rcu() testing.
5162 Set time (s) after boot for CPU-hotplug testing.
5165 Set time (jiffies) between CPU-hotplug operations,
5166 or zero to disable CPU-hotplug testing.
5169 Set the number of read-then-exit kthreads used
5171 task-exit processing.
5174 The number of times in a given read-then-exit
5175 episode that a set of read-then-exit kthreads
5180 read-then-exit testing episodes.
5183 Set task-shuffle interval (s). Shuffling tasks
5184 allows some CPUs to go into dyntick-idle mode
5189 is useful for hands-off automated testing.
5198 any other stall-related activity. Note that
5204 in scheduling-while-atomic splats.
5206 Use of this module parameter results in splats.
5217 grace-period kthread to test RCU CPU stall
5243 Test RCU's dyntick-idle handling. See also the
5292 Use expedited grace-period primitives, for
5296 real-time latency, and degrade energy efficiency.
5300 Use only normal grace-period primitives,
5303 real-time latency, CPU utilization, and
5305 increased grace-period latency. This parameter
5311 rcu_end_inkernel_boot() has been invoked), use
5312 only normal grace-period primitives. No effect
5318 post-boot attempt at an expedited RCU grace
5319 period to instead use normal non-expedited
5320 grace-period processing.
5328 set to the default value of -1.
5331 Set the minimum number of callback-queuing-time
5332 lock-contention events per jiffy required to
5333 cause the RCU Tasks flavors to switch to per-CPU
5336 the default value of -1.
5339 Set the number of callback queues to use for the
5341 of -1 allows this to be automatically (and
5343 for use in testing.
5349 number avoids disturbing real-time workloads,
5354 cancel laziness on that CPU. Use -1 to disable
5364 only printed prior to the stall-warning message
5420 force - Override the decision by the kernel to hide the
5430 E.g. to turn on cmt and turn off mba use:
5448 Set test-start holdoff period. The purpose of
5457 but the default has already reduced the per-pass
5462 Set number of readers. The default value of -1
5471 Set the read-side critical-section duration,
5475 Specify the read-protection implementation to test.
5494 See Documentation/admin-guide/cgroup-v1/cpusets.rst.
5498 Reserve I/O ports or memory so the kernel won't use
5502 reservetop= [X86-32]
5519 See Documentation/power/swsusp-and-swap-files.rst
5534 AMD-based UNRET and IBPB mitigations alone do not stop
5536 sibling threads. For that reason, STIBP is used on pro-
5540 off - no mitigation
5541 auto - automatically select a migitation
5542 auto,nosmt - automatically select a mitigation,
5546 ibpb - On AMD, mitigate short speculation
5551 ibpb,nosmt - Like "ibpb" above but will disable SMT
5555 unret - Force enable untrained return thunks,
5556 only effective on AMD f15h-f17h based
5558 unret,nosmt - Like unret, but will disable SMT when STIBP
5593 ro [KNL] Mount root device read-only on boot
5596 on Mark read-only kernel memory as read-only (default).
5597 off Leave read-only kernel memory writable for debugging.
5598 full Mark read-only kernel memory and aliases as read-only
5604 debug-uart get routed to the D+ and D- pins of the usb
5610 block/early-lookup.c for details.
5635 rw [KNL] Mount root device read-write on boot
5650 The default is 1 meaning that one can concurrently use
5656 cost of significant additional memory use for tables.
5687 to 10 seconds for built-in smp_call_function()
5694 that requesting even small non-zero numbers of
5701 The default of -1 specifies a number of kthreads
5706 test before initiating CPU-hotplug operations.
5710 CPU-hotplug operations. Specifying zero (which
5711 is the default) disables CPU-hotplug operations.
5717 Non-zero values are useful for automated tests.
5729 Use use_cpus_read_lock() instead of the default
5738 The probability weighting to use for the
5740 "wait" parameter. A value of -1 selects the
5741 default if all other weights are -1. However,
5743 value of -1 will instead select a weight of zero.
5746 The probability weighting to use for the
5748 non-zero "wait" parameter. See weight_single.
5751 The probability weighting to use for the
5759 The probability weighting to use for the
5761 non-zero "wait" parameter. See weight_single
5765 The probability weighting to use for the
5771 The probability weighting to use for the
5773 non-zero "wait" parameter. See weight_single
5780 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
5781 1 -- enable.
5792 0 -- disable.
5793 1 -- enable.
5796 serialnumber [BUGS=X86-32]
5798 sev=option[,option...] [X86-64] See Documentation/arch/x86/x86_64/boot-options.rst
5803 show_lapic= [APIC,X86] Advanced Programmable Interrupt Controller
5806 to set it to "all" by meaning -- no limit here.
5812 simeth= [IA-64]
5844 may poison objects when not in use. Also tracks the
5887 using the csdlock_debug- kernel parameter.
5892 system. By default, let CSD-lock acquisition
5894 for this value provides a 5-minute timeout.
5896 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
5897 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
5898 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
5899 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
5900 smsc-ircc2.ircc_irq= [HW] IRQ line
5901 smsc-ircc2.ircc_dma= [HW] DMA channel
5902 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
5908 CPUs) to use per physical CPU on systems capable of
5912 Default: -1 (no limit)
5915 [KNL] Should the soft-lockup detector generate panics.
5918 A value of 1 instructs the soft-lockup detector
5919 to panic the machine when a soft-lockup occurs. It is
5922 respective build-time switch to that functionality.
5925 [KNL] Should the soft-lockup detector generate
5930 See Documentation/admin-guide/laptops/sonypi.rst
5937 on - (default) Enable the HW or SW mitigation
5939 off - Disable the mitigation.
5946 on - unconditionally enable, implies
5948 off - unconditionally disable, implies
5950 auto - kernel detects whether your CPU model is
5967 retpoline - replace indirect branches
5968 retpoline,generic - Retpolines
5969 retpoline,lfence - LFENCE; indirect branch
5970 retpoline,amd - alias for retpoline,lfence
5971 eibrs - Enhanced/Auto IBRS
5972 eibrs,retpoline - Enhanced/Auto IBRS + Retpolines
5973 eibrs,lfence - Enhanced/Auto IBRS + LFENCE
5974 ibrs - use IBRS to protect kernel
5984 on - Unconditionally enable mitigations. Is
5987 off - Unconditionally disable mitigations. Is
5990 prctl - Indirect branch speculation is enabled,
5996 - Like "prctl" above, but only STIBP is
6002 - Same as "prctl" above, but all seccomp
6007 - Like "seccomp" above, but only STIBP is
6012 auto - Kernel selects the mitigation depending on
6023 off - Disable mitigation
6024 microcode - Enable microcode mitigation only
6025 safe-ret - Enable sw-only safe RET mitigation (default)
6026 ibpb - Enable mitigation by issuing IBPB on
6028 ibpb-vmexit - Issue IBPB only on VMEXIT
6029 (cloud-specific mitigation)
6054 on - Unconditionally disable Speculative Store Bypass
6055 off - Unconditionally enable Speculative Store Bypass
6056 auto - Kernel detects whether the CPU model contains an
6062 prctl - Control Speculative Store Bypass per thread
6066 seccomp - Same as "prctl" above, but all seccomp threads
6074 on,auto - On Power8 and Power9 insert a store-forwarding
6078 off - No action.
6097 off - not enabled
6099 warn - the kernel will emit rate-limited warnings
6107 fatal - the kernel will send SIGBUS to applications
6112 ratelimit:N -
6132 Certain CPUs are vulnerable to an MDS-like
6152 This kernel-boot parameter defaults to 128,
6153 but takes effect only when the low-order four
6170 instead of the compile-time CONFIG_NR_CPUS.
6174 grace-period sequence counter wrap for the
6175 srcu_data structure's ->srcu_gp_seq_needed field.
6190 Specifies the number of no-delay instances
6197 Specifies the per-grace-period phase, number of
6198 non-sleeping polls of readers. Beyond this limit,
6204 Specifies number of microseconds of non-sleeping
6205 delay between each non-sleeping poll of readers.
6208 Specifies the number of update-side contention
6213 set for contention-based conversions to occur.
6223 force-on: Unconditionally enable mitigation for
6225 force-off: Unconditionally disable mitigation for
6233 override the default stack gap protection. The value
6248 stacktrace_filter=[function-list]
6250 will trace at boot up. function-list is a comma-separated
6258 Set the STI (builtin display/keyboard on the HP-PARISC
6260 as the initial boot-console.
6320 to global on non-NUMA machines)
6329 amount of memory reserved for use by the client.
6340 This parameter controls use of the Protected
6343 swiotlb= [ARM,IA-64,PPC,MIPS,X86]
6345 <int> -- Number of I/O TLB slabs
6346 <int> -- Second integer after comma. Number of swiotlb
6349 force -- force using of bounce buffers even if they
6351 noforce -- Never use bounce buffers (for debugging)
6366 Ignore sysrq setting - this boot parameter will
6374 cache size. See Documentation/networking/ip-sysctl.rst
6381 Specify "mem" (for Suspend-to-RAM) or "standby" (for
6386 wakeup-capable RTC alarm.
6392 -1: disable all active trip points in all thermal zones
6396 -1: disable all critical trip points in all thermal zones
6403 -1: disable all passive trip points
6409 <deci-seconds>: poll all this frequency
6418 Specify if the kernel should make use of the cpu
6420 The scheduler will make use of this information and
6431 Prevent the CPU-hotplug component of torturing
6435 Dump the ftrace buffer at torture-test shutdown,
6439 with rotating-rust storage.
6444 disables verbose-printk() sleeping.
6447 Duration of each verbose-printk() sleep in jiffies.
6465 https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/
6503 local - Use the per CPU time stamp counter
6507 global - Event time stamps are synchronize across
6510 counter - Simple counting of events (1, 2, ..)
6514 uptime - Use jiffies as the time stamp.
6515 perf - Use the same clock that perf uses.
6516 mono - Use ktime_get_mono_fast_ns() for time stamps.
6517 mono_raw - Use ktime_get_raw_fast_ns() for time
6519 boot - Use ktime_get_boot_fast_ns() for time stamps.
6523 trace_event=[event-list]
6525 to facilitate early boot debugging. The event-list is a
6526 comma-separated list of trace events to enable. See
6529 trace_instance=[instance-info]
6549 trace_options=[option-list]
6551 The option-list is a comma delimited list of options
6565 trace_trigger=[trigger-list]
6602 See Documentation/admin-guide/mm/transhuge.rst
6610 - "tpm"
6611 - "tee"
6612 - "caam"
6622 - "kernel"
6623 - the same value as trusted.source: "tpm" or "tee"
6624 - "default"
6633 high-resolution timer mode on older hardware, and in
6635 [x86] noirqtime: Do not use TSC to do irq accounting.
6650 [x86] watchdog: Use TSC as the watchdog clocksource with
6657 tsc_early_khz= [X86] Skip early TSC calibration and use the given
6669 on - Enable TSX on the system. Although there are
6672 several previous speculation-related CVEs, and
6676 off - Disable TSX on the system. (Note that this
6684 auto - Disable TSX if X86_BUG_TAA is present,
6689 See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
6695 Similar to Micro-architectural Data Sampling (MDS)
6710 full - Enable TAA mitigation on vulnerable CPUs
6713 full,nosmt - Enable TAA mitigation and disable SMT on
6716 vulnerable to cross-thread TAA attacks.
6717 off - Unconditionally disable TAA mitigation
6719 On MDS-affected machines, tsx_async_abort=off can be
6731 Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
6737 See also Documentation/input/devices/joystick-parport.rst
6739 udbg-immortal [PPC] When debugging early kernel crashes that
6745 Set number of hash buckets for UDP/UDP-Lite connections
6747 uhci-hcd.ignore_oc=
6749 Some badly-designed motherboards generate lots of
6758 unwind_debug [X86-64]
6766 (default -1 = authorized (same as 1),
6772 for newly-detected USB devices (default 2). This
6800 [USB] Specifies timeout for the initial 64-byte
6807 [USB] A list of quirk entries to augment the built-in
6810 VendorID:ProductID:Flags. The IDs are 4-digit hex
6812 will change the built-in quirk; setting it if it is
6817 a 255-byte read);
6821 Set-Interface requests);
6826 (e.g morph devices), don't use reset);
6840 (bInterval-1).
6878 usb-storage.delay_use=
6882 usb-storage.quirks=
6884 override the built-in unusual_devs list. List
6887 and Product ID values (4-digit hex numbers) and
6889 to a common usb-storage quirk flag as follows:
6895 device capacity by one sector);
6896 d = NO_READ_DISC_INFO (don't use
6898 e = NO_READ_CAPACITY_16 (don't use
6900 f = NO_REPORT_OPCODES (don't use report opcodes
6906 sector if the number is odd);
6909 j = NO_REPORT_LUNS (don't use report luns
6911 k = NO_SAME (do not use WRITE_SAME, uas only)
6931 medium is write-protected).
6940 1 - undefined instruction events
6941 2 - system calls
6942 4 - invalid data aborts
6943 8 - SIGSEGV faults
6944 16 - SIGBUS faults
6960 vdso32= [X86] Control the 32-bit vDSO
6961 vdso32=1: enable 32-bit VDSO
6962 vdso32=0 or vdso32=2: disable 32-bit VDSO
6972 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
6974 vector= [IA-64,SMP]
6995 <size> := size (can use standard suffixes
7006 vga= [BOOT,X86-32] Select a particular video mode
7008 Documentation/admin-guide/svga.rst.
7009 Use vga=ask for menu.
7023 - Disable all of the above options
7044 vsyscall= [X86-64]
7047 code). Most statically-linked binaries and older
7048 versions of glibc use these calls. Because these
7061 them quite hard to use for exploits but
7071 see VGA-softcursor.txt. Default: 2 = underline.
7076 This is a 16-member array composed of values
7077 ranging from 0-255.
7082 This is a 16-member array composed of values
7083 ranging from 0-255.
7088 This is a 16-member array composed of values
7089 ranging from 0-255.
7094 Set system-wide default UTF-8 mode for all tty's.
7095 Default is 1, i.e. UTF-8 mode is enabled for all
7100 Format=<-1|0|1>
7101 Set system-wide default for whether a cursor
7102 is shown on new VTs. Default is -1,
7107 vt.italic= [VT] Default color for italic text; 0-15.
7110 vt.underline= [VT] Default color for underlined text; 0-15.
7114 see Documentation/watchdog/watchdog-parameters.rst
7115 or other driver-specific files in the
7128 to use in unbound workqueues.
7129 Format: <cpu-list>
7143 Per-cpu work items which run for longer than this
7146 them from noticeably delaying other per-cpu work
7155 Per-cpu workqueues are generally preferred because
7157 locality; unfortunately, per-cpu workqueues tend to
7160 Enabling this makes the per-cpu workqueues which
7170 Select the default affinity scope to use for unbound
7174 Documentation/core-api/workqueue.rst.
7187 forces round-robin CPU selection to flush out
7195 on - Enable writecombine, use WUC for ioremap_wc()
7196 off - Disable writecombine, use SUC for ioremap_wc()
7198 x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
7202 xen_512gb_limit [KNL,X86-64,XEN]
7204 to use only up to 512 GB of RAM. The reason to do so is
7212 ide-disks -- unplug primary master IDE devices
7213 aux-ide-disks -- unplug non-primary-master IDE devices
7214 nics -- unplug network devices
7215 all -- unplug all emulated devices (NICs and IDE disks)
7216 unnecessary -- unplugging emulated devices is
7219 never -- do not unplug even if version check succeeds
7227 Select whether to always use non-faulting (safe) MSR
7248 to Xen, for use by other domains. Can be also changed at runtime
7252 xen_timer_slop= [X86-64,XEN]
7277 preferred over the 2-level event handling, as it is
7279 much higher. Default is on (use fifo events).
7287 natively use the XIVE interrupt controller. This option
7294 xive.store-eoi=off [PPC]
7295 By default on POWER10 and above, the kernel will use
7297 is active. This option allows the XIVE driver to use
7300 xhci-hcd.quirks [USB,KNL]