Lines Matching +full:embedded +full:- +full:trace +full:- +full:extension
5 force -- enable ACPI if default was off
6 on -- enable ACPI but allow fallback to DT [arm64]
7 off -- disable ACPI if default was on
8 noirq -- do not use ACPI for IRQ routing
9 strict -- Be less tolerant of platforms that are not
11 rsdt -- prefer RSDT over (default) XSDT
12 copy_dsdt -- copy DSDT to memory
26 If set to vendor, prefer vendor-specific driver
58 Documentation/firmware-guide/acpi/debug.rst for more information about
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.
233 as soon as the kernel's real-mode entry point is called.
263 See Documentation/sound/alsa-configuration.rst
270 align_va_addr= [X86-64]
275 CPU-intensive style benchmark, and it can vary highly in
278 32: only for 32-bit processes
279 64: only for 64-bit processes
280 on: enable for both 32- and 64-bit processes
281 off: disable for both 32- and 64-bit processes
291 Allow execve() of 32-bit applications and setting of the
293 subset of the CPUs support 32-bit EL0. When this
294 parameter is present, the set of CPUs supporting 32-bit
296 and hot-unplug operations may be restricted.
298 See Documentation/arm64/asymmetric-32bit.rst for more
301 amd_iommu= [HW,X86-64]
304 fullflush - Deprecated, equivalent to iommu.strict=1
305 off - do not initialize any AMD IOMMU found in
307 force_isolation - Force device isolation for all
312 force_enable - Force enable the IOMMU on platforms known
316 amd_iommu_dump= [HW,X86-64]
322 amd_iommu_intr= [HW,X86-64]
325 legacy - Use legacy interrupt remapping mode.
326 vapic - Use virtual APIC mode, which allows IOMMU
328 This mode requires kvm-amd.avic=1.
342 Power management functions (SPARCstation-4/5 + deriv.)
344 Disable APC CPU standby support. SPARCstation-Fox does
345 not play well with APC CPU idle - disable it if you have
352 when initialising the APIC and IO-APIC components.
353 For X86-32, this can also be used to specify an APIC
373 to set it to "all" by meaning -- no limit here.
382 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
391 arm64.nomte [ARM64] Unconditionally disable Memory Tagging Extension
415 audit= [KNL] Enable the audit sub-system
417 0 | off - kernel audit is disabled and can not be
419 unset - kernel audit is initialized but disabled and
421 1 | on - kernel audit is initialized and partially
434 0 - Disable the BAU.
435 1 - Enable the BAU.
436 unset - Disable the BAU.
456 embedded devices based on command line input.
457 See Documentation/block/cmdline-partition.rst
468 See Documentation/admin-guide/bootconfig.rst
479 bttv.pll= See Documentation/admin-guide/media/bttv.rst
488 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
507 inclusive. See arch/mips/include/asm/pgtable-bits.h
517 - foo isn't auto-mounted if you mount all cgroups in
519 - foo isn't visible as an individually mountable
521 - if foo is an optional feature then the feature is
527 Specifying "pressure" disables per-cgroup pressure
541 nosocket -- Disable socket memory accounting.
542 nokmem -- Disable kernel memory accounting.
547 0 -- check protection applied by kernel (includes
549 1 -- check protection requested by application.
563 force such clocks to be always-on nor does it reserve
567 information, see Documentation/driver-api/clk.rst.
569 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
586 [X86-32] pit,hpet,tsc;
593 [X86-64] hpet,tsc
599 architected timer so that code using WFE-based polling
619 clocksource-wdtest.holdoff= [KNL]
638 cma=nn[MG]@[start[MG][-end[MG]]]
649 Sets the size of kernel per-numa memory area for
651 per-numa CMA altogether. And If this option is not
653 With per-numa CMA enabled, DMA users on node nid will
669 com20020= [HW,NET] ARCnet - COM20020 chipset
673 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
677 ARCnet - COM90xx chipset (memory-mapped buffers)
695 See Documentation/admin-guide/serial-console.rst for more
705 Start an early, polled-mode console on the 8250/16550
708 MMIO inter-register address stride is either 8-bit
709 (mmio), 16-bit (mmio16), or 32-bit (mmio32).
713 the h/w is not re-initialized.
734 syscall, or to executing "dmesg -S --raw" or to reading
754 disable the cpuidle sub-system
760 disable the cpufreq sub-system
768 [X86] Delay for N microsec between assert and de-assert
783 [KNL, X86-64] Select a region under 4G first, and
786 See Documentation/admin-guide/kdump/kdump.rst for further details.
791 start-[end] where start and end are both
793 Documentation/admin-guide/kdump/kdump.rst for an example.
796 [KNL, X86-64] range could be above 4G. Allow kernel
803 [KNL, X86-64] range under 4G. When crashkernel=X,high
808 low memory is needed to make sure DMA buffers for 32-bit
818 [KNL] Disable crypto self-tests
826 csdlock_debug= [KNL] Enable debug add-ons of cross-CPU function call
842 See also Documentation/input/devices/joystick-parport.rst
846 Documentation/admin-guide/dynamic-debug-howto.rst for
860 [KNL] verbose locking self-tests
863 self-tests.
865 (no extra messages), setting it to -1 (all bits set)
866 will print _a_lot_ more information - normally only
904 Format: { on, no-mount, off }
906 no-mount:
911 get a -EPERM as result when trying to register files
915 Default value is set in build-time with a kernel configuration.
931 Documentation/admin-guide/mm/hugetlbpage.rst.
978 against bounds-checking flaws in the kernel's
1032 entries for DMA-API debugging code. One entry is
1033 required per DMA-API allocation. Use this if the
1034 DMA-API debugging code disables itself because the
1038 With this option the DMA-API debugging driver
1053 Generic built-in EDID data sets are used, if one of
1058 available in Documentation/admin-guide/edid.rst. An EDID
1070 Control how the dt_cpu_ftrs device-tree binding is
1080 what data is available or for reverse-engineering.
1085 Documentation/admin-guide/dynamic-debug-howto.rst
1102 determined by stdout-path property in device tree's
1107 Start an early, polled-mode console on a Cadence
1118 Start an early, polled-mode console on the 8250/16550
1120 MMIO inter-register address stride is either 8-bit
1121 (mmio) or 32-bit (mmio32 or mmio32be).
1129 Start an early, polled-mode console on a pl011 serial
1133 the driver will use only 32-bit accessors to read/write
1142 Start an early, polled-mode console on a meson serial
1148 Start an early, polled-mode console on an msm serial
1154 Start an early, polled-mode console on an msm serial
1160 Start an early, polled-mode console on a serial port
1166 Start an early, polled-mode console on a serial port
1172 Use RISC-V SBI (Supervisor Binary Interface) for early
1190 Start an early, polled-mode console on a lantiq serial
1204 Start an early, polled-mode, output-only console on the
1209 Start an early, polled-mode console on the
1215 Start an early, polled-mode console on a Qualcomm
1223 coherent non-x86 systems that use system memory for
1334 attribute is added to range 0x100000000-0x180000000 and
1335 0x10a0000000-0x1120000000.
1339 range 0x240000000-0x43fffffff.
1351 Documentation/admin-guide/acpi/ssdt-overlays.rst for details.
1357 elanfreq= [X86-32]
1365 See Documentation/admin-guide/kdump/kdump.rst for details.
1381 0 -- permissive (log only, no denials).
1382 1 -- enforcing (deny and log).
1406 See also Documentation/fault-injection/.
1410 See Documentation/admin-guide/sysctl/net.rst for
1414 See Documentation/admin-guide/blockdev/floppy.rst.
1417 [IA-64] Avoid check_sal_cache_flush which may hang on
1422 forcepae [X86-32]
1423 Forcefully enable Physical Address Extension (PAE).
1435 [FTRACE] will dump the trace buffers on oops.
1441 ftrace_filter=[function-list]
1443 tracer at boot up. function-list is a comma-separated
1448 ftrace_notrace=[function-list]
1449 [FTRACE] Do not trace the functions specified in
1450 function-list. This list can be changed at run time
1454 ftrace_graph_filter=[function-list]
1457 function-list is a comma-separated list of functions
1461 ftrace_graph_notrace=[function-list]
1462 [FTRACE] Do not trace from the functions specified in
1463 function-list. This list is a comma-separated list of
1469 the max depth it will trace into a function. This value
1483 off -- Don't create device links from firmware info.
1484 permissive -- Create device links from firmware info
1487 on -- Create device links from firmware info and use it
1489 rpm -- Like "on", but also use to order runtime PM.
1500 See also Documentation/input/devices/joystick-parport.rst
1504 gart_fix_e820= [X86-64] disable the fix e820 for K8 GART
1508 gcov_persist= [GCOV] When non-zero (default), profiling data for
1518 gpio-mockup.gpio_mockup_ranges
1521 gpio-mockup.gpio_mockup_named_lines
1548 [KNL] Should the hard-lockup detector generate
1554 for 64-bit NUMA, off otherwise.
1557 hcl= [IA-64] SGI's Hardware Graph compatibility layer
1564 corresponding firmware-first mode error processing
1578 hpet= [X86-32,HPET] option to control HPET usage
1595 boot-time allocation of gigantic hugepages is skipped.
1603 Documentation/admin-guide/mm/hugetlbpage.rst.
1613 Documentation/admin-guide/mm/hugetlbpage.rst.
1639 by the CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time
1645 hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
1668 (disabled by default, and as a pre-condition
1670 i8042.direct [HW] Put keyboard port into non-translated mode
1684 suspend-to-ram transitions, only during s2r
1717 -1 -- never invert brightness
1718 0 -- machine default
1719 1 -- force brightness inversion
1724 ide-core.nodma= [HW] (E)IDE subsystem
1730 ide-generic.probe-mask= [HW] (E)IDE subsystem
1742 ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
1753 idle=nomwait: Disable mwait for CPU C-states
1781 legacy only accept legacy-NaN binaries, if supported
1783 2008 only accept 2008-NaN binaries, if supported
1792 'relaxed' straps the emulator for both legacy-NaN and
1793 2008-NaN, whereas 'strict' enables legacy-NaN only on
1802 Ignore loglevel setting - this will print /all/
1869 Formats: { "ima" | "ima-ng" | "ima-sig" }
1870 Default: "ima-ng"
1898 initcall_debug [KNL] Trace initcalls as they are executed. Useful
1902 initcall_blacklist= [KNL] Do not execute a comma-separated list of
1903 initcall functions. Useful for debugging built-in
1948 0 -- basic integrity auditing messages. (Default)
1949 1 -- additional integrity auditing messages.
1977 could harm performance of some high-throughput
1986 1 to 9 specify maximum depth of C-state.
1996 used along with the hardware-managed P-states (HWP)
2000 in favor of acpi-cpufreq. Forcing the intel_pstate driver
2001 instead of acpi-cpufreq may disable platform features, such
2003 P-States information being indicated to OSPM and therefore
2006 or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
2019 Allow per-logical-CPU P-State performance control limits using
2022 intremap= [X86-64, Intel-IOMMU]
2027 BIOS x2APIC opt-out request will be ignored
2051 0 - Try to allocate a 32-bit DMA address first, before
2053 1 - Allocate directly from the full usable range,
2055 greater than 32-bit addressing.
2059 0 - Lazy mode.
2065 1 - Strict mode.
2068 unset - Use value of CONFIG_IOMMU_DEFAULT_DMA_{LAZY,STRICT}.
2070 legacy driver-specific options takes precedence.
2075 0 - Use IOMMU translation for DMA.
2076 1 - Bypass the IOMMU for DMA.
2077 unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
2079 io7= [HW] IO7 for Marvel-based Alpha systems
2094 See Documentation/admin-guide/nfs/nfsroot.rst.
2118 Enables support for pseudo-NMIs in the kernel. This
2137 [Deprecated - use cpusets instead]
2138 Format: [flag-list,]<cpu-list>
2169 "number of CPUs in system - 1".
2195 The format of <cpu-list> is described above.
2199 ivrs_ioapic [HW,X86-64]
2200 Provide an override to the IOAPIC-ID<->DEVICE-ID
2202 example, to map IOAPIC-ID decimal 10 to
2206 ivrs_hpet [HW,X86-64]
2207 Provide an override to the HPET-ID<->DEVICE-ID
2209 example, to map HPET-ID decimal 0 to
2213 ivrs_acpihid [HW,X86-64]
2214 Provide an override to the ACPI-HID:UID<->DEVICE-ID
2216 example, to map UART-HID:UID AMD0020:0 to
2236 kernelcore= [KNL,X86,IA-64,PPC]
2239 the kernel for non-movable allocations. The requested
2249 subsystem. Note that allocations like PTEs-from-HighMem
2257 for non-movable allocations and remaining memory is used
2268 gdb or control-c on the dbgp connection. When
2269 not using this parameter you use sysrq-g to break into
2274 or a supported polling keyboard driver (non-usb).
2301 Configure the RouterBoard 532 series on-chip
2304 kmemleak= [KNL] Boot-time kmemleak enable/disable
2310 kprobe_event=[probe-list]
2312 The probe-list is a semicolon delimited list of probe
2320 See also Documentation/trace/kprobetrace.rst "Kernel
2358 kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM.
2361 kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
2363 Default is 1 (enabled) if in 64-bit or 32-bit PAE mode.
2365 kvm-arm.mode=
2368 nvhe: Standard nVHE-based mode, without support for
2371 protected: nVHE-based mode with support for guests whose
2377 kvm-arm.vgic_v3_group0_trap=
2378 [KVM,ARM] Trap guest accesses to GICv3 group-0
2381 kvm-arm.vgic_v3_group1_trap=
2382 [KVM,ARM] Trap guest accesses to GICv3 group-1
2385 kvm-arm.vgic_v3_common_trap=
2389 kvm-arm.vgic_v4_enable=
2401 kvm-intel.ept= [KVM,Intel] Disable extended page tables
2405 kvm-intel.emulate_invalid_guest_state=
2409 kvm-intel.flexpriority=
2413 kvm-intel.nested=
2417 kvm-intel.unrestricted_guest=
2422 kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
2423 CVE-2018-3620.
2434 kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification
2453 on - enable the interface for the mitigation
2518 For details see: Documentation/admin-guide/hw-vuln/l1tf.rst
2524 lapic [X86-32,APIC] Enable the local APIC even if BIOS
2528 value for LAPIC timer one-shot implementation. Default
2551 libata.force= [LIBATA] Force configurations. The format is comma-
2563 first fan-out link behind PMP device. It does not
2577 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
2589 hot-unplug link recovery
2626 Set the number of locking read-acquisition kthreads.
2631 Set the number of locking write-acquisition kthreads.
2634 Set time (s) after boot for CPU-hotplug testing.
2637 Set time (s) between CPU-hotplug operations, or
2638 zero to disable CPU-hotplug testing.
2641 Set task-shuffle interval (jiffies). Shuffling
2642 tasks allows some CPUs to go into dyntick-idle
2647 is useful for hands-off automated testing.
2680 7 (KERN_DEBUG) debug-level messages
2690 logo.nologo [FB] Disables display of the built-in Linux logo.
2708 an IEEE 1284-compliant printer is attached; if
2714 time-consuming boot-time autodetection (up to 250 ms per
2735 machvec= [IA-64] Force the use of a particular machine-vector
2741 Example: machtype=lemote-yeeloong-2f-7inch
2756 (loop.max_loop) unconditionally pre-created at init time. The default
2759 devices can be requested on-demand with the
2760 /dev/loop-control interface.
2762 mce [X86-32] Machine Check Exception
2764 mce=option [X86-64] See Documentation/x86/x86_64/boot-options.rst
2767 See Documentation/admin-guide/md.rst.
2774 Control mitigation for the Micro-architectural Data
2789 full - Enable MDS mitigation on vulnerable CPUs
2790 full,nosmt - Enable MDS mitigation and disable
2792 off - Unconditionally disable MDS mitigation
2794 On TAA-affected machines, mds=off can be prevented by
2803 For details see: Documentation/admin-guide/hw-vuln/mds.rst
2822 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
2827 per-device physically contiguous DMA buffers.
2835 See Documentation/admin-guide/mm/memory-hotplug.rst.
2860 Example: Exclude memory from 0x18690000-0x1869ffff
2874 memmap=<size>%<offset>-<oldtype>+<newtype>
2876 from <oldtype> to <newtype>. If "-<oldtype>" is left
2891 repeatable BIOS-originated corruption always
2937 mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control
2945 Refer to Documentation/virt/kvm/amd-memory-encryption.rst
2949 s2idle - Suspend-To-Idle
2950 shallow - Power-On Suspend or equivalent (if supported)
2951 deep - Suspend-To-RAM or equivalent (if supported)
2952 See Documentation/admin-guide/pm/sleep-states.rst.
2955 See Documentation/admin-guide/media/meye.rst.
2957 mfgpt_irq= [IA-32] Specify the IRQ to use for the
2958 Multi-Function General Purpose Timers on AMD Geode
2961 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
2975 0 - The attached screen is the 3.5" TFT
2976 1 - The attached screen is the 7" TFT
2977 2 - The VGA Shield is attached (1024x768)
2981 b - Enable backlight. The TFT backlight pin will be
2985 c - Enable the s3c camera interface.
2986 t - Reserved for enabling touchscreen support. The
2990 https://repo.or.cz/w/linux-2.6/mini2440.git
2995 arch-independent options, each of which is an
2996 aggregation of existing arch-specific options.
3009 ssbd=force-off [ARM64]
3027 have other ways of avoiding SMT-based attacks.
3052 module_blacklist= [KNL] Do not load a comma-separated list of
3066 movablecore= [KNL,X86,IA-64,PPC]
3077 movable_node [KNL] Boot-time switch to make hotplugable memory
3084 Format: <name>,<region-number>,<size>,<offset>
3087 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
3096 onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
3100 boundary - index of last SLC block on Flex-OneNAND.
3102 lock - Configure if Flex-OneNAND boundary should be locked.
3109 See arch/arm/mach-s3c/mach-jive.c
3137 something different and driver-specific.
3148 See Documentation/admin-guide/nfs/nfsroot.rst.
3150 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
3151 See Documentation/admin-guide/nfs/nfsroot.rst.
3154 See Documentation/admin-guide/nfs/nfsroot.rst.
3178 [NFS] enable 64-bit inode numbers.
3179 If zero, the NFS client will fake up a 32-bit inode
3181 of returning the full 64-bit number.
3182 The default is to return 64-bit inode numbers.
3212 [NFS4] Specify an additional fixed unique ident-
3243 driver. A non-zero value sets the minimum interval
3255 NMI stack-backtrace request.
3264 0 - turn hardlockup detector in nmi_watchdog off
3265 1 - turn hardlockup detector in nmi_watchdog on
3282 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
3286 no5lvl [X86-64] Disable 5-level paging mode. Forces
3287 kernel to use 4-level paging instead.
3318 caches in the slab allocator. Saves per-node memory,
3338 delayacct [KNL] Enable per-task delay accounting
3344 no_entry_flush [PPC] Don't flush the L1-D cache when entering the kernel.
3346 noexec [IA-64]
3349 On X86-32 available only on PAE configured kernels.
3350 noexec=on: enable non-executable mappings (default)
3351 noexec=off: disable non-executable mappings
3361 noexec32 [X86-64]
3362 This affects only 32-bit executables.
3363 noexec32=on: enable non-executable mappings (default)
3365 noexec32=off: disable non-executable mappings
3370 nofxsr [BUGS=X86-32] Disables x86 floating point extended
3372 legacy floating-point registers on task switch.
3398 [PPC] Don't flush the L1-D cache after accessing user data.
3402 enabling legacy floating-point and sse state.
3432 nohalt [IA-64] Tells the kernel not to use the power saving
3434 power-consumption. On the positive side, it reduces
3435 interrupt wake-up latency, which may improve performance
3437 real-time systems.
3447 compared. However, if this command-line option is
3472 noirqdebug [X86-32] Disables the code which attempts to detect and
3483 nointremap [X86-64, Intel-IOMMU] Do not enable interrupt
3485 [Deprecated - use intremap=off]
3487 nointroute [IA-64]
3491 nojitter [IA-64] Disables jitter checking for ITC timers.
3493 no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
3495 no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page
3498 no-vmw-sched-clock
3502 no-steal-acc [X86,PV_OPS,ARM64] Disable paravirtualized steal time
3506 nolapic [X86-32,APIC] Do not enable or use the local APIC.
3508 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
3513 nomca [IA-64] Disable machine check abort handling
3515 nomce [X86-32] Disable Machine Check Exception
3517 nomfgpt [X86-32] Disable Multi-Function General Purpose
3526 nopat [X86] Disable PAT (page attribute table extension of
3529 nopcid [X86-64] Disable the PCID cpu feature.
3534 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
3545 no-scroll [VGA] Disables scrollback.
3546 This is required for the Braillex ib80-piezo Braille
3549 nosbagart [IA-64]
3551 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
3553 nosgx [X86-64,SGX] Disables Intel SGX kernel support.
3558 nosoftlockup [KNL] Disable the soft-lockup detector.
3563 soft-lockup and NMI watchdog (hard-lockup).
3567 nox2apic [X86-64,APIC] Do not enable x2APIC mode.
3592 nptcg= [IA-64] Override max number of concurrent global TLB
3601 n. So during boot up some boot time memory for per-cpu
3602 variables need be pre-allocated for later physical cpu
3617 See Documentation/admin-guide/sysctl/vm.rst for details.
3620 See Documentation/core-api/debugging-via-ohci1394.rst for more
3645 running on a platform with a direct-mapped memory-side
3651 page_owner= [KNL] Boot-time page_owner enabling option.
3657 page_poison= [KNL] Boot-time parameter changing the state of
3667 reporting is disabled when it exceeds (MAX_ORDER-1).
3693 See Documentation/admin-guide/tainted-kernels.rst for
3701 Run kdump after running panic-notifiers and dumping
3739 Set to non-zero to probe primary and secondary ISA
3745 Set to non-zero if a chip is present that snoops speed
3793 Set to non-zero to probe tertiary and further ISA
3809 Set to non-zero to probe QDI controllers. By default
3814 Set to non-zero to probe Winbond controllers. Use
3836 See also Documentation/admin-guide/blockdev/paride.rst.
3865 bios [X86-32] force use of PCI BIOS, don't access
3867 has a non-standard PCI host bridge.
3868 nobios [X86-32] disallow use of PCI BIOS, only direct
3874 data in IO port 0xCFC, both 32-bit).
3876 Mechanism 2 (IO port 0xCF8 is an 8-bit port for
3877 the function, IO port 0xCFA, also 8-bit, sets
3879 through ports 0xC000-0xCFFF).
3886 root domains (aka PCI segments, in ACPI-speak).
3894 disable the use of MSI interrupts system-wide.
3899 primary IO-APIC for bridges that cannot disable
3906 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
3930 F0000h-100000h range.
3935 assign-busses [X86] Always assign all PCI bus
3963 bfsort Sort PCI devices into breadth-first order.
3966 nobfsort Don't sort PCI devices into breadth-first order.
3968 tuning and use the BIOS-configured MPS defaults.
3978 configuration allows peer-to-peer DMA between
3981 that hot-added devices will work.
3996 A PCI-PCI bridge can be specified if resource
4002 for 4096-byte alignment.
4004 end-to-end CRC checking).
4033 noats [PCIE, Intel-IOMMU, AMD-IOMMU]
4069 dpc-native Use native PCIe service for DPC only. May
4086 Keep all power-domains already enabled by bootloader on,
4092 See Documentation/admin-guide/blockdev/paride.rst.
4107 See Documentation/admin-guide/blockdev/paride.rst.
4110 See Documentation/admin-guide/blockdev/paride.rst.
4112 pirq= [SMP,APIC] Manual mp-table setup
4113 See Documentation/x86/i386/IO-APIC.rst.
4117 See also Documentation/admin-guide/parport.rst.
4128 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
4137 { on | off | curr | res | no-curr | no-res }
4177 none - Limited to cond_resched() calls
4178 voluntary - Limited to cond_resched() and might_sleep() calls
4179 full - Any section that isn't explicitly preempt disabled
4182 print-fatal-signals=
4188 coredump - etc.
4191 you might want to try "ulimit -i unlimited".
4203 or lockdep-detected issues (only if lock debug is on).
4212 on - unlimited logging to /dev/kmsg from userspace
4213 off - logging to /dev/kmsg disabled
4214 ratelimit - ratelimit the logging
4221 Limit processor to maximum C-state
4225 Ignore the _CST method to determine C-states,
4232 Param: "schedule" - profile schedule points.
4233 Param: "sleep" - profile D-state sleeping (millisecs).
4235 Param: "kvm" - profile VM exits.
4236 Param: <number> - step/bucket size as a power of 2 for
4250 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
4266 See Documentation/admin-guide/blockdev/paride.rst.
4268 pti= [X86-64] Control Page Table Isolation of user and
4273 on - unconditionally enable
4274 off - unconditionally disable
4275 auto - kernel detects whether your CPU model is
4280 nopti [X86-64]
4284 [KNL] Number of legacy pty's. Overwrites compiled-in
4292 See Documentation/admin-guide/md.rst.
4295 See Documentation/admin-guide/blockdev/ramdisk.rst.
4310 cross-syscall address exposures. This is only
4316 ras=option[,option,...] [KNL] RAS-specific options
4326 the specified list of CPUs to be no-callback CPUs.
4329 purpose, where "x" is "p" for RCU-preempt, and
4330 "s" for RCU-sched, and "N" is the CPU number.
4332 which can be useful for HPC and real-time
4341 This improves the real-time response for the
4358 RCU grace-period cleanup.
4362 RCU grace-period initialization.
4366 RCU grace-period pre-initialization, that is,
4367 the propagation of recent CPU-hotplug changes up
4372 per-CPU rcuc kthreads. Defaults to a non-zero
4384 cache-to-cache transfer latencies.
4390 and for NUMA systems with large remote-access
4403 Set the page-cache refill delay (in milliseconds)
4404 in response to low-memory conditions. The range
4408 Set delay from grace-period initialization to
4421 soliciting quiescent-state help from
4433 Set the SCHED_FIFO priority of the RCU per-CPU
4436 and for the RCU grace-period kthreads (rcu_bh,
4438 set, valid values are 1-99 and the default is 1
4439 (the least-favored priority). Otherwise, when
4440 RCU_BOOST is not set, valid values are 0-99 and
4441 the default is zero (non-realtime operation).
4447 the wakeup overhead on the global grace-period
4449 each group's NOCB grace-period kthread.
4457 batch limiting is re-enabled.
4461 RCU's force-quiescent-state scan will aggressively
4473 Cause the grace-period kthread to get an extra
4475 it should at force-quiescent-state time.
4481 this specifies an rcu_read_unlock()-time delay
4485 of RCU-protected pointers after the relevant
4495 grace-period primitives such as call_rcu().
4506 grace-period primitives.
4509 Set test-start holdoff period. The purpose of
4518 Test the double-argument variant of kfree_rcu().
4520 rcuscale.kfree_rcu_test_single, both the single-
4521 and double-argument variants are tested.
4524 Test the single-argument variant of kfree_rcu().
4526 rcuscale.kfree_rcu_test_double, both the single-
4527 and double-argument variants are tested.
4540 Set number of RCU readers. The value -1 selects
4542 "n" less than -1 selects N-n+1, where N is again
4543 the number of CPUs. For example, -2 selects N
4544 (the number of CPUs), -3 selects N+1, and so on.
4545 A value of "n" less than or equal to -N selects
4558 complete. This is useful for hands-off automated
4565 Write-side holdoff between grace periods,
4582 Enable RCU grace-period forward-progress testing
4586 Specify the fraction of a CPU-stall-warning
4587 period to do tight-loop forward-progress testing.
4591 forward-progress tests.
4595 need_resched() during tight-loop forward-progress
4599 Use conditional/asynchronous update-side
4603 Use expedited update-side primitives, if available.
4606 Use normal (non-expedited) asynchronous
4607 update-side primitives, if available.
4610 Use normal (non-expedited) synchronous
4611 update-side primitives, if available. If all
4615 they are all non-zero.
4623 Leak an RCU-protected pointer out of the reader.
4638 Set number of RCU callback-offload togglers.
4643 callback-offload toggling attempts.
4646 Set number of RCU readers. The value -1 selects
4647 N-1, where N is the number of CPUs. A value
4648 "n" less than -1 selects N-n-2, where N is again
4649 the number of CPUs. For example, -2 selects N
4650 (the number of CPUs), -3 selects N+1, and so on.
4653 Enable debug-object double-call_rcu() testing.
4656 Set time (s) after boot for CPU-hotplug testing.
4659 Set time (jiffies) between CPU-hotplug operations,
4660 or zero to disable CPU-hotplug testing.
4663 Set the number of read-then-exit kthreads used
4665 task-exit processing.
4668 The number of times in a given read-then-exit
4669 episode that a set of read-then-exit kthreads
4674 read-then-exit testing episodes.
4677 Set task-shuffle interval (s). Shuffling tasks
4678 allows some CPUs to go into dyntick-idle mode
4683 is useful for hands-off automated testing.
4692 to any other stall-related activity.
4702 grace-period kthread to test RCU CPU stall
4728 Test RCU's dyntick-idle handling. See also the
4754 Use expedited grace-period primitives, for
4758 real-time latency, and degrade energy efficiency.
4762 Use only normal grace-period primitives,
4765 real-time latency, CPU utilization, and
4767 increased grace-period latency. This parameter
4774 only normal grace-period primitives. No effect
4780 post-boot attempt at an expedited RCU grace
4781 period to instead use normal non-expedited
4782 grace-period processing.
4788 number avoids disturbing real-time workloads,
4805 force - Override the decision by the kernel to hide the
4833 Set test-start holdoff period. The purpose of
4842 but the default has already reduced the per-pass
4847 Set number of readers. The default value of -1
4856 Set the read-side critical-section duration,
4860 Specify the read-protection implementation to test.
4879 See Documentation/admin-guide/cgroup-v1/cpusets.rst.
4887 reservetop= [X86-32]
4904 See Documentation/power/swsusp-and-swap-files.rst
4920 during restoration read-only).
4943 ro [KNL] Mount root device read-only on boot
4946 on Mark read-only kernel memory as read-only (default).
4947 off Leave read-only kernel memory writable for debugging.
4952 debug-uart get routed to the D+ and D- pins of the usb
4974 rw [KNL] Mount root device read-write on boot
5014 to 10 seconds for built-in smp_call_function()
5021 that requesting even small non-zero numbers of
5028 The default of -1 specifies a number of kthreads
5033 test before initiating CPU-hotplug operations.
5037 CPU-hotplug operations. Specifying zero (which
5038 is the default) disables CPU-hotplug operations.
5044 Non-zero values are useful for automated tests.
5067 "wait" parameter. A value of -1 selects the
5068 default if all other weights are -1. However,
5070 value of -1 will instead select a weight of zero.
5075 non-zero "wait" parameter. See weight_single.
5088 non-zero "wait" parameter. See weight_single
5100 non-zero "wait" parameter. See weight_single
5107 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
5108 1 -- enable.
5119 0 -- disable.
5120 1 -- enable.
5126 0 -- disable.
5127 1 -- enable.
5130 serialnumber [BUGS=X86-32]
5135 simeth= [IA-64]
5201 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
5202 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
5203 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
5204 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
5205 smsc-ircc2.ircc_irq= [HW] IRQ line
5206 smsc-ircc2.ircc_dma= [HW] DMA channel
5207 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
5217 Default: -1 (no limit)
5220 [KNL] Should the soft-lockup detector generate panics.
5223 A value of 1 instructs the soft-lockup detector
5224 to panic the machine when a soft-lockup occurs. It is
5227 respective build-time switch to that functionality.
5230 [KNL] Should the soft-lockup detector generate
5235 See Documentation/admin-guide/laptops/sonypi.rst
5242 on - unconditionally enable, implies
5244 off - unconditionally disable, implies
5246 auto - kernel detects whether your CPU model is
5263 retpoline - replace indirect branches
5264 retpoline,generic - google's original retpoline
5265 retpoline,amd - AMD-specific minimal thunk
5275 on - Unconditionally enable mitigations. Is
5278 off - Unconditionally disable mitigations. Is
5281 prctl - Indirect branch speculation is enabled,
5287 - Like "prctl" above, but only STIBP is
5293 - Same as "prctl" above, but all seccomp
5298 - Like "seccomp" above, but only STIBP is
5303 auto - Kernel selects the mitigation depending on
5335 on - Unconditionally disable Speculative Store Bypass
5336 off - Unconditionally enable Speculative Store Bypass
5337 auto - Kernel detects whether the CPU model contains an
5343 prctl - Control Speculative Store Bypass per thread
5347 seccomp - Same as "prctl" above, but all seccomp threads
5355 on,auto - On Power8 and Power9 insert a store-forwarding
5359 off - No action.
5378 off - not enabled
5380 warn - the kernel will emit rate-limited warnings
5388 fatal - the kernel will send SIGBUS to applications
5393 ratelimit:N -
5413 Certain CPUs are vulnerable to an MDS-like
5431 grace-period sequence counter wrap for the
5432 srcu_data structure's ->srcu_gp_seq_needed field.
5454 force-on: Unconditionally enable mitigation for
5456 force-off: Unconditionally disable mitigation for
5479 stacktrace_filter=[function-list]
5481 will trace at boot up. function-list is a comma-separated
5489 Set the STI (builtin display/keyboard on the HP-PARISC
5491 as the initial boot-console.
5532 to global on non-NUMA machines)
5558 it if 0 is given (See Documentation/admin-guide/cgroup-v1/memory.rst)
5560 swiotlb= [ARM,IA-64,PPC,MIPS,X86]
5562 <int> -- Number of I/O TLB slabs
5563 force -- force using of bounce buffers even if they
5565 noforce -- Never use bounce buffers (for debugging)
5589 Ignore sysrq setting - this boot parameter will
5597 cache size. See Documentation/networking/ip-sysctl.rst
5603 Specify "mem" (for Suspend-to-RAM) or "standby" (for
5608 wakeup-capable RTC alarm.
5614 -1: disable all active trip points in all thermal zones
5618 -1: disable all critical trip points in all thermal zones
5629 -1: disable all passive trip points
5635 <deci-seconds>: poll all this frequency
5657 Prevent the CPU-hotplug component of torturing
5661 Dump the ftrace buffer at torture-test shutdown,
5665 with rotating-rust storage.
5670 disables verbose-printk() sleeping.
5673 Duration of each verbose-printk() sleep in jiffies.
5689 trace_event=[event-list]
5690 [FTRACE] Set and start specified trace events in order
5691 to facilitate early boot debugging. The event-list is a
5692 comma-separated list of trace events to enable. See
5693 also Documentation/trace/events.rst
5695 trace_options=[option-list]
5697 The option-list is a comma delimited list of options
5704 stack trace of each event), add to the command line:
5708 See also Documentation/trace/ftrace.rst "trace options"
5748 This option is useful, as it disables the trace before
5749 the WARNING dump is called, which prevents the trace to
5760 See Documentation/admin-guide/mm/transhuge.rst
5768 - "tpm"
5769 - "tee"
5780 high-resolution timer mode on older hardware, and in
5806 on - Enable TSX on the system. Although there are
5809 several previous speculation-related CVEs, and
5813 off - Disable TSX on the system. (Note that this
5821 auto - Disable TSX if X86_BUG_TAA is present,
5826 See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
5832 Similar to Micro-architectural Data Sampling (MDS)
5847 full - Enable TAA mitigation on vulnerable CPUs
5850 full,nosmt - Enable TAA mitigation and disable SMT on
5853 vulnerable to cross-thread TAA attacks.
5854 off - Unconditionally disable TAA mitigation
5856 On MDS-affected machines, tsx_async_abort=off can be
5868 Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
5874 See also Documentation/input/devices/joystick-parport.rst
5876 udbg-immortal [PPC] When debugging early kernel crashes that
5882 Set number of hash buckets for UDP/UDP-Lite connections
5884 uhci-hcd.ignore_oc=
5886 Some badly-designed motherboards generate lots of
5897 (default -1 = authorized except for wireless USB,
5903 for newly-detected USB devices (default 2). This
5931 [USB] Specifies timeout for the initial 64-byte
5938 [USB] A list of quirk entries to augment the built-in
5941 VendorID:ProductID:Flags. The IDs are 4-digit hex
5943 will change the built-in quirk; setting it if it is
5948 a 255-byte read);
5952 Set-Interface requests);
5971 (bInterval-1).
6006 usb-storage.delay_use=
6010 usb-storage.quirks=
6012 override the built-in unusual_devs list. List
6015 and Product ID values (4-digit hex numbers) and
6017 to a common usb-storage quirk flag as follows:
6059 medium is write-protected).
6068 1 - undefined instruction events
6069 2 - system calls
6070 4 - invalid data aborts
6071 8 - SIGSEGV faults
6072 16 - SIGBUS faults
6088 vdso32= [X86] Control the 32-bit vDSO
6089 vdso32=1: enable 32-bit VDSO
6090 vdso32=0 or vdso32=2: disable 32-bit VDSO
6100 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
6102 vector= [IA-64,SMP]
6133 vga= [BOOT,X86-32] Select a particular video mode
6135 Documentation/admin-guide/svga.rst.
6150 - Disable all of the above options
6171 vsyscall= [X86-64]
6174 code). Most statically-linked binaries and older
6198 see VGA-softcursor.txt. Default: 2 = underline.
6203 This is a 16-member array composed of values
6204 ranging from 0-255.
6209 This is a 16-member array composed of values
6210 ranging from 0-255.
6215 This is a 16-member array composed of values
6216 ranging from 0-255.
6221 Set system-wide default UTF-8 mode for all tty's.
6222 Default is 1, i.e. UTF-8 mode is enabled for all
6227 Format=<-1|0|1>
6228 Set system-wide default for whether a cursor
6229 is shown on new VTs. Default is -1,
6234 vt.italic= [VT] Default color for italic text; 0-15.
6237 vt.underline= [VT] Default color for underlined text; 0-15.
6241 see Documentation/watchdog/watchdog-parameters.rst
6242 or other driver-specific files in the
6268 that this also can be controlled per-workqueue for
6272 Per-cpu workqueues are generally preferred because
6274 locality; unfortunately, per-cpu workqueues tend to
6277 Enabling this makes the per-cpu workqueues which
6292 forces round-robin CPU selection to flush out
6297 x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
6301 xen_512gb_limit [KNL,X86-64,XEN]
6311 ide-disks -- unplug primary master IDE devices
6312 aux-ide-disks -- unplug non-primary-master IDE devices
6313 nics -- unplug network devices
6314 all -- unplug all emulated devices (NICs and IDE disks)
6315 unnecessary -- unplugging emulated devices is
6318 never -- do not unplug even if version check succeeds
6345 xen_timer_slop= [X86-64,XEN]
6363 preferred over the 2-level event handling, as it is
6390 xhci-hcd.quirks [USB,KNL]