use by PCI
Format: <irq>,<irq>...
- acpi_mask_gpe= [HW,ACPI]
+ acpi_mask_gpe= [HW,ACPI]
Due to the existence of _Lxx/_Exx, some GPEs triggered
by unsupported hardware/firmware features can result in
- GPE floodings that cannot be automatically disabled by
- the GPE dispatcher.
+ GPE floodings that cannot be automatically disabled by
+ the GPE dispatcher.
This facility can be used to prevent such uncontrolled
GPE floodings.
Format: <int>
for platform specific values (SB1, Loongson3 and
others).
- ccw_timeout_log [S390]
+ ccw_timeout_log [S390]
See Documentation/s390/CommonIO for details.
- cgroup_disable= [KNL] Disable a particular controller
+ cgroup_disable= [KNL] Disable a particular controller
Format: {name of the controller(s) to disable}
The effects of cgroup_disable=foo are:
- foo isn't auto-mounted if you mount all cgroups in
those clocks in any way. This parameter is useful for
debug and development, but should not be needed on a
platform with proper driver support. For more
- information, see Documentation/clk.txt.
+ information, see Documentation/driver-api/clk.rst.
clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
[Deprecated]
Sets the size of memory pool for coherent, atomic dma
allocations, by default set to 256K.
- code_bytes [X86] How many bytes of object code to print
- in an oops report.
- Range: 0 - 8192
- Default: 64
-
com20020= [HW,NET] ARCnet - COM20020 chipset
Format:
<io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
hvc<n> Use the hypervisor console device <n>. This is for
both Xen and PowerPC hypervisors.
- If the device connected to the port is not a TTY but a braille
- device, prepend "brl," before the device type, for instance
+ If the device connected to the port is not a TTY but a braille
+ device, prepend "brl," before the device type, for instance
console=brl,ttyS0
For now, only VisioBraille is supported.
consoleblank= [KNL] The console blank (screen saver) timeout in
seconds. A value of 0 disables the blank timer.
- Defaults to 0.
+ Defaults to 0.
coredump_filter=
[KNL] Change the default value for
or memory reserved is below 4G.
cryptomgr.notests
- [KNL] Disable crypto self-tests
+ [KNL] Disable crypto self-tests
cs89x0_dma= [HW,NET]
Format: <dma>
Format: <port#>,<type>
See also Documentation/input/devices/joystick-parport.rst
- ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot
+ ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot
time. See
Documentation/admin-guide/dynamic-debug-howto.rst for
details. Deprecated, see dyndbg.
causing system reset or hang due to sending
INIT from AP to BSP.
- disable_ddw [PPC/PSERIES]
+ disable_ddw [PPC/PSERIES]
Disable Dynamic DMA Window support. Use this if
to workaround buggy firmware.
parameter will force ia64_sal_cache_flush to call
ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
- forcepae [X86-32]
+ forcepae [X86-32]
Forcefully enable Physical Address Extension (PAE).
Many Pentium M systems disable PAE but may have a
functionally usable PAE implementation.
gamma= [HW,DRM]
- gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
+ gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
Format: off | on
default: on
x86-64 are 2M (when the CPU supports "pse") and 1G
(when the CPU supports the "pdpe1gb" cpuinfo flag).
- hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC)
- terminal devices. Valid values: 0..8
- hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
- If specified, z/VM IUCV HVC accepts connections
- from listed z/VM user IDs only.
+ hung_task_panic=
+ [KNL] Should the hung task detector generate panics.
+ Format: <integer>
+ A nonzero value instructs the kernel to panic when a
+ hung task is detected. The default value is controlled
+ by the CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time
+ option. The value selected by this boot parameter can
+ be changed later by the kernel.hung_task_panic sysctl.
+
+ hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC)
+ terminal devices. Valid values: 0..8
+ hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
+ If specified, z/VM IUCV HVC accepts connections
+ from listed z/VM user IDs only.
keep_bootcon [KNL]
Do not unregister boot console at start. This is only
useful for debugging when something happens in the window
between unregistering the boot console and initializing
the real console.
- i2c_bus= [HW] Override the default board specific I2C bus speed
- or register an additional I2C bus that is not
- registered from board initialization code.
- Format:
- <bus_id>,<clkrate>
+ i2c_bus= [HW] Override the default board specific I2C bus speed
+ or register an additional I2C bus that is not
+ registered from board initialization code.
+ Format:
+ <bus_id>,<clkrate>
i8042.debug [HW] Toggle i8042 debug mode
i8042.unmask_kbd_data
Default: only on s2r transitions on x86; most other
architectures force reset to be always executed
i8042.unlock [HW] Unlock (ignore) the keylock
- i8042.kbdreset [HW] Reset device connected to KBD port
+ i8042.kbdreset [HW] Reset device connected to KBD port
i810= [HW,DRM]
programs exec'd, files mmap'd for exec, and all files
opened for read by uid=0.
- ima_template= [IMA]
+ ima_template= [IMA]
Select one of defined IMA measurements template formats.
Formats: { "ima" | "ima-ng" | "ima-sig" }
Default: "ima-ng"
ima_template_fmt=
- [IMA] Define a custom template format.
+ [IMA] Define a custom template format.
Format: { "field1|...|fieldN" }
ima.ahash_minsize= [IMA] Minimum file size for asynchronous hash usage
inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
Format: <irq>
- int_pln_enable [x86] Enable power limit notification interrupt
+ int_pln_enable [x86] Enable power limit notification interrupt
integrity_audit=[IMA]
Format: { "0" | "1" }
0 disables intel_idle and fall back on acpi_idle.
1 to 9 specify maximum depth of C-state.
- intel_pstate= [X86]
- disable
- Do not enable intel_pstate as the default
- scaling driver for the supported processors
- passive
- Use intel_pstate as a scaling driver, but configure it
- to work with generic cpufreq governors (instead of
- enabling its internal governor). This mode cannot be
- used along with the hardware-managed P-states (HWP)
- feature.
- force
- Enable intel_pstate on systems that prohibit it by default
- in favor of acpi-cpufreq. Forcing the intel_pstate driver
- instead of acpi-cpufreq may disable platform features, such
- as thermal controls and power capping, that rely on ACPI
- P-States information being indicated to OSPM and therefore
- should be used with caution. This option does not work with
- processors that aren't supported by the intel_pstate driver
- or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
- no_hwp
- Do not enable hardware P state control (HWP)
- if available.
- hwp_only
- Only load intel_pstate on systems which support
- hardware P state control (HWP) if available.
- support_acpi_ppc
- Enforce ACPI _PPC performance limits. If the Fixed ACPI
- Description Table, specifies preferred power management
- profile as "Enterprise Server" or "Performance Server",
- then this feature is turned on by default.
- per_cpu_perf_limits
- Allow per-logical-CPU P-State performance control limits using
- cpufreq sysfs interface
+ intel_pstate= [X86]
+ disable
+ Do not enable intel_pstate as the default
+ scaling driver for the supported processors
+ passive
+ Use intel_pstate as a scaling driver, but configure it
+ to work with generic cpufreq governors (instead of
+ enabling its internal governor). This mode cannot be
+ used along with the hardware-managed P-states (HWP)
+ feature.
+ force
+ Enable intel_pstate on systems that prohibit it by default
+ in favor of acpi-cpufreq. Forcing the intel_pstate driver
+ instead of acpi-cpufreq may disable platform features, such
+ as thermal controls and power capping, that rely on ACPI
+ P-States information being indicated to OSPM and therefore
+ should be used with caution. This option does not work with
+ processors that aren't supported by the intel_pstate driver
+ or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
+ no_hwp
+ Do not enable hardware P state control (HWP)
+ if available.
+ hwp_only
+ Only load intel_pstate on systems which support
+ hardware P state control (HWP) if available.
+ support_acpi_ppc
+ Enforce ACPI _PPC performance limits. If the Fixed ACPI
+ Description Table, specifies preferred power management
+ profile as "Enterprise Server" or "Performance Server",
+ then this feature is turned on by default.
+ per_cpu_perf_limits
+ Allow per-logical-CPU P-State performance control limits using
+ cpufreq sysfs interface
intremap= [X86-64, Intel-IOMMU]
on enable Interrupt Remapping (default)
nopanic
merge
nomerge
- forcesac
soft
pt [x86, IA-64]
nobypass [PPC/POWERNV]
* [no]ncqtrim: Turn off queued DSM TRIM.
* nohrst, nosrst, norst: suppress hard, soft
- and both resets.
+ and both resets.
* rstonce: only attempt one reset during
hot-unplug link recovery
[KNL,SH] Allow user to override the default size for
per-device physically contiguous DMA buffers.
- memhp_default_state=online/offline
+ memhp_default_state=online/offline
[KNL] Set the initial state for the memory hotplug
onlining policy. If not specified, the default value is
set according to the
emulation library even if a 387 maths coprocessor
is present.
+ no5lvl [X86-64] Disable 5-level paging mode. Forces
+ kernel to use 4-level paging instead.
+
no_console_suspend
[HW] Never suspend the console
Disable suspending of consoles during suspend and
allow data leaks with this option, which is equivalent
to spectre_v2=off.
+ nospec_store_bypass_disable
+ [HW] Disable all mitigations for the Speculative Store Bypass vulnerability
+
noxsave [BUGS=X86] Disables x86 extended register state save
and restore using xsave. The kernel will fallback to
enabling legacy floating-point and sse state.
[X86,PV_OPS] Disable paravirtualized VMware scheduler
clock and use the default one.
- no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting.
+ no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting.
steal time is computed, but won't influence scheduler
behaviour
notsc [BUGS=X86-32] Disable Time Stamp Counter
nowatchdog [KNL] Disable both lockup detectors, i.e.
- soft-lockup and NMI watchdog (hard-lockup).
+ soft-lockup and NMI watchdog (hard-lockup).
nowb [ARM]
If the dependencies are under your control, you can
turn on cpu0_hotplug.
- nps_mtm_hs_ctr= [KNL,ARC]
+ nps_mtm_hs_ctr= [KNL,ARC]
This parameter sets the maximum duration, in
cycles, each HW thread of the CTOP can run
without interruptions, before HW switches it.
pci=option[,option...] [PCI] various PCI subsystem options:
earlydump [X86] dump PCI config space before the kernel
- changes anything
+ changes anything
off [X86] don't probe for the PCI bus
bios [X86-32] force use of PCI BIOS, don't access
the hardware directly. Use this if your machine
is enabled by default. If you need to use this,
please report a bug.
nocrs [X86] Ignore PCI host bridge windows from ACPI.
- If you need to use this, please report a bug.
+ If you need to use this, please report a bug.
routeirq Do IRQ routing for all PCI devices.
This is normally done in pci_enable_device(),
so this option is a temporary workaround
cache (risks via metadata attacks are mostly
unchanged). Debug options disable merging on their
own.
- For more information see Documentation/vm/slub.txt.
+ For more information see Documentation/vm/slub.rst.
slab_max_order= [MM, SLAB]
Determines the maximum allowed order for slabs.
slub_debug can create guard zones around objects and
may poison objects when not in use. Also tracks the
last alloc / free. For more information see
- Documentation/vm/slub.txt.
+ Documentation/vm/slub.rst.
slub_memcg_sysfs= [MM, SLUB]
Determines whether to enable sysfs directories for
Determines the maximum allowed order for slabs.
A high setting may cause OOMs due to memory
fragmentation. For more information see
- Documentation/vm/slub.txt.
+ Documentation/vm/slub.rst.
slub_min_objects= [MM, SLUB]
The minimum number of objects per slab. SLUB will
the number of objects indicated. The higher the number
of objects the smaller the overhead of tracking slabs
and the less frequently locks need to be acquired.
- For more information see Documentation/vm/slub.txt.
+ For more information see Documentation/vm/slub.rst.
slub_min_order= [MM, SLUB]
Determines the minimum page order for slabs. Must be
lower than slub_max_order.
- For more information see Documentation/vm/slub.txt.
+ For more information see Documentation/vm/slub.rst.
slub_nomerge [MM, SLUB]
Same with slab_nomerge. This is supported for legacy.
Not specifying this option is equivalent to
spectre_v2=auto.
+ spec_store_bypass_disable=
+ [HW] Control Speculative Store Bypass (SSB) Disable mitigation
+ (Speculative Store Bypass vulnerability)
+
+ Certain CPUs are vulnerable to an exploit against a
+ a common industry wide performance optimization known
+ as "Speculative Store Bypass" in which recent stores
+ to the same memory location may not be observed by
+ later loads during speculative execution. The idea
+ is that such stores are unlikely and that they can
+ be detected prior to instruction retirement at the
+ end of a particular speculation execution window.
+
+ In vulnerable processors, the speculatively forwarded
+ store can be used in a cache side channel attack, for
+ example to read memory to which the attacker does not
+ directly have access (e.g. inside sandboxed code).
+
+ This parameter controls whether the Speculative Store
+ Bypass optimization is used.
+
+ on - Unconditionally disable Speculative Store Bypass
+ off - Unconditionally enable Speculative Store Bypass
+ auto - Kernel detects whether the CPU model contains an
+ implementation of Speculative Store Bypass and
+ picks the most appropriate mitigation. If the
+ CPU is not vulnerable, "off" is selected. If the
+ CPU is vulnerable the default mitigation is
+ architecture and Kconfig dependent. See below.
+ prctl - Control Speculative Store Bypass per thread
+ via prctl. Speculative Store Bypass is enabled
+ for a process by default. The state of the control
+ is inherited on fork.
+ seccomp - Same as "prctl" above, but all seccomp threads
+ will disable SSB unless they explicitly opt out.
+
+ Not specifying this option is equivalent to
+ spec_store_bypass_disable=auto.
+
+ Default mitigations:
+ X86: If CONFIG_SECCOMP=y "seccomp", otherwise "prctl"
+
spia_io_base= [HW,MTD]
spia_fio_base=
spia_pedr=
Format: [always|madvise|never]
Can be used to control the default behavior of the system
with respect to transparent hugepages.
- See Documentation/vm/transhuge.txt for more details.
+ See Documentation/admin-guide/mm/transhuge.rst
+ for more details.
tsc= Disable clocksource stability checks for TSC.
Format: <string>
usbcore.initial_descriptor_timeout=
[USB] Specifies timeout for the initial 64-byte
- USB_REQ_GET_DESCRIPTOR request in milliseconds
+ USB_REQ_GET_DESCRIPTOR request in milliseconds
(default 5000 = 5.0 seconds).
usbcore.nousb [USB] Disable the USB subsystem
projects / mirror_ubuntu-eoan-kernel.git / commitdiff