dynamic table installation which will install SSDT
tables to /sys/firmware/acpi/tables/dynamic.
+ acpi_no_watchdog [HW,ACPI,WDT]
+ Ignore the ACPI-based watchdog interface (WDAT) and let
+ a native driver control the watchdog device instead.
+
acpi_rsdp= [ACPI,EFI,KEXEC]
Pass the RSDP address to the kernel, mostly used
on machines running EFI runtime service to boot the
bert_disable [ACPI]
Disable BERT OS support on buggy BIOSes.
+ bgrt_disable [ACPI][X86]
+ Disable BGRT to avoid flickering OEM logo.
+
bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
bttv.radio= Most important insmod options are available as
kernel args too.
A valid base address must be provided, and the serial
port must already be setup and configured.
+ ec_imx21,<addr>
+ ec_imx6q,<addr>
+ Start an early, polled-mode, output-only console on the
+ Freescale i.MX UART at the specified address. The UART
+ must already be setup and configured.
+
ar3700_uart,<addr>
Start an early, polled-mode console on the
Armada 3700 serial port at the specified
can be changed at run time by the max_graph_depth file
in the tracefs tracing directory. default: 0 (no limit)
+ fw_devlink= [KNL] Create device links between consumer and supplier
+ devices by scanning the firmware to infer the
+ consumer/supplier relationships. This feature is
+ especially useful when drivers are loaded as modules as
+ it ensures proper ordering of tasks like device probing
+ (suppliers first, then consumers), supplier boot state
+ clean up (only after all consumers have probed),
+ suspend/resume & runtime PM (consumers first, then
+ suppliers).
+ Format: { off | permissive | on | rpm }
+ off -- Don't create device links from firmware info.
+ permissive -- Create device links from firmware info
+ but use it only for ordering boot state clean
+ up (sync_state() calls).
+ on -- Create device links from firmware info and use it
+ to enforce probe and suspend/resume ordering.
+ rpm -- Like "on", but also use to order runtime PM.
+
gamecon.map[2|3]=
[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
support via parallel port (up to 5 devices per port)
provided by tboot because it makes the system
vulnerable to DMA attacks.
nobounce [Default off]
- Disable bounce buffer for unstrusted devices such as
+ Disable bounce buffer for untrusted devices such as
the Thunderbolt devices. This will treat the untrusted
devices as the trusted ones, hence might expose security
risks of DMA attacks.
No delay
ip= [IP_PNP]
- See Documentation/filesystems/nfs/nfsroot.txt.
+ See Documentation/admin-guide/nfs/nfsroot.rst.
ipcmni_extend [KNL] Extend the maximum number of unique System V
IPC identifiers from 32,768 to 16,777,216.
<name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
mtdparts= [MTD]
- See drivers/mtd/cmdlinepart.c.
+ See drivers/mtd/parsers/cmdlinepart.c
multitce=off [PPC] This parameter disables the use of the pSeries
firmware feature for updating multiple TCE entries
Default value is 0.
nfsaddrs= [NFS] Deprecated. Use ip= instead.
- See Documentation/filesystems/nfs/nfsroot.txt.
+ See Documentation/admin-guide/nfs/nfsroot.rst.
nfsroot= [NFS] nfs root filesystem for disk-less boxes.
- See Documentation/filesystems/nfs/nfsroot.txt.
+ See Documentation/admin-guide/nfs/nfsroot.rst.
nfsrootdebug [NFS] enable nfsroot debugging messages.
- See Documentation/filesystems/nfs/nfsroot.txt.
+ See Documentation/admin-guide/nfs/nfsroot.rst.
nfs.callback_nr_threads=
[NFSv4] set the total number of threads that the
This can be set from sysctl after boot.
See Documentation/admin-guide/sysctl/vm.rst for details.
- of_devlink [OF, KNL] Create device links between consumer and
- supplier devices by scanning the devictree to infer the
- consumer/supplier relationships. A consumer device
- will not be probed until all the supplier devices have
- probed successfully.
-
ohci1394_dma=early [HW] enable debugging via the ohci1394 driver.
See Documentation/debugging-via-ohci1394.txt for more
info.
Set threshold of queued RCU callbacks below which
batch limiting is re-enabled.
+ rcutree.qovld= [KNL]
+ Set threshold of queued RCU callbacks beyond which
+ RCU's force-quiescent-state scan will aggressively
+ enlist help from cond_resched() and sched IPIs to
+ help CPUs more quickly reach quiescent states.
+ Set to less than zero to make this be set based
+ on rcutree.qhimark at boot time and to zero to
+ disable more aggressive help enlistment.
+
rcutree.rcu_idle_gp_delay= [KNL]
Set wakeup interval for idle CPUs that have
RCU callbacks (RCU_FAST_NO_HZ=y).
rcupdate.rcu_cpu_stall_suppress= [KNL]
Suppress RCU CPU stall warning messages.
+ rcupdate.rcu_cpu_stall_suppress_at_boot= [KNL]
+ Suppress RCU CPU stall warning messages and
+ rcutorture writer stall warnings that occur
+ during early boot, that is, during the time
+ before the init task is spawned.
+
rcupdate.rcu_cpu_stall_timeout= [KNL]
Set timeout for RCU CPU stall warning messages.
incurs a small amount of overhead in the scheduler
but is useful for debugging and performance tuning.
+ sched_thermal_decay_shift=
+ [KNL, SMP] Set a decay shift for scheduler thermal
+ pressure signal. Thermal pressure signal follows the
+ default decay period of other scheduler pelt
+ signals(usually 32 ms but configurable). Setting
+ sched_thermal_decay_shift will left shift the decay
+ period for the thermal pressure signal by the shift
+ value.
+ i.e. with the default pelt decay period of 32 ms
+ sched_thermal_decay_shift thermal pressure decay pr
+ 1 64 ms
+ 2 128 ms
+ and so on.
+ Format: integer between 0 and 10
+ Default is 0.
+
skew_tick= [KNL] Offset the periodic timer tick per cpu to mitigate
xtime_lock contention on larger systems, and/or RCU lock
contention on all systems with CONFIG_MAXSMP set.
Format: <integer>
A nonzero value instructs the soft-lockup detector
- to panic the machine when a soft-lockup occurs. This
- is also controlled by CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC
- which is the respective build-time switch to that
- functionality.
+ to panic the machine when a soft-lockup occurs. It is
+ also controlled by the kernel.softlockup_panic sysctl
+ and CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC, which is the
+ respective build-time switch to that functionality.
softlockup_all_cpu_backtrace=
[KNL] Should the soft-lockup detector generate
topology updates sent by the hypervisor to this
LPAR.
+ torture.disable_onoff_at_boot= [KNL]
+ Prevent the CPU-hotplug component of torturing
+ until after init has spawned.
+
tp720= [HW,PS2]
tpm_suspend_pcr=[HW,TPM]