Format: <io>,<irq>,<mode>
See header of drivers/net/hamradio/baycom_ser_hdx.c.
+ bert_disable [ACPI]
+ Disable BERT OS support on buggy BIOSes.
+
+ bgrt_disable [ACPI][X86]
+ Disable BGRT to avoid flickering OEM logo.
+
blkdevparts= Manual partition parsing of block device(s) for
embedded devices based on command line input.
See Documentation/block/cmdline-partition.rst
See Documentation/admin-guide/bootconfig.rst
- 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.
0: default value, disable debugging
1: enable debugging at boot time
+ cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
+ Format:
+ <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
+
+ cpu0_hotplug [X86] Turn on CPU0 hotplug feature when
+ CONFIG_BOOTPARAM_HOTPLUG_CPU0 is off.
+ Some features depend on CPU0. Known dependencies are:
+ 1. Resume from suspend/hibernate depends on CPU0.
+ Suspend/hibernate will fail if CPU0 is offline and you
+ need to online CPU0 before suspend/hibernate.
+ 2. PIC interrupts also depend on CPU0. CPU0 can't be
+ removed if a PIC interrupt is detected.
+ It's said poweroff/reboot may depend on CPU0 on some
+ machines although I haven't seen such issues so far
+ after CPU0 is offline on a few tested machines.
+ If the dependencies are under your control, you can
+ turn on cpu0_hotplug.
+
cpuidle.off=1 [CPU_IDLE]
disable the cpuidle sub-system
on every CPU online, such as boot, and resume from suspend.
Default: 10000
- cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
- Format:
- <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
+ crash_kexec_post_notifiers
+ Run kdump after running panic-notifiers and dumping
+ kmsg. This only for the users who doubt kdump always
+ succeeds in any situation.
+ Note that this also increases risks of kdump failure,
+ because some panic notifiers can make the crashed
+ kernel more unstable.
crashkernel=size[KMG][@offset[KMG]]
[KNL] Using kexec, Linux can switch to a 'crash kernel'
hpet_mmap= [X86, HPET_MMAP] Allow userspace to mmap HPET
registers. Default set by CONFIG_HPET_MMAP_DEFAULT.
- hugetlb_cma= [HW,CMA] The size of a CMA area used for allocation
- of gigantic hugepages. Or using node format, the size
- of a CMA area per node can be specified.
- Format: nn[KMGTPE] or (node format)
- <node>:nn[KMGTPE][,<node>:nn[KMGTPE]]
-
- Reserve a CMA area of given size and allocate gigantic
- hugepages using the CMA allocator. If enabled, the
- boot-time allocation of gigantic hugepages is skipped.
-
hugepages= [HW] Number of HugeTLB pages to allocate at boot.
If this follows hugepagesz (below), it specifies
the number of pages of hugepagesz to be allocated.
Documentation/admin-guide/mm/hugetlbpage.rst.
Format: size[KMG]
+ hugetlb_cma= [HW,CMA] The size of a CMA area used for allocation
+ of gigantic hugepages. Or using node format, the size
+ of a CMA area per node can be specified.
+ Format: nn[KMGTPE] or (node format)
+ <node>:nn[KMGTPE][,<node>:nn[KMGTPE]]
+
+ Reserve a CMA area of given size and allocate gigantic
+ hugepages using the CMA allocator. If enabled, the
+ boot-time allocation of gigantic hugepages is skipped.
+
hugetlb_free_vmemmap=
[KNL] Reguires CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
enabled.
If there are multiple matching configurations changing
the same attribute, the last one is used.
- memblock=debug [KNL] Enable memblock debug messages.
-
load_ramdisk= [RAM] [Deprecated]
lockd.nlm_grace_period=P [NFS] Assign grace period.
mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
memory.
+ memblock=debug [KNL] Enable memblock debug messages.
+
memchunk=nn[KMG]
[KNL,SH] Allow user to override the default size for
per-device physically contiguous DMA buffers.
mtdparts= [MTD]
See drivers/mtd/parsers/cmdlinepart.c
- multitce=off [PPC] This parameter disables the use of the pSeries
- firmware feature for updating multiple TCE entries
- at a time.
-
mtdset= [ARM]
ARM/S3C2412 JIVE boot control
Used for mtrr cleanup. It is spare mtrr entries number.
Set to 2 or more if your graphical card needs more.
+ multitce=off [PPC] This parameter disables the use of the pSeries
+ firmware feature for updating multiple TCE entries
+ at a time.
+
n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
netdev= [NET] Network devices parameters
This usage is only documented in each driver source
file if at all.
+ netpoll.carrier_timeout=
+ [NET] Specifies amount of time (in seconds) that
+ netpoll should wait for a carrier. By default netpoll
+ waits 4 seconds.
+
nf_conntrack.acct=
[NETFILTER] Enable connection tracking flow accounting
0 to disable accounting
These settings can be accessed at runtime via
the nmi_watchdog and hardlockup_panic sysctls.
- netpoll.carrier_timeout=
- [NET] Specifies amount of time (in seconds) that
- netpoll should wait for a carrier. By default netpoll
- waits 4 seconds.
-
no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
emulation library even if a 387 maths coprocessor
is present.
nox2apic [X86-64,APIC] Do not enable x2APIC mode.
- cpu0_hotplug [X86] Turn on CPU0 hotplug feature when
- CONFIG_BOOTPARAM_HOTPLUG_CPU0 is off.
- Some features depend on CPU0. Known dependencies are:
- 1. Resume from suspend/hibernate depends on CPU0.
- Suspend/hibernate will fail if CPU0 is offline and you
- need to online CPU0 before suspend/hibernate.
- 2. PIC interrupts also depend on CPU0. CPU0 can't be
- removed if a PIC interrupt is detected.
- It's said poweroff/reboot may depend on CPU0 on some
- machines although I haven't seen such issues so far
- after CPU0 is offline on a few tested machines.
- If the dependencies are under your control, you can
- turn on cpu0_hotplug.
-
nps_mtm_hs_ctr= [KNL,ARC]
This parameter sets the maximum duration, in
cycles, each HW thread of the CTOP can run
panic_on_warn panic() instead of WARN(). Useful to cause kdump
on a WARN().
- crash_kexec_post_notifiers
- Run kdump after running panic-notifiers and dumping
- kmsg. This only for the users who doubt kdump always
- succeeds in any situation.
- Note that this also increases risks of kdump failure,
- because some panic notifiers can make the crashed
- kernel more unstable.
-
parkbd.port= [HW] Parallel port number the keyboard adapter is
connected to, default is 0.
Format: <parport#>
This will guarantee that all the other pcrs
are saved.
+ tp_printk [FTRACE]
+ Have the tracepoints sent to printk as well as the
+ tracing ring buffer. This is useful for early boot up
+ where the system hangs or reboots and does not give the
+ option for reading the tracing buffer or performing a
+ ftrace_dump_on_oops.
+
+ To turn off having tracepoints sent to printk,
+ echo 0 > /proc/sys/kernel/tracepoint_printk
+ Note, echoing 1 into this file without the
+ tracepoint_printk kernel cmdline option has no effect.
+
+ The tp_printk_stop_on_boot (see below) can also be used
+ to stop the printing of events to console at
+ late_initcall_sync.
+
+ ** CAUTION **
+
+ Having tracepoints sent to printk() and activating high
+ frequency tracepoints such as irq or sched, can cause
+ the system to live lock.
+
+ tp_printk_stop_on_boot [FTRACE]
+ When tp_printk (above) is set, it can cause a lot of noise
+ on the console. It may be useful to only include the
+ printing of events during boot up, as user space may
+ make the system inoperable.
+
+ This command line option will stop the printing of events
+ to console at the late_initcall_sync() time frame.
+
trace_buf_size=nn[KMG]
[FTRACE] will set tracing buffer size on each cpu.
See also Documentation/trace/ftrace.rst "trace options"
section.
- tp_printk [FTRACE]
- Have the tracepoints sent to printk as well as the
- tracing ring buffer. This is useful for early boot up
- where the system hangs or reboots and does not give the
- option for reading the tracing buffer or performing a
- ftrace_dump_on_oops.
-
- To turn off having tracepoints sent to printk,
- echo 0 > /proc/sys/kernel/tracepoint_printk
- Note, echoing 1 into this file without the
- tracepoint_printk kernel cmdline option has no effect.
-
- The tp_printk_stop_on_boot (see below) can also be used
- to stop the printing of events to console at
- late_initcall_sync.
-
- ** CAUTION **
-
- Having tracepoints sent to printk() and activating high
- frequency tracepoints such as irq or sched, can cause
- the system to live lock.
-
- tp_printk_stop_on_boot [FTRACE]
- When tp_printk (above) is set, it can cause a lot of noise
- on the console. It may be useful to only include the
- printing of events during boot up, as user space may
- make the system inoperable.
-
- This command line option will stop the printing of events
- to console at the late_initcall_sync() time frame.
-
traceoff_on_warning
[FTRACE] enable this option to disable tracing when a
warning is hit. This turns off "tracing_on". Tracing can
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