See Documentation/s390/CommonIO for details.
clk_ignore_unused
[CLK]
- Keep all clocks already enabled by bootloader on,
- even if no driver has claimed them. This 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.
+ Prevents the clock framework from automatically gating
+ clocks that have not been explicitly enabled by a Linux
+ device driver but are enabled in hardware at reset or
+ by the bootloader/firmware. Note that this does not
+ force such clocks to be always-on nor does it reserve
+ 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.
clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
[Deprecated]
Sets the size of kernel global memory area for
contiguous memory allocations and optionally the
placement constraint by the physical address range of
- memory allocations. For more information, see
+ memory allocations. A value of 0 disables CMA
+ altogether. For more information, see
include/linux/dma-contiguous.h
cmo_free_hint= [PPC] Format: { yes | no }
earlycon= [KNL] Output early console device and options.
+ cdns,<addr>
+ Start an early, polled-mode console on a cadence serial
+ port at the specified address. The cadence serial port
+ must already be setup and configured. Options are not
+ yet supported.
+
uart[8250],io,<addr>[,options]
uart[8250],mmio,<addr>[,options]
uart[8250],mmio32,<addr>[,options]
must already be setup and configured. Options are not
yet supported.
+ msm_serial,<addr>
+ Start an early, polled-mode console on an msm serial
+ port at the specified address. The serial port
+ must already be setup and configured. Options are not
+ yet supported.
+
+ msm_serial_dm,<addr>
+ Start an early, polled-mode console on an msm serial
+ dm port at the specified address. The serial port
+ must already be setup and configured. Options are not
+ yet supported.
+
smh Use ARM semihosting calls for early console.
earlyprintk= [X86,SH,BLACKFIN,ARM,M68k]
Format: {"off" | "on" | "skip[mbr]"}
efi= [EFI]
- Format: { "old_map" }
+ Format: { "old_map", "nochunk", "noruntime" }
old_map [X86-64]: switch to the old ioremap-based EFI
runtime services mapping. 32-bit still uses this one by
default.
+ nochunk: disable reading files in "chunks" in the EFI
+ boot stub, as chunking can cause problems with some
+ firmware implementations.
+ noruntime : disable EFI runtime services support
efi_no_storage_paranoia [EFI; X86]
Using this parameter you can use more than 50% of
.cdrom .chs .ignore_cable are additional options
See Documentation/ide/ide.txt.
+ ide-generic.probe-mask= [HW] (E)IDE subsystem
+ Format: <int>
+ Probe mask for legacy ISA IDE ports. Depending on
+ platform up to 6 ports are supported, enabled by
+ setting corresponding bits in the mask to 1. The
+ default value is 0x0, which has a special meaning.
+ On systems that have PCI, it triggers scanning the
+ PCI bus for the first and the second port, which
+ are then probed. On systems without PCI the value
+ of 0x0 enables probing the two first ports as if it
+ was 0x3.
+
ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
Claim all unknown PCI IDE storage controllers.
Set number of hash buckets for inode cache.
ima_appraise= [IMA] appraise integrity measurements
- Format: { "off" | "enforce" | "fix" }
+ Format: { "off" | "enforce" | "fix" | "log" }
default: "enforce"
ima_appraise_tcb [IMA]
kmemleak= [KNL] Boot-time kmemleak enable/disable
Valid arguments: on, off
Default: on
+ Built with CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y,
+ the default is off.
kmemcheck= [X86] Boot-time kmemcheck enable/disable/one-shot mode
Valid arguments: 0, 1, 2
lockd.nlm_udpport=M [NFS] Assign UDP port.
Format: <integer>
+ locktorture.nreaders_stress= [KNL]
+ Set the number of locking read-acquisition kthreads.
+ Defaults to being automatically set based on the
+ number of online CPUs.
+
+ locktorture.nwriters_stress= [KNL]
+ Set the number of locking write-acquisition kthreads.
+
+ locktorture.onoff_holdoff= [KNL]
+ Set time (s) after boot for CPU-hotplug testing.
+
+ locktorture.onoff_interval= [KNL]
+ Set time (s) between CPU-hotplug operations, or
+ zero to disable CPU-hotplug testing.
+
+ locktorture.shuffle_interval= [KNL]
+ Set task-shuffle interval (jiffies). Shuffling
+ tasks allows some CPUs to go into dyntick-idle
+ mode during the locktorture test.
+
+ locktorture.shutdown_secs= [KNL]
+ Set time (s) after boot system shutdown. This
+ is useful for hands-off automated testing.
+
+ locktorture.stat_interval= [KNL]
+ Time (s) between statistics printk()s.
+
+ locktorture.stutter= [KNL]
+ Time (s) to stutter testing, for example,
+ specifying five seconds causes the test to run for
+ five seconds, wait for five seconds, and so on.
+ This tests the locking primitive's ability to
+ transition abruptly to and from idle.
+
+ locktorture.torture_runnable= [BOOT]
+ Start locktorture running at boot time.
+
+ locktorture.torture_type= [KNL]
+ Specify the locking implementation to test.
+
+ locktorture.verbose= [KNL]
+ Enable additional printk() statements.
+
logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
Format: <irq>
nodsp [SH] Disable hardware DSP at boot time.
- noefi [X86] Disable EFI runtime services support.
+ noefi Disable EFI runtime services support.
noexec [IA-64]
Lazy RCU callbacks are those which RCU can
prove do nothing more than free memory.
+ rcutorture.cbflood_inter_holdoff= [KNL]
+ Set holdoff time (jiffies) between successive
+ callback-flood tests.
+
+ rcutorture.cbflood_intra_holdoff= [KNL]
+ Set holdoff time (jiffies) between successive
+ bursts of callbacks within a given callback-flood
+ test.
+
+ rcutorture.cbflood_n_burst= [KNL]
+ Set the number of bursts making up a given
+ callback-flood test. Set this to zero to
+ disable callback-flood testing.
+
+ rcutorture.cbflood_n_per_burst= [KNL]
+ Set the number of callbacks to be registered
+ in a given burst of a callback-flood test.
+
rcutorture.fqs_duration= [KNL]
Set duration of force_quiescent_state bursts.
Set time (s) between CPU-hotplug operations, or
zero to disable CPU-hotplug testing.
- rcutorture.rcutorture_runnable= [BOOT]
+ rcutorture.torture_runnable= [BOOT]
Start rcutorture running at boot time.
rcutorture.shuffle_interval= [KNL]
rcupdate.rcu_cpu_stall_timeout= [KNL]
Set timeout for RCU CPU stall warning messages.
+ rcupdate.rcu_task_stall_timeout= [KNL]
+ Set timeout in jiffies for RCU task stall warning
+ messages. Disable with a value less than or equal
+ to zero.
+
rdinit= [KNL]
Format: <full_path>
Run specified binary instead of /init from the ramdisk,
slram= [HW,MTD]
+ slab_nomerge [MM]
+ Disable merging of slabs with similar size. May be
+ necessary if there is some reason to distinguish
+ allocs to different slabs. Debug options disable
+ merging on their own.
+ For more information see Documentation/vm/slub.txt.
+
slab_max_order= [MM, SLAB]
Determines the maximum allowed order for slabs.
A high setting may cause OOMs due to memory
For more information see Documentation/vm/slub.txt.
slub_nomerge [MM, SLUB]
- Disable merging of slabs with similar size. May be
- necessary if there is some reason to distinguish
- allocs to different slabs. Debug options disable
- merging on their own.
- For more information see Documentation/vm/slub.txt.
+ Same with slab_nomerge. This is supported for legacy.
+ See slab_nomerge for more information.
smart2= [HW]
Format: <io1>[,<io2>[,...,<io8>]]
tdfx= [HW,DRM]
- test_suspend= [SUSPEND]
+ test_suspend= [SUSPEND][,N]
Specify "mem" (for Suspend-to-RAM) or "standby" (for
- standby suspend) as the system sleep state to briefly
- enter during system startup. The system is woken from
- this state using a wakeup-capable RTC alarm.
+ standby suspend) or "freeze" (for suspend type freeze)
+ as the system sleep state during system startup with
+ the optional capability to repeat N number of times.
+ The system is woken from this state using a
+ wakeup-capable RTC alarm.
thash_entries= [KNL,NET]
Set number of hash buckets for TCP connection
e.g. base its process migration decisions on it.
Default is on.
+ topology_updates= [KNL, PPC, NUMA]
+ Format: {off}
+ Specify if the kernel should ignore (off)
+ topology updates sent by the hypervisor to this
+ LPAR.
+
tp720= [HW,PS2]
tpm_suspend_pcr=[HW,TPM]
READ_DISC_INFO command);
e = NO_READ_CAPACITY_16 (don't use
READ_CAPACITY_16 command);
+ f = NO_REPORT_OPCODES (don't use report opcodes
+ command, uas only);
h = CAPACITY_HEURISTICS (decrease the
reported device capacity by one
sector if the number is odd);
bogus residue values);
s = SINGLE_LUN (the device has only one
Logical Unit);
+ t = NO_ATA_1X (don't allow ATA(12) and ATA(16)
+ commands, uas only);
u = IGNORE_UAS (don't bind to the uas driver);
w = NO_WP_DETECT (don't test whether the
medium is write-protected).