disable_radix [PPC]
Disable RADIX MMU mode on POWER9
+ disable_tlbie [PPC]
+ Disable TLBIE instruction. Currently does not work
+ with KVM, with HASH MMU, or with coherent accelerators.
+
disable_cpu_apicid= [X86,APIC,SMP]
Format: <int>
The number of initial APIC ID for the
specified address. The serial port must already be
setup and configured. Options are not yet supported.
+ sbi
+ Use RISC-V SBI (Supervisor Binary Interface) for early
+ console.
+
smh Use ARM semihosting calls for early console.
s3c2410,<addr>
the framebuffer, pass the 'ram' option so that it is
mapped with the correct attributes.
+ linflex,<addr>
+ Use early console provided by Freescale LinFlex UART
+ serial driver for NXP S32V234 SoCs. A valid base
+ address must be provided, and the serial port must
+ already be setup and configured.
+
earlyprintk= [X86,SH,ARM,M68k,S390]
earlyprintk=vga
earlyprintk=sclp
See comment before function elanfreq_setup() in
arch/x86/kernel/cpu/cpufreq/elanfreq.c.
- elevator= [IOSCHED]
- Format: { "mq-deadline" | "kyber" | "bfq" }
- See Documentation/block/deadline-iosched.rst,
- Documentation/block/kyber-iosched.rst and
- Documentation/block/bfq-iosched.rst for details.
-
elfcorehdr=[size[KMG]@]offset[KMG] [IA64,PPC,SH,X86,S390]
Specifies physical address of start of kernel core
image elf header and optionally the size. Generally
Note that using this option lowers the security
provided by tboot because it makes the system
vulnerable to DMA attacks.
+ nobounce [Default off]
+ Disable bounce buffer for unstrusted devices such as
+ the Thunderbolt devices. This will treat the untrusted
+ devices as the trusted ones, hence might expose security
+ risks of DMA attacks.
intel_idle.max_cstate= [KNL,HW,ACPI,X86]
0 disables intel_idle and fall back on acpi_idle.
synchronously.
iommu.passthrough=
- [ARM64] Configure DMA to bypass the IOMMU by default.
+ [ARM64, X86] Configure DMA to bypass the IOMMU by default.
Format: { "0" | "1" }
0 - Use IOMMU translation for DMA.
1 - Bypass the IOMMU for DMA.
machvec= [IA-64] Force the use of a particular machine-vector
(machvec) in a generic kernel.
- Example: machvec=hpzx1_swiotlb
+ Example: machvec=hpzx1
machtype= [Loongson] Share the same kernel image file between different
yeeloong laptop.
mem_encrypt=on: Activate SME
mem_encrypt=off: Do not activate SME
- Refer to Documentation/virtual/kvm/amd-memory-encryption.rst
+ Refer to Documentation/virt/kvm/amd-memory-encryption.rst
for details on when memory encryption can be activated.
mem_sleep_default= [SUSPEND] Default system suspend mode:
expose users to several CPU vulnerabilities.
Equivalent to: nopti [X86,PPC]
kpti=0 [ARM64]
- nospectre_v1 [PPC]
+ nospectre_v1 [X86,PPC]
nobp=0 [S390]
nospectre_v2 [X86,PPC,S390,ARM64]
spectre_v2_user=off [X86]
nosmt=force: Force disable SMT, cannot be undone
via the sysfs control file.
- nospectre_v1 [PPC] Disable mitigations for Spectre Variant 1 (bounds
- check bypass). With this option data leaks are possible
- in the system.
+ nospectre_v1 [X86,PPC] Disable mitigations for Spectre Variant 1
+ (bounds check bypass). With this option data leaks are
+ possible in the system.
nospectre_v2 [X86,PPC_FSL_BOOK3E,ARM64] Disable all mitigations for
the Spectre variant 2 (indirect branch prediction)
RCU_BOOST is not set, valid values are 0-99 and
the default is zero (non-realtime operation).
- rcutree.rcu_nocb_leader_stride= [KNL]
- Set the number of NOCB kthread groups, which
- defaults to the square root of the number of
- CPUs. Larger numbers reduces the wakeup overhead
- on the per-CPU grace-period kthreads, but increases
- that same overhead on each group's leader.
+ rcutree.rcu_nocb_gp_stride= [KNL]
+ Set the number of NOCB callback kthreads in
+ each group, which defaults to the square root
+ of the number of CPUs. Larger numbers reduce
+ the wakeup overhead on the global grace-period
+ kthread, but increases that same overhead on
+ each group's NOCB grace-period kthread.
rcutree.qhimark= [KNL]
Set threshold of queued RCU callbacks beyond which
rcutorture.verbose= [KNL]
Enable additional printk() statements.
+ rcupdate.rcu_cpu_stall_ftrace_dump= [KNL]
+ Dump ftrace buffer after reporting RCU CPU
+ stall warning.
+
rcupdate.rcu_cpu_stall_suppress= [KNL]
Suppress RCU CPU stall warning messages.
Run specified binary instead of /init from the ramdisk,
used for early userspace startup. See initrd.
+ rdrand= [X86]
+ force - Override the decision by the kernel to hide the
+ advertisement of RDRAND support (this affects
+ certain AMD processors because of buggy BIOS
+ support, specifically around the suspend/resume
+ path).
+
rdt= [HW,X86,RDT]
Turn on/off individual RDT features. List is:
cmt, mbmtotal, mbmlocal, l3cat, l3cdp, l2cat, l2cdp,
/sys/power/pm_test). Only available when CONFIG_PM_DEBUG
is set. Default value is 5.
+ svm= [PPC]
+ Format: { on | off | y | n | 1 | 0 }
+ This parameter controls use of the Protected
+ Execution Facility on pSeries.
+
swapaccount=[0|1]
[KNL] Enable accounting of swap in memory resource
controller if no parameter or 1 is given or disable
A hex value specifying bitmask with supplemental xhci
host controller quirks. Meaning of each bit can be
consulted in header drivers/usb/host/xhci.h.
+
+ xmon [PPC]
+ Format: { early | on | rw | ro | off }
+ Controls if xmon debugger is enabled. Default is off.
+ Passing only "xmon" is equivalent to "xmon=early".
+ early Call xmon as early as possible on boot; xmon
+ debugger is called from setup_arch().
+ on xmon debugger hooks will be installed so xmon
+ is only called on a kernel crash. Default mode,
+ i.e. either "ro" or "rw" mode, is controlled
+ with CONFIG_XMON_DEFAULT_RO_MODE.
+ rw xmon debugger hooks will be installed so xmon
+ is called only on a kernel crash, mode is write,
+ meaning SPR registers, memory and, other data
+ can be written using xmon commands.
+ ro same as "rw" option above but SPR registers,
+ memory, and other data can't be written using
+ xmon commands.
+ off xmon is disabled.
projects / linux-2.6-block.git / blobdiff