diff options
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 57 |
1 files changed, 39 insertions, 18 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 7ccd158b3894..782e9072407b 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1044,6 +1044,10 @@ 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> @@ -1090,6 +1094,12 @@ 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 @@ -1197,12 +1207,6 @@ 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 @@ -1732,6 +1736,11 @@ 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. @@ -1811,7 +1820,7 @@ 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. @@ -2373,7 +2382,7 @@ 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. @@ -2604,7 +2613,7 @@ 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] @@ -2965,9 +2974,9 @@ 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) @@ -3837,12 +3846,13 @@ 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 @@ -4047,6 +4057,10 @@ 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. @@ -4090,6 +4104,13 @@ 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, |