diff options
Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 64 |
1 files changed, 49 insertions, 15 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index a4f4d693e2c1..705fb915cbf7 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -460,6 +460,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted. driver will print ACPI tables for AMD IOMMU during IOMMU initialization. + amd_iommu_intr= [HW,X86-64] + Specifies one of the following AMD IOMMU interrupt + remapping modes: + legacy - Use legacy interrupt remapping mode. + vapic - Use virtual APIC mode, which allows IOMMU + to inject interrupts directly into guest. + This mode requires kvm-amd.avic=1. + (Default when IOMMU HW support is present.) + amijoy.map= [HW,JOY] Amiga joystick support Map of devices attached to JOY0DAT and JOY1DAT Format: <a>,<b> @@ -698,6 +707,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted. loops can be debugged more effectively on production systems. + clocksource.arm_arch_timer.fsl-a008585= + [ARM64] + Format: <bool> + Enable/disable the workaround of Freescale/NXP + erratum A-008585. This can be useful for KVM + guests, if the guest device tree doesn't show the + erratum. If unspecified, the workaround is + enabled based on the device tree. + clearcpuid=BITNUM [X86] Disable CPUID feature X for the kernel. See arch/x86/include/asm/cpufeatures.h for the valid bit @@ -1045,11 +1063,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. determined by the stdout-path property in device tree's chosen node. - 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. + cdns,<addr>[,options] + Start an early, polled-mode console on a Cadence + (xuartps) serial port at the specified address. Only + supported option is baud rate. If baud rate is not + specified, the serial port must already be setup and + configured. uart[8250],io,<addr>[,options] uart[8250],mmio,<addr>[,options] @@ -1364,6 +1383,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Format: <unsigned int> such that (rxsize & ~0x1fffc0) == 0. Default: 1024 + gpio-mockup.gpio_mockup_ranges + [HW] Sets the ranges of gpiochip of for this device. + Format: <start1>,<end1>,<start2>,<end2>... + hardlockup_all_cpu_backtrace= [KNL] Should the hard-lockup detector generate backtraces on all cpus. @@ -1643,6 +1666,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. initrd= [BOOT] Specify the location of the initial ramdisk + init_pkru= [x86] Specify the default memory protection keys rights + register contents for all processes. 0x55555554 by + default (disallow access to all but pkey 0). Can + override in debugfs after boot. + inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver Format: <irq> @@ -1688,7 +1716,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. intel_idle.max_cstate= [KNL,HW,ACPI,X86] 0 disables intel_idle and fall back on acpi_idle. - 1 to 6 specify maximum depth of C-state. + 1 to 9 specify maximum depth of C-state. intel_pstate= [X86] disable @@ -2161,10 +2189,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. than or equal to this physical address is ignored. maxcpus= [SMP] Maximum number of processors that an SMP kernel - should make use of. maxcpus=n : n >= 0 limits the - kernel to using 'n' processors. n=0 is a special case, - it is equivalent to "nosmp", which also disables - the IO APIC. + will bring up during bootup. maxcpus=n : n >= 0 limits + the kernel to bring up 'n' processors. Surely after + bootup you can bring up the other plugged cpu by executing + "echo 1 > /sys/devices/system/cpu/cpuX/online". So maxcpus + only takes effect during system bootup. + While n=0 is a special case, it is equivalent to "nosmp", + which also disables the IO APIC. max_loop= [LOOP] The number of loop block devices that get (loop.max_loop) unconditionally pre-created at init time. The default @@ -2571,8 +2602,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted. nodelayacct [KNL] Disable per-task delay accounting - nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects. - nodsp [SH] Disable hardware DSP at boot time. noefi Disable EFI runtime services support. @@ -2773,9 +2802,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. nr_cpus= [SMP] Maximum number of processors that an SMP kernel could support. nr_cpus=n : n >= 1 limits the kernel to - supporting 'n' processors. Later in runtime you can not - use hotplug cpu feature to put more cpu back to online. - just like you compile the kernel NR_CPUS=n + support 'n' processors. It could be larger than the + number of already plugged CPU during bootup, later in + runtime you can physically add extra cpu until it reaches + n. So during boot up some boot time memory for per-cpu + variables need be pre-allocated for later physical cpu + hot plugging. nr_uarts= [SERIAL] maximum number of UARTs to be registered. @@ -4238,6 +4270,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. u = IGNORE_UAS (don't bind to the uas driver); w = NO_WP_DETECT (don't test whether the medium is write-protected). + y = ALWAYS_SYNC (issue a SYNCHRONIZE_CACHE + even if the device claims no cache) Example: quirks=0419:aaf5:rl,0421:0433:rc user_debug= [KNL,ARM] |