diff options
Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 60 |
1 files changed, 51 insertions, 9 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 22a4b687ea5b..84c0214b64a7 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -167,7 +167,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. acpi= [HW,ACPI,X86,ARM64] Advanced Configuration and Power Interface - Format: { force | off | strict | noirq | rsdt } + Format: { force | off | strict | noirq | rsdt | + copy_dsdt } force -- enable ACPI if default was off off -- disable ACPI if default was on noirq -- do not use ACPI for IRQ routing @@ -789,8 +790,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. is passed, kernel could allocate physical memory region above 4G, that cause second kernel crash on system that require some amount of low memory, e.g. swiotlb - requires at least 64M+32K low memory. Kernel would - try to allocate 72M below 4G automatically. + requires at least 64M+32K low memory, also enough extra + low memory is needed to make sure DMA buffers for 32-bit + devices won't run out. Kernel would try to allocate at + at least 256M below 4G automatically. This one let user to specify own low range under 4G for second kernel instead. 0: to disable low allocation. @@ -971,6 +974,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. earlycon= [KNL] Output early console device and options. + When used with no options, the early console is + 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 @@ -1023,6 +1030,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. serial port must already be setup and configured. Options are not yet supported. + lpuart,<addr> + lpuart32,<addr> + Use early console provided by Freescale LP UART driver + found on Freescale Vybrid and QorIQ LS1021A processors. + A valid base address must be provided, and the serial + port must already be setup and configured. + earlyprintk= [X86,SH,BLACKFIN,ARM,M68k] earlyprintk=vga earlyprintk=efi @@ -1094,6 +1108,21 @@ bytes respectively. Such letter suffixes can also be entirely omitted. you are really sure that your UEFI does sane gc and fulfills the spec otherwise your board may brick. + efi_fake_mem= nn[KMG]@ss[KMG]:aa[,nn[KMG]@ss[KMG]:aa,..] [EFI; X86] + Add arbitrary attribute to specific memory range by + updating original EFI memory map. + Region of memory which aa attribute is added to is + from ss to ss+nn. + If efi_fake_mem=2G@4G:0x10000,2G@0x10a0000000:0x10000 + is specified, EFI_MEMORY_MORE_RELIABLE(0x10000) + attribute is added to range 0x100000000-0x180000000 and + 0x10a0000000-0x1120000000. + + Using this parameter you can do debugging of EFI memmap + related feature. For example, you can do debugging of + Address Range Mirroring feature even if your box + doesn't support it. + eisa_irq_edge= [PARISC,HW] See header of drivers/parisc/eisa.c. @@ -1246,6 +1275,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Format: <unsigned int> such that (rxsize & ~0x1fffc0) == 0. Default: 1024 + hardlockup_all_cpu_backtrace= + [KNL] Should the hard-lockup detector generate + backtraces on all cpus. + Format: <integer> + hashdist= [KNL,NUMA] Large hashes allocated during boot are distributed across NUMA nodes. Defaults on for 64-bit NUMA, off otherwise. @@ -1546,6 +1580,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. hwp_only Only load intel_pstate on systems which support hardware P state control (HWP) if available. + no_acpi + Don't use ACPI processor performance control objects + _PSS and _PPC specified limits. intremap= [X86-64, Intel-IOMMU] on enable Interrupt Remapping (default) @@ -1553,6 +1590,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. nosid disable Source ID checking no_x2apic_optout BIOS x2APIC opt-out request will be ignored + nopost disable Interrupt Posting iomem= Disable strict checking of access to MMIO memory strict regions from userspace. @@ -2314,11 +2352,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels Format: [panic,][nopanic,][num] Valid num: 0 or 1 - 0 - turn nmi_watchdog off - 1 - turn nmi_watchdog on + 0 - turn hardlockup detector in nmi_watchdog off + 1 - turn hardlockup detector in nmi_watchdog on When panic is specified, panic when an NMI watchdog timeout occurs (or 'nopanic' to override the opposite - default). + default). To disable both hard and soft lockup detectors, + please see 'nowatchdog'. This is useful when you use a panic=... timeout and need the box quickly up again. @@ -3074,9 +3113,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. cache-to-cache transfer latencies. rcutree.rcu_fanout_leaf= [KNL] - Increase the number of CPUs assigned to each - leaf rcu_node structure. Useful for very large - systems. + Change the number of CPUs assigned to each + leaf rcu_node structure. Useful for very + large systems, which will choose the value 64, + and for NUMA systems with large remote-access + latencies, which will choose a value aligned + with the appropriate hardware boundaries. rcutree.jiffies_till_sched_qs= [KNL] Set required age in jiffies for a |