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Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 59 |
1 files changed, 40 insertions, 19 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index b9f67781c577..c1b9aa8c5a52 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1,27 +1,37 @@ Kernel Parameters ~~~~~~~~~~~~~~~~~ -The following is a consolidated list of the kernel parameters as implemented -(mostly) by the __setup() macro and sorted into English Dictionary order -(defined as ignoring all punctuation and sorting digits before letters in a -case insensitive manner), and with descriptions where known. - -Module parameters for loadable modules are specified only as the -parameter name with optional '=' and value as appropriate, such as: - - modprobe usbcore blinkenlights=1 - -Module parameters for modules that are built into the kernel image -are specified on the kernel command line with the module name plus -'.' plus parameter name, with '=' and value if appropriate, such as: - - usbcore.blinkenlights=1 +The following is a consolidated list of the kernel parameters as +implemented by the __setup(), core_param() and module_param() macros +and sorted into English Dictionary order (defined as ignoring all +punctuation and sorting digits before letters in a case insensitive +manner), and with descriptions where known. + +The kernel parses parameters from the kernel command line up to "--"; +if it doesn't recognize a parameter and it doesn't contain a '.', the +parameter gets passed to init: parameters with '=' go into init's +environment, others are passed as command line arguments to init. +Everything after "--" is passed as an argument to init. + +Module parameters can be specified in two ways: via the kernel command +line with a module name prefix, or via modprobe, e.g.: + + (kernel command line) usbcore.blinkenlights=1 + (modprobe command line) modprobe usbcore blinkenlights=1 + +Parameters for modules which are built into the kernel need to be +specified on the kernel command line. modprobe looks through the +kernel command line (/proc/cmdline) and collects module parameters +when it loads a module, so the kernel command line can be used for +loadable modules too. Hyphens (dashes) and underscores are equivalent in parameter names, so log_buf_len=1M print-fatal-signals=1 can also be entered as log-buf-len=1M print_fatal_signals=1 +Double-quotes can be used to protect spaces in values, e.g.: + param="spaces in here" This document may not be entirely up to date and comprehensive. The command "modinfo -p ${modulename}" shows a current list of all parameters of a loadable @@ -1464,6 +1474,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. js= [HW,JOY] Analog joystick See Documentation/input/joystick.txt. + kaslr/nokaslr [X86] + Enable/disable kernel and module base offset ASLR + (Address Space Layout Randomization) if built into + the kernel. When CONFIG_HIBERNATION is selected, + kASLR is disabled by default. When kASLR is enabled, + hibernation will be disabled. + keepinitrd [HW,ARM] kernelcore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter @@ -2100,10 +2117,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted. noapic [SMP,APIC] Tells the kernel to not make use of any IOAPICs that may be present in the system. - nokaslr [X86] - Disable kernel and module base offset ASLR (Address - Space Layout Randomization) if built into the kernel. - noautogroup Disable scheduler automatic task group creation. nobats [PPC] Do not use BATs for mapping kernel lowmem @@ -2174,6 +2187,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. in certain environments such as networked servers or real-time systems. + nohibernate [HIBERNATION] Disable hibernation and resume. + nohz= [KNL] Boottime enable/disable dynamic ticks Valid arguments: on, off Default: on @@ -2970,6 +2985,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. noresume Don't check if there's a hibernation image present during boot. nocompress Don't compress/decompress hibernation images. + no Disable hibernation and resume. retain_initrd [RAM] Keep initrd memory after extraction @@ -3114,6 +3130,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. [KNL] Should the soft-lockup detector generate panics. Format: <integer> + softlockup_all_cpu_backtrace= + [KNL] Should the soft-lockup detector generate + backtraces on all cpus. + Format: <integer> + sonypi.*= [HW] Sony Programmable I/O Control Device driver See Documentation/laptops/sonypi.txt |