diff options
Diffstat (limited to 'upstream/opensuse-tumbleweed/man7/kernel-command-line.7')
| -rw-r--r-- | upstream/opensuse-tumbleweed/man7/kernel-command-line.7 | 442 |
1 files changed, 442 insertions, 0 deletions
diff --git a/upstream/opensuse-tumbleweed/man7/kernel-command-line.7 b/upstream/opensuse-tumbleweed/man7/kernel-command-line.7 new file mode 100644 index 00000000..a1a4c578 --- /dev/null +++ b/upstream/opensuse-tumbleweed/man7/kernel-command-line.7 @@ -0,0 +1,442 @@ +'\" t +.TH "KERNEL\-COMMAND\-LINE" "7" "" "systemd 254" "kernel-command-line" +.\" ----------------------------------------------------------------- +.\" * Define some portability stuff +.\" ----------------------------------------------------------------- +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.\" http://bugs.debian.org/507673 +.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.ie \n(.g .ds Aq \(aq +.el .ds Aq ' +.\" ----------------------------------------------------------------- +.\" * set default formatting +.\" ----------------------------------------------------------------- +.\" disable hyphenation +.nh +.\" disable justification (adjust text to left margin only) +.ad l +.\" ----------------------------------------------------------------- +.\" * MAIN CONTENT STARTS HERE * +.\" ----------------------------------------------------------------- +.SH "NAME" +kernel-command-line \- Kernel command line parameters +.SH "SYNOPSIS" +.PP +/proc/cmdline +.SH "DESCRIPTION" +.PP +The kernel, the programs running in the initrd and in the host system may be configured at boot via kernel command line arguments\&. In addition, various systemd tools look at the EFI variable +"SystemdOptions" +(if available)\&. Both sources are combined, but the kernel command line has higher priority\&. Please note that +\fIthe EFI variable is only used by systemd tools, and is ignored by the kernel and other user space tools\fR, so it is not a replacement for the kernel command line\&. +.PP +For command line parameters understood by the kernel, please see +\m[blue]\fBkernel\-parameters\&.html\fR\m[]\&\s-2\u[1]\d\s+2 +and +\fBbootparam\fR(7)\&. +.PP +For command line parameters understood by the initrd, see +\fBdracut.cmdline\fR(7), or the documentation of the specific initrd implementation of your installation\&. +.SH "CORE OS COMMAND LINE ARGUMENTS" +.PP +\fIsystemd\&.unit=\fR, \fIrd\&.systemd\&.unit=\fR, \fIsystemd\&.dump_core\fR, \fIsystemd\&.crash_chvt\fR, \fIsystemd\&.crash_shell\fR, \fIsystemd\&.crash_reboot\fR, \fIsystemd\&.confirm_spawn\fR, \fIsystemd\&.service_watchdogs\fR, \fIsystemd\&.show_status\fR, \fIsystemd\&.status_unit_format=\fR, \fIsystemd\&.log_target=\fR, \fIsystemd\&.log_level=\fR, \fIsystemd\&.log_location=\fR, \fIsystemd\&.log_color\fR, \fIsystemd\&.log_ratelimit_kmsg\fR, \fIsystemd\&.default_standard_output=\fR, \fIsystemd\&.default_standard_error=\fR, \fIsystemd\&.setenv=\fR, \fIsystemd\&.machine_id=\fR, \fIsystemd\&.set_credential=\fR, \fIsystemd\&.set_credential_binary=\fR, \fIsystemd\&.import_credentials=\fR, \fIsystemd\&.reload_limit_interval_sec=\fR, \fIsystemd\&.reload_limit_burst=\fR +.RS 4 +Parameters understood by the system and service manager to control system behavior\&. For details, see +\fBsystemd\fR(1)\&. +.RE +.PP +\fIsystemd\&.mask=\fR, \fIsystemd\&.wants=\fR, \fIsystemd\&.debug_shell\fR +.RS 4 +Additional parameters understood by +\fBsystemd-debug-generator\fR(8), to mask or start specific units at boot, or invoke a debug shell on tty9\&. +.RE +.PP +\fIsystemd\&.run=\fR, \fIsystemd\&.run_success_action=\fR, \fIsystemd\&.run_failure_action=\fR +.RS 4 +Additional parameters understood by +\fBsystemd-run-generator\fR(8), to run a command line specified on the kernel command line as system service after booting up\&. +.RE +.PP +\fIsystemd\&.early_core_pattern=\fR +.RS 4 +During early boot, the generation of core dump files is disabled until a core dump handler (if any) takes over\&. This parameter allows specifying an absolute path where core dump files should be stored until a handler is installed\&. The path should be absolute and may contain specifiers, see +\fBcore\fR(5) +for details\&. +.RE +.PP +\fIsystemd\&.restore_state=\fR +.RS 4 +This parameter is understood by several system tools to control whether or not they should restore system state from the previous boot\&. For details, see +\fBsystemd-backlight@.service\fR(8) +and +\fBsystemd-rfkill.service\fR(8)\&. +.RE +.PP +\fIsystemd\&.volatile=\fR +.RS 4 +This parameter controls whether the system shall boot up in volatile mode\&. Takes a boolean argument, or the special value +"state"\&. If false (the default), normal boot mode is selected, the root directory and +/var/ +are mounted as specified on the kernel command line or +/etc/fstab, or otherwise configured\&. If true, full state\-less boot mode is selected\&. In this case the root directory is mounted as volatile memory file system ("tmpfs"), and only +/usr/ +is mounted from the file system configured as root device, in read\-only mode\&. This enables fully state\-less boots were the vendor\-supplied OS is used as shipped, with only default configuration and no stored state in effect, as +/etc/ +and +/var/ +(as well as all other resources shipped in the root file system) are reset at boot and lost on shutdown\&. If this setting is set to +"state" +the root file system is mounted read\-only, however +/var/ +is mounted as a volatile memory file system ("tmpfs"), so that the system boots up with the normal configuration applied, but all state reset at boot and lost at shutdown\&. If this setting is set to +"overlay" +the root file system is set up as +"overlayfs" +mount combining the read\-only root directory with a writable +"tmpfs", so that no modifications are made to disk, but the file system may be modified nonetheless with all changes being lost at reboot\&. For details, see +\fBsystemd-volatile-root.service\fR(8) +and +\fBsystemd-fstab-generator\fR(8)\&. +.RE +.PP +\fIquiet\fR +.RS 4 +Parameter understood by both the kernel and the system and service manager to control console log verbosity\&. For details, see +\fBsystemd\fR(1)\&. +.RE +.PP +\fIdebug\fR +.RS 4 +Parameter understood by both the kernel and the system and service manager to control console log verbosity\&. For details, see +\fBsystemd\fR(1)\&. +.RE +.PP +\fI\-b\fR, \fIrd\&.emergency\fR, \fIemergency\fR, \fIrd\&.rescue\fR, \fIrescue\fR, \fIsingle\fR, \fIs\fR, \fIS\fR, \fI1\fR, \fI2\fR, \fI3\fR, \fI4\fR, \fI5\fR +.RS 4 +Parameters understood by the system and service manager, as compatibility and convenience options\&. For details, see +\fBsystemd\fR(1)\&. +.RE +.PP +\fIlocale\&.LANG=\fR, \fIlocale\&.LANGUAGE=\fR, \fIlocale\&.LC_CTYPE=\fR, \fIlocale\&.LC_NUMERIC=\fR, \fIlocale\&.LC_TIME=\fR, \fIlocale\&.LC_COLLATE=\fR, \fIlocale\&.LC_MONETARY=\fR, \fIlocale\&.LC_MESSAGES=\fR, \fIlocale\&.LC_PAPER=\fR, \fIlocale\&.LC_NAME=\fR, \fIlocale\&.LC_ADDRESS=\fR, \fIlocale\&.LC_TELEPHONE=\fR, \fIlocale\&.LC_MEASUREMENT=\fR, \fIlocale\&.LC_IDENTIFICATION=\fR +.RS 4 +Parameters understood by the system and service manager to control locale and language settings\&. For details, see +\fBsystemd\fR(1)\&. +.RE +.PP +\fIfsck\&.mode=\fR, \fIfsck\&.repair=\fR +.RS 4 +Parameters understood by the file system checker services\&. For details, see +\fBsystemd-fsck@.service\fR(8)\&. +.RE +.PP +\fIquotacheck\&.mode=\fR +.RS 4 +Parameter understood by the file quota checker service\&. For details, see +\fBsystemd-quotacheck.service\fR(8)\&. +.RE +.PP +\fIsystemd\&.journald\&.forward_to_syslog=\fR, \fIsystemd\&.journald\&.forward_to_kmsg=\fR, \fIsystemd\&.journald\&.forward_to_console=\fR, \fIsystemd\&.journald\&.forward_to_wall=\fR +.RS 4 +Parameters understood by the journal service\&. For details, see +\fBsystemd-journald.service\fR(8)\&. +.RE +.PP +\fIvconsole\&.keymap=\fR, \fIvconsole\&.keymap_toggle=\fR, \fIvconsole\&.font=\fR, \fIvconsole\&.font_map=\fR, \fIvconsole\&.font_unimap=\fR +.RS 4 +Parameters understood by the virtual console setup logic\&. For details, see +\fBvconsole.conf\fR(5)\&. +.RE +.PP +\fIudev\&.log_level=\fR, \fIrd\&.udev\&.log_level=\fR, \fIudev\&.children_max=\fR, \fIrd\&.udev\&.children_max=\fR, \fIudev\&.exec_delay=\fR, \fIrd\&.udev\&.exec_delay=\fR, \fIudev\&.event_timeout=\fR, \fIrd\&.udev\&.event_timeout=\fR, \fIudev\&.timeout_signal=\fR, \fIrd\&.udev\&.timeout_signal=\fR, \fIudev\&.blockdev_read_only\fR, \fIrd\&.udev\&.blockdev_read_only\fR, \fInet\&.ifnames=\fR, \fInet\&.naming\-scheme=\fR +.RS 4 +Parameters understood by the device event managing daemon\&. For details, see +\fBsystemd-udevd.service\fR(8)\&. +.RE +.PP +\fIplymouth\&.enable=\fR +.RS 4 +May be used to disable the Plymouth boot splash\&. For details, see +\fBplymouth\fR(8)\&. +.RE +.PP +\fIluks=\fR, \fIrd\&.luks=\fR, \fIluks\&.crypttab=\fR, \fIrd\&.luks\&.crypttab=\fR, \fIluks\&.name=\fR, \fIrd\&.luks\&.name=\fR, \fIluks\&.uuid=\fR, \fIrd\&.luks\&.uuid=\fR, \fIluks\&.options=\fR, \fIrd\&.luks\&.options=\fR, \fIluks\&.key=\fR, \fIrd\&.luks\&.key=\fR +.RS 4 +Configures the LUKS full\-disk encryption logic at boot\&. For details, see +\fBsystemd-cryptsetup-generator\fR(8)\&. +.RE +.PP +\fIfstab=\fR, \fIrd\&.fstab=\fR +.RS 4 +Configures the +/etc/fstab +logic at boot\&. For details, see +\fBsystemd-fstab-generator\fR(8)\&. +.RE +.PP +\fIroot=\fR, \fIrootfstype=\fR, \fIrootflags=\fR, \fIro\fR, \fIrw\fR +.RS 4 +Configures the root file system and its file system type and mount options, as well as whether it shall be mounted read\-only or read\-write initially\&. For details, see +\fBsystemd-fstab-generator\fR(8)\&. +.sp +If +\fIroot=\fR +is not set (or set to +"gpt\-auto") the automatic root partition discovery implemented by +\fBsystemd-gpt-auto-generator\fR(8) +will be in effect\&. In this case +\fIrootfstype=\fR, +\fIrootflags=\fR, +\fIro\fR, +\fIrw\fR +will be interpreted by +\fBsystemd\-gpt\-auto\-generator\fR\&. +.RE +.PP +\fImount\&.usr=\fR, \fImount\&.usrfstype=\fR, \fImount\&.usrflags=\fR +.RS 4 +Configures the /usr file system (if required) and its file system type and mount options\&. For details, see +\fBsystemd-fstab-generator\fR(8)\&. +.RE +.PP +\fIveritytab=\fR, \fIrd\&.veritytab=\fR, \fIroothash=\fR, \fIsystemd\&.verity=\fR, \fIrd\&.systemd\&.verity=\fR, \fIsystemd\&.verity_root_data=\fR, \fIsystemd\&.verity_root_hash=\fR, \fIsystemd\&.verity\&.root_options=\fR, \fIusrhash=\fR, \fIsystemd\&.verity_usr_data=\fR, \fIsystemd\&.verity_usr_hash=\fR, \fIsystemd\&.verity_usr_options=\fR +.RS 4 +Configures the integrity protection root hash for the root and +/usr +file systems, and other related parameters\&. For details, see +\fBsystemd-veritysetup-generator\fR(8)\&. +.RE +.PP +\fIsystemd\&.getty_auto=\fR +.RS 4 +Configures whether the +serial\-getty@\&.service +will run\&. For details, see +\fBsystemd-getty-generator\fR(8)\&. +.RE +.PP +\fIsystemd\&.gpt_auto=\fR, \fIrd\&.systemd\&.gpt_auto=\fR +.RS 4 +Configures whether GPT\-based partition auto\-discovery shall be attempted\&. For details, see +\fBsystemd-gpt-auto-generator\fR(8)\&. +.RE +.PP +\fIsystemd\&.image_policy=\fR, \fIrd\&.systemd\&.image_policy=\fR +.RS 4 +When GPT\-based partition auto\-discovery is used, configures the image dissection policy string to apply, as per +\fBsystemd.image-policy\fR(7)\&. For details see +\fBsystemd-gpt-auto-generator\fR(8)\&. +.RE +.PP +\fIsystemd\&.default_timeout_start_sec=\fR +.RS 4 +Overrides the default start job timeout +\fIDefaultTimeoutStartSec=\fR +at boot\&. For details, see +\fBsystemd-system.conf\fR(5)\&. +.RE +.PP +\fIsystemd\&.default_device_timeout_sec=\fR +.RS 4 +Overrides the default device timeout +\fIDefaultDeviceTimeoutSec=\fR +at boot\&. For details, see +\fBsystemd-system.conf\fR(5)\&. +.RE +.PP +\fIsystemd\&.watchdog_device=\fR +.RS 4 +Overrides the watchdog device path +\fIWatchdogDevice=\fR\&. For details, see +\fBsystemd-system.conf\fR(5)\&. +.RE +.PP +\fIsystemd\&.watchdog_sec=\fR +.RS 4 +Overrides the watchdog timeout settings otherwise configured with +\fIRuntimeWatchdog=\fR, +\fIRebootWatchdog=\fR +and +\fIKExecWatchdogSec=\fR\&. Takes a time value (if no unit is specified, seconds is the implicitly assumed time unit) or the special strings +"off" +or +"default"\&. For details, see +\fBsystemd-system.conf\fR(5)\&. +.RE +.PP +\fIsystemd\&.watchdog_pre_sec=\fR +.RS 4 +Overrides the watchdog pre\-timeout settings otherwise configured with +\fIRuntimeWatchdogPreSec=\fR\&. Takes a time value (if no unit is specified, seconds is the implicitly assumed time unit) or the special strings +"off" +or +"default"\&. For details, see +\fBsystemd-system.conf\fR(5)\&. +.RE +.PP +\fIsystemd\&.watchdog_pretimeout_governor=\fR +.RS 4 +Overrides the watchdog pre\-timeout settings otherwise configured with +\fIRuntimeWatchdogPreGovernor=\fR\&. Takes a string value\&. For details, see +\fBsystemd-system.conf\fR(5)\&. +.RE +.PP +\fIsystemd\&.cpu_affinity=\fR +.RS 4 +Overrides the CPU affinity mask for the service manager and the default for all child processes it forks\&. This takes precedence over +\fICPUAffinity=\fR, see +\fBsystemd-system.conf\fR(5) +for details\&. +.RE +.PP +\fImodules_load=\fR, \fIrd\&.modules_load=\fR +.RS 4 +Load a specific kernel module early at boot\&. For details, see +\fBsystemd-modules-load.service\fR(8)\&. +.RE +.PP +\fInameserver=\fR, \fIdomain=\fR +.RS 4 +Configures DNS server information and search domains, see +\fBsystemd-resolved.service\fR(8) +for details\&. +.RE +.PP +\fIresume=\fR, \fIresumeflags=\fR +.RS 4 +Enables resume from hibernation using the specified device and mount options\&. All +\fBfstab\fR(5)\-like paths are supported\&. For details, see +\fBsystemd-hibernate-resume-generator\fR(8)\&. +.RE +.PP +\fIsystemd\&.firstboot=\fR +.RS 4 +Takes a boolean argument, defaults to on\&. If off, +\fBsystemd-firstboot.service\fR(8) +will not query the user for basic system settings, even if the system boots up for the first time and the relevant settings are not initialized yet\&. Not to be confused with +\fIsystemd\&.condition\-first\-boot=\fR +(see below), which overrides the result of the +\fIConditionFirstBoot=\fR +unit file condition, and thus controls more than just +systemd\-firstboot\&.service +behaviour\&. +.RE +.PP +\fIsystemd\&.condition\-needs\-update=\fR +.RS 4 +Takes a boolean argument\&. If specified, overrides the result of +\fIConditionNeedsUpdate=\fR +unit condition checks\&. See +\fBsystemd.unit\fR(5) +for details\&. +.RE +.PP +\fIsystemd\&.condition\-first\-boot=\fR +.RS 4 +Takes a boolean argument\&. If specified, overrides the result of +\fIConditionFirstBoot=\fR +unit condition checks\&. See +\fBsystemd.unit\fR(5) +for details\&. Not to be confused with +\fIsystemd\&.firstboot=\fR +which only controls behaviour of the +systemd\-firstboot\&.service +system service but has no effect on the condition check (see above)\&. +.RE +.PP +\fIsystemd\&.clock\-usec=\fR +.RS 4 +Takes a decimal, numeric timestamp in μs since January 1st 1970, 00:00am, to set the system clock to\&. The system time is set to the specified timestamp early during boot\&. It is not propagated to the hardware clock (RTC)\&. +.RE +.PP +\fIsystemd\&.random\-seed=\fR +.RS 4 +Takes a base64 encoded random seed value to credit with full entropy to the kernel\*(Aqs random pool during early service manager initialization\&. This option is useful in testing environments where delays due to random pool initialization in entropy starved virtual machines shall be avoided\&. +.sp +Note that if this option is used the seed is accessible to unprivileged programs from +/proc/cmdline\&. This option is hence a security risk when used outside of test systems, since the (possibly) only seed used for initialization of the kernel\*(Aqs entropy pool might be easily acquired by unprivileged programs\&. +.sp +It is recommended to pass 512 bytes of randomized data (as that matches the Linux kernel pool size), which may be generated with a command like the following: +.sp +.if n \{\ +.RS 4 +.\} +.nf +dd if=/dev/urandom bs=512 count=1 status=none | base64 \-w 0 +.fi +.if n \{\ +.RE +.\} +.sp +Again: do not use this option outside of testing environments, it\*(Aqs a security risk elsewhere, as secret key material derived from the entropy pool can possibly be reconstructed by unprivileged programs\&. +.RE +.PP +\fIsystemd\&.hostname=\fR +.RS 4 +Accepts a hostname to set during early boot\&. If specified takes precedence over what is set in +/etc/hostname\&. Note that this does not bar later runtime changes to the hostname, it simply controls the initial hostname set during early boot\&. +.RE +.PP +\fIsystemd\&.tty\&.term\&.\fR\fI\fItty\fR\fR\fI=\fR, \fIsystemd\&.tty\&.rows\&.\fR\fI\fItty\fR\fR\fI=\fR, \fIsystemd\&.tty\&.columns\&.\fR\fI\fItty\fR\fR\fI=\fR +.RS 4 +These arguments allow configuring default values for +\fI$TERM\fR, +\fITTYRows=\fR, and +\fITTYColumns=\fR +for tty +\fItty\fR\&. Additionally, +\fIsystemd\&.tty\&.term\&.console\fR +will configure the +\fI$TERM\fR +value used by +\fBsystemd\fR +if not set explicitly using +\fITERM\fR +on the kernel command line\&. The tty name should be specified without the +/dev/ +prefix (e\&.g\&. +"systemd\&.tty\&.rows\&.ttyS0=80")\&. +.RE +.SH "HISTORY" +.PP +systemd 252 +.RS 4 +Kernel command\-line arguments +\fIsystemd\&.unified_cgroup_hierarchy\fR +and +\fIsystemd\&.legacy_systemd_cgroup_controller\fR +were deprecated\&. Please switch to the unified cgroup hierarchy\&. +.RE +.SH "SEE ALSO" +.PP +\fBsystemd\fR(1), +\fBsystemd-system.conf\fR(5), +\fBbootparam\fR(7), +\fBsystemd.system-credentials\fR(7) +\fBsmbios-type-11\fR(7), +\fBdracut.cmdline\fR(7), +\fBsystemd-debug-generator\fR(8), +\fBsystemd-fsck@.service\fR(8), +\fBsystemd-quotacheck.service\fR(8), +\fBsystemd-journald.service\fR(8), +\fBsystemd-vconsole-setup.service\fR(8), +\fBsystemd-udevd.service\fR(8), +\fBplymouth\fR(8), +\fBsystemd-cryptsetup-generator\fR(8), +\fBsystemd-veritysetup-generator\fR(8), +\fBsystemd-fstab-generator\fR(8), +\fBsystemd-getty-generator\fR(8), +\fBsystemd-gpt-auto-generator\fR(8), +\fBsystemd-volatile-root.service\fR(8), +\fBsystemd-modules-load.service\fR(8), +\fBsystemd-backlight@.service\fR(8), +\fBsystemd-rfkill.service\fR(8), +\fBsystemd-hibernate-resume-generator\fR(8), +\fBsystemd-firstboot.service\fR(8), +\fBbootctl\fR(1) +.SH "NOTES" +.IP " 1." 4 +kernel-parameters.html +.RS 4 +\%https://docs.kernel.org/admin-guide/kernel-parameters.html +.RE |