SYSTEMD-DEBUG-GENERATOR(8) systemd-debug-generator SYSTEMD-DEBUG-GENERATOR(8)
NAME
systemd-debug-generator - Generator for enabling a runtime debug shell
and masking specific units at boot
SYNOPSIS
/usr/lib/systemd/system-generators/systemd-debug-generator
DESCRIPTION
systemd-debug-generator is a generator that reads the kernel command
line and understands three options:
If the systemd.mask= or rd.systemd.mask= option is specified and
followed by a unit name, this unit is masked for the runtime (i.e. for
this session — from boot to shutdown), similarly to the effect of
systemctl(1)'s mask command. This is useful to boot with certain units
removed from the initial boot transaction for debugging system startup.
May be specified more than once. rd.systemd.mask= is honored only by
initial RAM disk (initrd) while systemd.mask= is honored only in the
main system.
If the systemd.wants= or rd.systemd.wants= option is specified and
followed by a unit name, a start job for this unit is added to the
initial transaction. This is useful to start one or more additional
units at boot. May be specified more than once. rd.systemd.wants= is
honored only by initial RAM disk (initrd) while systemd.wants= is
honored only in the main system.
If the systemd.debug_shell or rd.systemd.debug_shell option is
specified, the debug shell service "debug-shell.service" is pulled into
the boot transaction and a debug shell will be spawned during early
boot. By default, /dev/tty9 is used, but a specific tty can also be
specified, either with or without the /dev/ prefix. To set the tty to
use without enabling the debug shell, the systemd.default_debug_tty=
option can be used which also takes a tty with or without the /dev/
prefix. Note that the shell may also be turned on persistently by
enabling it with systemctl(1)'s enable command. rd.systemd.debug_shell
is honored only by initial RAM disk (initrd) while systemd.debug_shell
is honored only in the main system.
systemd-debug-generator implements systemd.generator(7).
SYSTEM CREDENTIALS
systemd.extra-unit.*
Credentials prefixed with "systemd.extra-unit." specify additional
units to add to the final system. Note that these additional units
are added to both the initrd and the final system.
ConditionPathExists=!/etc/initrd-release can be used to make sure
the unit is conditioned out in the initrd. Note that this can also
be used to mask units, by simply specifying an empty value.
Added in version 256.
systemd.unit-dropin.*
Credentials prefixed with "systemd.unit-dropin." add drop-ins for
the corresponding units in the final system. Each credential must be
suffixed with the full unit name including the unit extension. Its
contents must be a valid unit drop-in file. Optionally, the unit
name may be followed with "~", followed by the drop-in name without
the ".conf" suffix. If not specified, the name of the generated
drop-in will be "50-credential.conf". Note that these additional
drop-ins are added to both the initrd and the final system.
Added in version 256.
SEE ALSO
systemd(1), systemctl(1), kernel-command-line(7)
systemd 257.9 SYSTEMD-DEBUG-GENERATOR(8)
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