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)