man 8 systemd-debug-generator

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
       set, either 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).

SEE ALSO
       systemd(1), systemctl(1), kernel-command-line(7)

systemd 252                                         SYSTEMD-DEBUG-GENERATOR(8)