/usr/lib/systemd/system-generators/systemd-hibernate-resume-generator
systemd-hibernate-resume-generator is a generator that initiates the procedure to resume the system from hibernation. It instantiates the systemd-hibernate-resume@.service(8) unit according to the value of resume= parameter specified on the kernel command line, which will instruct the kernel to resume the system from the hibernation image on that device.
systemd-hibernate-resume-generator understands the following kernel command line parameters:
resume=
resumeflags=
noresume
systemd(1), systemd-hibernate-resume@.service(8), kernel-command-line(7)