runit-init is the first process the kernel starts. If runit-init is started as process no 1, it runs and
replaces itself with runit(8).
If runit-init is started while the system is up, it must be either called as init0 or init6:
init0 tells the Unix process no 1 to shutdown and halt the system. To signal runit(8) the system halt
request, runit-init removes all permissions of the file /etc/runit/reboot (chmod 0), and sets the
execute by owner permission of the file /etc/runit/stopit (chmod 100). Then a CONT signal is sent
to runit(8).
init6 tells the Unix process no 1 to shutdown and reboot the system. To signal runit(8) the system
reboot request, runit-init sets the execute by owner permission of the files /etc/runit/reboot and
/etc/runit/stopit (chmod 100). Then a CONT signal is sent to runit(8).