fshalt, scram, reboot – halt any local file systems and optionally shut down or reboot the system

fshalt [ –r [ kernelpath ] ]
reboot [ kernelpath ]

Fshalt syncs and halts all local cwfs(4) and hjfs(4) servers. If given –r, fshalt will then reboot the machine, optionally starting kernelpath. Else it will try to shut down the machine through /dev/pmctl (if available) or invoke scram. The halting and rebooting is done by copying all necessary commands into a ramfs(4) file system and changing directory there before attempting to halt file systems, so this will work even on standalone machines with their roots on local file systems.

Reboot restarts the machine it is invoked on. If an optional kernelpath is specified then the machine will load and start that kernel directly instead of returning to the system rom. (see cons(3)).

Scram shuts down the machine it is invoked on by writing power off to /dev/pmctl.


acpi(8), cons(3), reboot(8)

On standalone machines, it will be impossible to do anything if scram fails after invoking bare fshalt.
Scram falls back to trying aux/acpi if writing to /dev/pmctl fails.

Scram first appeared in 9front (May, 2011).