Joachim Wiberg
53c7ddcb22
This patch changes the behavior of SIGUSR1. Previously USR1 could be used to halt a running Finit system, similar to BusyBox init. However, compatibility with sysvinit and systemd has been deemed more important. Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
1.8 KiB
Finit Signals
Finit is often used on embedded and small Linux systems with BusyBox. Though Finit comes with its own tools for (poweroff, halt, reboot), for compatibility with the existing BusyBox toolset the following signals have been adopted:
SIGHUP
Same effect as finit q, init q, or initctl reload, reloads all
*.conf files in /etc/finit.d/
This also restarts the API (initctl) socket, like SysV init and systemd does on USR1 with their FIFO/D-Bus.
SIGUSR1
Since Finit 4.1 this signal causes Finit to restart its API (initctl) socket, like SysV init and systemd does on USR1 with their FIFO/D-Bus.
Finit <= 4.0 performed a system halt (like USR2 without power-off), but this caused compatibility problems with systemd and sysvinit on desktop systems. Hence, since Finit 4.1 it is no longer possible to halt a system with a signal.
SIGUSR2
Calls shutdown hooks, including HOOK_SHUTDOWN, stopping all running
processes, and unmounts all file systems. Then tells kernel to power
off the system, if ACPI or similar exists to actually do this. If the
kernel fails power-off, Finit falls back to halt.
SysV init N/A, systemd dumps its internal state to log.
SIGTERM
Like SIGUSR2, but tell kernel to reboot the system when done.
SysV init N/A, systemd rexecutes itself.
SIGINT
Sent from kernel when the CTRL-ALT-DEL key combo is pressed. SysV init
and systemd default to reboot with shutdown -r.
Finit currently forwards this to SIGTERM.
SIGPWR
Sent from a power daemon, like powstatd(8), on changes to the
UPS status. Traditionally SysV init read /etc/powerstatus and
acted on "OK", "FAIL", or "LOW" and then removed the file.
Finit currently forwards this to SIGUSR2.