[systemd-devel] New reboot flag: -c for 'power cycle'

[Lennart Poettering]

On So, 29.10.17 08:37, Jonathan de Boyne Pollard (J.deBoynePollard-newsgroups at NTLWorld.COM) wrote:

> Warner Losh, FreeBSD and embedded systems developer, has just invented a new
> shutdowngoal, in addition to the ones that we already know.  In addition to
> the conventional reset, power off, halt, and kexec goals; xe has added a
> power-off-and-then-on-again goal.  Xe has named it power cycle, and its use
> case is systems with hardware that can trigger a full power cycle under the
> kernel's controland where an ACPI reset or even an EFI ResetSystem() of type
> EfiResetColdjust do not cutthe mustard.

Hmm, not sure I follow? This appears to be an implementation detail on
how the reboot operation is executed, i.e. something you'd configure
on Linux with the existing "reboot=" kernel command line option. I am
not sure why this should leak into the init system?

On Linux there are plenty of ways to reboot the system, as reboot()
takes a firmware string these days. We also have reboot-to-firmware
and suchlike, but all of it is exposed through the same reboot
shutdown goal, you just set the right bits beforehand to make sure you
get what you want. Why would this new BSD concept be any different
than this?

> Please do not use SIGRTMIN+7 and SIGRTMIN+17 for an incompatible purpose.

But the meanings of these signals on PID 1 are not standardized across
UNIX anyway, are they? I mean, at least for systemd I pulled them out
of my hat, really...

Lennart

-- 
Lennart Poettering, Red Hat