pytools: obmcutil: Add `chassiskill` command

Nick reported an issue where the BMC became unusable after the host hit
a bug and began "spewing a lot of messages to the console".  Save
ourselves some DBus transactions and immediate execution of systemd
transitions by introducing a `chassiskill` command to directly deassert
the the power-up GPIO ourselves.  This will immediately terminate the
host and free up resources for the BMC to become responsive. As a bonus,
the PGOOD monitoring will then execute to clean up the resulting
inconsistent BMC/Host state for us.

Change-Id: I106a4202b6544b8e78b04938230a4eeee5f132bb
Requested-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
1 file changed