Older G4 and G3 models have a programmer's switch that can be used to
generate an interrupt to drop into the debugger.
This code hadn't been tested for a long time. It had been broken back
in 2005 in r153050.
Repair and modernize the code and add it to GENERIC.
Reviewed by: jhibbits (approved w/ removal of unused sc_dev var)
Sponsored by: Tag1 Consulting, Inc.
Differential Revision: https://reviews.freebsd.org/D29131
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
for that argument. This will allow DDB to detect the broad category of
reason why the debugger has been entered, which it can use for the
purposes of deciding which DDB script to run.
Assign approximate why values to all current consumers of the
kdb_enter() interface.
DDB when the interrupt button (aka the "programmer's switch") is pressed.
This isn't unfortunately an NMI, but it's a handy way to get into DDB
quickly if needed.
