debug-trigger listens for an external signal that the BMC is in some way unresponsive. When the signal is received it triggers a crash to collect debug data and reboots the system in the hope that it will recover.
debug-trigger implements a simple protocol over an LPC KCS device as its trigger source.
debug-trigger implements a single action once the trigger event is received, which is to crash the kernel via /proc/sysrq-trigger. For systems with kdump configured this results in collection of system state as context for why the system was externally unresponsive.