The system BIOS provides a basic power-on self-test (POST) during start up. When the server module is powered on or booted, it goes through a series of hardware tests called checkpoints. During POST code checkpoint testing, the BIOS tests the basic devices required for the server to operate. A series of checkpoint codes indicates POST progress.
The BIOS POST checkpoint memory testing is performed as follows:
The first megabyte of DRAM is tested by the BIOS before the BIOS code is shadowed (that is, copied from ROM to DRAM).
Once executing out of DRAM, the BIOS performs a simple memory test.
The BIOS polls the memory controllers for both correctable and non-correctable memory errors and logs those errors into the SP.
The message BMC Responding appears at the end of POST.