Removing the test which makes the function fails results in RAM being correctly recognized, and a successful MRC.BIN initialization :
System Agent Version 1.6.1 Build 2 memcfg DDR3 clock 1600 MHz memcfg channel assignment: A: 0, B 1, C 2 memcfg channel[0] config (00620040): ECC inactive enhanced interleave mode on rank interleave on DIMMA 16384 MB width x8 or x32 dual rank, selected DIMMB 0 MB width x8 or x32 single rank
However, it fails the memtest+ tests and can't boot the OS (weird graphic glitchs appears on screen), still investigating why