[DEBUG]  SPD @ 0x51
[INFO ]  SPD: module type is DDR4
[INFO ]  SPD: banks 16, ranks 2, rows 16, columns 10, density 8192 Mb
[INFO ]  SPD: device width 8 bits, bus width 64 bits
[INFO ]  SPD: module size is 16384 MB
[DEBUG]  SPD @ 0x53
[INFO ]  SPD: module type is DDR4
[INFO ]  SPD: banks 16, ranks 2, rows 16, columns 10, density 8192 Mb
[INFO ]  SPD: device width 8 bits, bus width 64 bits
[INFO ]  SPD: module size is 16384 MB
[EMERG]  FspMemoryInit error, status=0x80000007

it does not like my RAM for some reason

tested it with one DIMM only, still didn't work
tested it in a different board with stock firmware, worked
tested it in that other board with libreboot, worked
tested it again, having changed nothing whatsoever, in the original board, worked!