did the ASUS KFSN4-DRE ever receive family 15h support, in addition to 10h? or was that only the KGPE boards?
When I go to a "./src/mainboard/asus/kgpe-d16" or "./src/mainboard/asus/kcma-d8" and do this search: find . -type f -print0 | xargs -0 grep -n "15h" - there are multiple matches at their ./romstage.c and ./resourcemap.c , but when I'm doing the same at "./src/mainboard/asus/kfsn4-dre", there is only one match: ./romstage.c:42:#include <cpu/amd/family_10h-family_15h/init_cpus.h> , although there's the same single match for a "10h" search as well.
So it's a bit unclear if there's a "15h" support at KFSN4-DRE currently, and - if there is none - maybe this 15h code from KGPE-D16 and KCMA-D8 could be somehow re-used for KFSN4-DRE. Hopefully, Timothy Pearson could help to reply to your question, since he is a maintainer for KFSN4-DRE board.