4890 and 4870 so similar so 4890 didnt even need special driver in osx, it was using 4870's drivers
so plan is to merge efi part of 4870 rom into 4890 rom
problems:
1) we dont know if there any checks for device-id in code of efi rom
2) bios rom of 4890 is slightly larger than 4870's , so need to relocate MCuC section to fit efi rom
here is two roms for test, pc part is from msi 4890, since most 4890 is amd's design, the rom should work on other cards too
in first rom I changed matching in efi part and tried to relocate MCuC section
to second rom I also added small patch of efi code.
need to test both with macpro, and if possible with pc (to know if relocation of MCuC section done right)
make sure you made backup of your rom and have a way to flash it if smth goes wrong
good luck testing!
so plan is to merge efi part of 4870 rom into 4890 rom
problems:
1) we dont know if there any checks for device-id in code of efi rom
2) bios rom of 4890 is slightly larger than 4870's , so need to relocate MCuC section to fit efi rom
here is two roms for test, pc part is from msi 4890, since most 4890 is amd's design, the rom should work on other cards too
in first rom I changed matching in efi part and tried to relocate MCuC section
to second rom I also added small patch of efi code.
need to test both with macpro, and if possible with pc (to know if relocation of MCuC section done right)
make sure you made backup of your rom and have a way to flash it if smth goes wrong
good luck testing!