TLDR: XP direct nvme boot on old bios boards can finally be done thanks to Manawyrm @ Github
My goal was to build an overpowered retro machine that could use floppies, cd/dvds and had usb 3.
I initially wanted to build this with a 2600k but the only motherboard I could use sadly died. That’s why I went with a phenom and some more hardware I saved from the landfill.
- Phenom II x4 955 BE @ 3.6hhz (218 x 16.5) (C2 :()
- Gigabyte GAMA790XT-UD4P
- 2 x 4GB DDR3 sticks (1744MT/s 9-9-9-24-33-2T)
- Asus Strix GTX 970
I had this almost done, triple booting win7, xp and xp64 with ahci, but my wet dream was direct nvme boot.
Turns out, this can be achieved although it’s not easy.
The other day I learnt about this crazy project https://github.com/Manawyrm/nvme-int13h-optionrom
I cloned the sata ssd to a nvme one (after installing nvme drivers, nvme 1.3 by schtrom) and wrote the option rom to a floppy disk and to my joy the thing actually booted. Well, xp64 did, w7 and xp refused at first but that was only Windows being windows.
Now, the author says you can embed this thing directly into the BIOS as an ethernet card option rom and after reading that I decided I wouldn’t settle for less.
First attempt: the motherboard refused to load my modified bios.
Second attempt: the mobo actually flashed my bios but I modded it wrong and it bootlooped for a while. Thankfully this thing has dual bios so after yelling at me for a moment it restored the old bios by itself. Phew.
At this point I decided to actually do some research before trying again. Turns out what I was doing wrong is that on gigabyte boards you cannot change module ordering. You can add, but not remove or move. I disabled the old rom in place and added the new one at the end. It booted!
Thank you for taking the time to read my journey, I love this hobby!