Reviving this topic since I have delved into this stuff recently. I want to update my BIOS to support Resizable-BAR. While this is possible to do using ReBarUEFI on my current version, F9, I figure it is just less of a hassle to update to the version which supports it. This is available on the F12k version, which doesn’t have a capsule, however, if there is no performance loss to just update to the newest version, F12, I see no reason to not due so, since it is possible to downgrade using your guide if I really wanted to. I’m also willing to re-overclock my RAM if I have to. I would first like to know: if I do this, would there still be a point to modify the F12 BIOS to include the oldest microcode? I would expect all the security fixes/patches to already affect performance to the point where just using the default microcode wouldn’t make a difference.
Also, I have followed the first part of your guide, in case I want to downgrade once I flash to the newest BIOS, and I have run into a problem: I can’t seem to find my MAC address in the GbE export ( fptw64 -gbe -d gbe.bin). I know I can save the MAC address using another method, but I’m just wondering why it doesn’t show up in there. Also, does fptw64 -d bios.bin save the entire chip, or just the BIOS/UEFI region? If so, isn’t the GbE export command redundant? I saw a comment on here that says you need to unlock the flash descriptor, so I assume the answer is no, but I still wonder if it saves other parts.
Another thing I want to ask is if it is possible to downgrade using a programmer? Common ones recommended here are the CH341A-based programmers, but I’ve heard they possibly cannot deal with .cap files. I’ve also heard that using clips to clamp onto the chip is dubious and that flashing in-circuit can cause problems, but I’m not sure how accurate these claims are, so hopefully you can address them (8:03 - 9:13).
Edit: Where is a good place to get one of these programmers? The ones I find are either the old versions, or take a while to deliver. Are there any alternatives?