I had a quick look at the BD4 BIOS, and “MXIC 25L/U Series” and “Fudan FM25Q Series” flash chip should work just fine. But it seems that you need support for “Fudan FM25W Series”. The SPI ID for this flash chip is “A12818” according to section 10.1.1 of the datasheet. And I can indeed see this ID in the flash descriptor of the official PR9 BIOS.
The good news is that it will not be the same difficult situation as I had with the XMC chips for almost two years. I can already find support for this Fudan flash in the latest BIOS for
- Angxun: X99-DS4, X99-XD4, X99-P4 V9 (direct link to their page)
- Huananzhi: X99-AD3, X99-CD4, X99-F8D Plus (see direct links in this post)
- Machinist: X99-U9 (listed as “FM 25Wxx Series”), (see above post)
- Jginyue: X99-8D4/2.5G (also listed as “FM 25Wxx Series”), (see direct link in this post)
If I were you, I would do it like this
- Take your working 16M PR9 BIOS file as a starting point
- Use Uefitool to extract just the BIOS region (seems this is what you already did)
- Replace the BIOS region in your working 16M PR9 BIOS file
- Save to a new file, and flash with an external programmer
And thanks for giving me a heads up about the P4 BIOS, I will check and test this one further. A quick look at it tells me that you can indeed use AMIBCP and unhide the controls over Fan 2. It is currently set to “Full on Mode” instead of “Automatic Mode”.