Firmware consulting firm 3mdeb is working to upstream their open-source AMD firmware support into the official openSIL and Coreboot projects.
Background: Last week, 3mdeb had already released the first open-source firmware for a modern AMD Ryzen AM5 platform (their downstream "Dasharo" build), targeting an MSI PRO B850-P WIFI desktop motherboard.
What's new: With that work proven successful, 3mdeb engineer Michał Żygowski opened a pull request to openSIL to upstream AM5 platform support and support for AMD's Phoenix (Ryzen 8000 series) processors. The PR includes:
Fixes tied to their Coreboot bring-up work Updates for handling Phoenix desktop CPUs MMIO handling updates Support for the Promontory21 IP block (chipset initialization) Missing SMU / USB / GFX initialization pieces
Żygowski confirmed in the PR that with these changes he was able to boot both Ubuntu 26.04 and Windows 11 on an AM5 Phoenix platform with an AMD B850 chipset using Coreboot.
Corresponding Coreboot pull requests were also opened the same day, covering AMD Phoenix changes, Promontory21 handling, and an initial device tree for the MSI PRO B850-P WIFI board.
This marks meaningful progress toward mainline, fully open-source firmware support for modern AMD AM5 desktop platforms — something that's historically been difficult due to closed-source AMD firmware blobs (AGESA).
