How to build the EC for the Framework 12 ('sunflower')? #77

Hi, the build instructions on branch fwk-hx20-hx30-4410 don't work for the fwk-sunflower-26784 (FW12) branch because the build system appears to be very different. I've tried following the routine of the GitHub Actions workflow used to build sunflower-3.0.4-fa46a90 (on commit fa46a90) but I eventually fail with some strange Kconfig errors that I don't know how to interpret (attached below). According to a post on the Framework Community Forum, the issue appears to be that Framework uses a custom Zephyr version that mismatches... something... that makes the build fail. I tried to build on a Ubuntu 24.04 x86 VM.

I'm not experienced with GitHub Actions or EC build systems at all so I asked ChatGPT on how I should replicate the workflow on my VM. Eventually I got to the point shown in the log attached, but for all I know I've been going down the wrong path right from the start. Please help.

kconfig_errors_fw12ec.txt

All I want to do is change some hardcoded constants that define the PL1 limit of the FW12's CPU in various scenarios in zephyr/program/framework/sunflower/src/cpu_power.c.