Hi!
This is my first post in this mailing list. Nice to meet you all.
I have a feature request. (I'm not sure if I'm the first to request this, so feel free to direct me to any existing discussions about this topic, if there is one.)
Would it be possible to add a payload option "Tianocore with SeaBIOS CSM" in the config menu? Right now, we have to choose between a Tianocore payload and a SeaBIOS payload, or otherwise provide our own manually built payload.
It's possible for SeaBIOS to be built as a Compatibility Support Module (CSM) FOR UEFI BIOSes, and Tianocore can be built with the resulting CSM.
However, right now people need to first build SeaBIOS as a CSM, then build Tianocore with the CSM and then add it as a custom ELF executable payload during the "make menuconfig" or "make nconfig" stage of the Coreboot build procedure. Those are quite a few extra error-prone manual steps.
It would be really helpful if all these manual steps could be skipped by adding this payload option to the existing payload options and doing all the required intermediate building for us.
The vendor BIOS that I wish to replace with Coreboot already contains a UEFI with a CSM, and I'd like to preserve that functionality once I switch to Coreboot. I'm sure I'm not the only one who'd like to have the flexibility of being able to boot both modern OSes through UEFI and legacy OSes using the CSM.
Since new UEFI hardware will be shipping without CSMs as of 2020, having this in Coreboot by default would make Coreboot even more attractive to people who'd like to add back such legacy compatibility.
Thanks for considering this!