2014-08-08 18:18 GMT-06:00 David Hendricks dhendrix@google.com:
The good news is that HM76 (or at least very similar chipsets) are already supported in coreboot :-)
The bad news is that there are many other factors to consider which are specific to the platform you intend to target. Look around the codebase and try to find something that most matches the criteria you are targeting. The Kconfig files under src/mainboard/* list the components of each mainboard pretty well.
Porting to a totally new mainboard can take a few days or maybe weeks if you have all the CPU/chipset documentation, mainboard schematics, and requisite vendor-provided binaries (especially for Intel platforms). If you have none of the documentation or binaries then it can take several months assuming you're skilled and knowledgeable of x86 platforms, years if not.
Start with the Lenovo x230 (Ivy Bridge) since phcoder (a highly skilled and knowledgeable dude) wrote native RAM init code on his own, an impressive feat that probably took him a few months. If you have a business relationship with Intel you can ask them for a binary to do the same thing for whatever northbridge you are targeting.
HTH.
Thanks for the detailed response! Unfortunately, it doesn't look like I'll have time to work on this project for several months, if at all.
The specific motherboard I'd like to add support for comes from the Lenovo IdeaPad Z500 Touch. It has an i5-3230M and an HM76. Again, I'd be happy to donate hardware to anyone willing to work on support for this or similar motherboards.
-Alex