Why is it so hard to find coreboot-capable devices? The major obstacle is
Boot Guard, which renders modifying firmware totally impossible. Minor
obstacles might include proprietary secret firmware design.
I am not sure whether all ThinkPad Yogas don't have BG enabled, because I
simply can't test all of them. I do know how to test whether BG is enabled
and have the tools, but can't post them here because of the community
guideline (no proprietary software allowed).
A fully upgraded Yoga might be expensive. You can start with one with i5
processor and 8 GiB RAM (on board, can't be upgraded). It should be as
durable as X230. In addition, remember that there is currently no coreboot
implementation on this model. It is just theoretically possible to support
coreboot because some of them don't have BG. If you manage to flash coreboot
on them, it can be a big contribution to the coreboot community.
As for a comparison between X230 and Yoga:
Pros for X230:
Upgradeable memory.
Physical buttons for TrackPoint.
Non-ultrabook: indicator LEDs and removable battery.
VGA and Mini-DP ports, express card and ethernet.
Pros for Yoga:
Better screen.
AVX2 instruction set support.
Lower power consumption and faster battery charging.
