I flashed coreboot onto my x230, using a Raspberry Pi Model B Rev 2.0. These are the resources I used (other than the coreboot wiki):
There are 2 ways to provide power to the BIOS chip. One way is to enable Wake-On-LAN on the existing BIOS and connect the AC adapter and an Ethernet cable; the computer should then supply 3.3V to the chip. However, I was unable to get that working, so instead I connected the Pi's pin #17 to pin #8 of the Macronix chip (spec sheet).
Disassembly was dead-easy, though for next time, I ordered some plastic
pry tools. Since I couldn't read the chip's model (too much glue
residue), I read each of the four possible chips 3 times each, just in
case. In hindsight, before putting everything back together I could've
used the me_cleaner script to
remove the Intel ME firmware from the flash chip. Right now flashrom
reports that the Management Region is locked, meaning I'll have to do
another hardware flash to get rid of it (there are some cases where this
region has read/write permissions and you can just do an internal
flash).
Since flashing, I've had no issues, everything is working perfectly. I bought a 7260 ac card to replace my slow Centrino Wireless-N 2200 (since there's no whitelist anymore).