there is no "proper" way because there is no mrc.bin for the t440p. mrc.bin is the ram init blob used in pre-FSP Chromebooks. The t440p has to leverage this, because there is no native raminit option for the Haswell platform, unlike the older Sandy/Ivybridge platform. So mrc.bin must be extracted from a firmware image for a Haswell Chromebook -- it doesn't matter which one. It should be 190.2kb. Use coreboot master and don't screw with any config variables you don't understand, and you should be fine :)
good luck!
On Thu, Aug 20, 2020 at 7:13 PM yk via coreboot coreboot@coreboot.org wrote:
To anyone who has corebooted a t440p:
I followed the instructions here https://doc.coreboot.org/northbridge/intel/haswell/mrc.bin.html to obtain an mrc.bin for the t440p, but it seems like these instructions are generalized and are meant for chromebooks, and not thinkpads. I gave it a try anyways and my t440p beeps and flashes LED's (as configured in .config, to do so on fatal error). Months of searching, and I can't find any documentation or archived emails from this mailing list for obtaining an mrc.bin specifically for the t440p.
There exists this tutorial https://0xcb.dev/lenovo-t440p-coreboot/ but it tells me to use a forked version of coreboot which seems really fishy. I browsed the commits from that fork and I couldn't find anything that "automates obtaining mrc.bin" as it promises.
What is the proper way to obtain the mrc.bin and configure for t440p?
CONFIG_DCACHE_RAM_MRC_VAR_SIZE=0x30000 <-- also what should this value be if the mrc.bin is 186K? _______________________________________________ coreboot mailing list -- coreboot@coreboot.org To unsubscribe send an email to coreboot-leave@coreboot.org