Proper way to obtain mrc.bin for thinkpad t440p?
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?
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
Hi yk, As Matt said It is not just meant for chromebooks but haswell in general. Just follow the instructions given on the coreboot page to obtain mrc.bin and place it in the root coreboot directory as it says. That tutorial seems fishy to me as well. I'd suggest just run 'make menuconfig' and select t440p from mainboard menu. You don't need to change any values. The default values should work. Finally, build the coreboot image, split into 8MB + 4MB chunks and just flash the 4MB chip. Best, Harshit On Thu, Aug 20, 2020, 5:13 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
Hi all, That coreboot fork does not automate the process of obtaining mrc.bin at all. Instead, it contains a disassembled/decompiled version of MRC and uses that instead. I would not recommend using that fork because it's outdated. On coreboot master, there's https://review.coreboot.org/43559 which should fix hangs with libgfxinit when a VGA display is plugged in, and https://review.coreboot.org/44155 which might help with https://ticket.coreboot.org/issues/259 or similar issues. I don't have a T440p, though. On Fri, Aug 21, 2020 at 5:54 AM Harshit Sharma <harshitsharmajs@gmail.com> wrote:
Hi yk,
As Matt said It is not just meant for chromebooks but haswell in general. Just follow the instructions given on the coreboot page to obtain mrc.bin and place it in the root coreboot directory as it says.
That tutorial seems fishy to me as well. I'd suggest just run 'make menuconfig' and select t440p from mainboard menu. You don't need to change any values. The default values should work.
Finally, build the coreboot image, split into 8MB + 4MB chunks and just flash the 4MB chip.
Best, Harshit
On Thu, Aug 20, 2020, 5:13 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
_______________________________________________ coreboot mailing list -- coreboot@coreboot.org To unsubscribe send an email to coreboot-leave@coreboot.org
Hey everyone, Long time admirer, first time poster :) I have just flashed an x200 with libre and t440p last night with core as a first step into the community (with many more to come!). I have contacted both the t440p fork repo as well as the gentleman running the 0xcb website to alter their directions, however at this time they seem unresponsive. yk, I did the following to get it working: - backup stock bios and store - clone upstream coreboot (NOT the t440p fork) - build ifdtool and export the blobs (ifd.bin, me.bin, gbe.bin), put them somewhere accessible - obtain the mrc.bin as per instructions on the coreboot website, place that mrc.bin in the root dir of cloned repo - used the .config file from this tutorial: https://0xcb.dev/lenovo-t440p-coreboot/ and changed the filepaths to match location of ifd.bin, me.bin, and gbe.bin (afaik absolute filepaths must be used) - ran make nconfig: double check all values that .config was read properly, select Chipset and select "Add a System Agent Binary" make sure underneath it says "(mrc.bin) Intel System Agent path and filename", in the Chipset submenu go down to where it says "Add Intel descriptor.bin" and change that to wherever you put the ifd.bin. - build the compiler toolchain - build coreboot - split the images according to 0xcb's tutorial - flash each image to respective flash chips I hope this helps and brings you a successful boot! :)
participants (5)
-
aidan＠bitshift.net.au -
Angel Pons -
Harshit Sharma -
Matt DeVillier -
yk