On Tue, Mar 28, 2017 at 3:20 PM, <ttu...@codeaurora.org> wrote: > On 2017-03-24 17:42, Julius Werner wrote: >>> >>> * Google's recovery manifest (from linux_recovery.sh) can pull a >>> recovery image for a specific product, I have yet to find >>> depthcharge as a payload >>> * Obviously I haven't pulled all of the recovery images, but have >>> looked at ~10 >>> * those interested in recovery image, >>> /usr/sbin/chromeos_firmwareupdate --sb_extract yields a bios.bin >>> file that cbfstool can parse (i.e. is a coreboot.rom file) >> >> >> All non-x86 Chromebooks that use coreboot also use depthcharge. What >> exactly do you mean when you say you can't find it? If you parse >> bios.bin with cbfstool print, you should see a "fallback/payload" >> file... that is depthcharge. (coreboot always requires the payload to >> just be called "payload" in CBFS, regardless of what it actually is.) >> You can extract it and run 'strings' on it to confirm. > > > This was my understanding (Depthcharge being used as payload for all recent > Chromebooks). > What led me to question this understanding was: > * limited number of libpayload config files in coreboot source tree > * chromiumos build tree explicitly setting CONFIG_PAYLOAD="n" for all > coreboot boards > * u-boot.dtb file being present in all bios.bin files I looked at from > linux_recovery.sh manifest (including Kevin) > > As fallback/payload is compressed in bios.bin, I'm not sure what strings > will provide. > I did run strings on bios.bin (as well as looking at it in hex editor) and > found nothing > explicitly suggesting depthcharge (or u-boot for that matter) was the > payload. I made > assumption u-boot was payload based on presence of u-boot.dtb file in > bios.bin.
FWIW, you can 'cbfstool extract' the fallback/payload file from an existing image. It'll write an ELF file that you should be familiar with for inspection purposes (strings, readelf, objdump, etc). > > As has already been explained in this thread the coreboot build within > chromiumos tree does not include > building payload, this is a later step. My work to date has been solely > within confines of coreboot > build tree and directly generating depthcharge, etc. so this deferred > building of the payload came as a surprise. > > I welcome pointers to online documentation (either coreboot or chromiumos) > that more clearly discuss coreboot inclusion within chromiumos build and > development cycle. > > Thanks to all who have contributed to my current level of knowledge and I > know I am just scratching the surface. > Cheers, > T.mike -- coreboot mailing list: coreboot@coreboot.org https://www.coreboot.org/mailman/listinfo/coreboot