Quoting Caleb Connolly (2025-02-20 17:00:30) > Hi Stephen, > > On 2/20/25 20:58, Stephen Boyd wrote: > > This series supports running U-Boot as a payload on sc7180 Trogdor > > Chromebooks like Lazor or Wormdingler. This is a jumble of different > > patches to get to the final goal of booting a Linux distro from the eMMC > > on Lazor. I've yet to craft a USB stick with a stock distro but I'll > > probably do that next week. > > \o/ wow, this is awesome!
Thanks! > > you might have some luck booting pmOS, we build depthcharge compatible > images for trogdor > > https://images.postmarketos.org/bpo/edge/google-trogdor/ > > There's also a generic ARM64 EFI image that should work. You may need to > edit the image and remove efi/systemd/drivers/dtbloader.efi from the ESP: > > https://images.postmarketos.org/bpo/edge/postmarketos-trailblazer/ > Cool thanks for the pointers. I'm loading u-boot as a payload from depthcharge so that I don't have to remove the write protect on the flash. It's the altfw boot method. I tried to boot the Debian ISO from a USB stick but it looks like the FDT memory node isn't modified when I use u-boot to load the DTB from the one flashed to the eMMC for the ChromeOS installation. Does the efi_dt_fixup_protocol run in that case? I've never tried any of this stuff before so I'm learning while I go. I've been using this sort of flow to read the DTB from the FIT image that chromeos has: bootflow scan -l bootflow select 2 # Select the MMC partition for cros bootmethod bootflow read bootflow info fit=$hex_address_for_FDT_from_info_above imxtract ${fit} fdt-22 ${fdt_addr_r} # fdt-22 matches my board variant fdt addr ${fdt_addr_r} load usb 0:2 ${kernel_add_r} /EFI/BOOT/BOOTAA64.EFI bootefi ${kernel_addr_r} ${fdt_addr_r} This seems to work to get me to the installation menu but then when I run installation the kernel doesn't boot and it looks like memory hasn't been updated per the earlycon info that I see. I'll continue debugging. > > > > The first few patches add support for the particular SoC sc7180 used on > > Trogdor devices. The next set of patches move the coreboot logic out of > > x86 into lib to find the coreboot tables on ARM and stash them in global > > data. Then I have a handful of patches to let the coreboot commands and > > utilities parse and populate various things like pstore and DT with the > > proper data from the coreboot tables. Finally, I add the calls to > > coreboot dram parsing code in the snapdragon board so that if coreboot > > tables exist we get the memory info from coreboot instead of from an > > earlier stage DTB. > > > > I tested the spi driver with the crosec command. The cros bootflow > > method almost works, but it seems like chromeos userspace blows up > > spectacularly likely because crossystem can't figure out what board it > > is running on. I don't really care too much about booting chromeos > > userspace here so I'm going to ignore that problem and assume that I can > > boot some Linux distro because the eMMC can be read by U-Boot and the > > kernel boots. > > Guess it's time I finally get my hands on one of these devices :D > I bought a Lazor from eBay for a couple hundred dollars refurbished and it is basically brand new because the battery was replaced. I want to get the display working, which I think will require me to port the dsi and eDP bridge code over even though coreboot would have left everything largely configured.
