Strengthen the qemu end-to-end test: sample the framebuffer first pixel
every 0.5s for ~9s of stub time and require the exact transition order
red -> yellow -> green -> blue with no further transitions, plus a
final full-screen uniform-blue snapshot. Update README with run
instructions. All checks pass.
Minimal freestanding arm64 binary that depthcharge boots as a kernel:
parses depthcharge's /firmware/coreboot DTB node, walks the coreboot
table, finds LB_TAG_FRAMEBUFFER, and paints red/yellow/green/blue
checkpoints (~2s each) into the live boot-splash framebuffer.
Verified against coreboot tables header, Linux arm64 booting.rst, and
depthcharge's fit.c/boot64.c. Host parser tests pass against the live
/sys/firmware/fdt; full red->yellow->green->blue sequence verified
end-to-end under qemu-system-aarch64; packed image verifies with the
ChromeOS devkeys.
vhaudiquet