Table of contents Background info on the bootloader Symptom Meta: Following Along Up/Downgrade Versions New Hypothesis Debugging with QEMU Using an older QEMU Debug symbols Automation with .gdbinit Understanding program flow Wait, this isn’t GDB! The GDB text-mode user interface (TUI) The GDB Emacs user interface (M-x gdb) Debugging the failing loop Root cause Speculation Bonus: reading BIOS source Mitigation Conclusion Appendix: Resources I maintain two builds of the Linux kernel, a linux/arm64...