I was trying to upgrade the BIOS on an HP Z840 workstation at work today, and hit a wall. The live upgrade options (via hp-flash on the command line, and via a netboot image) were hard freezing the system.
Neither I, nor a local Linux expert, were quite sure what was going on.
Then I remembered something from working on WiFi routers; when all else failed, we’d read and install an image from an attached USB stick early during boot. There are far fewer ways for that to go wrong than most other ways of installing software. Maybe that would work too?
It did. When all else fails, try a USB stick.