Application Pre-emptive SafeBoot

[uiaunder]

I had a complex piece of code (display panel, RS485, PWM, etc.) that I fought for hours with and could never figure out why it kept throwing "attempt to modify read only flash" error when the app would try to initiate a safe boot. Presumably, I just wasn't getting something shut down correctly... so the result was that my attempt to safe boot, would simply crash and reboot my app. Actually, with enough testing, I discovered there were times when it would work, but it wasn't reliable.

At some point I hit upon the idea that I could simply stow a safe boot flag in EEPROM along with a build date/time, and, first thing in my app setup, before starting up any complexity, check that flag and if I'm in reboot mode for this build (build date/time matches), initiate a safe boot. That worked like a charm. So when it's time to safe boot, I still do it the normal way, but also set that reboot flag. That way, if it crashes, it'll still do a safe boot immediately after rebooting from the crash.

Another benefit I found to this little addition was a sort of fail safe in case a mod I made prevented me from getting through setup. At the start of setup, I set the safe boot flag, and at the end of SETUP I clear it. If I crash during SETUP, on next boot, the app will kick into SAFE BOOT, allowing me to fix whatever it was I broke.

Just mentioning this workaround for anyone else who stumbles into this situation like I did.