I tried to flash a variant of OpenWrt (OMR) for Raspberry Pi 3 B+ to sdcard. But upon bad configuration, the router is no longer accessible.
I tried to reflash the image again to the sdcard hoping that it will clear out the bad configuration but it didn't work (the configurations seem to remain in the sdcard).
I had to flash the sdcard with raspbian image before flashing OMR image to clear out the configurations.
- How do I flash image and clear out the data/configurations?
- I noticed when flashing in LuCI, there is an option to
Keep settings. How does it reset the settings when unticked? Where in the source code can I look it up?
I think that the SD card based routers differ pretty much from the "normal" ones, so most of the general advice you find is likely targeted toward normal routers with NOR/NAND flash handled via mtd.
You will need to look for Raspberry-specific advice, so I edited your topic title to attract the knowledgeable people...