Hello,

I'd like to highlight an issue with the current OpenWRT image being provided here for use with the IoT Router Carrier Board. There has been a hardware revision to the Raspberry Pi Compute Modules, and so any recently-manufactured board will not boot the image. Instead of booting, the green LED will flash 4 times slowly and 4 times quickly, which indicates “Unsupported Board Type”.

The fix I have been able to apply is to copy the DAT and ELF files from the boot partition of a newer image to the boot partition of this image. These files are compatible with the newer board revision, and booting is therefore successful. I didn't find it necessary to update the Kernel itself, and I didn't need to update any other OpenWRT components.

I'm highlighting this as new customers (like me) will likely find that the image just doesn't work, and without some troubleshooting effort it won't be clear why or what to do about it. I'm hoping an updated image can be provided with these newer files included so that others don't experience the same problems. The new bootloader will still work with older Compute Modules, so this won't introduce any compatibility concerns.

Thanks,

Alex Oughton