However, now that we've set the "program_usb_boot_mode" OTP bit, I can no longer flash the eMMC of the CM3. I have tried using our prototype boards and the CMIO board. I can successfully program CM3s without the USB boot mode bit set, but swapping the same setup for a netboot-enabled CM3, I only see the solid PWR/ACT LEDs, and rpiboot does not detect the CM3.
- Does enabling USB boot mode prevent the CM3 from booting in device mode? If so, have I effectively bricked my CM3?
- Is there a good way to flash the eMMC from a running system (also could be helpful for standard RPis)?
- Is there a way to force USB device mode using the OTG GPIO pin?