Can't boot the system on Raspberry Pi 3B+ #319
Description
We attempted to do an OP-TEE system boot on a Raspberry Pi 3B+ with a very new production date (February 2025), but after a week-long attempt it didn't work. We were able to determine that it should not be a problem with the device (since a normal Ubuntu Server burned into the device was able to boot and get serial output via UART), but when we followed the steps in the official documentation, we were unable to get any output via the serial port, and the Raspberry Pi 3B+ did not boot properly, as indicated by the red light being on constantly / the green light blinking (4 slow blinks followed by 7 fast blinks).
After confirming, we believe that the problem may be caused by our Raspberry Pi's newer CPU model (BCM2837B0). We would like to know if this problem is common to this CPU model? Alternatively, if we replace it with a BCM2710 model will we still experience the same problem? Any help would be appreciated!