I've been racking my brain on this one, I'm wondering if anyone can offer any ideas to whats going on?
I can confirm my UART is working during startup when the boot messages are being displayed. Once I disable the boot message logging (in sudo raspi-config, advanced, ...), and write a python script (found on elinux)
port = serial.Serial("/dev/ttyAMA0", baudrate=115200, timeout=3.0)
I get no output on the TXD line. (reverting back to the boot msg logging causes normal behavior during startup)
The problem is I can't have the boot process holding onto that device because I would like to send my own messages.