repurposing UART0


I am trying to use UART0 (J1) in user space as I need all the UARTS available for my project.

I have figured out how to compile my own version of u-boot to not capture the pins at boot time. But I am having troubles creating a virtual cape with the device tree to get those pins to work as a UART. I need to do it this way because I cannot have any information coming out the port at boot time.

I have been through the u-boot code and it appears that the offset of UART0_TXD is 170, and it appears that RXD should be 16C but it doesn’t seem to work.

I was able to configure pin 5 as a gpio and adjust the level of it and verify on my scope that I have the correct pin, but I can’t seem to get pin 4 to do anything. Also I have tried pin 5 in both 0x00 and 0x20 modes and cannot seem to get any output while using minicom.

I have spent many days on this problem now and must get this working, any help is much appreciated!