Emulating UART with Avatar2 for firmware debugging – visualizing output

When we start the firmware with our first Avatar2 script, we may not see any output in the console. This is because the debug interface was not emulated, meaning no software was mapped to the interface that would print log messages. In previous research on Shannon baseband, UART is commonly used as the debug interface. Therefore, the first peripheral we emulate is UART so that we can visualize the output from the running firmware.

Emulating UART involves creating a main function that handles outputs according to the UART protocol. This means that read and write functions will be associated with specific addresses in the memory of the UART interface in the firmware, which will output messages to the console. In the case of Shannon baseband, when reading, it accesses the offset containing the status register (0x18), which returns the status value. When writing at offset 0x0, it writes the current value...