nmon is a tiny (<1024 bytes) monitor program
for the RV32I processors.

It can operate with NO working RAM at all!

It uses only the processor registers and NS16550-compatible
UART port for operation, so it can be used for a memory
controller setup code debugging.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>