Simple Send using SFP via USART

This is a simple sample code to send and receive a file using SFP over LOOPBACK interface.

How to Build

$ cmake -B builddir
$ ninja -C builddir simple-sfp-send-recv

How to Test

In a terminal, run simple-sfp-send-recv

./builddir/samples/posix/simple-sfp-send-recv/simple-sfp-send-recv existing_file_on_system.txt file_to_create_on_system.txt

If it runs successfully, the program exits with 0.