Add instructions to update firmware via serial port using nxpprog

README.md

@@ -103,6 +103,18 @@ To upgrade the bootloader, use
 
     ipmitool -I lan -H host_name_mch -A none -T 0x82 -m 0x20 -t (112 + num_slot*2 in hexadecimal) hpm upgrade newboot.hpm activate
 
+### nxpprog
+> :warning: **Disclaimer:** Only supported in AFCv4.0.2
+
+In AFCv4, it's possible to program the firmware and bootloader via serial port using [nxpprog](https://github.com/lnls-dig/nxpprog). In order to use it, install nxpprog and then execute the following commands:
+To upgrade the application, use
+
+    ./nxpprog.py  <serial_device> <path_to_openMMC.bin> --addr 0x20000 --control
+
+To upgrade the bootloader, use
+
+    ./nxpprog.py  <serial_device> <path_to_newboot.bin> --control
+
 ## Debugging
 It is possible to debug the MMC firmware using OpenOCD and GDB. First, connect OpenOCD with the debug probe using the `out/openocd.cfg` file generated by cmake in the build directory: