jh7100-recover = pkgs.runCommandCC "jh7100-recover" {} ''
          mkdir -p $out/bin
          gcc -o $out/bin/jh7100-recover ${jh71xx-tools}/jh7100-recover.c
        '';
        jh7100-recover = pkgs.writeCBin "jh7100-recover" (builtins.readFile "${jh71xx-tools}/jh7100-recover.c");

I've not made a README yet, but it will be:

1. Attach the board via serial
2. nix run .#flashBootloader /dev/ttyUSB0

In reply to @matthewcroughan:defenestrate.it
Zhaofeng Li: Is it possible to flash the file with screen instead of xmodem on Windows?

advantages of xmodem over just cat:

• it knows when transfer starts and ends
• there's a crc checksum for each packet and if it doesn't work the board can request a resend
• that's about it

You can also use something like picocom which does the sending inside the terminal

picocom --send-cmd "sx -X -vv" -b {9600 or 115200} /dev/tty{...}

1. Do not apply power to the board
2. Attach the board via serial to your system, ensuring power is still not applied
3. Ensure the serial shows up in /dev/ttyUSB*
4. nix run github:matthewcroughan/visionfive-nix#flashBootloader /dev/ttyUSB0
5. Apply power to the board