Reset Arduino Leonardo to booloader mode from system

Hi,

I'm having issues trying to reflash the Arduino Leonardo of my LattePanda Sigma from the system. I can reset it and flash it using the reset button, but I would like to flash it without having physical access to the board.

The leonardo documentation explains that resetting the `/dev/ttyACM0` port to 1200 bauds should do the trick. It does restart the Arduino but not in bootloader mode. I've tried to play with DTR/CTS as well but with no luck.

Platformio is unable to flash it as well as it uses the 1200 bauds trick so it resets the board but not in bootloader mode.

Is there a trick specific to the LattePanda ?

Thanks in advance,