Hi, I managed to make something simple for writing that works. I leave it here for future reference and any possible feedback.
//write a fixed message in ttyRPMSG0
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#define TTY_RPMSG "/dev/ttyRPMSG0"
int main()
{
//open the device
int fd = open(TTY_RPMSG, O_RDWR | O_NOCTTY | O_SYNC | O_NDELAY);
//write a simple message and its lenght
write(fd, "restart", 7);
//close the device
close(fd);
return 0;
}
