This is an old thread but I'll reply to it anyway, in case someone else runs into this problem.
"However, I'm now stuck on how to get a terminal and send Linux commands to the board. I have a USB to UART adapter and I have now idea how to do it. is it even possible?"
Linux will use printf() (actually fprintf) to communicate with a terminal. Printf() in turn relies on _write() to output a string to the terminal. You'll have to implement a _write() function which in turn printf() will call. Such code will look something like this:
int __io_putchar(int ch)
{
/* Support printf over UART */
(void) HAL_UART_Transmit(&UartHandle, (uint8_t *) &ch, 1, 0xFFFFU);
return ch;
}
int _write(int file, char *ptr, int len)
{
/* Send chars over UART */
for (int i = 0; i < len; i++)
{
(void) __io_putchar(*ptr++);
}
return len;
}
Of course you will have to set up a UART to do this.
Also, if you aren't using an OS you can include stdio.h in your code and write these functions you can then use printf() in your code, which will send output to the UART, which you can connect to a terminal. This is very handy for debugging.
