USB output in ucom

Hello

I am still working on ucom console. My first cn_putc used ucomwrite(), 
but it always hung after reaching multi-user. I suspect a locking problem.

Another approach is to use USB transfers directly, bypassing a lot of
code in ucom.c, tty.c and tty_subr.c. I try this:

  error = usbd_create_xfer(sc->sc_bulkout_pipe,
      sc->sc_obufsize, USBD_SYNCHRONOUS, 0,
      &ucomcons_xfer_out);
  
  u_char *data = usbd_get_buffer(ucomcons_xfer_out;
  u_char *buf = __UNCONST("hello world!\nxxx\n");
  int cnt = 13;;
  
  if (sc->sc_methods->ucom_write != NULL)
          sc->sc_methods->ucom_write(sc->sc_parent, sc->sc_portno,
              data, buf, &cnt);
  else
          memcpy(data, buf, cnt);
  
  usbd_setup_xfer(ucomcons_xfer_out, sc, data, cnt,
      0, USBD_NO_TIMEOUT, NULL /* no cb */);
  
  usbd_transfer(ucomcons_xfer_out);

This actually output "ollow world!" on the serial line. How does the
"he" turns into a "o"? Is there a header to add, or some control characters
to insert?


-- 
Emmanuel Dreyfus
[email protected]