Function usb_set_interface

Bootloader/usb.c:333–356

}

static int usb_set_interface(int iface, int altsetting)
{
	int iface_count = 0;

	for (struct usbd_function_ctx_header *fh = &usb.functions;
	     fh != NULL;
	     fh = fh->next, iface_count += fh->function->interface_count) {
		if (iface - iface_count < fh->function->interface_count) {
			if (fh->function->configure != NULL)
				return (fh->function->configure(iface,
								iface - iface_count,
								altsetting,
								fh));

			/* Default to a single altsetting */
			if (altsetting != 0)
				return (-1);
			else
				return (0);
		}
	}

	return (-1);
}

static int usb_tx_config_desc(int idx, int reqlen)
{