os/arch/arm/src/amebasmart: allow booting normally when USB not attached

1. allow it to boot normally even with no USB attached, logs during USB disconnect period will be abandon
2. some of the boot up logs are missing because USB device is not ready yet
3. once USB attached, logs and tash can be input from usb port

os/arch/arm/src/amebasmart/amebasmart_usb.c

@@ -83,6 +83,7 @@ static _sema cdc_acm_attach_status_changed_sema;
 extern int cdc_acm_ready_flag;
 static uint8_t receive_data;
 static int received_flag = 0;
+static int attach_status = -1;
 /****************************************************************************
  * Private Type Definitions
  ****************************************************************************/
@@ -358,22 +359,28 @@ static void usb_xmitchars(FAR uart_dev_t *dev)
 		}
 		if (nbytes == CONFIG_CDC_ACM_BULK_IN_XFER_SIZE) {
 			nbytes = 0;
-			usbd_cdc_acm_transmit(buffer, CONFIG_CDC_ACM_BULK_IN_XFER_SIZE);
-			while (sem_wait(&g_usbdev.txsem) != 0) {
-				/* The only case that an error should occur here is if the wait was awakened
-				* by a signal.
-				*/
-				ASSERT(errno == EINTR);
+			/*we should only call usb TX when device is attached and ready, else abandon the data*/
+			if (attach_status == USBD_ATTACH_STATUS_ATTACHED && cdc_acm_ready_flag) { 
+				usbd_cdc_acm_transmit(buffer, CONFIG_CDC_ACM_BULK_IN_XFER_SIZE);
+				while (sem_wait(&g_usbdev.txsem) != 0) {
+					/* The only case that an error should occur here is if the wait was awakened
+					* by a signal.
+					*/
+					ASSERT(errno == EINTR);
+				}
 			}
 			priv->tx_level-=CONFIG_CDC_ACM_BULK_IN_XFER_SIZE;
 		}
 	}
-	usbd_cdc_acm_transmit(buffer, nbytes);
-	while (sem_wait(&g_usbdev.txsem) != 0) {
-		/* The only case that an error should occur here is if the wait was awakened
-		* by a signal.
-		*/
-		ASSERT(errno == EINTR);
+	/*we should only call usb TX when device is attached and ready, else abandon the data*/
+	if (attach_status == USBD_ATTACH_STATUS_ATTACHED && cdc_acm_ready_flag) { 
+		usbd_cdc_acm_transmit(buffer, nbytes);
+		while (sem_wait(&g_usbdev.txsem) != 0) {
+			/* The only case that an error should occur here is if the wait was awakened
+			* by a signal.
+			*/
+			ASSERT(errno == EINTR);
+		}
 	}
 	priv->tx_level-=nbytes;
 	rtw_mfree(buffer,0);
@@ -690,7 +697,11 @@ static void amebasmart_cdc_acm_cb_status_changed(uint8_t status)
 {
 	// struct amebasmart_usbdev_s *dev = (struct amebasmart_usbdev_s *)priv;
 	// DEBUGASSERT(dev);
-
+	/*when detached, we need to clear the rdy flag*/
+	attach_status = status;
+	if (status == USBD_ATTACH_STATUS_DETACHED) {
+		cdc_acm_ready_flag = -1;
+	}
 #if CONFIG_AMEBASMART_USBD_CDC_ACM_HOTPLUG
 	cdc_acm_attach_status = status;
 	rtw_up_sema(&cdc_acm_attach_status_changed_sema);
@@ -758,31 +769,14 @@ int amebasmart_up_usbinitialize(struct amebasmart_usbdev_s *priv)
 	return ret;
 }
 
-/*It takes sometime for USB initialization to complete, so during boot up stage, it /dev/console will be
- register with serial first to prevent opening an empty path, then once usb is ready, re-register it to usb and
- open the fd*/
-static int register_usb(void)
+void register_usb(void)
 {
-	while(!cdc_acm_ready_flag){
-		usleep(1000);
-	}
 	USB_DEV.isconsole = true;
 	uart_register("/dev/ttyACM0", &USB_DEV);
 	/*unregister /dev/console because serial was sharing the same fd during serial initialization*/
 	unregister_driver("/dev/console");
 	uart_register("/dev/console", &USB_DEV);
-	int fd;
-	fd = open("/dev/console", O_RDWR);
-	if(fd >= 0) {
-		dup2(fd, 1);
-		dup2(fd, 2);
-		return OK;
-	} else {
-		return -1;
-	}
-
 }
-
 void usb_initialize(void)
 {
 	struct amebasmart_usbdev_s *priv = NULL;
@@ -794,10 +788,4 @@ void usb_initialize(void)
 	if (ret != 0) {
 		udbg("amebasmart usb init fail\n");
 	}
-	ret = register_usb();
-	if (ret != OK) {
-		udbg("usb register failed");
-	}
 }
-
-

os/arch/arm/src/armv7-a/arm_initialize.c

@@ -188,7 +188,10 @@ void up_initialize(void)
 #ifdef USE_SERIALDRIVER
 	up_serialinit();
 #endif
-
+#ifdef CONFIG_AMEBASMART_USBDEVICE
+	/*if USB device enabled, we will unregister loguart and register /dev/console to usb*/
+	register_usb();
+#endif
 	/* Initialize the console device driver (if it is other than the standard
 	 * serial driver).
 	 */