Added option to disable serial port reordering

2 files changed, 22 insertions, 1 deletions

diff --git a/nuttx/arch/arm/src/stm32/Kconfig b/nuttx/arch/arm/src/stm32/Kconfig
index 7249b382f..abd8f9898 100644
--- a/nuttx/arch/arm/src/stm32/Kconfig
+++ b/nuttx/arch/arm/src/stm32/Kconfig
@@ -2417,6 +2417,20 @@ config SERIAL_TERMIOS
 		If this is not defined, then the terminal settings (baud, parity, etc).
 		are not configurable at runtime; serial streams cannot be flushed, etc..
 
+config SERIAL_DISABLE_REORDERING
+	bool "Disable reordering of ttySx devices."
+	depends on STM32_USART1 || STM32_USART2 || STM32_USART3 || STM32_UART4 || STM32_UART5 || STM32_USART6 || STM32_USART7 || STM32_USART8
+	default n
+	---help---
+		NuttX per default reorders the serial ports (/dev/ttySx) so that the
+		console is always on /dev/ttyS0. If more than one UART is in use this
+		can have however the side-effect that all port mappings
+		(hardware USART1 -> /dev/ttyS0) change if the console is moved to another
+		UART. This is in particular relevant if a project uses the USB console
+		in some configs and a serial console in other configs, but does not
+		want the side effect of having all serial port names change when just
+		the console is moved from serial to USB.
+
 endmenu
 
 config STM32_USART_SINGLEWIRE
diff --git a/nuttx/arch/arm/src/stm32/stm32_serial.c b/nuttx/arch/arm/src/stm32/stm32_serial.c
index 52a77e255..ff4cd7549 100644
--- a/nuttx/arch/arm/src/stm32/stm32_serial.c
+++ b/nuttx/arch/arm/src/stm32/stm32_serial.c
@@ -2417,6 +2417,10 @@ void up_serialinit(void)
 
 #if CONSOLE_UART > 0
   (void)uart_register("/dev/console", &uart_devs[CONSOLE_UART - 1]->dev);
+#ifndef CONFIG_SERIAL_DISABLE_REORDERING
+  /* If not disabled, register the console UART to ttyS0 and exclude
+   * it from initializing it further down
+   */
   (void)uart_register("/dev/ttyS0",   &uart_devs[CONSOLE_UART - 1]->dev);
   minor = 1;
 
@@ -2425,6 +2429,7 @@ void up_serialinit(void)
 # ifdef SERIAL_HAVE_CONSOLE_DMA
   up_dma_setup(&uart_devs[CONSOLE_UART - 1]->dev);
 # endif
+#endif /* CONFIG_SERIAL_DISABLE_REORDERING not defined */
 
 #endif /* CONSOLE_UART > 0 */
 
@@ -2434,12 +2439,14 @@ void up_serialinit(void)
 
   for (i = 0; i < STM32_NUSART; i++)
     {
+        
+#ifndef CONFIG_SERIAL_DISABLE_REORDERING
       /* Don't create a device for the console - we did that above */
-
       if ((uart_devs[i] == 0) || (uart_devs[i]->dev.isconsole))
         {
           continue;
         }
+#endif
 
       /* Register USARTs as devices in increasing order */