From: Michael Brown <mcb30@ipxe.org>
Date: Wed, 5 Nov 2025 12:16:22 +0000 (+0000)
Subject: [uart] Make baud rate a property of the UART
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=08d4d7fe9db04c8f44ac063d4b722fb3e8f3fffe;p=thirdparty%2Fipxe.git

[uart] Make baud rate a property of the UART

Make the current baud rate (if specified) a property of the UART, to
allow the default_serial_console() function to specify the default
baud rate as well as the default UART device.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
---

diff --git a/src/core/gdbserial.c b/src/core/gdbserial.c
index 0f74e5fe0..61add5d47 100644
--- a/src/core/gdbserial.c
+++ b/src/core/gdbserial.c
@@ -95,7 +95,9 @@ struct gdb_transport * gdbserial_configure ( const char *name,
 		return NULL;
 	uart_get ( gdbserial_uart );
 
-	if ( ( rc = uart_init ( gdbserial_uart, baud ) ) != 0 )
+	gdbserial_uart->baud = baud;
+
+	if ( ( rc = uart_init ( gdbserial_uart ) ) != 0 )
 		return NULL;
 
 	return &serial_gdb_transport;
diff --git a/src/core/serial.c b/src/core/serial.c
index f3b33cd90..34ae4a17b 100644
--- a/src/core/serial.c
+++ b/src/core/serial.c
@@ -74,8 +74,14 @@ struct uart *serial_console = NULL;
  * @ret uart		Serial console UART, or NULL
  */
 static struct uart * serial_comconsole ( void ) {
+	struct uart *uart = COMCONSOLE;
+	unsigned int baud = COMSPEED;
 
-	return COMCONSOLE;
+	/* Set default baud rate, if applicable */
+	if ( uart && baud )
+		uart->baud = baud;
+
+	return uart;
 }
 
 /**
@@ -154,9 +160,9 @@ static void serial_init ( void ) {
 		return;
 
 	/* Initialise UART */
-	if ( ( rc = uart_init ( uart, COMSPEED ) ) != 0 ) {
-		DBGC ( uart, "SERIAL could not initialise %s baud %d: %s\n",
-		       uart->name, COMSPEED, strerror ( rc ) );
+	if ( ( rc = uart_init ( uart ) ) != 0 ) {
+		DBGC ( uart, "SERIAL could not initialise %s: %s\n",
+		       uart->name, strerror ( rc ) );
 		return;
 	}
 
diff --git a/src/core/uart.c b/src/core/uart.c
index a645bd398..5bff9fdd5 100644
--- a/src/core/uart.c
+++ b/src/core/uart.c
@@ -49,8 +49,7 @@ static uint8_t null_uart_receive ( struct uart *uart __unused ) {
 	return 0;
 }
 
-static int null_uart_init ( struct uart *uart __unused,
-			    unsigned int baud __unused ) {
+static int null_uart_init ( struct uart *uart __unused ) {
 	return 0;
 }
 
diff --git a/src/drivers/uart/ns16550.c b/src/drivers/uart/ns16550.c
index 428771ab5..f00e834b4 100644
--- a/src/drivers/uart/ns16550.c
+++ b/src/drivers/uart/ns16550.c
@@ -115,10 +115,9 @@ static void ns16550_flush ( struct uart *uart ) {
  * Initialise UART
  *
  * @v uart		UART
- * @v baud		Baud rate, or zero to leave unchanged
  * @ret rc		Return status code
  */
-static int ns16550_init ( struct uart *uart, unsigned int baud ) {
+static int ns16550_init ( struct uart *uart ) {
 	struct ns16550_uart *ns16550 = uart->priv;
 	uint8_t dlm;
 	uint8_t dll;
@@ -137,8 +136,8 @@ static int ns16550_init ( struct uart *uart, unsigned int baud ) {
 	/* Configure divisor and line control register, if applicable */
 	ns16550_write ( ns16550, NS16550_LCR,
 			( NS16550_LCR_8N1 | NS16550_LCR_DLAB ) );
-	if ( baud ) {
-		ns16550->divisor = ( ( ns16550->clock / baud ) /
+	if ( uart->baud ) {
+		ns16550->divisor = ( ( ns16550->clock / uart->baud ) /
 				     NS16550_CLK_BIT );
 		dlm = ( ( ns16550->divisor >> 8 ) & 0xff );
 		dll = ( ( ns16550->divisor >> 0 ) & 0xff );
diff --git a/src/include/ipxe/uart.h b/src/include/ipxe/uart.h
index 15adfa932..f2ecf3ce9 100644
--- a/src/include/ipxe/uart.h
+++ b/src/include/ipxe/uart.h
@@ -22,6 +22,9 @@ struct uart {
 	/** List of registered UARTs */
 	struct list_head list;
 
+	/** Baud rate (if specified) */
+	unsigned int baud;
+
 	/** UART operations */
 	struct uart_operations *op;
 	/** Driver-private data */
@@ -56,10 +59,9 @@ struct uart_operations {
 	 * Initialise UART
 	 *
 	 * @v uart		UART
-	 * @v baud		Baud rate, or zero to leave unchanged
 	 * @ret rc		Return status code
 	 */
-	int ( * init ) ( struct uart *uart, unsigned int baud );
+	int ( * init ) ( struct uart *uart );
 	/**
 	 * Flush transmitted data
 	 *
@@ -109,13 +111,12 @@ uart_receive ( struct uart *uart ) {
  * Initialise UART
  *
  * @v uart		UART
- * @v baud		Baud rate, or zero to leave unchanged
  * @ret rc		Return status code
  */
 static inline __attribute__ (( always_inline )) int
-uart_init ( struct uart *uart, unsigned int baud ) {
+uart_init ( struct uart *uart ) {
 
-	return uart->op->init ( uart, baud );
+	return uart->op->init ( uart );
 }
 
 /**