Patch by Scott McNutt, 25 Apr 2004:
Add Nios GDB/JTAG Console support:
- Add stubs to support gdb via JTAG.
- Add support for console over JTAG.
- Minor cleanup.
diff --git a/cpu/nios/serial.c b/cpu/nios/serial.c
index 34257a2..4bdda25 100644
--- a/cpu/nios/serial.c
+++ b/cpu/nios/serial.c
@@ -26,6 +26,48 @@
 #include <watchdog.h>
 #include <nios-io.h>
 
+/*------------------------------------------------------------------
+ * JTAG acts as the serial port
+ *-----------------------------------------------------------------*/
+#if defined(CONFIG_CONSOLE_JTAG)
+
+static nios_jtag_t *jtag = (nios_jtag_t *)CFG_NIOS_CONSOLE;
+
+void serial_setbrg( void ){ return; }
+int serial_init( void ) { return(0);}
+
+void serial_putc (char c)
+{
+	while ((jtag->txcntl & NIOS_JTAG_TRDY) != 0)
+		WATCHDOG_RESET ();
+	jtag->txcntl = NIOS_JTAG_TRDY | (unsigned char)c;
+}
+
+void serial_puts (const char *s)
+{
+	while (*s != 0)
+		serial_putc (*s++);
+}
+
+int serial_tstc (void)
+{
+	return (jtag->rxcntl & NIOS_JTAG_RRDY);
+}
+
+int serial_getc (void)
+{
+	int c;
+	while (serial_tstc() == 0)
+		WATCHDOG_RESET ();
+	c = jtag->rxcntl & 0x0ff;
+	jtag->rxcntl = 0;
+	return (c);
+}
+
+/*------------------------------------------------------------------
+ * UART the serial port
+ *-----------------------------------------------------------------*/
+#else
 
 static nios_uart_t *uart = (nios_uart_t *)CFG_NIOS_CONSOLE;
 
@@ -34,12 +76,12 @@
 /* Everything's already setup for fixed-baud PTF
  * assignment
  */
-void serial_setbrg( void ){ return; }
-int serial_init( void ) { return(0);}
+void serial_setbrg (void){ return; }
+int serial_init (void) { return (0);}
 
 #else
 
-void serial_setbrg( void )
+void serial_setbrg (void)
 {
 	DECLARE_GLOBAL_DATA_PTR;
 	unsigned div;
@@ -49,39 +91,44 @@
 	return;
 }
 
-int serial_init( void )
+int serial_init (void)
 {
-	serial_setbrg();
-	return(0);
+	serial_setbrg ();
+	return (0);
 }
 
 #endif /* CFG_NIOS_FIXEDBAUD */
 
 
-void serial_putc( char c )
+/*-----------------------------------------------------------------------
+ * UART CONSOLE
+ *---------------------------------------------------------------------*/
+void serial_putc (char c)
 {
 	if (c == '\n')
-		serial_putc('\r');
-	while( (uart->status & NIOS_UART_TRDY) == 0 )
+		serial_putc ('\r');
+	while ((uart->status & NIOS_UART_TRDY) == 0)
 		WATCHDOG_RESET ();
 	uart->txdata = (unsigned char)c;
 }
 
-void serial_puts( const char *s )
+void serial_puts (const char *s)
 {
-	while( *s != 0 ) {
-		serial_putc( *s++ );
+	while (*s != 0) {
+		serial_putc (*s++);
 	}
 }
 
-int serial_tstc( void )
+int serial_tstc (void)
 {
-	return( uart->status & NIOS_UART_RRDY);
+	return (uart->status & NIOS_UART_RRDY);
 }
 
-int serial_getc( void )
+int serial_getc (void)
 {
-	while( serial_tstc() == 0 )
+	while (serial_tstc () == 0)
 		WATCHDOG_RESET ();
 	return( uart->rxdata & 0x00ff );
 }
+
+#endif /* CONFIG_JTAG_CONSOLE */