The BOCHS_DEBUG_HACK definition now only enables support for the bochs

debug output - to activate it, you now have to enable it in the kernel
settings file ("bochs_debug_output true").
Reimplemented the serial output so that it's flexible towards the base
port at run time.
Implemented support for kernel settings "serial_debug_port" (which can
now also be an index in the BIOS provided serial ports list), and
"serial_debug_speed".
That also means that you can finally use the same kernel executable
under BeOS Bochs and on a real system without any restrictions.


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@10642 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kernel/core/arch/x86/arch_dbg_console.c

@@ -1,17 +1,16 @@
 /*
-** Copyright 2002-2004, The Haiku Team. All rights reserved.
+ * Copyright 2002-2005, Axel Dörfler, [email protected]
-** Distributed under the terms of the Haiku License.
+ * Copyright 2001, Rob Judd <[email protected]>
-**
+ * Copyright 2002, Marcus Overhagen <[email protected]>
-** Copyright 2001, Travis Geiselbrecht. All rights reserved.
+ * Distributed under the terms of the Haiku License.
-** Distributed under the terms of the NewOS License.
+ *
-*/
+ * Copyright 2001, Travis Geiselbrecht. All rights reserved.
+ * Distributed under the terms of the NewOS License.
+ */
 
-/*
-** Modified 2001/09/05 by Rob Judd<[email protected]>
-** Modified 2002/09/28 by Marcus Overhagen <[email protected]>
-*/
 
-#include <kernel.h>
+#include <KernelExport.h>
+#include <driver_settings.h>
 #include <int.h>
 #include <arch/cpu.h>
 #include <arch/dbg_console.h>
@@ -19,23 +18,44 @@
 #include <boot/stage2.h>
 
 #include <string.h>
+#include <stdlib.h>
 
-/* define this only if not used as compile parameter
+
- * setting it to 1 will disable serial debug and
+/* If you've enabled Bochs debug output in the kernel driver
- * redirect it to Bochs
+ * settings and has defined this, serial debug output will be
+ * disabled and redirected to Bochs.
+ * Define this only if not used as compile parameter.
  */
 // #define BOCHS_DEBUG_HACK 0
 
-// Select between COM1 and COM2 for debug output
-#define USE_COM1 1
 
-static const int dbg_baud_rate = 115200;
+enum serial_register_offsets {
+	SERIAL_TRANSMIT_BUFFER		= 0,
+	SERIAL_RECEIVE_BUFFER		= 0,
+	SERIAL_DIVISOR_LATCH_LOW	= 0,
+	SERIAL_DIVISOR_LATCH_HIGH	= 1,
+	SERIAL_FIFO_CONTROL			= 2,
+	SERIAL_LINE_CONTROL			= 3,
+	SERIAL_MODEM_CONTROL		= 4,
+	SERIAL_LINE_STATUS			= 5,
+	SERIAL_MODEM_STATUS			= 6,
+};
+
+static const uint32 kSerialBaudRate = 115200;
+
+static uint16 sSerialBasePort = 0x3f8;
+	// COM1 is the default debug output port
+
+#if BOCHS_DEBUG_HACK
+static bool sBochsOutput = false;
+#endif
 
 
 char
 arch_dbg_con_read(void)
 {
 #if BOCHS_DEBUG_HACK
+	if (sBochsOutput) {
 		/* polling the keyboard, similar to code in keyboard
 		 * driver, but without using an interrupt
 		 */
@@ -77,37 +97,31 @@ arch_dbg_con_read(void)
 			}
 		} while (!ascii);
 		return ascii;
+	}
 #endif
 
-#if USE_COM1
+	while ((in8(sSerialBasePort + SERIAL_LINE_STATUS) & 0x1) == 0)
-	while ((in8(0x3fd) & 1) == 0)
 		;
-	return in8(0x3f8);
+
-#else
+	return in8(sSerialBasePort + SERIAL_RECEIVE_BUFFER);
-	while ((in8(0x2fd) & 1) == 0)
-		;
-	return in8(0x2f8);
-#endif
 }
 
 
 static void
-_arch_dbg_con_putch(const char c)
+put_char(const char c)
 {
 #if BOCHS_DEBUG_HACK
+	if (sBochsOutput) {
 		out8(c, 0xe9);
 		return;
+	}
 #endif
 
-#if USE_COM1
+	// wait until the transmitter empty bit is set
-	while ((in8(0x3fd) & 0x20) == 0)
+	while ((in8(sSerialBasePort + SERIAL_LINE_STATUS) & 0x20) == 0)
 		;
-	out8(c, 0x3f8);
+
-#else // COM2
+	out8(c, sSerialBasePort + SERIAL_TRANSMIT_BUFFER);
-	while ((in8(0x2fd) & 0x20) == 0)
-		;
-	out8(c, 0x2f8);
-#endif
 }
 
 
@@ -115,10 +129,10 @@ char
 arch_dbg_con_putch(const char c)
 {
 	if (c == '\n') {
-		_arch_dbg_con_putch('\r');
+		put_char('\r');
-		_arch_dbg_con_putch('\n');
+		put_char('\n');
 	} else if (c != '\r')
-		_arch_dbg_con_putch(c);
+		put_char(c);
 
 	return c;
 }
@@ -147,20 +161,77 @@ arch_dbg_con_early_boot_message(const char *string)
 status_t
 arch_dbg_con_init(kernel_args *args)
 {
-	short divisor = 115200 / dbg_baud_rate;
+	uint16 divisor = (uint16)(115200 / kSerialBaudRate);
 
-#if USE_COM1
+	// only use the port if we could find one, else use the standard port
-	out8(0x80, 0x3fb);	/* set up to load divisor latch	*/
+	if (args->platform_args.serial_base_ports[0] != 0)
-	out8(divisor & 0xf, 0x3f8);		/* LSB */
+		sSerialBasePort = args->platform_args.serial_base_ports[0];
-	out8(divisor >> 8, 0x3f9);		/* MSB */
-	out8(3, 0x3fb);		/* 8N1 */
-#else // COM2
-	out8(0x80, 0x2fb);	/* set up to load divisor latch	*/
-	out8(divisor & 0xf, 0x2f8);		/* LSB */
-	out8(divisor >> 8, 0x2f9);		/* MSB */
-	out8(3, 0x2fb);		/* 8N1 */
-#endif
 
-	return 0;
+	out8(0x80, sSerialBasePort + SERIAL_LINE_CONTROL);	/* set divisor latch access bit */
+	out8(divisor & 0xf, sSerialBasePort + SERIAL_DIVISOR_LATCH_LOW);
+	out8(divisor >> 8, sSerialBasePort + SERIAL_DIVISOR_LATCH_HIGH);
+	out8(3, sSerialBasePort + SERIAL_LINE_CONTROL);		/* 8N1 */
+
+	return B_OK;
 }
 
+
+status_t
+arch_dbg_con_init_settings(kernel_args *args)
+{
+	uint32 baudRate = kSerialBaudRate;
+	uint16 basePort = sSerialBasePort;
+	uint16 divisor;
+	void *handle;
+
+	// get debug settings
+	handle = load_driver_settings("kernel");
+	if (handle != NULL) {
+		const char *value;
+
+#ifdef BOCHS_DEBUG_HACK
+		sBochsOutput = get_driver_boolean_parameter(handle, "bochs_debug_output", false, false);
+#endif
+		value = get_driver_parameter(handle, "serial_debug_port", NULL, NULL);
+		if (value != NULL) {
+			int32 number = strtol(value, NULL, 0);
+			if (number < MAX_SERIAL_PORTS) {
+				// use as index into port array
+				if (args->platform_args.serial_base_ports[number] != 0)
+					basePort = args->platform_args.serial_base_ports[number];
+			} else {
+				// use as port number directly
+				basePort = number;
+			}
+		}
+
+		value = get_driver_parameter(handle, "serial_debug_speed", NULL, NULL);
+		if (value != NULL) {
+			int32 number = strtol(value, NULL, 0);
+			switch (number) {
+				case 9600:
+				case 19200:
+				case 38400:
+				case 57600:
+				case 115200:
+				//case 230400:
+					baudRate = number;
+			}
+		}
+
+		unload_driver_settings(handle);
+	}
+
+	if (sSerialBasePort == basePort && baudRate == kSerialBaudRate)
+		return B_OK;
+
+	sSerialBasePort = basePort;
+	divisor = (uint16)(115200 / baudRate);
+
+	out8(0x80, sSerialBasePort + SERIAL_LINE_CONTROL);	/* set divisor latch access bit */
+	out8(divisor & 0xf, sSerialBasePort + SERIAL_DIVISOR_LATCH_LOW);
+	out8(divisor >> 8, sSerialBasePort + SERIAL_DIVISOR_LATCH_HIGH);
+	out8(3, sSerialBasePort + SERIAL_LINE_CONTROL);		/* 8N1 */
+
+	return B_OK;
+}