implement KGDB on Toshiba RBTX4927, 2.6.24-rc7

Index: linux-2.6.24-rc7/drivers/serial/serial_txx9.c
===================================================================
@@ -1198,6 +1198,45 @@ MODULE_DEVICE_TABLE(pci, serial_txx9_pci
 
 static struct platform_device *serial_txx9_plat_devs;
 
+#ifdef CONFIG_EARLY_PRINTK
+
+/*
+ * Do NOT request the console resources, allows normal driver to initialize
+ * console later.
+ */
+
+static int prom_putchar_port = -1;
+
+void early_printk_serial_txx9_console_setup(void)
+{
+	prom_putchar_port = 0;
+}
+
+void prom_putchar(char ch)
+{
+	unsigned int status;
+	struct uart_txx9_port *up;
+
+	if (prom_putchar_port == -1)
+		return;
+
+	up = &serial_txx9_ports[prom_putchar_port];
+
+	if (ch == '\n')
+		prom_putchar('\r');
+
+	while (1) {
+		status = sio_in(up, TXX9_SICISR);
+		if (status & TXX9_SICISR_TRDY) {
+			sio_out(up, TXX9_SITFIFO, (u32)ch);
+			break;
+		}
+	}
+}
+
+#endif
+
+
 static int __init serial_txx9_init(void)
 {
 	int ret;

Index: linux-2.6.24-rc7/arch/mips/tx4927/toshiba_rbtx4927/toshiba_rbtx4927_setup.c
===================================================================
@@ -913,6 +913,12 @@ void __init toshiba_rbtx4927_setup(void)
         if (strstr(argptr, "console=") == NULL) {
                 strcat(argptr, " console=ttyS0,38400");
         }
+#ifdef CONFIG_EARLY_PRINTK
+	{
+		extern void early_printk_serial_txx9_console_setup(void);
+		early_printk_serial_txx9_console_setup();
+	}
+#endif
 #endif
 #endif
 

Index: linux-2.6.24-rc5/arch/mips/kernel/gdb-stub.c
===================================================================
@@ -656,6 +656,7 @@ void set_async_breakpoint(unsigned long 
 	*epc = (unsigned long)async_breakpoint;
 }
 
+#ifdef CONFIG_SMP
 static void kgdb_wait(void *arg)
 {
 	unsigned flags;

@@ -668,6 +669,7 @@ static void kgdb_wait(void *arg)
 
 	local_irq_restore(flags);
 }
+#endif
 
 /*
  * GDB stub needs to call kgdb_wait on all processor with interrupts

Index: linux-2.6.24-rc7/drivers/serial/serial_txx9.c
===================================================================
@@ -1237,6 +1237,96 @@ void prom_putchar(char ch)
 #endif
 
 
+/******************************************************************************/
+/* BEG: KDBG Routines                                                         */
+/******************************************************************************/
+
+#ifdef CONFIG_KGDB
+int kgdb_initialized;
+
+void txx9_sio_kgdb_hook(unsigned int port, unsigned int baud_rate)
+{
+	static struct resource kgdb_resource;
+	int ret;
+	struct uart_txx9_port *up = &serial_txx9_ports[port];
+
+	/* prevent initialization by driver */
+	kgdb_resource.name = "serial_txx9(debug)";
+	kgdb_resource.start = (resource_size_t)up->port.membase;
+	kgdb_resource.end = (resource_size_t)up->port.membase + 36 - 1;
+	kgdb_resource.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+
+	ret = request_resource(&iomem_resource, &kgdb_resource);
+	if (ret == -EBUSY)
+		printk(KERN_ERR
+			"txx9_sio_kgdb_hook(): request_resource failed\n");
+
+	return;
+}
+void
+txx9_sio_kdbg_init(unsigned int port_number)
+{
+	if (port_number == 1) {
+		txx9_sio_kgdb_hook(port_number, 38400);
+		kgdb_initialized = 1;
+	} else {
+		printk(KERN_ERR
+			"txx9_sio_kdbg_init(): Bad Port Number [%u] != [1]\n",
+			port_number);
+	}
+
+	return;
+}
+
+u8
+txx9_sio_kdbg_rd(void)
+{
+	unsigned int status, ch;
+	struct uart_txx9_port *up = &serial_txx9_ports[1];
+
+	if (!kgdb_initialized)
+		return 0;
+
+	while (1) {
+		status = sio_in(up, TXX9_SIDISR);
+		if (status & 0x1f) {
+			ch = sio_in(up, TXX9_SIRFIFO);
+			break;
+		}
+	}
+
+	return ch;
+}
+
+int
+txx9_sio_kdbg_wr(u8 ch)
+{
+	unsigned int status;
+	struct uart_txx9_port *up = &serial_txx9_ports[1];
+
+	if (!kgdb_initialized)
+		return 0;
+
+	while (1) {
+		status = sio_in(up, TXX9_SICISR);
+		if (status & TXX9_SICISR_TRDY) {
+			if (ch == '\n')
+				txx9_sio_kdbg_wr('\r');
+			sio_out(up, TXX9_SITFIFO, (u32)ch);
+
+			break;
+		}
+	}
+
+	return 1;
+}
+#endif /* CONFIG_KGDB */
+
+
+/******************************************************************************/
+/* END: KDBG Routines                                                         */
+/******************************************************************************/
+
 static int __init serial_txx9_init(void)
 {
 	int ret;

Index: linux-2.6.24-rc7/arch/mips/tx4927/toshiba_rbtx4927/toshiba_rbtx4927_setup.c
===================================================================
@@ -919,6 +919,12 @@ void __init toshiba_rbtx4927_setup(void)
 		early_printk_serial_txx9_console_setup();
 	}
 #endif
+#ifdef CONFIG_KGDB
+	{
+		extern void txx9_sio_kdbg_init(unsigned int port_number);
+		txx9_sio_kdbg_init(1);
+	}
+#endif
 #endif
 #endif
 

Index: linux-2.6.24-rc7/arch/mips/kernel/gdb-stub.c
===================================================================
@@ -131,6 +131,7 @@
 #include <linux/spinlock.h>
 #include <linux/slab.h>
 #include <linux/reboot.h>
+#include <linux/sysrq.h>
 
 #include <asm/asm.h>
 #include <asm/cacheflush.h>

@@ -1154,3 +1155,28 @@ static int __init register_gdb_console(v
 console_initcall(register_gdb_console);
 
 #endif
+
+#ifdef CONFIG_MAGIC_SYSRQ
+static void sysrq_handle_gdb(int key, struct tty_struct *tty)
+{
+	if (!initialized) {
+		printk(KERN_ALERT "Wait for gdb client connection ...\n");
+		set_debug_traps();
+	}
+
+	breakpoint();
+}
+static struct sysrq_key_op sysrq_gdb_op = {
+	.handler        = sysrq_handle_gdb,
+	.help_msg       = "Gdb",
+	.action_msg     = "GDB",
+};
+
+static int gdb_register_sysrq(void)
+{
+	printk(KERN_INFO "Registering GDB sysrq handler\n");
+	register_sysrq_key('g', &sysrq_gdb_op);
+	return 0;
+}
+module_init(gdb_register_sysrq);
+#endif