patch-2.4.6 linux/arch/mips/kernel/gdb-stub.c

• Lines: 161
• Date: Mon Jul 2 13:56:40 2001
• Orig file: v2.4.5/linux/arch/mips/kernel/gdb-stub.c
• Orig date: Sun Oct 1 20:35:15 2000

diff -u --recursive --new-file v2.4.5/linux/arch/mips/kernel/gdb-stub.c linux/arch/mips/kernel/gdb-stub.c
@@ -64,6 +64,61 @@
  * Host:                  Reply:
  * $m0,10#2a               +$00010203040506070809101112131415#42
  *
+ * 
+ *  ==============
+ *  MORE EXAMPLES:
+ *  ==============
+ *
+ *  For reference -- the following are the steps that one
+ *  company took (RidgeRun Inc) to get remote gdb debugging
+ *  going. In this scenario the host machine was a PC and the
+ *  target platform was a Galileo EVB64120A MIPS evaluation
+ *  board.
+ *   
+ *  Step 1:
+ *  First download gdb-5.0.tar.gz from the internet.
+ *  and then build/install the package.
+ * 
+ *  Example:
+ *    $ tar zxf gdb-5.0.tar.gz
+ *    $ cd gdb-5.0
+ *    $ ./configure --target=mips-linux-elf
+ *    $ make
+ *    $ install
+ *    $ which mips-linux-elf-gdb
+ *    /usr/local/bin/mips-linux-elf-gdb
+ * 
+ *  Step 2:
+ *  Configure linux for remote debugging and build it.
+ * 
+ *  Example:
+ *    $ cd ~/linux
+ *    $ make menuconfig <go to "Kernel Hacking" and turn on remote debugging>
+ *    $ make dep; make vmlinux
+ * 
+ *  Step 3:
+ *  Download the kernel to the remote target and start
+ *  the kernel running. It will promptly halt and wait 
+ *  for the host gdb session to connect. It does this
+ *  since the "Kernel Hacking" option has defined 
+ *  CONFIG_REMOTE_DEBUG which in turn enables your calls
+ *  to:
+ *     set_debug_traps();
+ *     breakpoint();
+ * 
+ *  Step 4:
+ *  Start the gdb session on the host.
+ * 
+ *  Example:
+ *    $ mips-linux-elf-gdb vmlinux
+ *    (gdb) set remotebaud 115200
+ *    (gdb) target remote /dev/ttyS1
+ *    ...at this point you are connected to 
+ *       the remote target and can use gdb
+ *       in the normal fasion. Setting 
+ *       breakpoints, single stepping,
+ *       printing variables, etc.
+ *
  */
 
 #include <linux/string.h>
@@ -71,6 +126,8 @@
 #include <linux/signal.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
+#include <linux/console.h>
+#include <linux/init.h>
 
 #include <asm/asm.h>
 #include <asm/mipsregs.h>
@@ -315,13 +372,10 @@
  * signals, which are primarily what GDB understands.  It also indicates
  * which hardware traps we need to commandeer when initializing the stub.
  */
-static struct hard_trap_info
-{
+static struct hard_trap_info {
 	unsigned char tt;		/* Trap type code for MIPS R3xxx and R4xxx */
 	unsigned char signo;		/* Signal that we map this trap into */
 } hard_trap_info[] = {
-	{ 4, SIGBUS },			/* address error (load) */
-	{ 5, SIGBUS },			/* address error (store) */
 	{ 6, SIGBUS },			/* instruction bus error */
 	{ 7, SIGBUS },			/* data bus error */
 	{ 9, SIGTRAP },			/* break */
@@ -350,6 +404,7 @@
 	for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
 		set_except_vector(ht->tt, trap_low);
   
+	putDebugChar('+'); /* 'hello world' */
 	/*
 	 * In case GDB is started before us, ack any packets
 	 * (presumably "$?#xx") sitting there.
@@ -373,7 +428,7 @@
  */
 extern void fltr_set_mem_err(void)
 {
-  /* FIXME: Needs to be written... */
+	/* FIXME: Needs to be written... */
 }
 
 /*
@@ -401,8 +456,7 @@
 
 	*intValue = 0;
 
-	while (**ptr)
-	{
+	while (**ptr) {
 		hexValue = hex(**ptr);
 		if (hexValue < 0)
 			break;
@@ -904,3 +958,47 @@
 			lw	$9,0($8)
 	");
 }
+
+#ifdef CONFIG_GDB_CONSOLE
+
+void gdb_puts(const char *str)
+{
+	int l = strlen(str);
+	char outbuf[18];
+
+	outbuf[0]='O';
+
+	while(l) {
+		int i = (l>8)?8:l;
+		mem2hex((char *)str, &outbuf[1], i, 0);
+		outbuf[(i*2)+1]=0;
+		putpacket(outbuf); 
+		str += i;
+		l -= i;
+	}
+}
+
+static kdev_t gdb_console_dev(struct console *con)
+{
+	return MKDEV(1, 3); /* /dev/null */
+}
+
+static void gdb_console_write(struct console *con, const char *s, unsigned n)
+{
+	gdb_puts(s);
+}
+
+static struct console gdb_console = {
+	name:	"gdb",
+	write:	gdb_console_write,
+	device:	gdb_console_dev,
+	flags:	CON_PRINTBUFFER,
+	index:	-1
+};
+
+__init void register_gdb_console(void)
+{
+	register_console(&gdb_console);
+}
+     
+#endif