Add gdbsym.c object to help with running gdb-to-qemu

src/arch/i386/core/gdbsym.c

+#include <stdio.h>
+#include <gpxe/init.h>
+#include <console.h>
+#include <realmode.h>
+
+extern char __text[];
+extern char __rodata[];
+extern char __data[];
+extern char __bss[];
+extern char __text16[];
+extern char __data16[];
+
+
+static void gdb_symbol_line ( void ) {
+	printf ( "Commands to start up gdb:\n\n" );
+	printf ( "gdb\n" );
+	printf ( "target remote localhost:1234\n" );
+	printf ( "add-symbol-file symbols %#lx", virt_to_phys ( __text ) );
+	printf ( " -s .rodata %#lx", virt_to_phys ( __rodata ) );
+	printf ( " -s .data %#lx", virt_to_phys ( __data ) );
+	printf ( " -s .bss %#lx", virt_to_phys ( __bss ) );
+	printf ( " -s .text16 %#x", ( ( rm_cs << 4 ) + (int)__text16 ) );
+	printf ( " -s .data16 %#x", ( ( rm_ds << 4 ) + (int)__data16 ) );
+	printf ( "\n" );
+	getkey();
+}
+
+INIT_FN ( INIT_GDBSYM, gdb_symbol_line, NULL, NULL );

src/config.h

 #undef	BUILD_ID		/* Include a custom build ID string,
 				 * e.g "test-foo" */
 #undef	NULL_TRAP		/* Attempt to catch NULL function calls */
+#define DUMP_GDBSYM		/* Dump GDB symbol table information */
 
 /* @END general.h */

src/core/config.c

  * Drag in miscellaneous objects
  *
  */
-#ifdef	NULL_TRAP
+#ifdef NULL_TRAP
 REQUIRE_OBJECT ( nulltrap );
 #endif
+#ifdef DUMP_GDBSYM
+REQUIRE_OBJECT ( gdbsym );
+#endif

src/include/gpxe/init.h

 
 /* Use double digits to avoid problems with "10" < "9" on alphabetic sort */
 #define	INIT_CONSOLE	02
-#define	INIT_CPU	03
-#define	INIT_TIMERS	04
+#define	INIT_GDBSYM	03
+#define	INIT_CPU	04
+#define	INIT_TIMERS	05
 #define	INIT_LOADBUF	08
 #define	INIT_PCMCIA	09
 #define	INIT_RPC	11