Cross compile gdbserver and use it in ARM linux (在ARM uClinux下编译和使用gdbserver)

1. get and unzip src
 
  # mkdir /usr/src/debug
  # cd /usr/src/debug
  # wget ftp://ftp.gnu.org/pub/gnu/gdb/gdb-6.3.tar.bz2
  # tar -jxvf gdb-6.3.tar.bz2

2. apply gdb patch for ARM
 
  # cp [PATCH_PATH]/gdb-6.3-tango-20050204.patch /usr/src/debug/gdb-6.3
  # patch -p1 < gdb-6.3-tango-20050204.patch

  replace [PATCH_PATH] to your patch path.
  use patch-gdb-5.2.1-arm7tdmi-20020920 in the reference document is another choice, it's more complexity which need modify some code before compile.

3. build gdb

  # mkdir /usr/src/debug/build_gdb
  # cd /usr/src/debug/build_gdb
  # ../gdb-6.3/configure --target=arm-linux --host=i386-pc-linux --prefix=/opt/gdebug
  # make
  # make install

4. build gdbserver

  # mkdir /usr/src/debug/build_gdbserver
  # cd /usr/src/debug/build_gdbserver
  # export PATH=[TOOLCHAIN_PATH]:$PATH
  # CC=arm-elf-gcc LDFLAGS='-Wl,-elf2flt' ../gdb-6.3/gdb/gdbserver/configure --target=arm-elf-linux --host=arm-elf-linux --prefix=/opt/gdebug/arm-linux
  # make
  # make install

  set [TOOLCHAIN_PATH] to your toolchain patch.
  after build, deploy the gdbserver binary to your target filesystem.

5.use gdb and gdbserve(command line or eclipse):

  examples:

  host pc ip:192.168.1.45
  board   ip:192.168.1.180  
  copy program and gdbserver to host/tftpboot/

  and then in Target borad:

  # mount 192.168.1.108:/tftpboot /mnt/nfs
  # cd /mnt/nfs
  # ./gdbserver 192.168.1.45:1234 gdbtest

  In host pc：
  # cd /usr/local/arm-gdb/bin/
  # copy gdbtest /usr/local/arm-gdb/bin/ 

  # ./arm-linux-gdb gdbtest
  (gdb)target remote 192.168.1.180:1234           
  (gdb)list   or l
  (gdb)break func
  (gdb)break 22
  (gdb)info br  
  (gdb)continue   or c  

  (gdb)next   or n
  (gdb)print or p    result
  (gdb) finish      

  (gdb) next
  (gdb) quit

Appendix:

1). reference: http://www.uclinux.org/pub/uClinux/archive/10734.html

2). gdb-6.3-tango-20050204.patch:

/* start of gdb-6.3-tango-20050204.patch */

diff -Nur gdb-6.3/gdb/arm-tdep.c gdb-6.3.patched/gdb/arm-tdep.c
--- gdb-6.3/gdb/arm-tdep.c 2004-08-02 19:02:20.000000000 -0700
+++ gdb-6.3.patched/gdb/arm-tdep.c 2005-02-04 10:14:11.000000000 -0800
@@ -1925,10 +1925,12 @@
 /* NOTE rearnsha 2002-02-18: for now we allow a non-multi-arch gdb to
    override these definitions.  */
 #ifndef ARM_LE_BREAKPOINT
-#define ARM_LE_BREAKPOINT {0xFE,0xDE,0xFF,0xE7}
+//#define ARM_LE_BREAKPOINT {0xFE,0xDE,0xFF,0xE7}
+#define ARM_LE_BREAKPOINT {0x01,0x00,0x9f,0xEF}
 #endif
 #ifndef ARM_BE_BREAKPOINT
-#define ARM_BE_BREAKPOINT {0xE7,0xFF,0xDE,0xFE}
+//#define ARM_BE_BREAKPOINT {0xE7,0xFF,0xDE,0xFE}
+#define ARM_BE_BREAKPOINT {0xEF,0x9f,0x00,0x01}
 #endif
 #ifndef THUMB_LE_BREAKPOINT
 #define THUMB_LE_BREAKPOINT {0xfe,0xdf}
diff -Nur gdb-6.3/gdb/config/arm/tm-embed.h gdb-6.3.patched/gdb/config/arm/tm-embed.h
--- gdb-6.3/gdb/config/arm/tm-embed.h 2004-04-30 13:52:16.000000000 -0700
+++ gdb-6.3.patched/gdb/config/arm/tm-embed.h 2005-02-04 10:14:11.000000000 -0800
@@ -27,7 +27,7 @@
 
 /* The remote stub should be able to single-step. */
 #undef SOFTWARE_SINGLE_STEP_P
-#define SOFTWARE_SINGLE_STEP_P() 0
+#define SOFTWARE_SINGLE_STEP_P() 1
 
 /* The first 0x20 bytes are the trap vectors.  */
 #undef LOWEST_PC
diff -Nur gdb-6.3/gdb/gdbserver/linux-arm-low.c gdb-6.3.patched/gdb/gdbserver/linux-arm-low.c
--- gdb-6.3/gdb/gdbserver/linux-arm-low.c 2004-02-29 08:43:49.000000000 -0800
+++ gdb-6.3.patched/gdb/gdbserver/linux-arm-low.c 2005-02-04 10:14:11.000000000 -0800
@@ -23,7 +23,7 @@
 #include "linux-low.h"
 
 #ifdef HAVE_SYS_REG_H
-#include <sys/reg.h>
+//#include <sys/reg.h>
 #endif
 
 #define arm_num_regs 26
diff -Nur gdb-6.3/gdb/gdbserver/linux-low.c gdb-6.3.patched/gdb/gdbserver/linux-low.c
--- gdb-6.3/gdb/gdbserver/linux-low.c 2004-10-16 10:42:00.000000000 -0700
+++ gdb-6.3.patched/gdb/gdbserver/linux-low.c 2005-02-04 10:14:11.000000000 -0800
@@ -78,6 +78,24 @@
 /* FIXME: Delete eventually.  */
 #define inferior_pid (pid_of (get_thread_process (current_inferior)))
 
+void send_area(char* buf) {
+
+  unsigned int x;
+  unsigned int code_start = ptrace (PTRACE_PEEKUSER, inferior_pid,
+                                    (PTRACE_ARG3_TYPE) 49*4, 0);
+  unsigned int data_start = ptrace (PTRACE_PEEKUSER, inferior_pid,
+                                    (PTRACE_ARG3_TYPE) 50*4, 0);
+  unsigned int bss_start = data_start;
+  unsigned int code_end = ptrace(PTRACE_PEEKUSER, inferior_pid,
+                                 (PTRACE_ARG3_TYPE) 51*4, 0);
+
+  printf("code at %p - %p, data at %p/n", code_start, code_end, data_start);
+
+  x = data_start - (code_end - code_start);
+  sprintf(buf,"Text=%x;Data=%x;Bss=%x;", code_start, x, x);
+};
+
+
 /* This function should only be called if the process got a SIGTRAP.
    The SIGTRAP could mean several things.
 
@@ -139,7 +157,7 @@
   void *new_process;
   int pid;
 
-  pid = fork ();
+  pid = vfork ();
   if (pid < 0)
     perror_with_name ("fork");
 
diff -Nur gdb-6.3/gdb/gdbserver/server.c gdb-6.3.patched/gdb/gdbserver/server.c
--- gdb-6.3/gdb/gdbserver/server.c 2004-03-04 19:44:27.000000000 -0800
+++ gdb-6.3.patched/gdb/gdbserver/server.c 2005-02-04 10:14:11.000000000 -0800
@@ -89,6 +89,12 @@
 handle_query (char *own_buf)
 {
   static struct inferior_list_entry *thread_ptr;
+ 
+  if (strcmp ("qOffsets", own_buf) == 0)
+    {
+        send_area(own_buf);
+        return;
+    }
 
   if (strcmp ("qSymbol::", own_buf) == 0)
     {

/* end of gdb-6.3-tango-20050204.patch */