gdb/arm-wince-tdep.c - gdb

Global variables defined

Functions defined

Macros defined

Source code

  1. /* Target-dependent code for Windows CE running on ARM processors,
  2.    for GDB.

  4.    Copyright (C) 2007-2015 Free Software Foundation, Inc.

  6.    This file is part of GDB.

  8.    This program is free software; you can redistribute it and/or modify
  9.    it under the terms of the GNU General Public License as published by
  10.    the Free Software Foundation; either version 3 of the License, or
  11.    (at your option) any later version.

  13.    This program is distributed in the hope that it will be useful,
  14.    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15.    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16.    GNU General Public License for more details.

  18.    You should have received a copy of the GNU General Public License
  19.    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

  21. #include "defs.h"
  22. #include "osabi.h"
  23. #include "gdbcore.h"
  24. #include "target.h"
  25. #include "frame.h"

  27. #include "arm-tdep.h"
  28. #include "windows-tdep.h"

  30. ‌static const gdb_byte arm_wince_le_breakpoint[] = { 0x10, 0x00, 0x00, 0xe6 };
  31. ‌static const gdb_byte arm_wince_thumb_le_breakpoint[] = { 0xfe, 0xdf };

  33. /* Description of the longjmp buffer.  */
  34. ‌#define ARM_WINCE_JB_ELEMENT_SIZE        INT_REGISTER_SIZE
  35. ‌#define ARM_WINCE_JB_PC                        10

  37. static CORE_ADDR
  38. ‌arm_pe_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
  39. {
  40.   struct gdbarch *gdbarch = get_frame_arch (frame);
  41.   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  42.   ULONGEST indirect;
  43.   struct bound_minimal_symbol indsym;
  44.   const char *symname;
  45.   CORE_ADDR next_pc;

  47.   /* The format of an ARM DLL trampoline is:

  49.        ldr  ip, [pc]
  50.        ldr  pc, [ip]
  51.        .dw __imp_<func>

  53.   */

  55.   if (pc == 0
  56.       || read_memory_unsigned_integer (pc + 0, 4, byte_order) != 0xe59fc000
  57.       || read_memory_unsigned_integer (pc + 4, 4, byte_order) != 0xe59cf000)
  58.     return 0;

  60.   indirect = read_memory_unsigned_integer (pc + 8, 4, byte_order);
  61.   if (indirect == 0)
  62.     return 0;

  64.   indsym = lookup_minimal_symbol_by_pc (indirect);
  65.   if (indsym.minsym == NULL)
  66.     return 0;

  68.   symname = MSYMBOL_LINKAGE_NAME (indsym.minsym);
  69.   if (symname == NULL || strncmp (symname, "__imp_", 6) != 0)
  70.     return 0;

  72.   next_pc = read_memory_unsigned_integer (indirect, 4, byte_order);
  73.   if (next_pc != 0)
  74.     return next_pc;

  76.   /* Check with the default arm gdbarch_skip_trampoline.  */
  77.   return arm_skip_stub (frame, pc);
  78. }

  80. /* GCC emits a call to __gccmain in the prologue of main.

  82.    The function below examines the code pointed at by PC and checks to
  83.    see if it corresponds to a call to __gccmain.  If so, it returns
  84.    the address of the instruction following that call.  Otherwise, it
  85.    simply returns PC.  */

  87. static CORE_ADDR
  88. ‌arm_wince_skip_main_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
  89. {
  90.   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  91.   ULONGEST this_instr;

  93.   this_instr = read_memory_unsigned_integer (pc, 4, byte_order);

  95.   /* bl offset <__gccmain> */
  96.   if ((this_instr & 0xfff00000) == 0xeb000000)
  97.     {
  98. ‌#define sign_extend(V, N) \
  99.   (((long) (V) ^ (1L << ((N) - 1))) - (1L << ((N) - 1)))

  101.       long offset = sign_extend (this_instr & 0x000fffff, 23) << 2;
  102.       CORE_ADDR call_dest = (pc + 8 + offset) & 0xffffffffU;
  103.       struct bound_minimal_symbol s = lookup_minimal_symbol_by_pc (call_dest);

  105.       if (s.minsym != NULL
  106.           && MSYMBOL_LINKAGE_NAME (s.minsym) != NULL
  107.           && strcmp (MSYMBOL_LINKAGE_NAME (s.minsym), "__gccmain") == 0)
  108.         pc += 4;
  109.     }

  111.   return pc;
  112. }

  114. static void
  115. ‌arm_wince_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
  116. {
  117.   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  119.   windows_init_abi (info, gdbarch);

  121.   tdep->arm_breakpoint = arm_wince_le_breakpoint;
  122.   tdep->arm_breakpoint_size = sizeof (arm_wince_le_breakpoint);
  123.   tdep->thumb_breakpoint = arm_wince_thumb_le_breakpoint;
  124.   tdep->thumb_breakpoint_size = sizeof (arm_wince_thumb_le_breakpoint);
  125.   tdep->struct_return = pcc_struct_return;

  127.   tdep->fp_model = ARM_FLOAT_SOFT_VFP;

  129.   tdep->jb_pc = ARM_WINCE_JB_PC;
  130.   tdep->jb_elt_size = ARM_WINCE_JB_ELEMENT_SIZE;

  132.   /* On ARM WinCE char defaults to signed.  */
  133.   set_gdbarch_char_signed (gdbarch, 1);

  135.   /* Shared library handling.  */
  136.   set_gdbarch_skip_trampoline_code (gdbarch, arm_pe_skip_trampoline_code);

  138.   /* Single stepping.  */
  139.   set_gdbarch_software_single_step (gdbarch, arm_software_single_step);

  141.   /* Skip call to __gccmain that gcc places in main.  */
  142.   set_gdbarch_skip_main_prologue (gdbarch, arm_wince_skip_main_prologue);
  143. }

  145. static enum gdb_osabi
  146. ‌arm_wince_osabi_sniffer (bfd *abfd)
  147. {
  148.   const char *target_name = bfd_get_target (abfd);

  150.   if (strcmp (target_name, "pei-arm-wince-little") == 0)
  151.     return GDB_OSABI_WINCE;

  153.   return GDB_OSABI_UNKNOWN;
  154. }

  156. /* Provide a prototype to silence -Wmissing-prototypes.  */
  157. void _initialize_arm_wince_tdep (void);

  159. void
  160. ‌_initialize_arm_wince_tdep (void)
  161. {
  162.   gdbarch_register_osabi_sniffer (bfd_arch_arm, bfd_target_coff_flavour,
  163.                                   arm_wince_osabi_sniffer);

  165.   gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_WINCE,
  166.                           arm_wince_init_abi);
  167. }