gdb/armobsd-tdep.c

   1 /* Target-dependent code for OpenBSD/arm.
   2
   3    Copyright (C) 2006-2013 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "osabi.h"
  22 #include "trad-frame.h"
  23 #include "tramp-frame.h"
  24
  25 #include "gdb_string.h"
  26
  27 #include "obsd-tdep.h"
  28 #include "arm-tdep.h"
  29 #include "solib-svr4.h"
  30
  31 /* Signal trampolines.  */
  32
  33 static void
  34 armobsd_sigframe_init (const struct tramp_frame *self,
  35                        struct frame_info *this_frame,
  36                        struct trad_frame_cache *cache,
  37                        CORE_ADDR func)
  38 {
  39   CORE_ADDR sp, sigcontext_addr, addr;
  40   int regnum;
  41
  42   /* We find the appropriate instance of `struct sigcontext' at a
  43      fixed offset in the signal frame.  */
  44   sp = get_frame_register_signed (this_frame, ARM_SP_REGNUM);
  45   sigcontext_addr = sp + 16;
  46
  47   /* PC.  */
  48   trad_frame_set_reg_addr (cache, ARM_PC_REGNUM, sigcontext_addr + 76);
  49
  50   /* GPRs.  */
  51   for (regnum = ARM_A1_REGNUM, addr = sigcontext_addr + 12;
  52        regnum <= ARM_LR_REGNUM; regnum++, addr += 4)
  53     trad_frame_set_reg_addr (cache, regnum, addr);
  54
  55   trad_frame_set_id (cache, frame_id_build (sp, func));
  56 }
  57
  58 static const struct tramp_frame armobsd_sigframe =
  59 {
  60   SIGTRAMP_FRAME,
  61   4,
  62   {
  63     { 0xe28d0010, -1 },         /* add     r0, sp, #16 */
  64     { 0xef000067, -1 },         /* swi     SYS_sigreturn */
  65     { 0xef000001, -1 },         /* swi     SYS_exit */
  66     { 0xeafffffc, -1 },         /* b       . - 8 */
  67     { TRAMP_SENTINEL_INSN, -1 }
  68   },
  69   armobsd_sigframe_init
  70 };
  71 \f
  72
  73 /* Override default thumb breakpoints.  */
  74 static const gdb_byte arm_obsd_thumb_le_breakpoint[] = {0xfe, 0xdf};
  75 static const gdb_byte arm_obsd_thumb_be_breakpoint[] = {0xdf, 0xfe};
  76
  77 static void
  78 armobsd_init_abi (struct gdbarch_info info,
  79                   struct gdbarch *gdbarch)
  80 {
  81   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  82
  83   if (tdep->fp_model == ARM_FLOAT_AUTO)
  84     tdep->fp_model = ARM_FLOAT_SOFT_VFP;
  85
  86   tramp_frame_prepend_unwinder (gdbarch, &armobsd_sigframe);
  87
  88   /* OpenBSD/arm uses SVR4-style shared libraries.  */
  89   set_solib_svr4_fetch_link_map_offsets
  90     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
  91   set_gdbarch_skip_solib_resolver (gdbarch, obsd_skip_solib_resolver);
  92
  93   tdep->jb_pc = 24;
  94   tdep->jb_elt_size = 4;
  95
  96   set_gdbarch_regset_from_core_section
  97     (gdbarch, armbsd_regset_from_core_section);
  98
  99   /* OpenBSD/arm uses -fpcc-struct-return by default.  */
 100   tdep->struct_return = pcc_struct_return;
 101
 102   /* Single stepping.  */
 103   set_gdbarch_software_single_step (gdbarch, arm_software_single_step);
 104
 105   /* Breakpoints.  */
 106   switch (info.byte_order)
 107     {
 108     case BFD_ENDIAN_BIG:
 109       tdep->thumb_breakpoint = arm_obsd_thumb_be_breakpoint;
 110       tdep->thumb_breakpoint_size = sizeof (arm_obsd_thumb_be_breakpoint);
 111       break;
 112
 113     case BFD_ENDIAN_LITTLE:
 114       tdep->thumb_breakpoint = arm_obsd_thumb_le_breakpoint;
 115       tdep->thumb_breakpoint_size = sizeof (arm_obsd_thumb_le_breakpoint);
 116       break;
 117     }
 118 }
 119 \f
 120
 121 static enum gdb_osabi
 122 armobsd_core_osabi_sniffer (bfd *abfd)
 123 {
 124   if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
 125     return GDB_OSABI_OPENBSD_ELF;
 126
 127   return GDB_OSABI_UNKNOWN;
 128 }
 129
 130 /* Provide a prototype to silence -Wmissing-prototypes.  */
 131 extern initialize_file_ftype _initialize_armobsd_tdep;
 132
 133 void
 134 _initialize_armobsd_tdep (void)
 135 {
 136   /* BFD doesn't set a flavour for NetBSD style a.out core files.  */
 137   gdbarch_register_osabi_sniffer (bfd_arch_arm, bfd_target_unknown_flavour,
 138                                   armobsd_core_osabi_sniffer);
 139
 140   gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_OPENBSD_ELF,
 141                           armobsd_init_abi);
 142 }