gdb/armobsd-tdep.c

   1 /* Target-dependent code for OpenBSD/arm.
   2
   3    Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   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.
  12
  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.
  17
  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/>.  */
  20
  21 #include "defs.h"
  22 #include "osabi.h"
  23 #include "trad-frame.h"
  24 #include "tramp-frame.h"
  25
  26 #include "gdb_string.h"
  27
  28 #include "obsd-tdep.h"
  29 #include "arm-tdep.h"
  30 #include "solib-svr4.h"
  31
  32 /* Signal trampolines.  */
  33
  34 static void
  35 armobsd_sigframe_init (const struct tramp_frame *self,
  36                        struct frame_info *this_frame,
  37                        struct trad_frame_cache *cache,
  38                        CORE_ADDR func)
  39 {
  40   CORE_ADDR sp, sigcontext_addr, addr;
  41   int regnum;
  42
  43   /* We find the appropriate instance of `struct sigcontext' at a
  44      fixed offset in the signal frame.  */
  45   sp = get_frame_register_signed (this_frame, ARM_SP_REGNUM);
  46   sigcontext_addr = sp + 16;
  47
  48   /* PC.  */
  49   trad_frame_set_reg_addr (cache, ARM_PC_REGNUM, sigcontext_addr + 76);
  50
  51   /* GPRs.  */
  52   for (regnum = ARM_A1_REGNUM, addr = sigcontext_addr + 12;
  53        regnum <= ARM_LR_REGNUM; regnum++, addr += 4)
  54     trad_frame_set_reg_addr (cache, regnum, addr);
  55
  56   trad_frame_set_id (cache, frame_id_build (sp, func));
  57 }
  58
  59 static const struct tramp_frame armobsd_sigframe =
  60 {
  61   SIGTRAMP_FRAME,
  62   4,
  63   {
  64     { 0xe28d0010, -1 },         /* add     r0, sp, #16 */
  65     { 0xef000067, -1 },         /* swi     SYS_sigreturn */
  66     { 0xef000001, -1 },         /* swi     SYS_exit */
  67     { 0xeafffffc, -1 },         /* b       . - 8 */
  68     { TRAMP_SENTINEL_INSN, -1 }
  69   },
  70   armobsd_sigframe_init
  71 };
  72 \f
  73
  74 /* Override default thumb breakpoints.  */
  75 static const char arm_obsd_thumb_le_breakpoint[] = {0xfe, 0xdf};
  76 static const char arm_obsd_thumb_be_breakpoint[] = {0xdf, 0xfe};
  77
  78 static void
  79 armobsd_init_abi (struct gdbarch_info info,
  80                   struct gdbarch *gdbarch)
  81 {
  82   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  83
  84   if (tdep->fp_model == ARM_FLOAT_AUTO)
  85     tdep->fp_model = ARM_FLOAT_SOFT_VFP;
  86
  87   tramp_frame_prepend_unwinder (gdbarch, &armobsd_sigframe);
  88
  89   /* OpenBSD/arm uses SVR4-style shared libraries.  */
  90   set_solib_svr4_fetch_link_map_offsets
  91     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
  92   set_gdbarch_skip_solib_resolver (gdbarch, obsd_skip_solib_resolver);
  93
  94   tdep->jb_pc = 24;
  95   tdep->jb_elt_size = 4;
  96
  97   set_gdbarch_regset_from_core_section
  98     (gdbarch, armbsd_regset_from_core_section);
  99
 100   /* OpenBSD/arm uses -fpcc-struct-return by default.  */
 101   tdep->struct_return = pcc_struct_return;
 102
 103   /* Single stepping.  */
 104   set_gdbarch_software_single_step (gdbarch, arm_software_single_step);
 105
 106   /* Breakpoints.  */
 107   switch (info.byte_order)
 108     {
 109     case BFD_ENDIAN_BIG:
 110       tdep->thumb_breakpoint = arm_obsd_thumb_be_breakpoint;
 111       tdep->thumb_breakpoint_size = sizeof (arm_obsd_thumb_be_breakpoint);
 112       break;
 113
 114     case BFD_ENDIAN_LITTLE:
 115       tdep->thumb_breakpoint = arm_obsd_thumb_le_breakpoint;
 116       tdep->thumb_breakpoint_size = sizeof (arm_obsd_thumb_le_breakpoint);
 117       break;
 118     }
 119 }
 120 \f
 121
 122 static enum gdb_osabi
 123 armobsd_core_osabi_sniffer (bfd *abfd)
 124 {
 125   if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
 126     return GDB_OSABI_OPENBSD_ELF;
 127
 128   return GDB_OSABI_UNKNOWN;
 129 }
 130
 131 /* Provide a prototype to silence -Wmissing-prototypes.  */
 132 extern initialize_file_ftype _initialize_armobsd_tdep;
 133
 134 void
 135 _initialize_armobsd_tdep (void)
 136 {
 137   /* BFD doesn't set a flavour for NetBSD style a.out core files.  */
 138   gdbarch_register_osabi_sniffer (bfd_arch_arm, bfd_target_unknown_flavour,
 139                                   armobsd_core_osabi_sniffer);
 140
 141   gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_OPENBSD_ELF,
 142                           armobsd_init_abi);
 143 }