gdb/armobsd-tdep.c

   1 /* Target-dependent code for OpenBSD/arm.
   2
   3    Copyright (C) 2006, 2007 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 2 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, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20    Boston, MA 02110-1301, USA.  */
  21
  22 #include "defs.h"
  23 #include "osabi.h"
  24 #include "trad-frame.h"
  25 #include "tramp-frame.h"
  26
  27 #include "gdb_string.h"
  28
  29 #include "obsd-tdep.h"
  30 #include "arm-tdep.h"
  31 #include "solib-svr4.h"
  32
  33 /* Signal trampolines.  */
  34
  35 static void
  36 armobsd_sigframe_init (const struct tramp_frame *self,
  37                        struct frame_info *next_frame,
  38                        struct trad_frame_cache *cache,
  39                        CORE_ADDR func)
  40 {
  41   CORE_ADDR sp, sigcontext_addr, addr;
  42   int regnum;
  43
  44   /* We find the appropriate instance of `struct sigcontext' at a
  45      fixed offset in the signal frame.  */
  46   sp = frame_unwind_register_signed (next_frame, ARM_SP_REGNUM);
  47   sigcontext_addr = sp + 16;
  48
  49   /* PC.  */
  50   trad_frame_set_reg_addr (cache, ARM_PC_REGNUM, sigcontext_addr + 76);
  51
  52   /* GPRs.  */
  53   for (regnum = ARM_A1_REGNUM, addr = sigcontext_addr + 12;
  54        regnum <= ARM_LR_REGNUM; regnum++, addr += 4)
  55     trad_frame_set_reg_addr (cache, regnum, addr);
  56
  57   trad_frame_set_id (cache, frame_id_build (sp, func));
  58 }
  59
  60 static const struct tramp_frame armobsd_sigframe =
  61 {
  62   SIGTRAMP_FRAME,
  63   4,
  64   {
  65     { 0xe28d0010, -1 },         /* add     r0, sp, #16 */
  66     { 0xef000067, -1 },         /* swi     SYS_sigreturn */
  67     { 0xef000001, -1 },         /* swi     SYS_exit */
  68     { 0xeafffffc, -1 },         /* b       . - 8 */
  69     { TRAMP_SENTINEL_INSN, -1 }
  70   },
  71   armobsd_sigframe_init
  72 };
  73 \f
  74
  75 /* Override default thumb breakpoints.  */
  76 static const char arm_obsd_thumb_le_breakpoint[] = {0xfe, 0xdf};
  77 static const char arm_obsd_thumb_be_breakpoint[] = {0xdf, 0xfe};
  78
  79 static void
  80 armobsd_init_abi (struct gdbarch_info info,
  81                   struct gdbarch *gdbarch)
  82 {
  83   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  84
  85   if (tdep->fp_model == ARM_FLOAT_AUTO)
  86     tdep->fp_model = ARM_FLOAT_SOFT_VFP;
  87
  88   tramp_frame_prepend_unwinder (gdbarch, &armobsd_sigframe);
  89
  90   /* OpenBSD/arm uses SVR4-style shared libraries.  */
  91   set_solib_svr4_fetch_link_map_offsets
  92     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
  93   set_gdbarch_skip_solib_resolver (gdbarch, obsd_skip_solib_resolver);
  94
  95   tdep->jb_pc = 24;
  96   tdep->jb_elt_size = 4;
  97
  98   set_gdbarch_regset_from_core_section
  99     (gdbarch, armbsd_regset_from_core_section);
 100
 101   /* OpenBSD/arm uses -fpcc-struct-return by default.  */
 102   tdep->struct_return = pcc_struct_return;
 103
 104   /* Single stepping.  */
 105   set_gdbarch_software_single_step (gdbarch, arm_software_single_step);
 106
 107   /* Breakpoints.  */
 108   switch (info.byte_order)
 109     {
 110     case BFD_ENDIAN_BIG:
 111       tdep->thumb_breakpoint = arm_obsd_thumb_be_breakpoint;
 112       tdep->thumb_breakpoint_size = sizeof (arm_obsd_thumb_be_breakpoint);
 113       break;
 114
 115     case BFD_ENDIAN_LITTLE:
 116       tdep->thumb_breakpoint = arm_obsd_thumb_le_breakpoint;
 117       tdep->thumb_breakpoint_size = sizeof (arm_obsd_thumb_le_breakpoint);
 118       break;
 119     }
 120 }
 121 \f
 122
 123 static enum gdb_osabi
 124 armobsd_core_osabi_sniffer (bfd *abfd)
 125 {
 126   if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
 127     return GDB_OSABI_OPENBSD_ELF;
 128
 129   return GDB_OSABI_UNKNOWN;
 130 }
 131
 132 void
 133 _initialize_armobsd_tdep (void)
 134 {
 135   /* BFD doesn't set a flavour for NetBSD style a.out core files.  */
 136   gdbarch_register_osabi_sniffer (bfd_arch_arm, bfd_target_unknown_flavour,
 137                                   armobsd_core_osabi_sniffer);
 138
 139   gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_OPENBSD_ELF,
 140                           armobsd_init_abi);
 141 }