gdb/ppcnbsd-tdep.c

   1 /* Target-dependent code for NetBSD/powerpc.
   2
   3    Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007
   4    Free Software Foundation, Inc.
   5
   6    Contributed by Wasabi Systems, Inc.
   7
   8    This file is part of GDB.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 2 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  23    Boston, MA 02110-1301, USA.  */
  24
  25 #include "defs.h"
  26 #include "gdbtypes.h"
  27 #include "osabi.h"
  28 #include "regcache.h"
  29 #include "regset.h"
  30 #include "trad-frame.h"
  31 #include "tramp-frame.h"
  32
  33 #include "gdb_assert.h"
  34 #include "gdb_string.h"
  35
  36 #include "ppc-tdep.h"
  37 #include "ppcnbsd-tdep.h"
  38 #include "solib-svr4.h"
  39
  40 /* Register offsets from <machine/reg.h>.  */
  41 struct ppc_reg_offsets ppcnbsd_reg_offsets;
  42 \f
  43
  44 /* Core file support.  */
  45
  46 /* NetBSD/powerpc register sets.  */
  47
  48 struct regset ppcnbsd_gregset =
  49 {
  50   &ppcnbsd_reg_offsets,
  51   ppc_supply_gregset
  52 };
  53
  54 struct regset ppcnbsd_fpregset =
  55 {
  56   &ppcnbsd_reg_offsets,
  57   ppc_supply_fpregset
  58 };
  59
  60 /* Return the appropriate register set for the core section identified
  61    by SECT_NAME and SECT_SIZE.  */
  62
  63 static const struct regset *
  64 ppcnbsd_regset_from_core_section (struct gdbarch *gdbarch,
  65                                   const char *sect_name, size_t sect_size)
  66 {
  67   if (strcmp (sect_name, ".reg") == 0 && sect_size >= 148)
  68     return &ppcnbsd_gregset;
  69
  70   if (strcmp (sect_name, ".reg2") == 0 && sect_size >= 264)
  71     return &ppcnbsd_fpregset;
  72
  73   return NULL;
  74 }
  75 \f
  76
  77 /* NetBSD is confused.  It appears that 1.5 was using the correct SVR4
  78    convention but, 1.6 switched to the below broken convention.  For
  79    the moment use the broken convention.  Ulgh!.  */
  80
  81 static enum return_value_convention
  82 ppcnbsd_return_value (struct gdbarch *gdbarch, struct type *valtype,
  83                       struct regcache *regcache, gdb_byte *readbuf,
  84                       const gdb_byte *writebuf)
  85 {
  86 #if 0
  87   if ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT
  88        || TYPE_CODE (valtype) == TYPE_CODE_UNION)
  89       && !((TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 8)
  90             && TYPE_VECTOR (valtype))
  91       && !(TYPE_LENGTH (valtype) == 1
  92            || TYPE_LENGTH (valtype) == 2
  93            || TYPE_LENGTH (valtype) == 4
  94            || TYPE_LENGTH (valtype) == 8))
  95     return RETURN_VALUE_STRUCT_CONVENTION;
  96   else
  97 #endif
  98     return ppc_sysv_abi_broken_return_value (gdbarch, valtype, regcache,
  99                                              readbuf, writebuf);
 100 }
 101 \f
 102
 103 /* Signal trampolines.  */
 104
 105 static const struct tramp_frame ppcnbsd2_sigtramp;
 106
 107 static void
 108 ppcnbsd_sigtramp_cache_init (const struct tramp_frame *self,
 109                              struct frame_info *next_frame,
 110                              struct trad_frame_cache *this_cache,
 111                              CORE_ADDR func)
 112 {
 113   struct gdbarch *gdbarch = get_frame_arch (next_frame);
 114   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 115   CORE_ADDR addr, base;
 116   int i;
 117
 118   base = frame_unwind_register_unsigned (next_frame,
 119                                          gdbarch_sp_regnum (current_gdbarch));
 120   if (self == &ppcnbsd2_sigtramp)
 121     addr = base + 0x10 + 2 * tdep->wordsize;
 122   else
 123     addr = base + 0x18 + 2 * tdep->wordsize;
 124   for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
 125     {
 126       int regnum = i + tdep->ppc_gp0_regnum;
 127       trad_frame_set_reg_addr (this_cache, regnum, addr);
 128     }
 129   trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, addr);
 130   addr += tdep->wordsize;
 131   trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, addr);
 132   addr += tdep->wordsize;
 133   trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, addr);
 134   addr += tdep->wordsize;
 135   trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, addr);
 136   addr += tdep->wordsize;
 137   trad_frame_set_reg_addr (this_cache,
 138                            gdbarch_pc_regnum (current_gdbarch),
 139                            addr); /* SRR0? */
 140   addr += tdep->wordsize;
 141
 142   /* Construct the frame ID using the function start.  */
 143   trad_frame_set_id (this_cache, frame_id_build (base, func));
 144 }
 145
 146 static const struct tramp_frame ppcnbsd_sigtramp =
 147 {
 148   SIGTRAMP_FRAME,
 149   4,
 150   {
 151     { 0x3821fff0, -1 },         /* add r1,r1,-16 */
 152     { 0x4e800021, -1 },         /* blrl */
 153     { 0x38610018, -1 },         /* addi r3,r1,24 */
 154     { 0x38000127, -1 },         /* li r0,295 */
 155     { 0x44000002, -1 },         /* sc */
 156     { 0x38000001, -1 },         /* li r0,1 */
 157     { 0x44000002, -1 },         /* sc */
 158     { TRAMP_SENTINEL_INSN, -1 }
 159   },
 160   ppcnbsd_sigtramp_cache_init
 161 };
 162
 163 /* NetBSD 2.0 introduced a slightly different signal trampoline.  */
 164
 165 static const struct tramp_frame ppcnbsd2_sigtramp =
 166 {
 167   SIGTRAMP_FRAME,
 168   4,
 169   {
 170     { 0x3821fff0, -1 },         /* add r1,r1,-16 */
 171     { 0x4e800021, -1 },         /* blrl */
 172     { 0x38610010, -1 },         /* addi r3,r1,16 */
 173     { 0x38000127, -1 },         /* li r0,295 */
 174     { 0x44000002, -1 },         /* sc */
 175     { 0x38000001, -1 },         /* li r0,1 */
 176     { 0x44000002, -1 },         /* sc */
 177     { TRAMP_SENTINEL_INSN, -1 }
 178   },
 179   ppcnbsd_sigtramp_cache_init
 180 };
 181 \f
 182
 183 static void
 184 ppcnbsd_init_abi (struct gdbarch_info info,
 185                   struct gdbarch *gdbarch)
 186 {
 187   /* For NetBSD, this is an on again, off again thing.  Some systems
 188      do use the broken struct convention, and some don't.  */
 189   set_gdbarch_return_value (gdbarch, ppcnbsd_return_value);
 190
 191   /* NetBSD uses SVR4-style shared libraries.  */
 192   set_solib_svr4_fetch_link_map_offsets
 193     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 194
 195   set_gdbarch_regset_from_core_section
 196     (gdbarch, ppcnbsd_regset_from_core_section);
 197
 198   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd_sigtramp);
 199   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd2_sigtramp);
 200 }
 201 \f
 202
 203 /* Provide a prototype to silence -Wmissing-prototypes.  */
 204 void _initialize_ppcnbsd_tdep (void);
 205
 206 void
 207 _initialize_ppcnbsd_tdep (void)
 208 {
 209   gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_NETBSD_ELF,
 210                           ppcnbsd_init_abi);
 211
 212   /* Avoid initializing the register offsets again if they were
 213      already initailized by ppcnbsd-nat.c.  */
 214   if (ppcnbsd_reg_offsets.pc_offset == 0)
 215     {
 216       /* General-purpose registers.  */
 217       ppcnbsd_reg_offsets.r0_offset = 0;
 218       ppcnbsd_reg_offsets.lr_offset = 128;
 219       ppcnbsd_reg_offsets.cr_offset = 132;
 220       ppcnbsd_reg_offsets.xer_offset = 136;
 221       ppcnbsd_reg_offsets.ctr_offset = 140;
 222       ppcnbsd_reg_offsets.pc_offset = 144;
 223       ppcnbsd_reg_offsets.ps_offset = -1;
 224       ppcnbsd_reg_offsets.mq_offset = -1;
 225
 226       /* Floating-point registers.  */
 227       ppcnbsd_reg_offsets.f0_offset = 0;
 228       ppcnbsd_reg_offsets.fpscr_offset = 256;
 229
 230       /* AltiVec registers.  */
 231       ppcnbsd_reg_offsets.vr0_offset = 0;
 232       ppcnbsd_reg_offsets.vrsave_offset = 512;
 233       ppcnbsd_reg_offsets.vscr_offset = 524;
 234     }
 235 }