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 3 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, see <http://www.gnu.org/licenses/>.  */
  22
  23 #include "defs.h"
  24 #include "gdbtypes.h"
  25 #include "osabi.h"
  26 #include "regcache.h"
  27 #include "regset.h"
  28 #include "trad-frame.h"
  29 #include "tramp-frame.h"
  30
  31 #include "gdb_assert.h"
  32 #include "gdb_string.h"
  33
  34 #include "ppc-tdep.h"
  35 #include "ppcnbsd-tdep.h"
  36 #include "solib-svr4.h"
  37
  38 /* Register offsets from <machine/reg.h>.  */
  39 struct ppc_reg_offsets ppcnbsd_reg_offsets;
  40 \f
  41
  42 /* Core file support.  */
  43
  44 /* NetBSD/powerpc register sets.  */
  45
  46 struct regset ppcnbsd_gregset =
  47 {
  48   &ppcnbsd_reg_offsets,
  49   ppc_supply_gregset
  50 };
  51
  52 struct regset ppcnbsd_fpregset =
  53 {
  54   &ppcnbsd_reg_offsets,
  55   ppc_supply_fpregset
  56 };
  57
  58 /* Return the appropriate register set for the core section identified
  59    by SECT_NAME and SECT_SIZE.  */
  60
  61 static const struct regset *
  62 ppcnbsd_regset_from_core_section (struct gdbarch *gdbarch,
  63                                   const char *sect_name, size_t sect_size)
  64 {
  65   if (strcmp (sect_name, ".reg") == 0 && sect_size >= 148)
  66     return &ppcnbsd_gregset;
  67
  68   if (strcmp (sect_name, ".reg2") == 0 && sect_size >= 264)
  69     return &ppcnbsd_fpregset;
  70
  71   return NULL;
  72 }
  73 \f
  74
  75 /* NetBSD is confused.  It appears that 1.5 was using the correct SVR4
  76    convention but, 1.6 switched to the below broken convention.  For
  77    the moment use the broken convention.  Ulgh!.  */
  78
  79 static enum return_value_convention
  80 ppcnbsd_return_value (struct gdbarch *gdbarch, struct type *valtype,
  81                       struct regcache *regcache, gdb_byte *readbuf,
  82                       const gdb_byte *writebuf)
  83 {
  84 #if 0
  85   if ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT
  86        || TYPE_CODE (valtype) == TYPE_CODE_UNION)
  87       && !((TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 8)
  88             && TYPE_VECTOR (valtype))
  89       && !(TYPE_LENGTH (valtype) == 1
  90            || TYPE_LENGTH (valtype) == 2
  91            || TYPE_LENGTH (valtype) == 4
  92            || TYPE_LENGTH (valtype) == 8))
  93     return RETURN_VALUE_STRUCT_CONVENTION;
  94   else
  95 #endif
  96     return ppc_sysv_abi_broken_return_value (gdbarch, valtype, regcache,
  97                                              readbuf, writebuf);
  98 }
  99 \f
 100
 101 /* Signal trampolines.  */
 102
 103 static const struct tramp_frame ppcnbsd2_sigtramp;
 104
 105 static void
 106 ppcnbsd_sigtramp_cache_init (const struct tramp_frame *self,
 107                              struct frame_info *next_frame,
 108                              struct trad_frame_cache *this_cache,
 109                              CORE_ADDR func)
 110 {
 111   struct gdbarch *gdbarch = get_frame_arch (next_frame);
 112   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 113   CORE_ADDR addr, base;
 114   int i;
 115
 116   base = frame_unwind_register_unsigned (next_frame,
 117                                          gdbarch_sp_regnum (current_gdbarch));
 118   if (self == &ppcnbsd2_sigtramp)
 119     addr = base + 0x10 + 2 * tdep->wordsize;
 120   else
 121     addr = base + 0x18 + 2 * tdep->wordsize;
 122   for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
 123     {
 124       int regnum = i + tdep->ppc_gp0_regnum;
 125       trad_frame_set_reg_addr (this_cache, regnum, addr);
 126     }
 127   trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, addr);
 128   addr += tdep->wordsize;
 129   trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, addr);
 130   addr += tdep->wordsize;
 131   trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, addr);
 132   addr += tdep->wordsize;
 133   trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, addr);
 134   addr += tdep->wordsize;
 135   trad_frame_set_reg_addr (this_cache,
 136                            gdbarch_pc_regnum (current_gdbarch),
 137                            addr); /* SRR0? */
 138   addr += tdep->wordsize;
 139
 140   /* Construct the frame ID using the function start.  */
 141   trad_frame_set_id (this_cache, frame_id_build (base, func));
 142 }
 143
 144 static const struct tramp_frame ppcnbsd_sigtramp =
 145 {
 146   SIGTRAMP_FRAME,
 147   4,
 148   {
 149     { 0x3821fff0, -1 },         /* add r1,r1,-16 */
 150     { 0x4e800021, -1 },         /* blrl */
 151     { 0x38610018, -1 },         /* addi r3,r1,24 */
 152     { 0x38000127, -1 },         /* li r0,295 */
 153     { 0x44000002, -1 },         /* sc */
 154     { 0x38000001, -1 },         /* li r0,1 */
 155     { 0x44000002, -1 },         /* sc */
 156     { TRAMP_SENTINEL_INSN, -1 }
 157   },
 158   ppcnbsd_sigtramp_cache_init
 159 };
 160
 161 /* NetBSD 2.0 introduced a slightly different signal trampoline.  */
 162
 163 static const struct tramp_frame ppcnbsd2_sigtramp =
 164 {
 165   SIGTRAMP_FRAME,
 166   4,
 167   {
 168     { 0x3821fff0, -1 },         /* add r1,r1,-16 */
 169     { 0x4e800021, -1 },         /* blrl */
 170     { 0x38610010, -1 },         /* addi r3,r1,16 */
 171     { 0x38000127, -1 },         /* li r0,295 */
 172     { 0x44000002, -1 },         /* sc */
 173     { 0x38000001, -1 },         /* li r0,1 */
 174     { 0x44000002, -1 },         /* sc */
 175     { TRAMP_SENTINEL_INSN, -1 }
 176   },
 177   ppcnbsd_sigtramp_cache_init
 178 };
 179 \f
 180
 181 static void
 182 ppcnbsd_init_abi (struct gdbarch_info info,
 183                   struct gdbarch *gdbarch)
 184 {
 185   /* For NetBSD, this is an on again, off again thing.  Some systems
 186      do use the broken struct convention, and some don't.  */
 187   set_gdbarch_return_value (gdbarch, ppcnbsd_return_value);
 188
 189   /* NetBSD uses SVR4-style shared libraries.  */
 190   set_solib_svr4_fetch_link_map_offsets
 191     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 192
 193   set_gdbarch_regset_from_core_section
 194     (gdbarch, ppcnbsd_regset_from_core_section);
 195
 196   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd_sigtramp);
 197   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd2_sigtramp);
 198 }
 199 \f
 200
 201 /* Provide a prototype to silence -Wmissing-prototypes.  */
 202 void _initialize_ppcnbsd_tdep (void);
 203
 204 void
 205 _initialize_ppcnbsd_tdep (void)
 206 {
 207   gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_NETBSD_ELF,
 208                           ppcnbsd_init_abi);
 209
 210   /* Avoid initializing the register offsets again if they were
 211      already initailized by ppcnbsd-nat.c.  */
 212   if (ppcnbsd_reg_offsets.pc_offset == 0)
 213     {
 214       /* General-purpose registers.  */
 215       ppcnbsd_reg_offsets.r0_offset = 0;
 216       ppcnbsd_reg_offsets.gpr_size = 4;
 217       ppcnbsd_reg_offsets.xr_size = 4;
 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       ppcnbsd_reg_offsets.fpscr_size = 4;
 230
 231       /* AltiVec registers.  */
 232       ppcnbsd_reg_offsets.vr0_offset = 0;
 233       ppcnbsd_reg_offsets.vrsave_offset = 512;
 234       ppcnbsd_reg_offsets.vscr_offset = 524;
 235     }
 236 }