gdb/ppcnbsd-tdep.c

   1 /* Target-dependent code for NetBSD/powerpc.
   2
   3    Copyright (C) 2002-2013 Free Software Foundation, Inc.
   4
   5    Contributed by Wasabi Systems, Inc.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #include "defs.h"
  23 #include "gdbtypes.h"
  24 #include "osabi.h"
  25 #include "regcache.h"
  26 #include "regset.h"
  27 #include "trad-frame.h"
  28 #include "tramp-frame.h"
  29
  30 #include "gdb_assert.h"
  31 #include "gdb_string.h"
  32
  33 #include "ppc-tdep.h"
  34 #include "ppcnbsd-tdep.h"
  35 #include "solib-svr4.h"
  36
  37 /* Register offsets from <machine/reg.h>.  */
  38 struct ppc_reg_offsets ppcnbsd_reg_offsets;
  39 \f
  40
  41 /* Core file support.  */
  42
  43 /* NetBSD/powerpc register sets.  */
  44
  45 struct regset ppcnbsd_gregset =
  46 {
  47   &ppcnbsd_reg_offsets,
  48   ppc_supply_gregset
  49 };
  50
  51 struct regset ppcnbsd_fpregset =
  52 {
  53   &ppcnbsd_reg_offsets,
  54   ppc_supply_fpregset
  55 };
  56
  57 /* Return the appropriate register set for the core section identified
  58    by SECT_NAME and SECT_SIZE.  */
  59
  60 static const struct regset *
  61 ppcnbsd_regset_from_core_section (struct gdbarch *gdbarch,
  62                                   const char *sect_name, size_t sect_size)
  63 {
  64   if (strcmp (sect_name, ".reg") == 0 && sect_size >= 148)
  65     return &ppcnbsd_gregset;
  66
  67   if (strcmp (sect_name, ".reg2") == 0 && sect_size >= 264)
  68     return &ppcnbsd_fpregset;
  69
  70   return NULL;
  71 }
  72 \f
  73
  74 /* NetBSD is confused.  It appears that 1.5 was using the correct SVR4
  75    convention but, 1.6 switched to the below broken convention.  For
  76    the moment use the broken convention.  Ulgh!  */
  77
  78 static enum return_value_convention
  79 ppcnbsd_return_value (struct gdbarch *gdbarch, struct value *function,
  80                       struct type *valtype, struct regcache *regcache,
  81                       gdb_byte *readbuf, const gdb_byte *writebuf)
  82 {
  83 #if 0
  84   if ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT
  85        || TYPE_CODE (valtype) == TYPE_CODE_UNION)
  86       && !((TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 8)
  87             && TYPE_VECTOR (valtype))
  88       && !(TYPE_LENGTH (valtype) == 1
  89            || TYPE_LENGTH (valtype) == 2
  90            || TYPE_LENGTH (valtype) == 4
  91            || TYPE_LENGTH (valtype) == 8))
  92     return RETURN_VALUE_STRUCT_CONVENTION;
  93   else
  94 #endif
  95     return ppc_sysv_abi_broken_return_value (gdbarch, function, valtype,
  96                                              regcache, readbuf, writebuf);
  97 }
  98 \f
  99
 100 /* Signal trampolines.  */
 101
 102 static const struct tramp_frame ppcnbsd2_sigtramp;
 103
 104 static void
 105 ppcnbsd_sigtramp_cache_init (const struct tramp_frame *self,
 106                              struct frame_info *this_frame,
 107                              struct trad_frame_cache *this_cache,
 108                              CORE_ADDR func)
 109 {
 110   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 111   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 112   CORE_ADDR addr, base;
 113   int i;
 114
 115   base = get_frame_register_unsigned (this_frame,
 116                                       gdbarch_sp_regnum (gdbarch));
 117   if (self == &ppcnbsd2_sigtramp)
 118     addr = base + 0x10 + 2 * tdep->wordsize;
 119   else
 120     addr = base + 0x18 + 2 * tdep->wordsize;
 121   for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
 122     {
 123       int regnum = i + tdep->ppc_gp0_regnum;
 124       trad_frame_set_reg_addr (this_cache, regnum, addr);
 125     }
 126   trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, addr);
 127   addr += tdep->wordsize;
 128   trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, addr);
 129   addr += tdep->wordsize;
 130   trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, addr);
 131   addr += tdep->wordsize;
 132   trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, addr);
 133   addr += tdep->wordsize;
 134   trad_frame_set_reg_addr (this_cache, gdbarch_pc_regnum (gdbarch),
 135                            addr); /* SRR0?  */
 136   addr += tdep->wordsize;
 137
 138   /* Construct the frame ID using the function start.  */
 139   trad_frame_set_id (this_cache, frame_id_build (base, func));
 140 }
 141
 142 static const struct tramp_frame ppcnbsd_sigtramp =
 143 {
 144   SIGTRAMP_FRAME,
 145   4,
 146   {
 147     { 0x3821fff0, -1 },         /* add r1,r1,-16 */
 148     { 0x4e800021, -1 },         /* blrl */
 149     { 0x38610018, -1 },         /* addi r3,r1,24 */
 150     { 0x38000127, -1 },         /* li r0,295 */
 151     { 0x44000002, -1 },         /* sc */
 152     { 0x38000001, -1 },         /* li r0,1 */
 153     { 0x44000002, -1 },         /* sc */
 154     { TRAMP_SENTINEL_INSN, -1 }
 155   },
 156   ppcnbsd_sigtramp_cache_init
 157 };
 158
 159 /* NetBSD 2.0 introduced a slightly different signal trampoline.  */
 160
 161 static const struct tramp_frame ppcnbsd2_sigtramp =
 162 {
 163   SIGTRAMP_FRAME,
 164   4,
 165   {
 166     { 0x3821fff0, -1 },         /* add r1,r1,-16 */
 167     { 0x4e800021, -1 },         /* blrl */
 168     { 0x38610010, -1 },         /* addi r3,r1,16 */
 169     { 0x38000127, -1 },         /* li r0,295 */
 170     { 0x44000002, -1 },         /* sc */
 171     { 0x38000001, -1 },         /* li r0,1 */
 172     { 0x44000002, -1 },         /* sc */
 173     { TRAMP_SENTINEL_INSN, -1 }
 174   },
 175   ppcnbsd_sigtramp_cache_init
 176 };
 177 \f
 178
 179 static void
 180 ppcnbsd_init_abi (struct gdbarch_info info,
 181                   struct gdbarch *gdbarch)
 182 {
 183   /* For NetBSD, this is an on again, off again thing.  Some systems
 184      do use the broken struct convention, and some don't.  */
 185   set_gdbarch_return_value (gdbarch, ppcnbsd_return_value);
 186
 187   /* NetBSD uses SVR4-style shared libraries.  */
 188   set_solib_svr4_fetch_link_map_offsets
 189     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 190
 191   set_gdbarch_regset_from_core_section
 192     (gdbarch, ppcnbsd_regset_from_core_section);
 193
 194   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd_sigtramp);
 195   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd2_sigtramp);
 196 }
 197 \f
 198
 199 /* Provide a prototype to silence -Wmissing-prototypes.  */
 200 void _initialize_ppcnbsd_tdep (void);
 201
 202 void
 203 _initialize_ppcnbsd_tdep (void)
 204 {
 205   gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_NETBSD_ELF,
 206                           ppcnbsd_init_abi);
 207
 208   /* Avoid initializing the register offsets again if they were
 209      already initailized by ppcnbsd-nat.c.  */
 210   if (ppcnbsd_reg_offsets.pc_offset == 0)
 211     {
 212       /* General-purpose registers.  */
 213       ppcnbsd_reg_offsets.r0_offset = 0;
 214       ppcnbsd_reg_offsets.gpr_size = 4;
 215       ppcnbsd_reg_offsets.xr_size = 4;
 216       ppcnbsd_reg_offsets.lr_offset = 128;
 217       ppcnbsd_reg_offsets.cr_offset = 132;
 218       ppcnbsd_reg_offsets.xer_offset = 136;
 219       ppcnbsd_reg_offsets.ctr_offset = 140;
 220       ppcnbsd_reg_offsets.pc_offset = 144;
 221       ppcnbsd_reg_offsets.ps_offset = -1;
 222       ppcnbsd_reg_offsets.mq_offset = -1;
 223
 224       /* Floating-point registers.  */
 225       ppcnbsd_reg_offsets.f0_offset = 0;
 226       ppcnbsd_reg_offsets.fpscr_offset = 256;
 227       ppcnbsd_reg_offsets.fpscr_size = 4;
 228
 229       /* AltiVec registers.  */
 230       ppcnbsd_reg_offsets.vr0_offset = 0;
 231       ppcnbsd_reg_offsets.vrsave_offset = 512;
 232       ppcnbsd_reg_offsets.vscr_offset = 524;
 233     }
 234 }