gdb/ppcnbsd-tdep.c

   1 /* Target-dependent code for NetBSD/powerpc.
   2
   3    Copyright (C) 2002-2014 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 <string.h>
  31
  32 #include "ppc-tdep.h"
  33 #include "ppcnbsd-tdep.h"
  34 #include "solib-svr4.h"
  35
  36 /* Register offsets from <machine/reg.h>.  */
  37 struct ppc_reg_offsets ppcnbsd_reg_offsets;
  38 \f
  39
  40 /* Core file support.  */
  41
  42 /* NetBSD/powerpc register sets.  */
  43
  44 const struct regset ppcnbsd_gregset =
  45 {
  46   &ppcnbsd_reg_offsets,
  47   ppc_supply_gregset
  48 };
  49
  50 const struct regset ppcnbsd_fpregset =
  51 {
  52   &ppcnbsd_reg_offsets,
  53   ppc_supply_fpregset
  54 };
  55
  56 /* Return the appropriate register set for the core section identified
  57    by SECT_NAME and SECT_SIZE.  */
  58
  59 static const struct regset *
  60 ppcnbsd_regset_from_core_section (struct gdbarch *gdbarch,
  61                                   const char *sect_name, size_t sect_size)
  62 {
  63   if (strcmp (sect_name, ".reg") == 0 && sect_size >= 148)
  64     return &ppcnbsd_gregset;
  65
  66   if (strcmp (sect_name, ".reg2") == 0 && sect_size >= 264)
  67     return &ppcnbsd_fpregset;
  68
  69   return NULL;
  70 }
  71 \f
  72
  73 /* NetBSD is confused.  It appears that 1.5 was using the correct SVR4
  74    convention but, 1.6 switched to the below broken convention.  For
  75    the moment use the broken convention.  Ulgh!  */
  76
  77 static enum return_value_convention
  78 ppcnbsd_return_value (struct gdbarch *gdbarch, struct value *function,
  79                       struct type *valtype, struct regcache *regcache,
  80                       gdb_byte *readbuf, const gdb_byte *writebuf)
  81 {
  82 #if 0
  83   if ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT
  84        || TYPE_CODE (valtype) == TYPE_CODE_UNION)
  85       && !((TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 8)
  86             && TYPE_VECTOR (valtype))
  87       && !(TYPE_LENGTH (valtype) == 1
  88            || TYPE_LENGTH (valtype) == 2
  89            || TYPE_LENGTH (valtype) == 4
  90            || TYPE_LENGTH (valtype) == 8))
  91     return RETURN_VALUE_STRUCT_CONVENTION;
  92   else
  93 #endif
  94     return ppc_sysv_abi_broken_return_value (gdbarch, function, valtype,
  95                                              regcache, readbuf, writebuf);
  96 }
  97 \f
  98
  99 /* Signal trampolines.  */
 100
 101 static const struct tramp_frame ppcnbsd2_sigtramp;
 102
 103 static void
 104 ppcnbsd_sigtramp_cache_init (const struct tramp_frame *self,
 105                              struct frame_info *this_frame,
 106                              struct trad_frame_cache *this_cache,
 107                              CORE_ADDR func)
 108 {
 109   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 110   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 111   CORE_ADDR addr, base;
 112   int i;
 113
 114   base = get_frame_register_unsigned (this_frame,
 115                                       gdbarch_sp_regnum (gdbarch));
 116   if (self == &ppcnbsd2_sigtramp)
 117     addr = base + 0x10 + 2 * tdep->wordsize;
 118   else
 119     addr = base + 0x18 + 2 * tdep->wordsize;
 120   for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
 121     {
 122       int regnum = i + tdep->ppc_gp0_regnum;
 123       trad_frame_set_reg_addr (this_cache, regnum, addr);
 124     }
 125   trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, addr);
 126   addr += tdep->wordsize;
 127   trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, addr);
 128   addr += tdep->wordsize;
 129   trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, addr);
 130   addr += tdep->wordsize;
 131   trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, addr);
 132   addr += tdep->wordsize;
 133   trad_frame_set_reg_addr (this_cache, gdbarch_pc_regnum (gdbarch),
 134                            addr); /* SRR0?  */
 135   addr += tdep->wordsize;
 136
 137   /* Construct the frame ID using the function start.  */
 138   trad_frame_set_id (this_cache, frame_id_build (base, func));
 139 }
 140
 141 static const struct tramp_frame ppcnbsd_sigtramp =
 142 {
 143   SIGTRAMP_FRAME,
 144   4,
 145   {
 146     { 0x3821fff0, -1 },         /* add r1,r1,-16 */
 147     { 0x4e800021, -1 },         /* blrl */
 148     { 0x38610018, -1 },         /* addi r3,r1,24 */
 149     { 0x38000127, -1 },         /* li r0,295 */
 150     { 0x44000002, -1 },         /* sc */
 151     { 0x38000001, -1 },         /* li r0,1 */
 152     { 0x44000002, -1 },         /* sc */
 153     { TRAMP_SENTINEL_INSN, -1 }
 154   },
 155   ppcnbsd_sigtramp_cache_init
 156 };
 157
 158 /* NetBSD 2.0 introduced a slightly different signal trampoline.  */
 159
 160 static const struct tramp_frame ppcnbsd2_sigtramp =
 161 {
 162   SIGTRAMP_FRAME,
 163   4,
 164   {
 165     { 0x3821fff0, -1 },         /* add r1,r1,-16 */
 166     { 0x4e800021, -1 },         /* blrl */
 167     { 0x38610010, -1 },         /* addi r3,r1,16 */
 168     { 0x38000127, -1 },         /* li r0,295 */
 169     { 0x44000002, -1 },         /* sc */
 170     { 0x38000001, -1 },         /* li r0,1 */
 171     { 0x44000002, -1 },         /* sc */
 172     { TRAMP_SENTINEL_INSN, -1 }
 173   },
 174   ppcnbsd_sigtramp_cache_init
 175 };
 176 \f
 177
 178 static void
 179 ppcnbsd_init_abi (struct gdbarch_info info,
 180                   struct gdbarch *gdbarch)
 181 {
 182   /* For NetBSD, this is an on again, off again thing.  Some systems
 183      do use the broken struct convention, and some don't.  */
 184   set_gdbarch_return_value (gdbarch, ppcnbsd_return_value);
 185
 186   /* NetBSD uses SVR4-style shared libraries.  */
 187   set_solib_svr4_fetch_link_map_offsets
 188     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 189
 190   set_gdbarch_regset_from_core_section
 191     (gdbarch, ppcnbsd_regset_from_core_section);
 192
 193   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd_sigtramp);
 194   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd2_sigtramp);
 195 }
 196 \f
 197
 198 /* Provide a prototype to silence -Wmissing-prototypes.  */
 199 void _initialize_ppcnbsd_tdep (void);
 200
 201 void
 202 _initialize_ppcnbsd_tdep (void)
 203 {
 204   gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_NETBSD_ELF,
 205                           ppcnbsd_init_abi);
 206
 207   /* Avoid initializing the register offsets again if they were
 208      already initailized by ppcnbsd-nat.c.  */
 209   if (ppcnbsd_reg_offsets.pc_offset == 0)
 210     {
 211       /* General-purpose registers.  */
 212       ppcnbsd_reg_offsets.r0_offset = 0;
 213       ppcnbsd_reg_offsets.gpr_size = 4;
 214       ppcnbsd_reg_offsets.xr_size = 4;
 215       ppcnbsd_reg_offsets.lr_offset = 128;
 216       ppcnbsd_reg_offsets.cr_offset = 132;
 217       ppcnbsd_reg_offsets.xer_offset = 136;
 218       ppcnbsd_reg_offsets.ctr_offset = 140;
 219       ppcnbsd_reg_offsets.pc_offset = 144;
 220       ppcnbsd_reg_offsets.ps_offset = -1;
 221       ppcnbsd_reg_offsets.mq_offset = -1;
 222
 223       /* Floating-point registers.  */
 224       ppcnbsd_reg_offsets.f0_offset = 0;
 225       ppcnbsd_reg_offsets.fpscr_offset = 256;
 226       ppcnbsd_reg_offsets.fpscr_size = 4;
 227
 228       /* AltiVec registers.  */
 229       ppcnbsd_reg_offsets.vr0_offset = 0;
 230       ppcnbsd_reg_offsets.vrsave_offset = 512;
 231       ppcnbsd_reg_offsets.vscr_offset = 524;
 232     }
 233 }