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, SP_REGNUM);
 119   if (self == &ppcnbsd2_sigtramp)
 120     addr = base + 0x10 + 2 * tdep->wordsize;
 121   else
 122     addr = base + 0x18 + 2 * tdep->wordsize;
 123   for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
 124     {
 125       int regnum = i + tdep->ppc_gp0_regnum;
 126       trad_frame_set_reg_addr (this_cache, regnum, addr);
 127     }
 128   trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, addr);
 129   addr += tdep->wordsize;
 130   trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, addr);
 131   addr += tdep->wordsize;
 132   trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, addr);
 133   addr += tdep->wordsize;
 134   trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, addr);
 135   addr += tdep->wordsize;
 136   trad_frame_set_reg_addr (this_cache, PC_REGNUM, addr); /* SRR0? */
 137   addr += tdep->wordsize;
 138
 139   /* Construct the frame ID using the function start.  */
 140   trad_frame_set_id (this_cache, frame_id_build (base, func));
 141 }
 142
 143 static const struct tramp_frame ppcnbsd_sigtramp =
 144 {
 145   SIGTRAMP_FRAME,
 146   4,
 147   {
 148     { 0x3821fff0, -1 },         /* add r1,r1,-16 */
 149     { 0x4e800021, -1 },         /* blrl */
 150     { 0x38610018, -1 },         /* addi r3,r1,24 */
 151     { 0x38000127, -1 },         /* li r0,295 */
 152     { 0x44000002, -1 },         /* sc */
 153     { 0x38000001, -1 },         /* li r0,1 */
 154     { 0x44000002, -1 },         /* sc */
 155     { TRAMP_SENTINEL_INSN, -1 }
 156   },
 157   ppcnbsd_sigtramp_cache_init
 158 };
 159
 160 /* NetBSD 2.0 introduced a slightly different signal trampoline.  */
 161
 162 static const struct tramp_frame ppcnbsd2_sigtramp =
 163 {
 164   SIGTRAMP_FRAME,
 165   4,
 166   {
 167     { 0x3821fff0, -1 },         /* add r1,r1,-16 */
 168     { 0x4e800021, -1 },         /* blrl */
 169     { 0x38610010, -1 },         /* addi r3,r1,16 */
 170     { 0x38000127, -1 },         /* li r0,295 */
 171     { 0x44000002, -1 },         /* sc */
 172     { 0x38000001, -1 },         /* li r0,1 */
 173     { 0x44000002, -1 },         /* sc */
 174     { TRAMP_SENTINEL_INSN, -1 }
 175   },
 176   ppcnbsd_sigtramp_cache_init
 177 };
 178 \f
 179
 180 static void
 181 ppcnbsd_init_abi (struct gdbarch_info info,
 182                   struct gdbarch *gdbarch)
 183 {
 184   /* For NetBSD, this is an on again, off again thing.  Some systems
 185      do use the broken struct convention, and some don't.  */
 186   set_gdbarch_return_value (gdbarch, ppcnbsd_return_value);
 187
 188   /* NetBSD uses SVR4-style shared libraries.  */
 189   set_solib_svr4_fetch_link_map_offsets
 190     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 191
 192   set_gdbarch_regset_from_core_section
 193     (gdbarch, ppcnbsd_regset_from_core_section);
 194
 195   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd_sigtramp);
 196   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd2_sigtramp);
 197 }
 198 \f
 199
 200 /* Provide a prototype to silence -Wmissing-prototypes.  */
 201 void _initialize_ppcnbsd_tdep (void);
 202
 203 void
 204 _initialize_ppcnbsd_tdep (void)
 205 {
 206   gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_NETBSD_ELF,
 207                           ppcnbsd_init_abi);
 208
 209   /* Avoid initializing the register offsets again if they were
 210      already initailized by ppcnbsd-nat.c.  */
 211   if (ppcnbsd_reg_offsets.pc_offset == 0)
 212     {
 213       /* General-purpose registers.  */
 214       ppcnbsd_reg_offsets.r0_offset = 0;
 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
 227       /* AltiVec registers.  */
 228       ppcnbsd_reg_offsets.vr0_offset = 0;
 229       ppcnbsd_reg_offsets.vrsave_offset = 512;
 230       ppcnbsd_reg_offsets.vscr_offset = 524;
 231     }
 232 }