gdb/ppcnbsd-tdep.c

   1 /* Target-dependent code for NetBSD/powerpc.
   2
   3    Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
   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 *func_type,
  81                       struct type *valtype, struct regcache *regcache,
  82                       gdb_byte *readbuf, 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, func_type, valtype,
  97                                              regcache, 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 *this_frame,
 108                              struct trad_frame_cache *this_cache,
 109                              CORE_ADDR func)
 110 {
 111   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 112   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 113   CORE_ADDR addr, base;
 114   int i;
 115
 116   base = get_frame_register_unsigned (this_frame,
 117                                       gdbarch_sp_regnum (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, gdbarch_pc_regnum (gdbarch),
 136                            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.gpr_size = 4;
 216       ppcnbsd_reg_offsets.xr_size = 4;
 217       ppcnbsd_reg_offsets.lr_offset = 128;
 218       ppcnbsd_reg_offsets.cr_offset = 132;
 219       ppcnbsd_reg_offsets.xer_offset = 136;
 220       ppcnbsd_reg_offsets.ctr_offset = 140;
 221       ppcnbsd_reg_offsets.pc_offset = 144;
 222       ppcnbsd_reg_offsets.ps_offset = -1;
 223       ppcnbsd_reg_offsets.mq_offset = -1;
 224
 225       /* Floating-point registers.  */
 226       ppcnbsd_reg_offsets.f0_offset = 0;
 227       ppcnbsd_reg_offsets.fpscr_offset = 256;
 228       ppcnbsd_reg_offsets.fpscr_size = 4;
 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 }