gdb/ppcnbsd-tdep.c

   1 /* Target-dependent code for NetBSD/powerpc.
   2
   3    Copyright (C) 2002, 2003, 2004, 2005, 2006 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 2 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, write to the Free Software
  21    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  22    Boston, MA 02110-1301, USA.  */
  23
  24 #include "defs.h"
  25 #include "gdbtypes.h"
  26 #include "osabi.h"
  27 #include "regcache.h"
  28 #include "regset.h"
  29 #include "trad-frame.h"
  30 #include "tramp-frame.h"
  31
  32 #include "gdb_assert.h"
  33 #include "gdb_string.h"
  34
  35 #include "ppc-tdep.h"
  36 #include "ppcnbsd-tdep.h"
  37 #include "solib-svr4.h"
  38
  39 /* Register offsets from <machine/reg.h>.  */
  40 struct ppc_reg_offsets ppcnbsd_reg_offsets;
  41 \f
  42
  43 /* Core file support.  */
  44
  45 /* NetBSD/powerpc register set.  */
  46
  47 struct regset ppcnbsd_gregset =
  48 {
  49   &ppcnbsd_reg_offsets,
  50   ppc_supply_gregset
  51 };
  52
  53 struct regset ppcnbsd_fpregset =
  54 {
  55   &ppcnbsd_reg_offsets,
  56   ppc_supply_fpregset
  57 };
  58
  59 /* Return the appropriate register set for the core section identified
  60    by SECT_NAME and SECT_SIZE.  */
  61
  62 static const struct regset *
  63 ppcnbsd_regset_from_core_section (struct gdbarch *gdbarch,
  64                                   const char *sect_name, size_t sect_size)
  65 {
  66   if (strcmp (sect_name, ".reg") == 0 && sect_size >= 148)
  67     return &ppcnbsd_gregset;
  68
  69   if (strcmp (sect_name, ".reg2") == 0 && sect_size >= 264)
  70     return &ppcnbsd_fpregset;
  71
  72   return NULL;
  73 }
  74 \f
  75
  76 /* NetBSD is confused.  It appears that 1.5 was using the correct SVR4
  77    convention but, 1.6 switched to the below broken convention.  For
  78    the moment use the broken convention.  Ulgh!.  */
  79
  80 static enum return_value_convention
  81 ppcnbsd_return_value (struct gdbarch *gdbarch, struct type *valtype,
  82                       struct regcache *regcache, gdb_byte *readbuf,
  83                       const gdb_byte *writebuf)
  84 {
  85 #if 0
  86   if ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT
  87        || TYPE_CODE (valtype) == TYPE_CODE_UNION)
  88       && !((TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 8)
  89             && TYPE_VECTOR (valtype))
  90       && !(TYPE_LENGTH (valtype) == 1
  91            || TYPE_LENGTH (valtype) == 2
  92            || TYPE_LENGTH (valtype) == 4
  93            || TYPE_LENGTH (valtype) == 8))
  94     return RETURN_VALUE_STRUCT_CONVENTION;
  95   else
  96 #endif
  97     return ppc_sysv_abi_broken_return_value (gdbarch, valtype, regcache,
  98                                              readbuf, writebuf);
  99 }
 100 \f
 101
 102 /* Signal trampolines.  */
 103
 104 static const struct tramp_frame ppcnbsd2_sigtramp;
 105
 106 static void
 107 ppcnbsd_sigtramp_cache_init (const struct tramp_frame *self,
 108                              struct frame_info *next_frame,
 109                              struct trad_frame_cache *this_cache,
 110                              CORE_ADDR func)
 111 {
 112   struct gdbarch *gdbarch = get_frame_arch (next_frame);
 113   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 114   CORE_ADDR addr, base;
 115   int i;
 116
 117   base = frame_unwind_register_unsigned (next_frame, SP_REGNUM);
 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, PC_REGNUM, 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.lr_offset = 128;
 215       ppcnbsd_reg_offsets.cr_offset = 132;
 216       ppcnbsd_reg_offsets.xer_offset = 136;
 217       ppcnbsd_reg_offsets.ctr_offset = 140;
 218       ppcnbsd_reg_offsets.pc_offset = 144;
 219       ppcnbsd_reg_offsets.ps_offset = -1;
 220       ppcnbsd_reg_offsets.mq_offset = -1;
 221
 222       /* Floating-point registers.  */
 223       ppcnbsd_reg_offsets.f0_offset = 0;
 224       ppcnbsd_reg_offsets.fpscr_offset = 256;
 225
 226       /* AltiVec registers.  */
 227       ppcnbsd_reg_offsets.vr0_offset = 0;
 228       ppcnbsd_reg_offsets.vrsave_offset = 512;
 229       ppcnbsd_reg_offsets.vscr_offset = 524;
 230     }
 231 }