gdb/ppcnbsd-tdep.c

   1 /* Target-dependent code for PowerPC systems running NetBSD.
   2
   3    Copyright 2002, 2003, 2004 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., 59 Temple Place - Suite 330,
  22    Boston, MA 02111-1307, USA.  */
  23
  24 #include "defs.h"
  25 #include "gdbcore.h"
  26 #include "regcache.h"
  27 #include "target.h"
  28 #include "breakpoint.h"
  29 #include "value.h"
  30 #include "osabi.h"
  31
  32 #include "ppc-tdep.h"
  33 #include "ppcnbsd-tdep.h"
  34 #include "nbsd-tdep.h"
  35 #include "tramp-frame.h"
  36 #include "trad-frame.h"
  37 #include "gdb_assert.h"
  38 #include "solib-svr4.h"
  39
  40 #define REG_FIXREG_OFFSET(x)    ((x) * 4)
  41 #define REG_LR_OFFSET           (32 * 4)
  42 #define REG_CR_OFFSET           (33 * 4)
  43 #define REG_XER_OFFSET          (34 * 4)
  44 #define REG_CTR_OFFSET          (35 * 4)
  45 #define REG_PC_OFFSET           (36 * 4)
  46 #define SIZEOF_STRUCT_REG       (37 * 4)
  47
  48 #define FPREG_FPR_OFFSET(x)     ((x) * 8)
  49 #define FPREG_FPSCR_OFFSET      (32 * 8)
  50 #define SIZEOF_STRUCT_FPREG     (33 * 8)
  51
  52 void
  53 ppcnbsd_supply_reg (char *regs, int regno)
  54 {
  55   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
  56   int i;
  57
  58   for (i = 0; i <= 31; i++)
  59     {
  60       if (regno == tdep->ppc_gp0_regnum + i || regno == -1)
  61         supply_register (tdep->ppc_gp0_regnum + i,
  62                          regs + REG_FIXREG_OFFSET (i));
  63     }
  64
  65   if (regno == tdep->ppc_lr_regnum || regno == -1)
  66     supply_register (tdep->ppc_lr_regnum, regs + REG_LR_OFFSET);
  67
  68   if (regno == tdep->ppc_cr_regnum || regno == -1)
  69     supply_register (tdep->ppc_cr_regnum, regs + REG_CR_OFFSET);
  70
  71   if (regno == tdep->ppc_xer_regnum || regno == -1)
  72     supply_register (tdep->ppc_xer_regnum, regs + REG_XER_OFFSET);
  73
  74   if (regno == tdep->ppc_ctr_regnum || regno == -1)
  75     supply_register (tdep->ppc_ctr_regnum, regs + REG_CTR_OFFSET);
  76
  77   if (regno == PC_REGNUM || regno == -1)
  78     supply_register (PC_REGNUM, regs + REG_PC_OFFSET);
  79 }
  80
  81 void
  82 ppcnbsd_fill_reg (char *regs, int regno)
  83 {
  84   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
  85   int i;
  86
  87   for (i = 0; i <= 31; i++)
  88     {
  89       if (regno == tdep->ppc_gp0_regnum + i || regno == -1)
  90         regcache_collect (tdep->ppc_gp0_regnum + i,
  91                           regs + REG_FIXREG_OFFSET (i));
  92     }
  93
  94   if (regno == tdep->ppc_lr_regnum || regno == -1)
  95     regcache_collect (tdep->ppc_lr_regnum, regs + REG_LR_OFFSET);
  96
  97   if (regno == tdep->ppc_cr_regnum || regno == -1)
  98     regcache_collect (tdep->ppc_cr_regnum, regs + REG_CR_OFFSET);
  99
 100   if (regno == tdep->ppc_xer_regnum || regno == -1)
 101     regcache_collect (tdep->ppc_xer_regnum, regs + REG_XER_OFFSET);
 102
 103   if (regno == tdep->ppc_ctr_regnum || regno == -1)
 104     regcache_collect (tdep->ppc_ctr_regnum, regs + REG_CTR_OFFSET);
 105
 106   if (regno == PC_REGNUM || regno == -1)
 107     regcache_collect (PC_REGNUM, regs + REG_PC_OFFSET);
 108 }
 109
 110 void
 111 ppcnbsd_supply_fpreg (char *fpregs, int regno)
 112 {
 113   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
 114   int i;
 115
 116   /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
 117      point registers.  Traditionally, GDB's register set has still
 118      listed the floating point registers for such machines, so this
 119      code is harmless.  However, the new E500 port actually omits the
 120      floating point registers entirely from the register set --- they
 121      don't even have register numbers assigned to them.
 122
 123      It's not clear to me how best to update this code, so this assert
 124      will alert the first person to encounter the NetBSD/E500
 125      combination to the problem.  */
 126   gdb_assert (ppc_floating_point_unit_p (current_gdbarch));
 127
 128   for (i = 0; i < ppc_num_fprs; i++)
 129     {
 130       if (regno == tdep->ppc_fp0_regnum + i || regno == -1)
 131         supply_register (tdep->ppc_fp0_regnum + i,
 132                          fpregs + FPREG_FPR_OFFSET (i));
 133     }
 134
 135   if (regno == tdep->ppc_fpscr_regnum || regno == -1)
 136     supply_register (tdep->ppc_fpscr_regnum, fpregs + FPREG_FPSCR_OFFSET);
 137 }
 138
 139 void
 140 ppcnbsd_fill_fpreg (char *fpregs, int regno)
 141 {
 142   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
 143   int i;
 144
 145   /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
 146      point registers.  Traditionally, GDB's register set has still
 147      listed the floating point registers for such machines, so this
 148      code is harmless.  However, the new E500 port actually omits the
 149      floating point registers entirely from the register set --- they
 150      don't even have register numbers assigned to them.
 151
 152      It's not clear to me how best to update this code, so this assert
 153      will alert the first person to encounter the NetBSD/E500
 154      combination to the problem.  */
 155   gdb_assert (ppc_floating_point_unit_p (current_gdbarch));
 156
 157   for (i = 0; i < ppc_num_fprs; i++)
 158     {
 159       if (regno == tdep->ppc_fp0_regnum + i || regno == -1)
 160         regcache_collect (tdep->ppc_fp0_regnum + i,
 161                           fpregs + FPREG_FPR_OFFSET (i));
 162     }
 163
 164   if (regno == tdep->ppc_fpscr_regnum || regno == -1)
 165     regcache_collect (tdep->ppc_fpscr_regnum, fpregs + FPREG_FPSCR_OFFSET);
 166 }
 167
 168 static void
 169 fetch_core_registers (char *core_reg_sect, unsigned core_reg_size, int which,
 170                       CORE_ADDR ignore)
 171 {
 172   char *regs, *fpregs;
 173
 174   /* We get everything from one section.  */
 175   if (which != 0)
 176     return;
 177
 178   regs = core_reg_sect;
 179   fpregs = core_reg_sect + SIZEOF_STRUCT_REG;
 180
 181   /* Integer registers.  */
 182   ppcnbsd_supply_reg (regs, -1);
 183
 184   /* Floating point registers.  */
 185   ppcnbsd_supply_fpreg (fpregs, -1);
 186 }
 187
 188 static void
 189 fetch_elfcore_registers (char *core_reg_sect, unsigned core_reg_size, int which,
 190                          CORE_ADDR ignore)
 191 {
 192   switch (which)
 193     {
 194     case 0:  /* Integer registers.  */
 195       if (core_reg_size != SIZEOF_STRUCT_REG)
 196         warning ("Wrong size register set in core file.");
 197       else
 198         ppcnbsd_supply_reg (core_reg_sect, -1);
 199       break;
 200
 201     case 2:  /* Floating point registers.  */
 202       if (core_reg_size != SIZEOF_STRUCT_FPREG)
 203         warning ("Wrong size FP register set in core file.");
 204       else
 205         ppcnbsd_supply_fpreg (core_reg_sect, -1);
 206       break;
 207
 208     default:
 209       /* Don't know what kind of register request this is; just ignore it.  */
 210       break;
 211     }
 212 }
 213
 214 static struct core_fns ppcnbsd_core_fns =
 215 {
 216   bfd_target_unknown_flavour,           /* core_flavour */
 217   default_check_format,                 /* check_format */
 218   default_core_sniffer,                 /* core_sniffer */
 219   fetch_core_registers,                 /* core_read_registers */
 220   NULL                                  /* next */
 221 };
 222
 223 static struct core_fns ppcnbsd_elfcore_fns =
 224 {
 225   bfd_target_elf_flavour,               /* core_flavour */
 226   default_check_format,                 /* check_format */
 227   default_core_sniffer,                 /* core_sniffer */
 228   fetch_elfcore_registers,              /* core_read_registers */
 229   NULL                                  /* next */
 230 };
 231
 232 /* NetBSD is confused.  It appears that 1.5 was using the correct SVr4
 233    convention but, 1.6 switched to the below broken convention.  For
 234    the moment use the broken convention.  Ulgh!.  */
 235
 236 static enum return_value_convention
 237 ppcnbsd_return_value (struct gdbarch *gdbarch, struct type *valtype,
 238                       struct regcache *regcache, void *readbuf,
 239                       const void *writebuf)
 240 {
 241   if ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT
 242        || TYPE_CODE (valtype) == TYPE_CODE_UNION)
 243       && !((TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 8)
 244             && TYPE_VECTOR (valtype))
 245       && !(TYPE_LENGTH (valtype) == 1
 246            || TYPE_LENGTH (valtype) == 2
 247            || TYPE_LENGTH (valtype) == 4
 248            || TYPE_LENGTH (valtype) == 8))
 249     return RETURN_VALUE_STRUCT_CONVENTION;
 250   else
 251     return ppc_sysv_abi_broken_return_value (gdbarch, valtype, regcache,
 252                                              readbuf, writebuf);
 253 }
 254
 255 static void
 256 ppcnbsd_sigtramp_cache_init (const struct tramp_frame *self,
 257                              struct frame_info *next_frame,
 258                              struct trad_frame_cache *this_cache,
 259                              CORE_ADDR func)
 260 {
 261   CORE_ADDR base;
 262   CORE_ADDR offset;
 263   int i;
 264   struct gdbarch *gdbarch = get_frame_arch (next_frame);
 265   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 266
 267   base = frame_unwind_register_unsigned (next_frame, SP_REGNUM);
 268   offset = base + 0x18 + 2 * tdep->wordsize;
 269   for (i = 0; i < 32; i++)
 270     {
 271       int regnum = i + tdep->ppc_gp0_regnum;
 272       trad_frame_set_reg_addr (this_cache, regnum, offset);
 273       offset += tdep->wordsize;
 274     }
 275   trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, offset);
 276   offset += tdep->wordsize;
 277   trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, offset);
 278   offset += tdep->wordsize;
 279   trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, offset);
 280   offset += tdep->wordsize;
 281   trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, offset);
 282   offset += tdep->wordsize;
 283   trad_frame_set_reg_addr (this_cache, PC_REGNUM, offset); /* SRR0? */
 284   offset += tdep->wordsize;
 285
 286   /* Construct the frame ID using the function start.  */
 287   trad_frame_set_id (this_cache, frame_id_build (base, func));
 288 }
 289
 290 /* Given the NEXT frame, examine the instructions at and around this
 291    frame's resume address (aka PC) to see of they look like a signal
 292    trampoline.  Return the address of the trampolines first
 293    instruction, or zero if it isn't a signal trampoline.  */
 294
 295 static const struct tramp_frame ppcnbsd_sigtramp = {
 296   4, /* insn size */
 297   { /* insn */
 298     0x38610018, /* addi r3,r1,24 */
 299     0x38000127, /* li r0,295 */
 300     0x44000002, /* sc */
 301     0x38000001, /* li r0,1 */
 302     0x44000002, /* sc */
 303     TRAMP_SENTINEL_INSN
 304   },
 305   ppcnbsd_sigtramp_cache_init
 306 };
 307
 308 static void
 309 ppcnbsd_init_abi (struct gdbarch_info info,
 310                   struct gdbarch *gdbarch)
 311 {
 312   /* For NetBSD, this is an on again, off again thing.  Some systems
 313      do use the broken struct convention, and some don't.  */
 314   set_gdbarch_return_value (gdbarch, ppcnbsd_return_value);
 315   set_solib_svr4_fetch_link_map_offsets (gdbarch,
 316                                 nbsd_ilp32_solib_svr4_fetch_link_map_offsets);
 317   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd_sigtramp);
 318 }
 319
 320 void
 321 _initialize_ppcnbsd_tdep (void)
 322 {
 323   gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_NETBSD_ELF,
 324                           ppcnbsd_init_abi);
 325
 326   deprecated_add_core_fns (&ppcnbsd_core_fns);
 327   deprecated_add_core_fns (&ppcnbsd_elfcore_fns);
 328 }