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 < ppc_num_gprs; i++)
  59     {
  60       if (regno == tdep->ppc_gp0_regnum + i || regno == -1)
  61         regcache_raw_supply (current_regcache, tdep->ppc_gp0_regnum + i,
  62                              regs + REG_FIXREG_OFFSET (i));
  63     }
  64
  65   if (regno == tdep->ppc_lr_regnum || regno == -1)
  66     regcache_raw_supply (current_regcache, tdep->ppc_lr_regnum,
  67                          regs + REG_LR_OFFSET);
  68
  69   if (regno == tdep->ppc_cr_regnum || regno == -1)
  70     regcache_raw_supply (current_regcache, tdep->ppc_cr_regnum,
  71                          regs + REG_CR_OFFSET);
  72
  73   if (regno == tdep->ppc_xer_regnum || regno == -1)
  74     regcache_raw_supply (current_regcache, tdep->ppc_xer_regnum,
  75                          regs + REG_XER_OFFSET);
  76
  77   if (regno == tdep->ppc_ctr_regnum || regno == -1)
  78     regcache_raw_supply (current_regcache, tdep->ppc_ctr_regnum,
  79                          regs + REG_CTR_OFFSET);
  80
  81   if (regno == PC_REGNUM || regno == -1)
  82     regcache_raw_supply (current_regcache, PC_REGNUM,
  83                          regs + REG_PC_OFFSET);
  84 }
  85
  86 void
  87 ppcnbsd_fill_reg (char *regs, int regno)
  88 {
  89   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
  90   int i;
  91
  92   for (i = 0; i < ppc_num_gprs; i++)
  93     {
  94       if (regno == tdep->ppc_gp0_regnum + i || regno == -1)
  95         regcache_collect (tdep->ppc_gp0_regnum + i,
  96                           regs + REG_FIXREG_OFFSET (i));
  97     }
  98
  99   if (regno == tdep->ppc_lr_regnum || regno == -1)
 100     regcache_collect (tdep->ppc_lr_regnum, regs + REG_LR_OFFSET);
 101
 102   if (regno == tdep->ppc_cr_regnum || regno == -1)
 103     regcache_collect (tdep->ppc_cr_regnum, regs + REG_CR_OFFSET);
 104
 105   if (regno == tdep->ppc_xer_regnum || regno == -1)
 106     regcache_collect (tdep->ppc_xer_regnum, regs + REG_XER_OFFSET);
 107
 108   if (regno == tdep->ppc_ctr_regnum || regno == -1)
 109     regcache_collect (tdep->ppc_ctr_regnum, regs + REG_CTR_OFFSET);
 110
 111   if (regno == PC_REGNUM || regno == -1)
 112     regcache_collect (PC_REGNUM, regs + REG_PC_OFFSET);
 113 }
 114
 115 void
 116 ppcnbsd_supply_fpreg (char *fpregs, int regno)
 117 {
 118   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
 119   int i;
 120
 121   /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
 122      point registers.  Traditionally, GDB's register set has still
 123      listed the floating point registers for such machines, so this
 124      code is harmless.  However, the new E500 port actually omits the
 125      floating point registers entirely from the register set --- they
 126      don't even have register numbers assigned to them.
 127
 128      It's not clear to me how best to update this code, so this assert
 129      will alert the first person to encounter the NetBSD/E500
 130      combination to the problem.  */
 131   gdb_assert (ppc_floating_point_unit_p (current_gdbarch));
 132
 133   for (i = 0; i < ppc_num_fprs; i++)
 134     {
 135       if (regno == tdep->ppc_fp0_regnum + i || regno == -1)
 136         regcache_raw_supply (current_regcache, tdep->ppc_fp0_regnum + i,
 137                              fpregs + FPREG_FPR_OFFSET (i));
 138     }
 139
 140   if (regno == tdep->ppc_fpscr_regnum || regno == -1)
 141     regcache_raw_supply (current_regcache, tdep->ppc_fpscr_regnum,
 142                          fpregs + FPREG_FPSCR_OFFSET);
 143 }
 144
 145 void
 146 ppcnbsd_fill_fpreg (char *fpregs, int regno)
 147 {
 148   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
 149   int i;
 150
 151   /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
 152      point registers.  Traditionally, GDB's register set has still
 153      listed the floating point registers for such machines, so this
 154      code is harmless.  However, the new E500 port actually omits the
 155      floating point registers entirely from the register set --- they
 156      don't even have register numbers assigned to them.
 157
 158      It's not clear to me how best to update this code, so this assert
 159      will alert the first person to encounter the NetBSD/E500
 160      combination to the problem.  */
 161   gdb_assert (ppc_floating_point_unit_p (current_gdbarch));
 162
 163   for (i = 0; i < ppc_num_fprs; i++)
 164     {
 165       if (regno == tdep->ppc_fp0_regnum + i || regno == -1)
 166         regcache_collect (tdep->ppc_fp0_regnum + i,
 167                           fpregs + FPREG_FPR_OFFSET (i));
 168     }
 169
 170   if (regno == tdep->ppc_fpscr_regnum || regno == -1)
 171     regcache_collect (tdep->ppc_fpscr_regnum, fpregs + FPREG_FPSCR_OFFSET);
 172 }
 173
 174 static void
 175 fetch_core_registers (char *core_reg_sect, unsigned core_reg_size, int which,
 176                       CORE_ADDR ignore)
 177 {
 178   char *regs, *fpregs;
 179
 180   /* We get everything from one section.  */
 181   if (which != 0)
 182     return;
 183
 184   regs = core_reg_sect;
 185   fpregs = core_reg_sect + SIZEOF_STRUCT_REG;
 186
 187   /* Integer registers.  */
 188   ppcnbsd_supply_reg (regs, -1);
 189
 190   /* Floating point registers.  */
 191   ppcnbsd_supply_fpreg (fpregs, -1);
 192 }
 193
 194 static void
 195 fetch_elfcore_registers (char *core_reg_sect, unsigned core_reg_size, int which,
 196                          CORE_ADDR ignore)
 197 {
 198   switch (which)
 199     {
 200     case 0:  /* Integer registers.  */
 201       if (core_reg_size != SIZEOF_STRUCT_REG)
 202         warning ("Wrong size register set in core file.");
 203       else
 204         ppcnbsd_supply_reg (core_reg_sect, -1);
 205       break;
 206
 207     case 2:  /* Floating point registers.  */
 208       if (core_reg_size != SIZEOF_STRUCT_FPREG)
 209         warning ("Wrong size FP register set in core file.");
 210       else
 211         ppcnbsd_supply_fpreg (core_reg_sect, -1);
 212       break;
 213
 214     default:
 215       /* Don't know what kind of register request this is; just ignore it.  */
 216       break;
 217     }
 218 }
 219
 220 static struct core_fns ppcnbsd_core_fns =
 221 {
 222   bfd_target_unknown_flavour,           /* core_flavour */
 223   default_check_format,                 /* check_format */
 224   default_core_sniffer,                 /* core_sniffer */
 225   fetch_core_registers,                 /* core_read_registers */
 226   NULL                                  /* next */
 227 };
 228
 229 static struct core_fns ppcnbsd_elfcore_fns =
 230 {
 231   bfd_target_elf_flavour,               /* core_flavour */
 232   default_check_format,                 /* check_format */
 233   default_core_sniffer,                 /* core_sniffer */
 234   fetch_elfcore_registers,              /* core_read_registers */
 235   NULL                                  /* next */
 236 };
 237
 238 /* NetBSD is confused.  It appears that 1.5 was using the correct SVr4
 239    convention but, 1.6 switched to the below broken convention.  For
 240    the moment use the broken convention.  Ulgh!.  */
 241
 242 static enum return_value_convention
 243 ppcnbsd_return_value (struct gdbarch *gdbarch, struct type *valtype,
 244                       struct regcache *regcache, void *readbuf,
 245                       const void *writebuf)
 246 {
 247   if ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT
 248        || TYPE_CODE (valtype) == TYPE_CODE_UNION)
 249       && !((TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 8)
 250             && TYPE_VECTOR (valtype))
 251       && !(TYPE_LENGTH (valtype) == 1
 252            || TYPE_LENGTH (valtype) == 2
 253            || TYPE_LENGTH (valtype) == 4
 254            || TYPE_LENGTH (valtype) == 8))
 255     return RETURN_VALUE_STRUCT_CONVENTION;
 256   else
 257     return ppc_sysv_abi_broken_return_value (gdbarch, valtype, regcache,
 258                                              readbuf, writebuf);
 259 }
 260
 261 static void
 262 ppcnbsd_sigtramp_cache_init (const struct tramp_frame *self,
 263                              struct frame_info *next_frame,
 264                              struct trad_frame_cache *this_cache,
 265                              CORE_ADDR func)
 266 {
 267   CORE_ADDR base;
 268   CORE_ADDR offset;
 269   int i;
 270   struct gdbarch *gdbarch = get_frame_arch (next_frame);
 271   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 272
 273   base = frame_unwind_register_unsigned (next_frame, SP_REGNUM);
 274   offset = base + 0x18 + 2 * tdep->wordsize;
 275   for (i = 0; i < ppc_num_gprs; i++)
 276     {
 277       int regnum = i + tdep->ppc_gp0_regnum;
 278       trad_frame_set_reg_addr (this_cache, regnum, offset);
 279       offset += tdep->wordsize;
 280     }
 281   trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, offset);
 282   offset += tdep->wordsize;
 283   trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, offset);
 284   offset += tdep->wordsize;
 285   trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, offset);
 286   offset += tdep->wordsize;
 287   trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, offset);
 288   offset += tdep->wordsize;
 289   trad_frame_set_reg_addr (this_cache, PC_REGNUM, offset); /* SRR0? */
 290   offset += tdep->wordsize;
 291
 292   /* Construct the frame ID using the function start.  */
 293   trad_frame_set_id (this_cache, frame_id_build (base, func));
 294 }
 295
 296 /* Given the NEXT frame, examine the instructions at and around this
 297    frame's resume address (aka PC) to see of they look like a signal
 298    trampoline.  Return the address of the trampolines first
 299    instruction, or zero if it isn't a signal trampoline.  */
 300
 301 static const struct tramp_frame ppcnbsd_sigtramp = {
 302   SIGTRAMP_FRAME,
 303   4, /* insn size */
 304   { /* insn */
 305     { 0x38610018, -1 }, /* addi r3,r1,24 */
 306     { 0x38000127, -1 }, /* li r0,295 */
 307     { 0x44000002, -1 }, /* sc */
 308     { 0x38000001, -1 }, /* li r0,1 */
 309     { 0x44000002, -1 }, /* sc */
 310     { TRAMP_SENTINEL_INSN, -1 }
 311   },
 312   ppcnbsd_sigtramp_cache_init
 313 };
 314
 315 static void
 316 ppcnbsd_init_abi (struct gdbarch_info info,
 317                   struct gdbarch *gdbarch)
 318 {
 319   /* For NetBSD, this is an on again, off again thing.  Some systems
 320      do use the broken struct convention, and some don't.  */
 321   set_gdbarch_return_value (gdbarch, ppcnbsd_return_value);
 322   set_solib_svr4_fetch_link_map_offsets (gdbarch,
 323                                 nbsd_ilp32_solib_svr4_fetch_link_map_offsets);
 324   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd_sigtramp);
 325 }
 326
 327 void
 328 _initialize_ppcnbsd_tdep (void)
 329 {
 330   gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_NETBSD_ELF,
 331                           ppcnbsd_init_abi);
 332
 333   deprecated_add_core_fns (&ppcnbsd_core_fns);
 334   deprecated_add_core_fns (&ppcnbsd_elfcore_fns);
 335 }