gdb/z8k-tdep.c

   1 /* Target-machine dependent code for Zilog Z8000, for GDB.
   2
   3    Copyright 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
   4    2002 Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 59 Temple Place - Suite 330,
  21    Boston, MA 02111-1307, USA.  */
  22
  23 /*
  24    Contributed by Steve Chamberlain
  25    sac@cygnus.com
  26  */
  27
  28 #include "defs.h"
  29 #include "frame.h"
  30 #include "symtab.h"
  31 #include "gdbcmd.h"
  32 #include "gdbtypes.h"
  33 #include "dis-asm.h"
  34 #include "gdbcore.h"
  35 #include "regcache.h"
  36
  37 #include "value.h" /* For read_register() */
  38
  39
  40 static int read_memory_pointer (CORE_ADDR x);
  41
  42 /* Return the saved PC from this frame.
  43
  44    If the frame has a memory copy of SRP_REGNUM, use that.  If not,
  45    just use the register SRP_REGNUM itself.  */
  46
  47 CORE_ADDR
  48 z8k_frame_saved_pc (struct frame_info *frame)
  49 {
  50   return read_memory_pointer (frame->frame + (BIG ? 4 : 2));
  51 }
  52
  53 #define IS_PUSHL(x) (BIG ? ((x & 0xfff0) == 0x91e0):((x & 0xfff0) == 0x91F0))
  54 #define IS_PUSHW(x) (BIG ? ((x & 0xfff0) == 0x93e0):((x & 0xfff0)==0x93f0))
  55 #define IS_MOVE_FP(x) (BIG ? x == 0xa1ea : x == 0xa1fa)
  56 #define IS_MOV_SP_FP(x) (BIG ? x == 0x94ea : x == 0x0d76)
  57 #define IS_SUB2_SP(x) (x==0x1b87)
  58 #define IS_MOVK_R5(x) (x==0x7905)
  59 #define IS_SUB_SP(x) ((x & 0xffff) == 0x020f)
  60 #define IS_PUSH_FP(x) (BIG ? (x == 0x93ea) : (x == 0x93fa))
  61
  62 /* work out how much local space is on the stack and
  63    return the pc pointing to the first push */
  64
  65 static CORE_ADDR
  66 skip_adjust (CORE_ADDR pc, int *size)
  67 {
  68   *size = 0;
  69
  70   if (IS_PUSH_FP (read_memory_short (pc))
  71       && IS_MOV_SP_FP (read_memory_short (pc + 2)))
  72     {
  73       /* This is a function with an explict frame pointer */
  74       pc += 4;
  75       *size += 2;               /* remember the frame pointer */
  76     }
  77
  78   /* remember any stack adjustment */
  79   if (IS_SUB_SP (read_memory_short (pc)))
  80     {
  81       *size += read_memory_short (pc + 2);
  82       pc += 4;
  83     }
  84   return pc;
  85 }
  86
  87 static CORE_ADDR examine_frame (CORE_ADDR, CORE_ADDR * regs, CORE_ADDR);
  88 static CORE_ADDR
  89 examine_frame (CORE_ADDR pc, CORE_ADDR *regs, CORE_ADDR sp)
  90 {
  91   int w = read_memory_short (pc);
  92   int offset = 0;
  93   int regno;
  94
  95   for (regno = 0; regno < NUM_REGS; regno++)
  96     regs[regno] = 0;
  97
  98   while (IS_PUSHW (w) || IS_PUSHL (w))
  99     {
 100       /* work out which register is being pushed to where */
 101       if (IS_PUSHL (w))
 102         {
 103           regs[w & 0xf] = offset;
 104           regs[(w & 0xf) + 1] = offset + 2;
 105           offset += 4;
 106         }
 107       else
 108         {
 109           regs[w & 0xf] = offset;
 110           offset += 2;
 111         }
 112       pc += 2;
 113       w = read_memory_short (pc);
 114     }
 115
 116   if (IS_MOVE_FP (w))
 117     {
 118       /* We know the fp */
 119
 120     }
 121   else if (IS_SUB_SP (w))
 122     {
 123       /* Subtracting a value from the sp, so were in a function
 124          which needs stack space for locals, but has no fp.  We fake up
 125          the values as if we had an fp */
 126       regs[FP_REGNUM] = sp;
 127     }
 128   else
 129     {
 130       /* This one didn't have an fp, we'll fake it up */
 131       regs[SP_REGNUM] = sp;
 132     }
 133   /* stack pointer contains address of next frame */
 134   /*  regs[fp_regnum()] = fp; */
 135   regs[SP_REGNUM] = sp;
 136   return pc;
 137 }
 138
 139 CORE_ADDR
 140 z8k_skip_prologue (CORE_ADDR start_pc)
 141 {
 142   CORE_ADDR dummy[NUM_REGS];
 143
 144   return examine_frame (start_pc, dummy, 0);
 145 }
 146
 147 CORE_ADDR
 148 z8k_addr_bits_remove (CORE_ADDR addr)
 149 {
 150   return (addr & PTR_MASK);
 151 }
 152
 153 static int
 154 read_memory_pointer (CORE_ADDR x)
 155 {
 156   return read_memory_integer (ADDR_BITS_REMOVE (x), BIG ? 4 : 2);
 157 }
 158
 159 CORE_ADDR
 160 z8k_frame_chain (struct frame_info *thisframe)
 161 {
 162   if (!inside_entry_file (get_frame_pc (thisframe)))
 163     {
 164       return read_memory_pointer (thisframe->frame);
 165     }
 166   return 0;
 167 }
 168
 169 /* Put here the code to store, into a struct frame_saved_regs,
 170    the addresses of the saved registers of frame described by FRAME_INFO.
 171    This includes special registers such as pc and fp saved in special
 172    ways in the stack frame.  sp is even more special:
 173    the address we return for it IS the sp for the next frame.  */
 174
 175 void
 176 z8k_frame_init_saved_regs (struct frame_info *frame_info)
 177 {
 178   CORE_ADDR pc;
 179   int w;
 180
 181   frame_saved_regs_zalloc (frame_info);
 182   pc = get_pc_function_start (get_frame_pc (frame_info));
 183
 184   /* wander down the instruction stream */
 185   examine_frame (pc, frame_info->saved_regs, frame_info->frame);
 186
 187 }
 188
 189 void
 190 z8k_push_dummy_frame (void)
 191 {
 192   internal_error (__FILE__, __LINE__, "failed internal consistency check");
 193 }
 194
 195 int
 196 gdb_print_insn_z8k (bfd_vma memaddr, disassemble_info *info)
 197 {
 198   if (BIG)
 199     return print_insn_z8001 (memaddr, info);
 200   else
 201     return print_insn_z8002 (memaddr, info);
 202 }
 203
 204 /* Fetch the instruction at ADDR, returning 0 if ADDR is beyond LIM or
 205    is not the address of a valid instruction, the address of the next
 206    instruction beyond ADDR otherwise.  *PWORD1 receives the first word
 207    of the instruction. */
 208
 209 CORE_ADDR
 210 NEXT_PROLOGUE_INSN (CORE_ADDR addr, CORE_ADDR lim, short *pword1)
 211 {
 212   char buf[2];
 213   if (addr < lim + 8)
 214     {
 215       read_memory (addr, buf, 2);
 216       *pword1 = extract_signed_integer (buf, 2);
 217
 218       return addr + 2;
 219     }
 220   return 0;
 221 }
 222
 223 #if 0
 224 /* Put here the code to store, into a struct frame_saved_regs,
 225    the addresses of the saved registers of frame described by FRAME_INFO.
 226    This includes special registers such as pc and fp saved in special
 227    ways in the stack frame.  sp is even more special:
 228    the address we return for it IS the sp for the next frame.
 229
 230    We cache the result of doing this in the frame_cache_obstack, since
 231    it is fairly expensive.  */
 232
 233 void
 234 frame_find_saved_regs (struct frame_info *fip, struct frame_saved_regs *fsrp)
 235 {
 236   int locals;
 237   CORE_ADDR pc;
 238   CORE_ADDR adr;
 239   int i;
 240
 241   memset (fsrp, 0, sizeof *fsrp);
 242
 243   pc = skip_adjust (get_pc_function_start (get_frame_pc (fip)), &locals);
 244
 245   {
 246     adr = get_frame_base (fip) - locals;
 247     for (i = 0; i < 8; i++)
 248       {
 249         int word = read_memory_short (pc);
 250
 251         pc += 2;
 252         if (IS_PUSHL (word))
 253           {
 254             fsrp->regs[word & 0xf] = adr;
 255             fsrp->regs[(word & 0xf) + 1] = adr - 2;
 256             adr -= 4;
 257           }
 258         else if (IS_PUSHW (word))
 259           {
 260             fsrp->regs[word & 0xf] = adr;
 261             adr -= 2;
 262           }
 263         else
 264           break;
 265       }
 266
 267   }
 268
 269   fsrp->regs[PC_REGNUM] = fip->frame + 4;
 270   fsrp->regs[FP_REGNUM] = fip->frame;
 271
 272 }
 273 #endif
 274
 275 int
 276 z8k_saved_pc_after_call (struct frame_info *frame)
 277 {
 278   return ADDR_BITS_REMOVE
 279     (read_memory_integer (read_register (SP_REGNUM), PTR_SIZE));
 280 }
 281
 282
 283 void
 284 extract_return_value (struct type *type, char *regbuf, char *valbuf)
 285 {
 286   int b;
 287   int len = TYPE_LENGTH (type);
 288
 289   for (b = 0; b < len; b += 2)
 290     {
 291       int todo = len - b;
 292
 293       if (todo > 2)
 294         todo = 2;
 295       memcpy (valbuf + b, regbuf + b, todo);
 296     }
 297 }
 298
 299 void
 300 write_return_value (struct type *type, char *valbuf)
 301 {
 302   int reg;
 303   int len;
 304
 305   for (len = 0; len < TYPE_LENGTH (type); len += 2)
 306     deprecated_write_register_bytes (REGISTER_BYTE (len / 2 + 2),
 307                                      valbuf + len, 2);
 308 }
 309
 310 void
 311 store_struct_return (CORE_ADDR addr, CORE_ADDR sp)
 312 {
 313   write_register (2, addr);
 314 }
 315
 316
 317 static void
 318 z8k_print_register_hook (int regno)
 319 {
 320   if ((regno & 1) == 0 && regno < 16)
 321     {
 322       unsigned char l[4];
 323
 324       frame_register_read (deprecated_selected_frame, regno, l + 0);
 325       frame_register_read (deprecated_selected_frame, regno + 1, l + 2);
 326       printf_unfiltered ("\t");
 327       printf_unfiltered ("0x%02x%02x%02x%02x", l[0], l[1], l[2], l[3]);
 328     }
 329
 330   if ((regno & 3) == 0 && regno < 16)
 331     {
 332       unsigned char l[8];
 333
 334       frame_register_read (deprecated_selected_frame, regno, l + 0);
 335       frame_register_read (deprecated_selected_frame, regno + 1, l + 2);
 336       frame_register_read (deprecated_selected_frame, regno + 2, l + 4);
 337       frame_register_read (deprecated_selected_frame, regno + 3, l + 6);
 338
 339       printf_unfiltered ("\t");
 340       printf_unfiltered ("0x%02x%02x%02x%02x%02x%02x%02x%02x",
 341                          l[0], l[1], l[2], l[3], l[4], l[5], l[6], l[7]);
 342     }
 343   if (regno == 15)
 344     {
 345       unsigned short rval;
 346       int i;
 347
 348       frame_register_read (deprecated_selected_frame, regno, (char *) (&rval));
 349
 350       printf_unfiltered ("\n");
 351       for (i = 0; i < 10; i += 2)
 352         {
 353           printf_unfiltered ("(sp+%d=%04x)", i,
 354                              (unsigned int)read_memory_short (rval + i));
 355         }
 356     }
 357 }
 358
 359 static void
 360 z8k_print_registers_info (struct gdbarch *gdbarch,
 361                           struct ui_file *file,
 362                           struct frame_info *frame,
 363                           int regnum, int print_all)
 364 {
 365   int i;
 366   const int numregs = NUM_REGS + NUM_PSEUDO_REGS;
 367   char *raw_buffer = alloca (MAX_REGISTER_RAW_SIZE);
 368   char *virtual_buffer = alloca (MAX_REGISTER_VIRTUAL_SIZE);
 369
 370   for (i = 0; i < numregs; i++)
 371     {
 372       /* Decide between printing all regs, non-float / vector regs, or
 373          specific reg.  */
 374       if (regnum == -1)
 375         {
 376           if (!print_all)
 377             {
 378               if (TYPE_CODE (REGISTER_VIRTUAL_TYPE (i)) == TYPE_CODE_FLT)
 379                 continue;
 380               if (TYPE_VECTOR (REGISTER_VIRTUAL_TYPE (i)))
 381                 continue;
 382             }
 383         }
 384       else
 385         {
 386           if (i != regnum)
 387             continue;
 388         }
 389
 390       /* If the register name is empty, it is undefined for this
 391          processor, so don't display anything.  */
 392       if (REGISTER_NAME (i) == NULL || *(REGISTER_NAME (i)) == '\0')
 393         continue;
 394
 395       fputs_filtered (REGISTER_NAME (i), file);
 396       print_spaces_filtered (15 - strlen (REGISTER_NAME (i)), file);
 397
 398       /* Get the data in raw format.  */
 399       if (! frame_register_read (frame, i, raw_buffer))
 400         {
 401           fprintf_filtered (file, "*value not available*\n");
 402           continue;
 403         }
 404
 405       /* FIXME: cagney/2002-08-03: This code shouldn't be necessary.
 406          The function frame_register_read() should have returned the
 407          pre-cooked register so no conversion is necessary.  */
 408       /* Convert raw data to virtual format if necessary.  */
 409       if (REGISTER_CONVERTIBLE (i))
 410         {
 411           REGISTER_CONVERT_TO_VIRTUAL (i, REGISTER_VIRTUAL_TYPE (i),
 412                                        raw_buffer, virtual_buffer);
 413         }
 414       else
 415         {
 416           memcpy (virtual_buffer, raw_buffer,
 417                   REGISTER_VIRTUAL_SIZE (i));
 418         }
 419
 420       /* If virtual format is floating, print it that way, and in raw
 421          hex.  */
 422       if (TYPE_CODE (REGISTER_VIRTUAL_TYPE (i)) == TYPE_CODE_FLT)
 423         {
 424           int j;
 425
 426           val_print (REGISTER_VIRTUAL_TYPE (i), virtual_buffer, 0, 0,
 427                      file, 0, 1, 0, Val_pretty_default);
 428
 429           fprintf_filtered (file, "\t(raw 0x");
 430           for (j = 0; j < REGISTER_RAW_SIZE (i); j++)
 431             {
 432               int idx;
 433               if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
 434                 idx = j;
 435               else
 436                 idx = REGISTER_RAW_SIZE (i) - 1 - j;
 437               fprintf_filtered (file, "%02x", (unsigned char) raw_buffer[idx]);
 438             }
 439           fprintf_filtered (file, ")");
 440         }
 441       else
 442         {
 443           /* Print the register in hex.  */
 444           val_print (REGISTER_VIRTUAL_TYPE (i), virtual_buffer, 0, 0,
 445                      file, 'x', 1, 0, Val_pretty_default);
 446           /* If not a vector register, print it also according to its
 447              natural format.  */
 448           if (TYPE_VECTOR (REGISTER_VIRTUAL_TYPE (i)) == 0)
 449             {
 450               fprintf_filtered (file, "\t");
 451               val_print (REGISTER_VIRTUAL_TYPE (i), virtual_buffer, 0, 0,
 452                          file, 0, 1, 0, Val_pretty_default);
 453             }
 454         }
 455
 456       /* Some z8k specific info.  */
 457       z8k_print_register_hook (i);
 458
 459       fprintf_filtered (file, "\n");
 460     }
 461 }
 462
 463 void
 464 z8k_do_registers_info (int regnum, int all)
 465 {
 466   z8k_print_registers_info (current_gdbarch, gdb_stdout,
 467                             deprecated_selected_frame, regnum, all);
 468 }
 469
 470 void
 471 z8k_pop_frame (void)
 472 {
 473 }
 474
 475 struct cmd_list_element *setmemorylist;
 476
 477 void
 478 z8k_set_pointer_size (int newsize)
 479 {
 480   static int oldsize = 0;
 481
 482   if (oldsize != newsize)
 483     {
 484       printf_unfiltered ("pointer size set to %d bits\n", newsize);
 485       oldsize = newsize;
 486       if (newsize == 32)
 487         {
 488           BIG = 1;
 489         }
 490       else
 491         {
 492           BIG = 0;
 493         }
 494       /* FIXME: This code should be using the GDBARCH framework to
 495          handle changed type sizes.  If this problem is ever fixed
 496          (the direct reference to _initialize_gdbtypes() below
 497          eliminated) then Makefile.in should be updated so that
 498          z8k-tdep.c is again compiled with -Werror. */
 499       _initialize_gdbtypes ();
 500     }
 501 }
 502
 503 static void
 504 segmented_command (char *args, int from_tty)
 505 {
 506   z8k_set_pointer_size (32);
 507 }
 508
 509 static void
 510 unsegmented_command (char *args, int from_tty)
 511 {
 512   z8k_set_pointer_size (16);
 513 }
 514
 515 static void
 516 set_memory (char *args, int from_tty)
 517 {
 518   printf_unfiltered ("\"set memory\" must be followed by the name of a memory subcommand.\n");
 519   help_list (setmemorylist, "set memory ", -1, gdb_stdout);
 520 }
 521
 522 void
 523 _initialize_z8ktdep (void)
 524 {
 525   tm_print_insn = gdb_print_insn_z8k;
 526
 527   add_prefix_cmd ("memory", no_class, set_memory,
 528                   "set the memory model", &setmemorylist, "set memory ", 0,
 529                   &setlist);
 530   add_cmd ("segmented", class_support, segmented_command,
 531            "Set segmented memory model.", &setmemorylist);
 532   add_cmd ("unsegmented", class_support, unsegmented_command,
 533            "Set unsegmented memory model.", &setmemorylist);
 534
 535 }