gdb/config/m68k/tm-m68k.h

   1 /* Parameters for execution on a 68000 series machine.
   2    Copyright 1986, 1987, 1989, 1990, 1992 Free Software Foundation, Inc.
   3
   4 This file is part of GDB.
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or
   9 (at your option) any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  19
  20 /* Generic 68000 stuff, to be included by other tm-*.h files.  */
  21
  22 #define IEEE_FLOAT 1
  23
  24 /* Define the bit, byte, and word ordering of the machine.  */
  25 #define TARGET_BYTE_ORDER BIG_ENDIAN
  26
  27 /* Offset from address of function to start of its code.
  28    Zero on most machines.  */
  29
  30 #define FUNCTION_START_OFFSET 0
  31
  32 /* Advance PC across any function entry prologue instructions
  33    to reach some "real" code.  */
  34
  35 #if !defined(SKIP_PROLOGUE)
  36 #define SKIP_PROLOGUE(ip)   {(ip) = m68k_skip_prologue(ip);}
  37 extern CORE_ADDR m68k_skip_prologue PARAMS ((CORE_ADDR ip));
  38 #endif
  39
  40 /* Immediately after a function call, return the saved pc.
  41    Can't always go through the frames for this because on some machines
  42    the new frame is not set up until the new function executes
  43    some instructions.  */
  44
  45 #ifdef __STDC__
  46 struct frame_info;
  47 struct frame_saved_regs;
  48 #endif
  49
  50 extern CORE_ADDR m68k_saved_pc_after_call PARAMS ((struct frame_info *));
  51 extern void m68k_find_saved_regs PARAMS ((struct frame_info *, struct frame_saved_regs *));
  52
  53 #define SAVED_PC_AFTER_CALL(frame) \
  54   m68k_saved_pc_after_call(frame)
  55
  56 /* Stack grows downward.  */
  57
  58 #define INNER_THAN <
  59
  60 /* Stack must be kept short aligned when doing function calls.  */
  61
  62 #define STACK_ALIGN(ADDR) (((ADDR) + 1) & ~1)
  63
  64 /* Sequence of bytes for breakpoint instruction.
  65    This is a TRAP instruction.  The last 4 bits (0xf below) is the
  66    vector.  Systems which don't use 0xf should define BPT_VECTOR
  67    themselves before including this file.  */
  68
  69 #if !defined (BPT_VECTOR)
  70 #define BPT_VECTOR 0xf
  71 #endif
  72
  73 #if !defined (BREAKPOINT)
  74 #define BREAKPOINT {0x4e, (0x40 | BPT_VECTOR)}
  75 #endif
  76
  77 /* We default to vector 1 for the "remote" target, but allow targets
  78    to override.  */
  79 #if !defined (REMOTE_BPT_VECTOR)
  80 #define REMOTE_BPT_VECTOR 1
  81 #endif
  82
  83 #if !defined (REMOTE_BREAKPOINT)
  84 #define REMOTE_BREAKPOINT {0x4e, (0x40 | REMOTE_BPT_VECTOR)}
  85 #endif
  86
  87 /* If your kernel resets the pc after the trap happens you may need to
  88    define this before including this file.  */
  89
  90 #if !defined (DECR_PC_AFTER_BREAK)
  91 #define DECR_PC_AFTER_BREAK 2
  92 #endif
  93
  94 /* Nonzero if instruction at PC is a return instruction.  */
  95 /* Allow any of the return instructions, including a trapv and a return
  96    from interupt.  */
  97
  98 #define ABOUT_TO_RETURN(pc) ((read_memory_integer (pc, 2) & ~0x3) == 0x4e74)
  99
 100 /* Say how long (ordinary) registers are.  This is a piece of bogosity
 101    used in push_word and a few other places; REGISTER_RAW_SIZE is the
 102    real way to know how big a register is.  */
 103
 104 #define REGISTER_SIZE 4
 105
 106 #define REGISTER_BYTES_FP (16*4 + 8 + 8*12 + 3*4)
 107 #define REGISTER_BYTES_NOFP (16*4 + 8)
 108
 109 #ifndef NUM_REGS
 110 #define NUM_REGS 29
 111 #endif
 112
 113 #ifndef REGISTER_BYTES_OK
 114 #define REGISTER_BYTES_OK(b) \
 115    ((b) == REGISTER_BYTES_FP \
 116     || (b) == REGISTER_BYTES_NOFP)
 117 #endif
 118
 119 #ifndef REGISTER_BYTES
 120 #define REGISTER_BYTES (16*4 + 8 + 8*12 + 3*4)
 121 #endif
 122
 123 /* Index within `registers' of the first byte of the space for
 124    register N.  */
 125
 126 #define REGISTER_BYTE(N)  \
 127  ((N) >= FPC_REGNUM ? (((N) - FPC_REGNUM) * 4) + 168    \
 128   : (N) >= FP0_REGNUM ? (((N) - FP0_REGNUM) * 12) + 72  \
 129   : (N) * 4)
 130
 131 /* Number of bytes of storage in the actual machine representation
 132    for register N.  On the 68000, all regs are 4 bytes
 133    except the floating point regs which are 12 bytes.  */
 134 /* Note that the unsigned cast here forces the result of the
 135    subtraction to very high positive values if N < FP0_REGNUM */
 136
 137 #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 12 : 4)
 138
 139 /* Number of bytes of storage in the program's representation
 140    for register N.  On the 68000, all regs are 4 bytes
 141    except the floating point regs which are 8-byte doubles.  */
 142
 143 #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 8 : 4)
 144
 145 /* Largest value REGISTER_RAW_SIZE can have.  */
 146
 147 #define MAX_REGISTER_RAW_SIZE 12
 148
 149 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 150
 151 #define MAX_REGISTER_VIRTUAL_SIZE 8
 152
 153 /* Nonzero if register N requires conversion
 154    from raw format to virtual format.  */
 155
 156 #define REGISTER_CONVERTIBLE(N) (((unsigned)(N) - FP0_REGNUM) < 8)
 157
 158 #include "floatformat.h"
 159
 160 /* Convert data from raw format for register REGNUM in buffer FROM
 161    to virtual format with type TYPE in buffer TO.  */
 162
 163 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,TYPE,FROM,TO) \
 164 do                                                                      \
 165   {                                                                     \
 166     DOUBLEST dbl_tmp_val;                                                       \
 167     floatformat_to_doublest (&floatformat_m68881_ext, (FROM), &dbl_tmp_val); \
 168     store_floating ((TO), TYPE_LENGTH (TYPE), dbl_tmp_val);             \
 169   } while (0)
 170
 171 /* Convert data from virtual format with type TYPE in buffer FROM
 172    to raw format for register REGNUM in buffer TO.  */
 173
 174 #define REGISTER_CONVERT_TO_RAW(TYPE,REGNUM,FROM,TO)    \
 175 do                                                                      \
 176   {                                                                     \
 177     DOUBLEST dbl_tmp_val;                                               \
 178     dbl_tmp_val = extract_floating ((FROM), TYPE_LENGTH (TYPE));        \
 179     floatformat_from_doublest (&floatformat_m68881_ext, &dbl_tmp_val, (TO)); \
 180   } while (0)
 181
 182 /* Return the GDB type object for the "standard" data type of data
 183    in register N.  This should be int for D0-D7, double for FP0-FP7,
 184    and void pointer for all others (A0-A7, PC, SR, FPCONTROL etc).
 185    Note, for registers which contain addresses return pointer to void,
 186    not pointer to char, because we don't want to attempt to print
 187    the string after printing the address.  */
 188
 189 #define REGISTER_VIRTUAL_TYPE(N) \
 190   ((unsigned) (N) >= FPC_REGNUM ? lookup_pointer_type (builtin_type_void) : \
 191    (unsigned) (N) >= FP0_REGNUM ? builtin_type_double :                     \
 192    (unsigned) (N) >=  A0_REGNUM ? lookup_pointer_type (builtin_type_void) : \
 193    builtin_type_int)
 194
 195 /* Initializer for an array of names of registers.
 196    Entries beyond the first NUM_REGS are ignored.  */
 197
 198 #define REGISTER_NAMES  \
 199  {"d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7", \
 200   "a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp", \
 201   "ps", "pc",  \
 202   "fp0", "fp1", "fp2", "fp3", "fp4", "fp5", "fp6", "fp7", \
 203   "fpcontrol", "fpstatus", "fpiaddr", "fpcode", "fpflags" }
 204
 205 /* Register numbers of various important registers.
 206    Note that some of these values are "real" register numbers,
 207    and correspond to the general registers of the machine,
 208    and some are "phony" register numbers which are too large
 209    to be actual register numbers as far as the user is concerned
 210    but do serve to get the desired values when passed to read_register.  */
 211
 212 #define D0_REGNUM 0
 213 #define A0_REGNUM 8
 214 #define A1_REGNUM 9
 215 #define FP_REGNUM 14            /* Contains address of executing stack frame */
 216 #define SP_REGNUM 15            /* Contains address of top of stack */
 217 #define PS_REGNUM 16            /* Contains processor status */
 218 #define PC_REGNUM 17            /* Contains program counter */
 219 #define FP0_REGNUM 18           /* Floating point register 0 */
 220 #define FPC_REGNUM 26           /* 68881 control register */
 221 #define FPS_REGNUM 27           /* 68881 status register */
 222 #define FPI_REGNUM 28           /* 68881 iaddr register */
 223
 224 /* Store the address of the place in which to copy the structure the
 225    subroutine will return.  This is called from call_function. */
 226
 227 #define STORE_STRUCT_RETURN(ADDR, SP) \
 228   { write_register (A1_REGNUM, (ADDR)); }
 229
 230 /* Extract from an array REGBUF containing the (raw) register state
 231    a function return value of type TYPE, and copy that, in virtual format,
 232    into VALBUF.  This is assuming that floating point values are returned
 233    as doubles in d0/d1.  */
 234
 235 #if !defined (EXTRACT_RETURN_VALUE)
 236 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 237   memcpy ((VALBUF),                                                     \
 238           (char *)(REGBUF) +                                            \
 239                  (TYPE_LENGTH(TYPE) >= 4 ? 0 : 4 - TYPE_LENGTH(TYPE)),  \
 240           TYPE_LENGTH(TYPE))
 241 #endif
 242
 243 /* Write into appropriate registers a function return value
 244    of type TYPE, given in virtual format.  Assumes floats are passed
 245    in d0/d1.  */
 246
 247 #if !defined (STORE_RETURN_VALUE)
 248 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 249   write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
 250 #endif
 251
 252 /* Extract from an array REGBUF containing the (raw) register state
 253    the address in which a function should return its structure value,
 254    as a CORE_ADDR (or an expression that can be used as one).  */
 255
 256 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(CORE_ADDR *)(REGBUF))
 257 \f
 258 /* Describe the pointer in each stack frame to the previous stack frame
 259    (its caller).  */
 260
 261 /* FRAME_CHAIN takes a frame's nominal address and produces the frame's
 262    chain-pointer.
 263    In the case of the 68000, the frame's nominal address
 264    is the address of a 4-byte word containing the calling frame's address.  */
 265
 266 /* If we are chaining from sigtramp, then manufacture a sigtramp frame
 267    (which isn't really on the stack.  I'm not sure this is right for anything
 268    but BSD4.3 on an hp300.  */
 269 #define FRAME_CHAIN(thisframe)  \
 270   (thisframe->signal_handler_caller \
 271    ? thisframe->frame \
 272    : (!inside_entry_file ((thisframe)->pc) \
 273       ? read_memory_integer ((thisframe)->frame, 4) \
 274       : 0))
 275
 276 /* Define other aspects of the stack frame.  */
 277
 278 /* A macro that tells us whether the function invocation represented
 279    by FI does not have a frame on the stack associated with it.  If it
 280    does not, FRAMELESS is set to 1, else 0.  */
 281 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
 282   do { \
 283     if ((FI)->signal_handler_caller) \
 284       (FRAMELESS) = 0; \
 285     else \
 286       (FRAMELESS) = frameless_look_for_prologue(FI); \
 287   } while (0)
 288
 289 /* This was determined by experimentation on hp300 BSD 4.3.  Perhaps
 290    it corresponds to some offset in /usr/include/sys/user.h or
 291    something like that.  Using some system include file would
 292    have the advantage of probably being more robust in the face
 293    of OS upgrades, but the disadvantage of being wrong for
 294    cross-debugging.  */
 295
 296 #define SIG_PC_FP_OFFSET 530
 297
 298 #define FRAME_SAVED_PC(FRAME) \
 299   (((FRAME)->signal_handler_caller \
 300     ? ((FRAME)->next \
 301        ? read_memory_integer ((FRAME)->next->frame + SIG_PC_FP_OFFSET, 4) \
 302        : read_memory_integer (read_register (SP_REGNUM) \
 303                               + SIG_PC_FP_OFFSET - 8, 4) \
 304        ) \
 305     : read_memory_integer ((FRAME)->frame + 4, 4)) \
 306    )
 307
 308 #define FRAME_ARGS_ADDRESS(fi) ((fi)->frame)
 309
 310 #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
 311
 312 /* Set VAL to the number of args passed to frame described by FI.
 313    Can set VAL to -1, meaning no way to tell.  */
 314
 315 /* We can't tell how many args there are
 316    now that the C compiler delays popping them.  */
 317 #if !defined (FRAME_NUM_ARGS)
 318 #define FRAME_NUM_ARGS(val,fi) (val = -1)
 319 #endif
 320
 321 /* Return number of bytes at start of arglist that are not really args.  */
 322
 323 #define FRAME_ARGS_SKIP 8
 324
 325 /* Put here the code to store, into a struct frame_saved_regs,
 326    the addresses of the saved registers of frame described by FRAME_INFO.
 327    This includes special registers such as pc and fp saved in special
 328    ways in the stack frame.  sp is even more special:
 329    the address we return for it IS the sp for the next frame.  */
 330
 331 #if !defined (FRAME_FIND_SAVED_REGS)
 332 #define FRAME_FIND_SAVED_REGS(fi,fsr) m68k_find_saved_regs ((fi), &(fsr))
 333 #endif /* no FIND_FRAME_SAVED_REGS.  */
 334
 335 \f
 336 /* Things needed for making the inferior call functions.  */
 337
 338 /* The CALL_DUMMY macro is the sequence of instructions, as disassembled
 339    by gdb itself:
 340
 341    These instructions exist only so that m68k_find_saved_regs can parse
 342    them as a "prologue"; they are never executed.
 343
 344         fmovemx fp0-fp7,sp@-                    0xf227 0xe0ff
 345         moveml d0-a5,sp@-                       0x48e7 0xfffc
 346         clrw sp@-                               0x4267
 347         movew ccr,sp@-                          0x42e7
 348
 349    The arguments are pushed at this point by GDB; no code is needed in
 350    the dummy for this.  The CALL_DUMMY_START_OFFSET gives the position
 351    of the following jsr instruction.  That is where we start
 352    executing.
 353
 354         jsr @#0x32323232                        0x4eb9 0x3232 0x3232
 355         addal #0x69696969,sp                    0xdffc 0x6969 0x6969
 356         trap #<your BPT_VECTOR number here>     0x4e4?
 357         nop                                     0x4e71
 358
 359    Note this is CALL_DUMMY_LENGTH bytes (28 for the above example).
 360
 361    The dummy frame always saves the floating-point registers, whether they
 362    actually exist on this target or not.  */
 363
 364 /* FIXME: Wrong to hardwire this as BPT_VECTOR when sometimes it
 365    should be REMOTE_BPT_VECTOR.  Best way to fix it would be to define
 366    CALL_DUMMY_BREAKPOINT_OFFSET.  */
 367
 368 #define CALL_DUMMY {0xf227e0ff, 0x48e7fffc, 0x426742e7, 0x4eb93232, 0x3232dffc, 0x69696969, (0x4e404e71 | (BPT_VECTOR << 16))}
 369 #define CALL_DUMMY_LENGTH 28            /* Size of CALL_DUMMY */
 370 #define CALL_DUMMY_START_OFFSET 12      /* Offset to jsr instruction*/
 371 #define CALL_DUMMY_BREAKPOINT_OFFSET (CALL_DUMMY_START_OFFSET + 12)
 372
 373 /* Insert the specified number of args and function address
 374    into a call sequence of the above form stored at DUMMYNAME.
 375    We use the BFD routines to store a big-endian value of known size.  */
 376
 377 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p)     \
 378 { bfd_putb32 (fun,     (unsigned char *) dummyname + CALL_DUMMY_START_OFFSET + 2);  \
 379   bfd_putb32 (nargs*4, (unsigned char *) dummyname + CALL_DUMMY_START_OFFSET + 8); }
 380
 381 /* Push an empty stack frame, to record the current PC, etc.  */
 382
 383 #define PUSH_DUMMY_FRAME        { m68k_push_dummy_frame (); }
 384
 385 extern void m68k_push_dummy_frame PARAMS ((void));
 386
 387 extern void m68k_pop_frame PARAMS ((void));
 388
 389 /* Discard from the stack the innermost frame, restoring all registers.  */
 390
 391 #define POP_FRAME               { m68k_pop_frame (); }
 392
 393 /* Offset from SP to first arg on stack at first instruction of a function */
 394
 395 #define SP_ARG0 (1 * 4)
 396
 397 #define TARGET_M68K