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