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