gdb/config/m68k/tm-m68k.h

   1 /* Parameters for execution on a 68000 series machine.
   2    Copyright 1986, 1987, 1989, 1990, 1992, 1993, 1994, 1995, 1996, 1998,
   3    1999, 2000 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, USA.  */
  21
  22 #include "regcache.h"
  23
  24 /* Generic 68000 stuff, to be included by other tm-*.h files.  */
  25
  26 /* Define the bit, byte, and word ordering of the machine.  */
  27 #define TARGET_BYTE_ORDER BFD_ENDIAN_BIG
  28
  29 #define TARGET_LONG_DOUBLE_FORMAT &floatformat_m68881_ext
  30
  31 #define TARGET_LONG_DOUBLE_BIT 96
  32
  33 /* Offset from address of function to start of its code.
  34    Zero on most machines.  */
  35
  36 #define FUNCTION_START_OFFSET 0
  37
  38 /* Advance PC across any function entry prologue instructions
  39    to reach some "real" code.  */
  40
  41 #if !defined(SKIP_PROLOGUE)
  42 #define SKIP_PROLOGUE(ip) (m68k_skip_prologue (ip))
  43 #endif
  44 extern CORE_ADDR m68k_skip_prologue (CORE_ADDR ip);
  45
  46 /* Immediately after a function call, return the saved pc.
  47    Can't always go through the frames for this because on some machines
  48    the new frame is not set up until the new function executes
  49    some instructions.  */
  50
  51 struct frame_info;
  52 struct frame_saved_regs;
  53
  54 extern CORE_ADDR m68k_saved_pc_after_call (struct frame_info *);
  55 extern void m68k_find_saved_regs (struct frame_info *,
  56                                   struct frame_saved_regs *);
  57
  58 #define SAVED_PC_AFTER_CALL(frame) \
  59   m68k_saved_pc_after_call(frame)
  60
  61 /* Stack grows downward.  */
  62
  63 #define INNER_THAN(lhs,rhs) ((lhs) < (rhs))
  64
  65 /* Stack must be kept short aligned when doing function calls.  */
  66
  67 #define STACK_ALIGN(ADDR) (((ADDR) + 1) & ~1)
  68
  69 /* Sequence of bytes for breakpoint instruction.
  70    This is a TRAP instruction.  The last 4 bits (0xf below) is the
  71    vector.  Systems which don't use 0xf should define BPT_VECTOR
  72    themselves before including this file.  */
  73
  74 #if !defined (BPT_VECTOR)
  75 #define BPT_VECTOR 0xf
  76 #endif
  77
  78 #if !defined (BREAKPOINT)
  79 #define BREAKPOINT {0x4e, (0x40 | BPT_VECTOR)}
  80 #endif
  81
  82 /* We default to vector 1 for the "remote" target, but allow targets
  83    to override.  */
  84 #if !defined (REMOTE_BPT_VECTOR)
  85 #define REMOTE_BPT_VECTOR 1
  86 #endif
  87
  88 #if !defined (REMOTE_BREAKPOINT)
  89 #define REMOTE_BREAKPOINT {0x4e, (0x40 | REMOTE_BPT_VECTOR)}
  90 #endif
  91
  92 /* If your kernel resets the pc after the trap happens you may need to
  93    define this before including this file.  */
  94
  95 #if !defined (DECR_PC_AFTER_BREAK)
  96 #define DECR_PC_AFTER_BREAK 2
  97 #endif
  98
  99 /* Say how long (ordinary) registers are.  This is a piece of bogosity
 100    used in push_word and a few other places; REGISTER_RAW_SIZE is the
 101    real way to know how big a register is.  */
 102
 103 #define REGISTER_SIZE 4
 104
 105 #define REGISTER_BYTES_FP (16*4 + 8 + 8*12 + 3*4)
 106 #define REGISTER_BYTES_NOFP (16*4 + 8)
 107
 108 #ifndef NUM_REGS
 109 #define NUM_REGS 29
 110 #endif
 111
 112 #define NUM_FREGS (NUM_REGS-24)
 113
 114 #ifndef REGISTER_BYTES_OK
 115 #define REGISTER_BYTES_OK(b) \
 116    ((b) == REGISTER_BYTES_FP \
 117     || (b) == REGISTER_BYTES_NOFP)
 118 #endif
 119
 120 #ifndef REGISTER_BYTES
 121 #define REGISTER_BYTES (16*4 + 8 + 8*12 + 3*4)
 122 #endif
 123
 124 /* Index within `registers' of the first byte of the space for
 125    register N.  */
 126
 127 #define REGISTER_BYTE(N)  \
 128  ((N) >= FPC_REGNUM ? (((N) - FPC_REGNUM) * 4) + 168    \
 129   : (N) >= FP0_REGNUM ? (((N) - FP0_REGNUM) * 12) + 72  \
 130   : (N) * 4)
 131
 132 /* Number of bytes of storage in the actual machine representation
 133    for register N.  On the 68000, all regs are 4 bytes
 134    except the floating point regs which are 12 bytes.  */
 135 /* Note that the unsigned cast here forces the result of the
 136    subtraction to very high positive values if N < FP0_REGNUM */
 137
 138 #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 12 : 4)
 139
 140 /* Number of bytes of storage in the program's representation
 141    for register N.  On the 68000, all regs are 4 bytes
 142    except the floating point regs which are 12-byte long doubles.  */
 143
 144 #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 12 : 4)
 145
 146 /* Largest value REGISTER_RAW_SIZE can have.  */
 147
 148 #define MAX_REGISTER_RAW_SIZE 12
 149
 150 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 151
 152 #define MAX_REGISTER_VIRTUAL_SIZE 12
 153
 154 /* Return the GDB type object for the "standard" data type of data
 155    in register N.  This should be int for D0-D7, long double for FP0-FP7,
 156    and void pointer for all others (A0-A7, PC, SR, FPCONTROL etc).
 157    Note, for registers which contain addresses return pointer to void,
 158    not pointer to char, because we don't want to attempt to print
 159    the string after printing the address.  */
 160
 161 #define REGISTER_VIRTUAL_TYPE(N) \
 162   ((unsigned) (N) >= FPC_REGNUM ? lookup_pointer_type (builtin_type_void) : \
 163    (unsigned) (N) >= FP0_REGNUM ? builtin_type_long_double :                \
 164    (unsigned) (N) >=  A0_REGNUM ? lookup_pointer_type (builtin_type_void) : \
 165    builtin_type_int)
 166
 167 /* Initializer for an array of names of registers.
 168    Entries beyond the first NUM_REGS are ignored.  */
 169
 170 #define REGISTER_NAMES  \
 171  {"d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7", \
 172   "a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp", \
 173   "ps", "pc",  \
 174   "fp0", "fp1", "fp2", "fp3", "fp4", "fp5", "fp6", "fp7", \
 175   "fpcontrol", "fpstatus", "fpiaddr", "fpcode", "fpflags" }
 176
 177 /* Register numbers of various important registers.
 178    Note that some of these values are "real" register numbers,
 179    and correspond to the general registers of the machine,
 180    and some are "phony" register numbers which are too large
 181    to be actual register numbers as far as the user is concerned
 182    but do serve to get the desired values when passed to read_register.  */
 183
 184 #define D0_REGNUM 0
 185 #define A0_REGNUM 8
 186 #define A1_REGNUM 9
 187 #define FP_REGNUM 14            /* Contains address of executing stack frame */
 188 #define SP_REGNUM 15            /* Contains address of top of stack */
 189 #define PS_REGNUM 16            /* Contains processor status */
 190 #define PC_REGNUM 17            /* Contains program counter */
 191 #define FP0_REGNUM 18           /* Floating point register 0 */
 192 #define FPC_REGNUM 26           /* 68881 control register */
 193 #define FPS_REGNUM 27           /* 68881 status register */
 194 #define FPI_REGNUM 28           /* 68881 iaddr register */
 195
 196 /* Store the address of the place in which to copy the structure the
 197    subroutine will return.  This is called from call_function. */
 198
 199 #define STORE_STRUCT_RETURN(ADDR, SP) \
 200   { write_register (A1_REGNUM, (ADDR)); }
 201
 202 /* Extract from an array REGBUF containing the (raw) register state
 203    a function return value of type TYPE, and copy that, in virtual format,
 204    into VALBUF.  This is assuming that floating point values are returned
 205    as doubles in d0/d1.  */
 206
 207 #if !defined (EXTRACT_RETURN_VALUE)
 208 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 209   memcpy ((VALBUF),                                                     \
 210           (char *)(REGBUF) +                                            \
 211                  (TYPE_LENGTH(TYPE) >= 4 ? 0 : 4 - TYPE_LENGTH(TYPE)),  \
 212           TYPE_LENGTH(TYPE))
 213 #endif
 214
 215 /* Write into appropriate registers a function return value
 216    of type TYPE, given in virtual format.  Assumes floats are passed
 217    in d0/d1.  */
 218
 219 #if !defined (STORE_RETURN_VALUE)
 220 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 221   write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
 222 #endif
 223
 224 /* Extract from an array REGBUF containing the (raw) register state
 225    the address in which a function should return its structure value,
 226    as a CORE_ADDR (or an expression that can be used as one).  */
 227
 228 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(CORE_ADDR *)(REGBUF))
 229 \f
 230 /* Describe the pointer in each stack frame to the previous stack frame
 231    (its caller).  */
 232
 233 /* FRAME_CHAIN takes a frame's nominal address and produces the frame's
 234    chain-pointer.
 235    In the case of the 68000, the frame's nominal address
 236    is the address of a 4-byte word containing the calling frame's address.  */
 237
 238 /* If we are chaining from sigtramp, then manufacture a sigtramp frame
 239    (which isn't really on the stack.  I'm not sure this is right for anything
 240    but BSD4.3 on an hp300.  */
 241 #define FRAME_CHAIN(thisframe)  \
 242   (thisframe->signal_handler_caller \
 243    ? thisframe->frame \
 244    : (!inside_entry_file ((thisframe)->pc) \
 245       ? read_memory_integer ((thisframe)->frame, 4) \
 246       : 0))
 247
 248 /* Define other aspects of the stack frame.  */
 249
 250 /* A macro that tells us whether the function invocation represented
 251    by FI does not have a frame on the stack associated with it.  If it
 252    does not, FRAMELESS is set to 1, else 0.  */
 253 #define FRAMELESS_FUNCTION_INVOCATION(FI) \
 254      (((FI)->signal_handler_caller) ? 0 : frameless_look_for_prologue(FI))
 255
 256 /* This was determined by experimentation on hp300 BSD 4.3.  Perhaps
 257    it corresponds to some offset in /usr/include/sys/user.h or
 258    something like that.  Using some system include file would
 259    have the advantage of probably being more robust in the face
 260    of OS upgrades, but the disadvantage of being wrong for
 261    cross-debugging.  */
 262
 263 #define SIG_PC_FP_OFFSET 530
 264
 265 #define FRAME_SAVED_PC(FRAME) \
 266   (((FRAME)->signal_handler_caller \
 267     ? ((FRAME)->next \
 268        ? read_memory_integer ((FRAME)->next->frame + SIG_PC_FP_OFFSET, 4) \
 269        : read_memory_integer (read_register (SP_REGNUM) \
 270                               + SIG_PC_FP_OFFSET - 8, 4) \
 271        ) \
 272     : read_memory_integer ((FRAME)->frame + 4, 4)) \
 273    )
 274
 275 #define FRAME_ARGS_ADDRESS(fi) ((fi)->frame)
 276
 277 #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
 278
 279 /* Set VAL to the number of args passed to frame described by FI.
 280    Can set VAL to -1, meaning no way to tell.  */
 281
 282 /* We can't tell how many args there are
 283    now that the C compiler delays popping them.  */
 284 #if !defined (FRAME_NUM_ARGS)
 285 #define FRAME_NUM_ARGS(fi) (-1)
 286 #endif
 287
 288 /* Return number of bytes at start of arglist that are not really args.  */
 289
 290 #define FRAME_ARGS_SKIP 8
 291
 292 /* Put here the code to store, into a struct frame_saved_regs,
 293    the addresses of the saved registers of frame described by FRAME_INFO.
 294    This includes special registers such as pc and fp saved in special
 295    ways in the stack frame.  sp is even more special:
 296    the address we return for it IS the sp for the next frame.  */
 297
 298 #if !defined (FRAME_FIND_SAVED_REGS)
 299 #define FRAME_FIND_SAVED_REGS(fi,fsr) m68k_find_saved_regs ((fi), &(fsr))
 300 #endif /* no FIND_FRAME_SAVED_REGS.  */
 301 \f
 302
 303 /* Things needed for making the inferior call functions.  */
 304
 305 /* The CALL_DUMMY macro is the sequence of instructions, as disassembled
 306    by gdb itself:
 307
 308    These instructions exist only so that m68k_find_saved_regs can parse
 309    them as a "prologue"; they are never executed.
 310
 311    fmovemx fp0-fp7,sp@-                 0xf227 0xe0ff
 312    moveml d0-a5,sp@-                    0x48e7 0xfffc
 313    clrw sp@-                            0x4267
 314    movew ccr,sp@-                               0x42e7
 315
 316    The arguments are pushed at this point by GDB; no code is needed in
 317    the dummy for this.  The CALL_DUMMY_START_OFFSET gives the position
 318    of the following jsr instruction.  That is where we start
 319    executing.
 320
 321    jsr @#0x32323232                     0x4eb9 0x3232 0x3232
 322    addal #0x69696969,sp                 0xdffc 0x6969 0x6969
 323    trap #<your BPT_VECTOR number here>  0x4e4?
 324    nop                                  0x4e71
 325
 326    Note this is CALL_DUMMY_LENGTH bytes (28 for the above example).
 327
 328    The dummy frame always saves the floating-point registers, whether they
 329    actually exist on this target or not.  */
 330
 331 /* FIXME: Wrong to hardwire this as BPT_VECTOR when sometimes it
 332    should be REMOTE_BPT_VECTOR.  Best way to fix it would be to define
 333    CALL_DUMMY_BREAKPOINT_OFFSET.  */
 334
 335 #define CALL_DUMMY {0xf227e0ff, 0x48e7fffc, 0x426742e7, 0x4eb93232, 0x3232dffc, 0x69696969, (0x4e404e71 | (BPT_VECTOR << 16))}
 336 #define CALL_DUMMY_LENGTH 28    /* Size of CALL_DUMMY */
 337 #define CALL_DUMMY_START_OFFSET 12      /* Offset to jsr instruction */
 338 #define CALL_DUMMY_BREAKPOINT_OFFSET (CALL_DUMMY_START_OFFSET + 12)
 339
 340 /* Insert the specified number of args and function address
 341    into a call sequence of the above form stored at DUMMYNAME.
 342    We use the BFD routines to store a big-endian value of known size.  */
 343
 344 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p)     \
 345 { bfd_putb32 (fun,     (unsigned char *) dummyname + CALL_DUMMY_START_OFFSET + 2);  \
 346   bfd_putb32 (nargs*4, (unsigned char *) dummyname + CALL_DUMMY_START_OFFSET + 8); }
 347
 348 /* Push an empty stack frame, to record the current PC, etc.  */
 349
 350 #define PUSH_DUMMY_FRAME        { m68k_push_dummy_frame (); }
 351
 352 extern void m68k_push_dummy_frame (void);
 353
 354 extern void m68k_pop_frame (void);
 355
 356 /* Discard from the stack the innermost frame, restoring all registers.  */
 357
 358 #define POP_FRAME               { m68k_pop_frame (); }
 359
 360 /* Offset from SP to first arg on stack at first instruction of a function */
 361
 362 #define SP_ARG0 (1 * 4)
 363
 364 #define TARGET_M68K
 365
 366 /* Figure out where the longjmp will land.  Slurp the args out of the stack.
 367    We expect the first arg to be a pointer to the jmp_buf structure from which
 368    we extract the pc (JB_PC) that we will land at.  The pc is copied into ADDR.
 369    This routine returns true on success */
 370
 371 extern int m68k_get_longjmp_target (CORE_ADDR *);