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., 675 Mass Ave, Cambridge, MA 02139, 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 #endif
  48
  49 extern CORE_ADDR m68k_saved_pc_after_call PARAMS ((struct frame_info *));
  50
  51 #define SAVED_PC_AFTER_CALL(frame) \
  52   m68k_saved_pc_after_call(frame)
  53
  54 /* Stack grows downward.  */
  55
  56 #define INNER_THAN <
  57
  58 /* Sequence of bytes for breakpoint instruction.
  59    This is a TRAP instruction.  The last 4 bits (0xf below) is the
  60    vector.  Systems which don't use 0xf should define BPT_VECTOR
  61    themselves before including this file.  */
  62
  63 #if !defined (BPT_VECTOR)
  64 #define BPT_VECTOR 0xf
  65 #endif
  66
  67 #if !defined (BREAKPOINT)
  68 #define BREAKPOINT {0x4e, (0x40 | BPT_VECTOR)}
  69 #endif
  70
  71 /* We always use vector 1 for the "remote" target.  This is hardcoded in
  72    m68k-stub.c.  */
  73 #define REMOTE_BPT_VECTOR 1
  74 #define REMOTE_BREAKPOINT {0x4e, (0x40 | REMOTE_BPT_VECTOR)}
  75
  76 /* If your kernel resets the pc after the trap happens you may need to
  77    define this before including this file.  */
  78
  79 #if !defined (DECR_PC_AFTER_BREAK)
  80 #define DECR_PC_AFTER_BREAK 2
  81 #endif
  82
  83 /* Nonzero if instruction at PC is a return instruction.  */
  84 /* Allow any of the return instructions, including a trapv and a return
  85    from interupt.  */
  86
  87 #define ABOUT_TO_RETURN(pc) ((read_memory_integer (pc, 2) & ~0x3) == 0x4e74)
  88
  89 /* Return 1 if P points to an invalid floating point value.  */
  90
  91 #define INVALID_FLOAT(p, len) 0   /* Just a first guess; not checked */
  92
  93 /* Say how long registers are.  */
  94
  95 #define REGISTER_TYPE long
  96
  97 #define REGISTER_BYTES_FP (16*4 + 8 + 8*12 + 3*4)
  98 #define REGISTER_BYTES_NOFP (16*4 + 8)
  99
 100 #ifndef NUM_REGS
 101 #define NUM_REGS 29
 102 #endif
 103
 104 #ifndef REGISTER_BYTES_OK
 105 #define REGISTER_BYTES_OK(b) \
 106    ((b) == REGISTER_BYTES_FP \
 107     || (b) == REGISTER_BYTES_NOFP)
 108 #endif
 109
 110 #ifndef REGISTER_BYTES
 111 #define REGISTER_BYTES (16*4 + 8 + 8*12 + 3*4)
 112 #endif
 113
 114 /* Index within `registers' of the first byte of the space for
 115    register N.  */
 116
 117 #define REGISTER_BYTE(N)  \
 118  ((N) >= FPC_REGNUM ? (((N) - FPC_REGNUM) * 4) + 168    \
 119   : (N) >= FP0_REGNUM ? (((N) - FP0_REGNUM) * 12) + 72  \
 120   : (N) * 4)
 121
 122 /* Number of bytes of storage in the actual machine representation
 123    for register N.  On the 68000, all regs are 4 bytes
 124    except the floating point regs which are 12 bytes.  */
 125 /* Note that the unsigned cast here forces the result of the
 126    subtraction to very high positive values if N < FP0_REGNUM */
 127
 128 #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 12 : 4)
 129
 130 /* Number of bytes of storage in the program's representation
 131    for register N.  On the 68000, all regs are 4 bytes
 132    except the floating point regs which are 8-byte doubles.  */
 133
 134 #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 8 : 4)
 135
 136 /* Largest value REGISTER_RAW_SIZE can have.  */
 137
 138 #define MAX_REGISTER_RAW_SIZE 12
 139
 140 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 141
 142 #define MAX_REGISTER_VIRTUAL_SIZE 8
 143
 144 /* Nonzero if register N requires conversion
 145    from raw format to virtual format.  */
 146
 147 #define REGISTER_CONVERTIBLE(N) (((unsigned)(N) - FP0_REGNUM) < 8)
 148
 149 /* Put the declaration out here because if it's in the macros, PCC
 150    will complain.  */
 151 extern const struct ext_format ext_format_68881;
 152
 153 /* Convert data from raw format for register REGNUM in buffer FROM
 154    to virtual format with type TYPE in buffer TO.  */
 155
 156 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,TYPE,FROM,TO) \
 157 { \
 158   double val; \
 159   ieee_extended_to_double (&ext_format_68881, (FROM), &val); \
 160   store_floating ((TO), TYPE_LENGTH (TYPE), val); \
 161 }
 162
 163 /* Convert data from virtual format with type TYPE in buffer FROM
 164    to raw format for register REGNUM in buffer TO.  */
 165
 166 #define REGISTER_CONVERT_TO_RAW(TYPE,REGNUM,FROM,TO)    \
 167 { \
 168   double val = extract_floating ((FROM), TYPE_LENGTH (TYPE)); \
 169   double_to_ieee_extended (&ext_format_68881, &val, (TO)); \
 170 }
 171
 172 /* Return the GDB type object for the "standard" data type
 173    of data in register N.  */
 174 /* Note, for registers which contain addresses return
 175    pointer to void, not pointer to char, because we don't
 176    want to attempt to print the string after printing the address.  */
 177 #define REGISTER_VIRTUAL_TYPE(N) \
 178  (((unsigned)(N) - FP0_REGNUM) < 8 ? builtin_type_double :           \
 179   (N) == PC_REGNUM || (N) == FP_REGNUM || (N) == SP_REGNUM ?         \
 180   lookup_pointer_type (builtin_type_void) : builtin_type_int)
 181
 182 /* Initializer for an array of names of registers.
 183    Entries beyond the first NUM_REGS are ignored.  */
 184
 185 #define REGISTER_NAMES  \
 186  {"d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7", \
 187   "a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp", \
 188   "ps", "pc",  \
 189   "fp0", "fp1", "fp2", "fp3", "fp4", "fp5", "fp6", "fp7", \
 190   "fpcontrol", "fpstatus", "fpiaddr", "fpcode", "fpflags" }
 191
 192 /* Register numbers of various important registers.
 193    Note that some of these values are "real" register numbers,
 194    and correspond to the general registers of the machine,
 195    and some are "phony" register numbers which are too large
 196    to be actual register numbers as far as the user is concerned
 197    but do serve to get the desired values when passed to read_register.  */
 198
 199 #define A1_REGNUM 9
 200 #define FP_REGNUM 14            /* Contains address of executing stack frame */
 201 #define SP_REGNUM 15            /* Contains address of top of stack */
 202 #define PS_REGNUM 16            /* Contains processor status */
 203 #define PC_REGNUM 17            /* Contains program counter */
 204 #define FP0_REGNUM 18           /* Floating point register 0 */
 205 #define FPC_REGNUM 26           /* 68881 control register */
 206 #define FPS_REGNUM 27           /* 68881 status register */
 207 #define FPI_REGNUM 28           /* 68881 iaddr register */
 208
 209 /* Store the address of the place in which to copy the structure the
 210    subroutine will return.  This is called from call_function. */
 211
 212 #define STORE_STRUCT_RETURN(ADDR, SP) \
 213   { write_register (A1_REGNUM, (ADDR)); }
 214
 215 /* Extract from an array REGBUF containing the (raw) register state
 216    a function return value of type TYPE, and copy that, in virtual format,
 217    into VALBUF.  This is assuming that floating point values are returned
 218    as doubles in d0/d1.  */
 219
 220 #if !defined (EXTRACT_RETURN_VALUE)
 221 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 222   memcpy ((VALBUF),                                                     \
 223           (char *)(REGBUF) +                                            \
 224                  (TYPE_LENGTH(TYPE) >= 4 ? 0 : 4 - TYPE_LENGTH(TYPE)),  \
 225           TYPE_LENGTH(TYPE))
 226 #endif
 227
 228 /* Write into appropriate registers a function return value
 229    of type TYPE, given in virtual format.  Assumes floats are passed
 230    in d0/d1.  */
 231
 232 #if !defined (STORE_RETURN_VALUE)
 233 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 234   write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
 235 #endif
 236
 237 /* Extract from an array REGBUF containing the (raw) register state
 238    the address in which a function should return its structure value,
 239    as a CORE_ADDR (or an expression that can be used as one).  */
 240
 241 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(CORE_ADDR *)(REGBUF))
 242 \f
 243 /* Describe the pointer in each stack frame to the previous stack frame
 244    (its caller).  */
 245
 246 /* FRAME_CHAIN takes a frame's nominal address and produces the frame's
 247    chain-pointer.
 248    In the case of the 68000, the frame's nominal address
 249    is the address of a 4-byte word containing the calling frame's address.  */
 250
 251 /* If we are chaining from sigtramp, then manufacture a sigtramp frame
 252    (which isn't really on the stack.  I'm not sure this is right for anything
 253    but BSD4.3 on an hp300.  */
 254 #define FRAME_CHAIN(thisframe)  \
 255   (thisframe->signal_handler_caller \
 256    ? thisframe->frame \
 257    : (!inside_entry_file ((thisframe)->pc) \
 258       ? read_memory_integer ((thisframe)->frame, 4) \
 259       : 0))
 260
 261 /* Define other aspects of the stack frame.  */
 262
 263 /* A macro that tells us whether the function invocation represented
 264    by FI does not have a frame on the stack associated with it.  If it
 265    does not, FRAMELESS is set to 1, else 0.  */
 266 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
 267   do { \
 268     if ((FI)->signal_handler_caller) \
 269       (FRAMELESS) = 0; \
 270     else \
 271       (FRAMELESS) = frameless_look_for_prologue(FI); \
 272   } while (0)
 273
 274 /* This was determined by experimentation on hp300 BSD 4.3.  Perhaps
 275    it corresponds to some offset in /usr/include/sys/user.h or
 276    something like that.  Using some system include file would
 277    have the advantage of probably being more robust in the face
 278    of OS upgrades, but the disadvantage of being wrong for
 279    cross-debugging.  */
 280
 281 #define SIG_PC_FP_OFFSET 530
 282
 283 #define FRAME_SAVED_PC(FRAME) \
 284   (((FRAME)->signal_handler_caller \
 285     ? ((FRAME)->next \
 286        ? read_memory_integer ((FRAME)->next->frame + SIG_PC_FP_OFFSET, 4) \
 287        : read_memory_integer (read_register (SP_REGNUM) \
 288                               + SIG_PC_FP_OFFSET - 8, 4) \
 289        ) \
 290     : read_memory_integer ((FRAME)->frame + 4, 4)) \
 291    )
 292
 293 #define FRAME_ARGS_ADDRESS(fi) ((fi)->frame)
 294
 295 #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
 296
 297 /* Set VAL to the number of args passed to frame described by FI.
 298    Can set VAL to -1, meaning no way to tell.  */
 299
 300 /* We can't tell how many args there are
 301    now that the C compiler delays popping them.  */
 302 #if !defined (FRAME_NUM_ARGS)
 303 #define FRAME_NUM_ARGS(val,fi) (val = -1)
 304 #endif
 305
 306 /* Return number of bytes at start of arglist that are not really args.  */
 307
 308 #define FRAME_ARGS_SKIP 8
 309
 310 /* Put here the code to store, into a struct frame_saved_regs,
 311    the addresses of the saved registers of frame described by FRAME_INFO.
 312    This includes special registers such as pc and fp saved in special
 313    ways in the stack frame.  sp is even more special:
 314    the address we return for it IS the sp for the next frame.  */
 315
 316 #if !defined (FRAME_FIND_SAVED_REGS)
 317 #define FRAME_FIND_SAVED_REGS(fi,fsr) m68k_find_saved_regs ((fi), &(fsr))
 318 #endif /* no FIND_FRAME_SAVED_REGS.  */
 319
 320 \f
 321 /* Things needed for making the inferior call functions.  */
 322
 323 /* The CALL_DUMMY macro is the sequence of instructions, as disassembled
 324    by gdb itself:
 325
 326    These instructions exist only so that m68k_find_saved_regs can parse
 327    them as a "prologue"; they are never executed.
 328
 329         fmovemx fp0-fp7,sp@-                    0xf227 0xe0ff
 330         moveml d0-a5,sp@-                       0x48e7 0xfffc
 331         clrw sp@-                               0x4267
 332         movew ccr,sp@-                          0x42e7
 333
 334    The arguments are pushed at this point by GDB; no code is needed in
 335    the dummy for this.  The CALL_DUMMY_START_OFFSET gives the position
 336    of the following jsr instruction.  That is where we start
 337    executing.
 338
 339         jsr @#0x32323232                        0x4eb9 0x3232 0x3232
 340         addal #0x69696969,sp                    0xdffc 0x6969 0x6969
 341         trap #<your BPT_VECTOR number here>     0x4e4?
 342         nop                                     0x4e71
 343
 344    Note this is CALL_DUMMY_LENGTH bytes (28 for the above example).
 345
 346    The dummy frame always saves the floating-point registers, whether they
 347    actually exist on this target or not.  */
 348
 349 /* FIXME: Wrong to hardwire this as BPT_VECTOR when sometimes it
 350    should be REMOTE_BPT_VECTOR.  Best way to fix it would be to define
 351    CALL_DUMMY_BREAKPOINT_OFFSET.  */
 352
 353 #define CALL_DUMMY {0xf227e0ff, 0x48e7fffc, 0x426742e7, 0x4eb93232, 0x3232dffc, 0x69696969, (0x4e404e71 | (BPT_VECTOR << 16))}
 354 #define CALL_DUMMY_LENGTH 28            /* Size of CALL_DUMMY */
 355 #define CALL_DUMMY_START_OFFSET 12      /* Offset to jsr instruction*/
 356
 357 /* Insert the specified number of args and function address
 358    into a call sequence of the above form stored at DUMMYNAME.
 359    We use the BFD routines to store a big-endian value of known size.  */
 360
 361 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p)     \
 362 { bfd_putb32 (fun,     (unsigned char *) dummyname + CALL_DUMMY_START_OFFSET + 2);  \
 363   bfd_putb32 (nargs*4, (unsigned char *) dummyname + CALL_DUMMY_START_OFFSET + 8); }
 364
 365 /* Push an empty stack frame, to record the current PC, etc.  */
 366
 367 #define PUSH_DUMMY_FRAME        { m68k_push_dummy_frame (); }
 368
 369 extern void m68k_push_dummy_frame PARAMS ((void));
 370
 371 extern void m68k_pop_frame PARAMS ((void));
 372
 373 /* Discard from the stack the innermost frame, restoring all registers.  */
 374
 375 #define POP_FRAME               { m68k_pop_frame (); }
 376
 377 /* Offset from SP to first arg on stack at first instruction of a function */
 378
 379 #define SP_ARG0 (1 * 4)