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(lhs,rhs) ((lhs) < (rhs))
  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 /* Say how long (ordinary) registers are.  This is a piece of bogosity
  95    used in push_word and a few other places; REGISTER_RAW_SIZE is the
  96    real way to know how big a register is.  */
  97
  98 #define REGISTER_SIZE 4
  99
 100 #define REGISTER_BYTES_FP (16*4 + 8 + 8*12 + 3*4)
 101 #define REGISTER_BYTES_NOFP (16*4 + 8)
 102
 103 #ifndef NUM_REGS
 104 #define NUM_REGS 29
 105 #endif
 106
 107 #ifndef REGISTER_BYTES_OK
 108 #define REGISTER_BYTES_OK(b) \
 109    ((b) == REGISTER_BYTES_FP \
 110     || (b) == REGISTER_BYTES_NOFP)
 111 #endif
 112
 113 #ifndef REGISTER_BYTES
 114 #define REGISTER_BYTES (16*4 + 8 + 8*12 + 3*4)
 115 #endif
 116
 117 /* Index within `registers' of the first byte of the space for
 118    register N.  */
 119
 120 #define REGISTER_BYTE(N)  \
 121  ((N) >= FPC_REGNUM ? (((N) - FPC_REGNUM) * 4) + 168    \
 122   : (N) >= FP0_REGNUM ? (((N) - FP0_REGNUM) * 12) + 72  \
 123   : (N) * 4)
 124
 125 /* Number of bytes of storage in the actual machine representation
 126    for register N.  On the 68000, all regs are 4 bytes
 127    except the floating point regs which are 12 bytes.  */
 128 /* Note that the unsigned cast here forces the result of the
 129    subtraction to very high positive values if N < FP0_REGNUM */
 130
 131 #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 12 : 4)
 132
 133 /* Number of bytes of storage in the program's representation
 134    for register N.  On the 68000, all regs are 4 bytes
 135    except the floating point regs which are 8-byte doubles.  */
 136
 137 #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 8 : 4)
 138
 139 /* Largest value REGISTER_RAW_SIZE can have.  */
 140
 141 #define MAX_REGISTER_RAW_SIZE 12
 142
 143 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 144
 145 #define MAX_REGISTER_VIRTUAL_SIZE 8
 146
 147 /* Nonzero if register N requires conversion
 148    from raw format to virtual format.  */
 149
 150 #define REGISTER_CONVERTIBLE(N) (((unsigned)(N) - FP0_REGNUM) < 8)
 151
 152 #include "floatformat.h"
 153
 154 /* Convert data from raw format for register REGNUM in buffer FROM
 155    to virtual format with type TYPE in buffer TO.  */
 156
 157 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,TYPE,FROM,TO) \
 158 do                                                                      \
 159   {                                                                     \
 160     DOUBLEST dbl_tmp_val;                                                       \
 161     floatformat_to_doublest (&floatformat_m68881_ext, (FROM), &dbl_tmp_val); \
 162     store_floating ((TO), TYPE_LENGTH (TYPE), dbl_tmp_val);             \
 163   } while (0)
 164
 165 /* Convert data from virtual format with type TYPE in buffer FROM
 166    to raw format for register REGNUM in buffer TO.  */
 167
 168 #define REGISTER_CONVERT_TO_RAW(TYPE,REGNUM,FROM,TO)    \
 169 do                                                                      \
 170   {                                                                     \
 171     DOUBLEST dbl_tmp_val;                                               \
 172     dbl_tmp_val = extract_floating ((FROM), TYPE_LENGTH (TYPE));        \
 173     floatformat_from_doublest (&floatformat_m68881_ext, &dbl_tmp_val, (TO)); \
 174   } while (0)
 175
 176 /* Return the GDB type object for the "standard" data type of data
 177    in register N.  This should be int for D0-D7, double for FP0-FP7,
 178    and void pointer for all others (A0-A7, PC, SR, FPCONTROL etc).
 179    Note, for registers which contain addresses return pointer to void,
 180    not pointer to char, because we don't want to attempt to print
 181    the string after printing the address.  */
 182
 183 #define REGISTER_VIRTUAL_TYPE(N) \
 184   ((unsigned) (N) >= FPC_REGNUM ? lookup_pointer_type (builtin_type_void) : \
 185    (unsigned) (N) >= FP0_REGNUM ? builtin_type_double :                     \
 186    (unsigned) (N) >=  A0_REGNUM ? lookup_pointer_type (builtin_type_void) : \
 187    builtin_type_int)
 188
 189 /* Initializer for an array of names of registers.
 190    Entries beyond the first NUM_REGS are ignored.  */
 191
 192 #define REGISTER_NAMES  \
 193  {"d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7", \
 194   "a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp", \
 195   "ps", "pc",  \
 196   "fp0", "fp1", "fp2", "fp3", "fp4", "fp5", "fp6", "fp7", \
 197   "fpcontrol", "fpstatus", "fpiaddr", "fpcode", "fpflags" }
 198
 199 /* Register numbers of various important registers.
 200    Note that some of these values are "real" register numbers,
 201    and correspond to the general registers of the machine,
 202    and some are "phony" register numbers which are too large
 203    to be actual register numbers as far as the user is concerned
 204    but do serve to get the desired values when passed to read_register.  */
 205
 206 #define D0_REGNUM 0
 207 #define A0_REGNUM 8
 208 #define A1_REGNUM 9
 209 #define FP_REGNUM 14            /* Contains address of executing stack frame */
 210 #define SP_REGNUM 15            /* Contains address of top of stack */
 211 #define PS_REGNUM 16            /* Contains processor status */
 212 #define PC_REGNUM 17            /* Contains program counter */
 213 #define FP0_REGNUM 18           /* Floating point register 0 */
 214 #define FPC_REGNUM 26           /* 68881 control register */
 215 #define FPS_REGNUM 27           /* 68881 status register */
 216 #define FPI_REGNUM 28           /* 68881 iaddr register */
 217
 218 /* Store the address of the place in which to copy the structure the
 219    subroutine will return.  This is called from call_function. */
 220
 221 #define STORE_STRUCT_RETURN(ADDR, SP) \
 222   { write_register (A1_REGNUM, (ADDR)); }
 223
 224 /* Extract from an array REGBUF containing the (raw) register state
 225    a function return value of type TYPE, and copy that, in virtual format,
 226    into VALBUF.  This is assuming that floating point values are returned
 227    as doubles in d0/d1.  */
 228
 229 #if !defined (EXTRACT_RETURN_VALUE)
 230 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 231   memcpy ((VALBUF),                                                     \
 232           (char *)(REGBUF) +                                            \
 233                  (TYPE_LENGTH(TYPE) >= 4 ? 0 : 4 - TYPE_LENGTH(TYPE)),  \
 234           TYPE_LENGTH(TYPE))
 235 #endif
 236
 237 /* Write into appropriate registers a function return value
 238    of type TYPE, given in virtual format.  Assumes floats are passed
 239    in d0/d1.  */
 240
 241 #if !defined (STORE_RETURN_VALUE)
 242 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 243   write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
 244 #endif
 245
 246 /* Extract from an array REGBUF containing the (raw) register state
 247    the address in which a function should return its structure value,
 248    as a CORE_ADDR (or an expression that can be used as one).  */
 249
 250 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(CORE_ADDR *)(REGBUF))
 251 \f
 252 /* Describe the pointer in each stack frame to the previous stack frame
 253    (its caller).  */
 254
 255 /* FRAME_CHAIN takes a frame's nominal address and produces the frame's
 256    chain-pointer.
 257    In the case of the 68000, the frame's nominal address
 258    is the address of a 4-byte word containing the calling frame's address.  */
 259
 260 /* If we are chaining from sigtramp, then manufacture a sigtramp frame
 261    (which isn't really on the stack.  I'm not sure this is right for anything
 262    but BSD4.3 on an hp300.  */
 263 #define FRAME_CHAIN(thisframe)  \
 264   (thisframe->signal_handler_caller \
 265    ? thisframe->frame \
 266    : (!inside_entry_file ((thisframe)->pc) \
 267       ? read_memory_integer ((thisframe)->frame, 4) \
 268       : 0))
 269
 270 /* Define other aspects of the stack frame.  */
 271
 272 /* A macro that tells us whether the function invocation represented
 273    by FI does not have a frame on the stack associated with it.  If it
 274    does not, FRAMELESS is set to 1, else 0.  */
 275 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
 276   do { \
 277     if ((FI)->signal_handler_caller) \
 278       (FRAMELESS) = 0; \
 279     else \
 280       (FRAMELESS) = frameless_look_for_prologue(FI); \
 281   } while (0)
 282
 283 /* This was determined by experimentation on hp300 BSD 4.3.  Perhaps
 284    it corresponds to some offset in /usr/include/sys/user.h or
 285    something like that.  Using some system include file would
 286    have the advantage of probably being more robust in the face
 287    of OS upgrades, but the disadvantage of being wrong for
 288    cross-debugging.  */
 289
 290 #define SIG_PC_FP_OFFSET 530
 291
 292 #define FRAME_SAVED_PC(FRAME) \
 293   (((FRAME)->signal_handler_caller \
 294     ? ((FRAME)->next \
 295        ? read_memory_integer ((FRAME)->next->frame + SIG_PC_FP_OFFSET, 4) \
 296        : read_memory_integer (read_register (SP_REGNUM) \
 297                               + SIG_PC_FP_OFFSET - 8, 4) \
 298        ) \
 299     : read_memory_integer ((FRAME)->frame + 4, 4)) \
 300    )
 301
 302 #define FRAME_ARGS_ADDRESS(fi) ((fi)->frame)
 303
 304 #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
 305
 306 /* Set VAL to the number of args passed to frame described by FI.
 307    Can set VAL to -1, meaning no way to tell.  */
 308
 309 /* We can't tell how many args there are
 310    now that the C compiler delays popping them.  */
 311 #if !defined (FRAME_NUM_ARGS)
 312 #define FRAME_NUM_ARGS(val,fi) (val = -1)
 313 #endif
 314
 315 /* Return number of bytes at start of arglist that are not really args.  */
 316
 317 #define FRAME_ARGS_SKIP 8
 318
 319 /* Put here the code to store, into a struct frame_saved_regs,
 320    the addresses of the saved registers of frame described by FRAME_INFO.
 321    This includes special registers such as pc and fp saved in special
 322    ways in the stack frame.  sp is even more special:
 323    the address we return for it IS the sp for the next frame.  */
 324
 325 #if !defined (FRAME_FIND_SAVED_REGS)
 326 #define FRAME_FIND_SAVED_REGS(fi,fsr) m68k_find_saved_regs ((fi), &(fsr))
 327 #endif /* no FIND_FRAME_SAVED_REGS.  */
 328
 329 \f
 330 /* Things needed for making the inferior call functions.  */
 331
 332 /* The CALL_DUMMY macro is the sequence of instructions, as disassembled
 333    by gdb itself:
 334
 335    These instructions exist only so that m68k_find_saved_regs can parse
 336    them as a "prologue"; they are never executed.
 337
 338         fmovemx fp0-fp7,sp@-                    0xf227 0xe0ff
 339         moveml d0-a5,sp@-                       0x48e7 0xfffc
 340         clrw sp@-                               0x4267
 341         movew ccr,sp@-                          0x42e7
 342
 343    The arguments are pushed at this point by GDB; no code is needed in
 344    the dummy for this.  The CALL_DUMMY_START_OFFSET gives the position
 345    of the following jsr instruction.  That is where we start
 346    executing.
 347
 348         jsr @#0x32323232                        0x4eb9 0x3232 0x3232
 349         addal #0x69696969,sp                    0xdffc 0x6969 0x6969
 350         trap #<your BPT_VECTOR number here>     0x4e4?
 351         nop                                     0x4e71
 352
 353    Note this is CALL_DUMMY_LENGTH bytes (28 for the above example).
 354
 355    The dummy frame always saves the floating-point registers, whether they
 356    actually exist on this target or not.  */
 357
 358 /* FIXME: Wrong to hardwire this as BPT_VECTOR when sometimes it
 359    should be REMOTE_BPT_VECTOR.  Best way to fix it would be to define
 360    CALL_DUMMY_BREAKPOINT_OFFSET.  */
 361
 362 #define CALL_DUMMY {0xf227e0ff, 0x48e7fffc, 0x426742e7, 0x4eb93232, 0x3232dffc, 0x69696969, (0x4e404e71 | (BPT_VECTOR << 16))}
 363 #define CALL_DUMMY_LENGTH 28            /* Size of CALL_DUMMY */
 364 #define CALL_DUMMY_START_OFFSET 12      /* Offset to jsr instruction*/
 365 #define CALL_DUMMY_BREAKPOINT_OFFSET (CALL_DUMMY_START_OFFSET + 12)
 366
 367 /* Insert the specified number of args and function address
 368    into a call sequence of the above form stored at DUMMYNAME.
 369    We use the BFD routines to store a big-endian value of known size.  */
 370
 371 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p)     \
 372 { bfd_putb32 (fun,     (unsigned char *) dummyname + CALL_DUMMY_START_OFFSET + 2);  \
 373   bfd_putb32 (nargs*4, (unsigned char *) dummyname + CALL_DUMMY_START_OFFSET + 8); }
 374
 375 /* Push an empty stack frame, to record the current PC, etc.  */
 376
 377 #define PUSH_DUMMY_FRAME        { m68k_push_dummy_frame (); }
 378
 379 extern void m68k_push_dummy_frame PARAMS ((void));
 380
 381 extern void m68k_pop_frame PARAMS ((void));
 382
 383 /* Discard from the stack the innermost frame, restoring all registers.  */
 384
 385 #define POP_FRAME               { m68k_pop_frame (); }
 386
 387 /* Offset from SP to first arg on stack at first instruction of a function */
 388
 389 #define SP_ARG0 (1 * 4)
 390
 391 #define TARGET_M68K