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 #define NUM_FREGS (NUM_REGS-24)
 108
 109 #ifndef REGISTER_BYTES_OK
 110 #define REGISTER_BYTES_OK(b) \
 111    ((b) == REGISTER_BYTES_FP \
 112     || (b) == REGISTER_BYTES_NOFP)
 113 #endif
 114
 115 #ifndef REGISTER_BYTES
 116 #define REGISTER_BYTES (16*4 + 8 + 8*12 + 3*4)
 117 #endif
 118
 119 /* Index within `registers' of the first byte of the space for
 120    register N.  */
 121
 122 #define REGISTER_BYTE(N)  \
 123  ((N) >= FPC_REGNUM ? (((N) - FPC_REGNUM) * 4) + 168    \
 124   : (N) >= FP0_REGNUM ? (((N) - FP0_REGNUM) * 12) + 72  \
 125   : (N) * 4)
 126
 127 /* Number of bytes of storage in the actual machine representation
 128    for register N.  On the 68000, all regs are 4 bytes
 129    except the floating point regs which are 12 bytes.  */
 130 /* Note that the unsigned cast here forces the result of the
 131    subtraction to very high positive values if N < FP0_REGNUM */
 132
 133 #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 12 : 4)
 134
 135 /* Number of bytes of storage in the program's representation
 136    for register N.  On the 68000, all regs are 4 bytes
 137    except the floating point regs which are 8-byte doubles.  */
 138
 139 #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 8 : 4)
 140
 141 /* Largest value REGISTER_RAW_SIZE can have.  */
 142
 143 #define MAX_REGISTER_RAW_SIZE 12
 144
 145 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 146
 147 #define MAX_REGISTER_VIRTUAL_SIZE 8
 148
 149 /* Nonzero if register N requires conversion
 150    from raw format to virtual format.  */
 151
 152 #define REGISTER_CONVERTIBLE(N) (((unsigned)(N) - FP0_REGNUM) < 8)
 153
 154 #include "floatformat.h"
 155
 156 /* Convert data from raw format for register REGNUM in buffer FROM
 157    to virtual format with type TYPE in buffer TO.  */
 158
 159 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,TYPE,FROM,TO) \
 160 do                                                                      \
 161   {                                                                     \
 162     DOUBLEST dbl_tmp_val;                                                       \
 163     floatformat_to_doublest (&floatformat_m68881_ext, (FROM), &dbl_tmp_val); \
 164     store_floating ((TO), TYPE_LENGTH (TYPE), dbl_tmp_val);             \
 165   } while (0)
 166
 167 /* Convert data from virtual format with type TYPE in buffer FROM
 168    to raw format for register REGNUM in buffer TO.  */
 169
 170 #define REGISTER_CONVERT_TO_RAW(TYPE,REGNUM,FROM,TO)    \
 171 do                                                                      \
 172   {                                                                     \
 173     DOUBLEST dbl_tmp_val;                                               \
 174     dbl_tmp_val = extract_floating ((FROM), TYPE_LENGTH (TYPE));        \
 175     floatformat_from_doublest (&floatformat_m68881_ext, &dbl_tmp_val, (TO)); \
 176   } while (0)
 177
 178 /* Return the GDB type object for the "standard" data type of data
 179    in register N.  This should be int for D0-D7, double for FP0-FP7,
 180    and void pointer for all others (A0-A7, PC, SR, FPCONTROL etc).
 181    Note, for registers which contain addresses return pointer to void,
 182    not pointer to char, because we don't want to attempt to print
 183    the string after printing the address.  */
 184
 185 #define REGISTER_VIRTUAL_TYPE(N) \
 186   ((unsigned) (N) >= FPC_REGNUM ? lookup_pointer_type (builtin_type_void) : \
 187    (unsigned) (N) >= FP0_REGNUM ? builtin_type_double :                     \
 188    (unsigned) (N) >=  A0_REGNUM ? lookup_pointer_type (builtin_type_void) : \
 189    builtin_type_int)
 190
 191 /* Initializer for an array of names of registers.
 192    Entries beyond the first NUM_REGS are ignored.  */
 193
 194 #define REGISTER_NAMES  \
 195  {"d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7", \
 196   "a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp", \
 197   "ps", "pc",  \
 198   "fp0", "fp1", "fp2", "fp3", "fp4", "fp5", "fp6", "fp7", \
 199   "fpcontrol", "fpstatus", "fpiaddr", "fpcode", "fpflags" }
 200
 201 /* Register numbers of various important registers.
 202    Note that some of these values are "real" register numbers,
 203    and correspond to the general registers of the machine,
 204    and some are "phony" register numbers which are too large
 205    to be actual register numbers as far as the user is concerned
 206    but do serve to get the desired values when passed to read_register.  */
 207
 208 #define D0_REGNUM 0
 209 #define A0_REGNUM 8
 210 #define A1_REGNUM 9
 211 #define FP_REGNUM 14            /* Contains address of executing stack frame */
 212 #define SP_REGNUM 15            /* Contains address of top of stack */
 213 #define PS_REGNUM 16            /* Contains processor status */
 214 #define PC_REGNUM 17            /* Contains program counter */
 215 #define FP0_REGNUM 18           /* Floating point register 0 */
 216 #define FPC_REGNUM 26           /* 68881 control register */
 217 #define FPS_REGNUM 27           /* 68881 status register */
 218 #define FPI_REGNUM 28           /* 68881 iaddr register */
 219
 220 /* Store the address of the place in which to copy the structure the
 221    subroutine will return.  This is called from call_function. */
 222
 223 #define STORE_STRUCT_RETURN(ADDR, SP) \
 224   { write_register (A1_REGNUM, (ADDR)); }
 225
 226 /* Extract from an array REGBUF containing the (raw) register state
 227    a function return value of type TYPE, and copy that, in virtual format,
 228    into VALBUF.  This is assuming that floating point values are returned
 229    as doubles in d0/d1.  */
 230
 231 #if !defined (EXTRACT_RETURN_VALUE)
 232 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 233   memcpy ((VALBUF),                                                     \
 234           (char *)(REGBUF) +                                            \
 235                  (TYPE_LENGTH(TYPE) >= 4 ? 0 : 4 - TYPE_LENGTH(TYPE)),  \
 236           TYPE_LENGTH(TYPE))
 237 #endif
 238
 239 /* Write into appropriate registers a function return value
 240    of type TYPE, given in virtual format.  Assumes floats are passed
 241    in d0/d1.  */
 242
 243 #if !defined (STORE_RETURN_VALUE)
 244 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 245   write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
 246 #endif
 247
 248 /* Extract from an array REGBUF containing the (raw) register state
 249    the address in which a function should return its structure value,
 250    as a CORE_ADDR (or an expression that can be used as one).  */
 251
 252 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(CORE_ADDR *)(REGBUF))
 253 \f
 254 /* Describe the pointer in each stack frame to the previous stack frame
 255    (its caller).  */
 256
 257 /* FRAME_CHAIN takes a frame's nominal address and produces the frame's
 258    chain-pointer.
 259    In the case of the 68000, the frame's nominal address
 260    is the address of a 4-byte word containing the calling frame's address.  */
 261
 262 /* If we are chaining from sigtramp, then manufacture a sigtramp frame
 263    (which isn't really on the stack.  I'm not sure this is right for anything
 264    but BSD4.3 on an hp300.  */
 265 #define FRAME_CHAIN(thisframe)  \
 266   (thisframe->signal_handler_caller \
 267    ? thisframe->frame \
 268    : (!inside_entry_file ((thisframe)->pc) \
 269       ? read_memory_integer ((thisframe)->frame, 4) \
 270       : 0))
 271
 272 /* Define other aspects of the stack frame.  */
 273
 274 /* A macro that tells us whether the function invocation represented
 275    by FI does not have a frame on the stack associated with it.  If it
 276    does not, FRAMELESS is set to 1, else 0.  */
 277 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
 278   do { \
 279     if ((FI)->signal_handler_caller) \
 280       (FRAMELESS) = 0; \
 281     else \
 282       (FRAMELESS) = frameless_look_for_prologue(FI); \
 283   } while (0)
 284
 285 /* This was determined by experimentation on hp300 BSD 4.3.  Perhaps
 286    it corresponds to some offset in /usr/include/sys/user.h or
 287    something like that.  Using some system include file would
 288    have the advantage of probably being more robust in the face
 289    of OS upgrades, but the disadvantage of being wrong for
 290    cross-debugging.  */
 291
 292 #define SIG_PC_FP_OFFSET 530
 293
 294 #define FRAME_SAVED_PC(FRAME) \
 295   (((FRAME)->signal_handler_caller \
 296     ? ((FRAME)->next \
 297        ? read_memory_integer ((FRAME)->next->frame + SIG_PC_FP_OFFSET, 4) \
 298        : read_memory_integer (read_register (SP_REGNUM) \
 299                               + SIG_PC_FP_OFFSET - 8, 4) \
 300        ) \
 301     : read_memory_integer ((FRAME)->frame + 4, 4)) \
 302    )
 303
 304 #define FRAME_ARGS_ADDRESS(fi) ((fi)->frame)
 305
 306 #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
 307
 308 /* Set VAL to the number of args passed to frame described by FI.
 309    Can set VAL to -1, meaning no way to tell.  */
 310
 311 /* We can't tell how many args there are
 312    now that the C compiler delays popping them.  */
 313 #if !defined (FRAME_NUM_ARGS)
 314 #define FRAME_NUM_ARGS(val,fi) (val = -1)
 315 #endif
 316
 317 /* Return number of bytes at start of arglist that are not really args.  */
 318
 319 #define FRAME_ARGS_SKIP 8
 320
 321 /* Put here the code to store, into a struct frame_saved_regs,
 322    the addresses of the saved registers of frame described by FRAME_INFO.
 323    This includes special registers such as pc and fp saved in special
 324    ways in the stack frame.  sp is even more special:
 325    the address we return for it IS the sp for the next frame.  */
 326
 327 #if !defined (FRAME_FIND_SAVED_REGS)
 328 #define FRAME_FIND_SAVED_REGS(fi,fsr) m68k_find_saved_regs ((fi), &(fsr))
 329 #endif /* no FIND_FRAME_SAVED_REGS.  */
 330
 331 \f
 332 /* Things needed for making the inferior call functions.  */
 333
 334 /* The CALL_DUMMY macro is the sequence of instructions, as disassembled
 335    by gdb itself:
 336
 337    These instructions exist only so that m68k_find_saved_regs can parse
 338    them as a "prologue"; they are never executed.
 339
 340         fmovemx fp0-fp7,sp@-                    0xf227 0xe0ff
 341         moveml d0-a5,sp@-                       0x48e7 0xfffc
 342         clrw sp@-                               0x4267
 343         movew ccr,sp@-                          0x42e7
 344
 345    The arguments are pushed at this point by GDB; no code is needed in
 346    the dummy for this.  The CALL_DUMMY_START_OFFSET gives the position
 347    of the following jsr instruction.  That is where we start
 348    executing.
 349
 350         jsr @#0x32323232                        0x4eb9 0x3232 0x3232
 351         addal #0x69696969,sp                    0xdffc 0x6969 0x6969
 352         trap #<your BPT_VECTOR number here>     0x4e4?
 353         nop                                     0x4e71
 354
 355    Note this is CALL_DUMMY_LENGTH bytes (28 for the above example).
 356
 357    The dummy frame always saves the floating-point registers, whether they
 358    actually exist on this target or not.  */
 359
 360 /* FIXME: Wrong to hardwire this as BPT_VECTOR when sometimes it
 361    should be REMOTE_BPT_VECTOR.  Best way to fix it would be to define
 362    CALL_DUMMY_BREAKPOINT_OFFSET.  */
 363
 364 #define CALL_DUMMY {0xf227e0ff, 0x48e7fffc, 0x426742e7, 0x4eb93232, 0x3232dffc, 0x69696969, (0x4e404e71 | (BPT_VECTOR << 16))}
 365 #define CALL_DUMMY_LENGTH 28            /* Size of CALL_DUMMY */
 366 #define CALL_DUMMY_START_OFFSET 12      /* Offset to jsr instruction*/
 367 #define CALL_DUMMY_BREAKPOINT_OFFSET (CALL_DUMMY_START_OFFSET + 12)
 368
 369 /* Insert the specified number of args and function address
 370    into a call sequence of the above form stored at DUMMYNAME.
 371    We use the BFD routines to store a big-endian value of known size.  */
 372
 373 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p)     \
 374 { bfd_putb32 (fun,     (unsigned char *) dummyname + CALL_DUMMY_START_OFFSET + 2);  \
 375   bfd_putb32 (nargs*4, (unsigned char *) dummyname + CALL_DUMMY_START_OFFSET + 8); }
 376
 377 /* Push an empty stack frame, to record the current PC, etc.  */
 378
 379 #define PUSH_DUMMY_FRAME        { m68k_push_dummy_frame (); }
 380
 381 extern void m68k_push_dummy_frame PARAMS ((void));
 382
 383 extern void m68k_pop_frame PARAMS ((void));
 384
 385 /* Discard from the stack the innermost frame, restoring all registers.  */
 386
 387 #define POP_FRAME               { m68k_pop_frame (); }
 388
 389 /* Offset from SP to first arg on stack at first instruction of a function */
 390
 391 #define SP_ARG0 (1 * 4)
 392
 393 #define TARGET_M68K