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 <
  59
  60 /* Sequence of bytes for breakpoint instruction.
  61    This is a TRAP instruction.  The last 4 bits (0xf below) is the
  62    vector.  Systems which don't use 0xf should define BPT_VECTOR
  63    themselves before including this file.  */
  64
  65 #if !defined (BPT_VECTOR)
  66 #define BPT_VECTOR 0xf
  67 #endif
  68
  69 #if !defined (BREAKPOINT)
  70 #define BREAKPOINT {0x4e, (0x40 | BPT_VECTOR)}
  71 #endif
  72
  73 /* We default to vector 1 for the "remote" target, but allow targets
  74    to override.  */
  75 #if !defined (REMOTE_BPT_VECTOR)
  76 #define REMOTE_BPT_VECTOR 1
  77 #endif
  78
  79 #if !defined (REMOTE_BREAKPOINT)
  80 #define REMOTE_BREAKPOINT {0x4e, (0x40 | REMOTE_BPT_VECTOR)}
  81 #endif
  82
  83 /* If your kernel resets the pc after the trap happens you may need to
  84    define this before including this file.  */
  85
  86 #if !defined (DECR_PC_AFTER_BREAK)
  87 #define DECR_PC_AFTER_BREAK 2
  88 #endif
  89
  90 /* Nonzero if instruction at PC is a return instruction.  */
  91 /* Allow any of the return instructions, including a trapv and a return
  92    from interupt.  */
  93
  94 #define ABOUT_TO_RETURN(pc) ((read_memory_integer (pc, 2) & ~0x3) == 0x4e74)
  95
  96 /* Say how long (ordinary) registers are.  This is a piece of bogosity
  97    used in push_word and a few other places; REGISTER_RAW_SIZE is the
  98    real way to know how big a register is.  */
  99
 100 #define REGISTER_SIZE 4
 101
 102 #define REGISTER_BYTES_FP (16*4 + 8 + 8*12 + 3*4)
 103 #define REGISTER_BYTES_NOFP (16*4 + 8)
 104
 105 #ifndef NUM_REGS
 106 #define NUM_REGS 29
 107 #endif
 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 { \
 161   double dbl_tmp_val; \
 162   floatformat_to_double (&floatformat_m68881_ext, (FROM), &dbl_tmp_val); \
 163   store_floating ((TO), TYPE_LENGTH (TYPE), dbl_tmp_val); \
 164 }
 165
 166 /* Convert data from virtual format with type TYPE in buffer FROM
 167    to raw format for register REGNUM in buffer TO.  */
 168
 169 #define REGISTER_CONVERT_TO_RAW(TYPE,REGNUM,FROM,TO)    \
 170 { \
 171   double dbl_tmp_val = extract_floating ((FROM), TYPE_LENGTH (TYPE)); \
 172   floatformat_from_double (&floatformat_m68881_ext, &dbl_tmp_val, (TO)); \
 173 }
 174
 175 /* Return the GDB type object for the "standard" data type
 176    of data in register N.  */
 177 /* Note, for registers which contain addresses return
 178    pointer to void, not pointer to char, because we don't
 179    want to attempt to print the string after printing the address.  */
 180 #define REGISTER_VIRTUAL_TYPE(N) \
 181  (((unsigned)(N) - FP0_REGNUM) < 8 ? builtin_type_double :           \
 182   (N) == PC_REGNUM || (N) == FP_REGNUM || (N) == SP_REGNUM ?         \
 183   lookup_pointer_type (builtin_type_void) : builtin_type_int)
 184
 185 /* Initializer for an array of names of registers.
 186    Entries beyond the first NUM_REGS are ignored.  */
 187
 188 #define REGISTER_NAMES  \
 189  {"d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7", \
 190   "a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp", \
 191   "ps", "pc",  \
 192   "fp0", "fp1", "fp2", "fp3", "fp4", "fp5", "fp6", "fp7", \
 193   "fpcontrol", "fpstatus", "fpiaddr", "fpcode", "fpflags" }
 194
 195 /* Register numbers of various important registers.
 196    Note that some of these values are "real" register numbers,
 197    and correspond to the general registers of the machine,
 198    and some are "phony" register numbers which are too large
 199    to be actual register numbers as far as the user is concerned
 200    but do serve to get the desired values when passed to read_register.  */
 201
 202 #define D0_REGNUM 0
 203 #define A0_REGNUM 8
 204 #define A1_REGNUM 9
 205 #define FP_REGNUM 14            /* Contains address of executing stack frame */
 206 #define SP_REGNUM 15            /* Contains address of top of stack */
 207 #define PS_REGNUM 16            /* Contains processor status */
 208 #define PC_REGNUM 17            /* Contains program counter */
 209 #define FP0_REGNUM 18           /* Floating point register 0 */
 210 #define FPC_REGNUM 26           /* 68881 control register */
 211 #define FPS_REGNUM 27           /* 68881 status register */
 212 #define FPI_REGNUM 28           /* 68881 iaddr register */
 213
 214 /* Store the address of the place in which to copy the structure the
 215    subroutine will return.  This is called from call_function. */
 216
 217 #define STORE_STRUCT_RETURN(ADDR, SP) \
 218   { write_register (A1_REGNUM, (ADDR)); }
 219
 220 /* Extract from an array REGBUF containing the (raw) register state
 221    a function return value of type TYPE, and copy that, in virtual format,
 222    into VALBUF.  This is assuming that floating point values are returned
 223    as doubles in d0/d1.  */
 224
 225 #if !defined (EXTRACT_RETURN_VALUE)
 226 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 227   memcpy ((VALBUF),                                                     \
 228           (char *)(REGBUF) +                                            \
 229                  (TYPE_LENGTH(TYPE) >= 4 ? 0 : 4 - TYPE_LENGTH(TYPE)),  \
 230           TYPE_LENGTH(TYPE))
 231 #endif
 232
 233 /* Write into appropriate registers a function return value
 234    of type TYPE, given in virtual format.  Assumes floats are passed
 235    in d0/d1.  */
 236
 237 #if !defined (STORE_RETURN_VALUE)
 238 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 239   write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
 240 #endif
 241
 242 /* Extract from an array REGBUF containing the (raw) register state
 243    the address in which a function should return its structure value,
 244    as a CORE_ADDR (or an expression that can be used as one).  */
 245
 246 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(CORE_ADDR *)(REGBUF))
 247 \f
 248 /* Describe the pointer in each stack frame to the previous stack frame
 249    (its caller).  */
 250
 251 /* FRAME_CHAIN takes a frame's nominal address and produces the frame's
 252    chain-pointer.
 253    In the case of the 68000, the frame's nominal address
 254    is the address of a 4-byte word containing the calling frame's address.  */
 255
 256 /* If we are chaining from sigtramp, then manufacture a sigtramp frame
 257    (which isn't really on the stack.  I'm not sure this is right for anything
 258    but BSD4.3 on an hp300.  */
 259 #define FRAME_CHAIN(thisframe)  \
 260   (thisframe->signal_handler_caller \
 261    ? thisframe->frame \
 262    : (!inside_entry_file ((thisframe)->pc) \
 263       ? read_memory_integer ((thisframe)->frame, 4) \
 264       : 0))
 265
 266 /* Define other aspects of the stack frame.  */
 267
 268 /* A macro that tells us whether the function invocation represented
 269    by FI does not have a frame on the stack associated with it.  If it
 270    does not, FRAMELESS is set to 1, else 0.  */
 271 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
 272   do { \
 273     if ((FI)->signal_handler_caller) \
 274       (FRAMELESS) = 0; \
 275     else \
 276       (FRAMELESS) = frameless_look_for_prologue(FI); \
 277   } while (0)
 278
 279 /* This was determined by experimentation on hp300 BSD 4.3.  Perhaps
 280    it corresponds to some offset in /usr/include/sys/user.h or
 281    something like that.  Using some system include file would
 282    have the advantage of probably being more robust in the face
 283    of OS upgrades, but the disadvantage of being wrong for
 284    cross-debugging.  */
 285
 286 #define SIG_PC_FP_OFFSET 530
 287
 288 #define FRAME_SAVED_PC(FRAME) \
 289   (((FRAME)->signal_handler_caller \
 290     ? ((FRAME)->next \
 291        ? read_memory_integer ((FRAME)->next->frame + SIG_PC_FP_OFFSET, 4) \
 292        : read_memory_integer (read_register (SP_REGNUM) \
 293                               + SIG_PC_FP_OFFSET - 8, 4) \
 294        ) \
 295     : read_memory_integer ((FRAME)->frame + 4, 4)) \
 296    )
 297
 298 #define FRAME_ARGS_ADDRESS(fi) ((fi)->frame)
 299
 300 #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
 301
 302 /* Set VAL to the number of args passed to frame described by FI.
 303    Can set VAL to -1, meaning no way to tell.  */
 304
 305 /* We can't tell how many args there are
 306    now that the C compiler delays popping them.  */
 307 #if !defined (FRAME_NUM_ARGS)
 308 #define FRAME_NUM_ARGS(val,fi) (val = -1)
 309 #endif
 310
 311 /* Return number of bytes at start of arglist that are not really args.  */
 312
 313 #define FRAME_ARGS_SKIP 8
 314
 315 /* Put here the code to store, into a struct frame_saved_regs,
 316    the addresses of the saved registers of frame described by FRAME_INFO.
 317    This includes special registers such as pc and fp saved in special
 318    ways in the stack frame.  sp is even more special:
 319    the address we return for it IS the sp for the next frame.  */
 320
 321 #if !defined (FRAME_FIND_SAVED_REGS)
 322 #define FRAME_FIND_SAVED_REGS(fi,fsr) m68k_find_saved_regs ((fi), &(fsr))
 323 #endif /* no FIND_FRAME_SAVED_REGS.  */
 324
 325 \f
 326 /* Things needed for making the inferior call functions.  */
 327
 328 /* The CALL_DUMMY macro is the sequence of instructions, as disassembled
 329    by gdb itself:
 330
 331    These instructions exist only so that m68k_find_saved_regs can parse
 332    them as a "prologue"; they are never executed.
 333
 334         fmovemx fp0-fp7,sp@-                    0xf227 0xe0ff
 335         moveml d0-a5,sp@-                       0x48e7 0xfffc
 336         clrw sp@-                               0x4267
 337         movew ccr,sp@-                          0x42e7
 338
 339    The arguments are pushed at this point by GDB; no code is needed in
 340    the dummy for this.  The CALL_DUMMY_START_OFFSET gives the position
 341    of the following jsr instruction.  That is where we start
 342    executing.
 343
 344         jsr @#0x32323232                        0x4eb9 0x3232 0x3232
 345         addal #0x69696969,sp                    0xdffc 0x6969 0x6969
 346         trap #<your BPT_VECTOR number here>     0x4e4?
 347         nop                                     0x4e71
 348
 349    Note this is CALL_DUMMY_LENGTH bytes (28 for the above example).
 350
 351    The dummy frame always saves the floating-point registers, whether they
 352    actually exist on this target or not.  */
 353
 354 /* FIXME: Wrong to hardwire this as BPT_VECTOR when sometimes it
 355    should be REMOTE_BPT_VECTOR.  Best way to fix it would be to define
 356    CALL_DUMMY_BREAKPOINT_OFFSET.  */
 357
 358 #define CALL_DUMMY {0xf227e0ff, 0x48e7fffc, 0x426742e7, 0x4eb93232, 0x3232dffc, 0x69696969, (0x4e404e71 | (BPT_VECTOR << 16))}
 359 #define CALL_DUMMY_LENGTH 28            /* Size of CALL_DUMMY */
 360 #define CALL_DUMMY_START_OFFSET 12      /* Offset to jsr instruction*/
 361 #define CALL_DUMMY_BREAKPOINT_OFFSET (CALL_DUMMY_START_OFFSET + 12)
 362
 363 /* Insert the specified number of args and function address
 364    into a call sequence of the above form stored at DUMMYNAME.
 365    We use the BFD routines to store a big-endian value of known size.  */
 366
 367 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p)     \
 368 { bfd_putb32 (fun,     (unsigned char *) dummyname + CALL_DUMMY_START_OFFSET + 2);  \
 369   bfd_putb32 (nargs*4, (unsigned char *) dummyname + CALL_DUMMY_START_OFFSET + 8); }
 370
 371 /* Push an empty stack frame, to record the current PC, etc.  */
 372
 373 #define PUSH_DUMMY_FRAME        { m68k_push_dummy_frame (); }
 374
 375 extern void m68k_push_dummy_frame PARAMS ((void));
 376
 377 extern void m68k_pop_frame PARAMS ((void));
 378
 379 /* Discard from the stack the innermost frame, restoring all registers.  */
 380
 381 #define POP_FRAME               { m68k_pop_frame (); }
 382
 383 /* Offset from SP to first arg on stack at first instruction of a function */
 384
 385 #define SP_ARG0 (1 * 4)