gdb/tm-arm.h

   1 /* Definitions to make GDB target for an ARM under RISCiX (4.3bsd).
   2    Copyright (C) 1986, 1987, 1989, 1991 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 #define TARGET_BYTE_ORDER LITTLE_ENDIAN
  21
  22 /* IEEE format floating point */
  23
  24 #define IEEE_FLOAT
  25
  26 /* I provide my own xfer_core_file to cope with shared libraries */
  27
  28 #define XFER_CORE_FILE
  29
  30 /* Define this if the C compiler puts an underscore at the front
  31    of external names before giving them to the linker.  */
  32
  33 #define NAMES_HAVE_UNDERSCORE
  34
  35 /* Offset from address of function to start of its code.
  36    Zero on most machines.  */
  37
  38 #define FUNCTION_START_OFFSET 0
  39
  40 /* Advance PC across any function entry prologue instructions
  41    to reach some "real" code.  */
  42
  43 #define SKIP_PROLOGUE(pc) pc = skip_prologue(pc)
  44
  45 /* Immediately after a function call, return the saved pc.
  46    Can't always go through the frames for this because on some machines
  47    the new frame is not set up until the new function executes
  48    some instructions.  */
  49
  50 #define SAVED_PC_AFTER_CALL(frame) (read_register (LR_REGNUM) & 0x03fffffc)
  51
  52 /* I don't know the real values for these.  */
  53 #define TARGET_UPAGES UPAGES
  54 #define TARGET_NBPG NBPG
  55
  56 /* Address of end of stack space.  */
  57
  58 #define STACK_END_ADDR (0x01000000 - (TARGET_UPAGES * TARGET_NBPG))
  59
  60 /* Stack grows downward.  */
  61
  62 #define INNER_THAN <
  63
  64 /* Sequence of bytes for breakpoint instruction.  */
  65
  66 #define BREAKPOINT {0x00,0x00,0x18,0xef} /* BKPT_SWI from <sys/ptrace.h> */
  67
  68 /* Amount PC must be decremented by after a breakpoint.
  69    This is often the number of bytes in BREAKPOINT
  70    but not always.  */
  71
  72 #define DECR_PC_AFTER_BREAK 0
  73
  74 /* Nonzero if instruction at PC is a return instruction.  */
  75
  76 #define ABOUT_TO_RETURN(pc) \
  77       ((read_memory_integer(pc, 4) & 0x0fffffff == 0x01b0f00e) || \
  78        (read_memory_integer(pc, 4) & 0x0ffff800 == 0x09eba800))
  79
  80 /* Return 1 if P points to an invalid floating point value.
  81    LEN is the length in bytes.  */
  82
  83 #define INVALID_FLOAT(p, len) 0
  84
  85 /* code to execute to print interesting information about the
  86  * floating point processor (if any)
  87  * No need to define if there is nothing to do.
  88  */
  89 #define FLOAT_INFO { arm_float_info (); }
  90
  91 /* Say how long (ordinary) registers are.  */
  92
  93 #define REGISTER_TYPE long
  94
  95 /* Number of machine registers */
  96
  97 /* Note: I make a fake copy of the pc in register 25 (calling it ps) so
  98    that I can clear the status bits from pc (register 15) */
  99
 100 #define NUM_REGS 26
 101
 102 /* Initializer for an array of names of registers.
 103    There should be NUM_REGS strings in this initializer.  */
 104
 105 #define REGISTER_NAMES \
 106       { "a1", "a2", "a3", "a4",                                 \
 107         "v1", "v2", "v3", "v4", "v5", "v6",                     \
 108         "sl", "fp", "ip", "sp", "lr", "pc",                     \
 109         "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", "fps", "ps" }
 110
 111 /* Register numbers of various important registers.
 112    Note that some of these values are "real" register numbers,
 113    and correspond to the general registers of the machine,
 114    and some are "phony" register numbers which are too large
 115    to be actual register numbers as far as the user is concerned
 116    but do serve to get the desired values when passed to read_register.  */
 117
 118 #define AP_REGNUM 11
 119 #define FP_REGNUM 11            /* Contains address of executing stack frame */
 120 #define SP_REGNUM 13            /* Contains address of top of stack */
 121 #define LR_REGNUM 14            /* address to return to from a function call */
 122 #define PC_REGNUM 15            /* Contains program counter */
 123 #define F0_REGNUM 16            /* first floating point register */
 124 #define FPS_REGNUM 24           /* floating point status register */
 125 #define PS_REGNUM 25            /* Contains processor status */
 126
 127
 128 /* Total amount of space needed to store our copies of the machine's
 129    register state, the array `registers'.  */
 130 #define REGISTER_BYTES (16*4 + 12*8 + 4 + 4)
 131
 132 /* Index within `registers' of the first byte of the space for
 133    register N.  */
 134
 135 #define REGISTER_BYTE(N) (((N) < F0_REGNUM) ? (N)*4 : \
 136                           (((N) < PS_REGNUM) ? 16*4 + ((N) - 16)*12 : \
 137                            16*4 + 8*12 + ((N) - FPS_REGNUM) * 4))
 138
 139 /* Number of bytes of storage in the actual machine representation
 140    for register N.  On the vax, all regs are 4 bytes.  */
 141
 142 #define REGISTER_RAW_SIZE(N) (((N) < F0_REGNUM || (N) >= FPS_REGNUM) ? 4 : 12)
 143
 144 /* Number of bytes of storage in the program's representation
 145    for register N.  On the vax, all regs are 4 bytes.  */
 146
 147 #define REGISTER_VIRTUAL_SIZE(N) (((N) < F0_REGNUM || (N) >= FPS_REGNUM) ? 4 : 8)
 148
 149 /* Largest value REGISTER_RAW_SIZE can have.  */
 150
 151 #define MAX_REGISTER_RAW_SIZE 12
 152
 153 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 154
 155 #define MAX_REGISTER_VIRTUAL_SIZE 8
 156
 157 /* Nonzero if register N requires conversion
 158    from raw format to virtual format.  */
 159
 160 #define REGISTER_CONVERTIBLE(N) ((unsigned)(N) - F0_REGNUM < 8)
 161
 162 /* Convert data from raw format for register REGNUM
 163    to virtual format for register REGNUM.  */
 164
 165 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO)     \
 166   if (REGISTER_CONVERTIBLE(REGNUM))                                     \
 167       convert_from_extended((FROM), (TO));                              \
 168   else                                                                  \
 169       bcopy ((FROM), (TO), 4);
 170
 171 /* Convert data from virtual format for register REGNUM
 172    to raw format for register REGNUM.  */
 173
 174 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
 175   if (REGISTER_CONVERTIBLE(REGNUM))                     \
 176     convert_to_extended((FROM), (TO));          \
 177   else                                                  \
 178     bcopy ((FROM), (TO), 4);
 179
 180 /* Return the GDB type object for the "standard" data type
 181    of data in register N.  */
 182
 183 #define REGISTER_VIRTUAL_TYPE(N) \
 184  (((unsigned)(N) - F0_REGNUM) < 8 ? builtin_type_double : builtin_type_int)
 185 \f
 186 /* The system C compiler uses a similar structure return convention to gcc */
 187
 188 #define USE_STRUCT_CONVENTION(gcc_p, type) (TYPE_LENGTH (type) > 4)
 189
 190 /* Store the address of the place in which to copy the structure the
 191    subroutine will return.  This is called from call_function. */
 192
 193 #define STORE_STRUCT_RETURN(ADDR, SP) \
 194   { write_register (0, (ADDR)); }
 195
 196 /* Extract from an array REGBUF containing the (raw) register state
 197    a function return value of type TYPE, and copy that, in virtual format,
 198    into VALBUF.  */
 199
 200 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 201   if (TYPE_CODE (TYPE) == TYPE_CODE_FLT)                                \
 202     convert_from_extended(REGBUF + REGISTER_BYTE (F0_REGNUM), VALBUF);  \
 203   else                                                                  \
 204     bcopy (REGBUF, VALBUF, TYPE_LENGTH (TYPE))
 205
 206 /* Write into appropriate registers a function return value
 207    of type TYPE, given in virtual format.  */
 208
 209 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 210   if (TYPE_CODE (TYPE) == TYPE_CODE_FLT) {                              \
 211     char _buf[MAX_REGISTER_RAW_SIZE];                                   \
 212     convert_to_extended(VALBUF, _buf);                                  \
 213     write_register_bytes (REGISTER_BYTE (F0_REGNUM), _buf, MAX_REGISTER_RAW_SIZE); \
 214   } else                                                                \
 215     write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
 216
 217 /* Extract from an array REGBUF containing the (raw) register state
 218    the address in which a function should return its structure value,
 219    as a CORE_ADDR (or an expression that can be used as one).  */
 220
 221 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(int *)(REGBUF))
 222
 223 /* Specify that for the native compiler variables for a particular
 224    lexical context are listed after the beginning LBRAC instead of
 225    before in the executables list of symbols.  */
 226 #define VARIABLES_INSIDE_BLOCK(desc, gcc_p) (!(gcc_p))
 227
 228 \f
 229 /* Describe the pointer in each stack frame to the previous stack frame
 230    (its caller).  */
 231
 232 /* FRAME_CHAIN takes a frame's nominal address
 233    and produces the frame's chain-pointer.
 234
 235    FRAME_CHAIN_COMBINE takes the chain pointer and the frame's nominal address
 236    and produces the nominal address of the caller frame.
 237
 238    However, if FRAME_CHAIN_VALID returns zero,
 239    it means the given frame is the outermost one and has no caller.
 240    In that case, FRAME_CHAIN_COMBINE is not used.  */
 241
 242 /* In the case of the ARM, the frame's nominal address is the FP value,
 243    and 12 bytes before comes the saved previous FP value as a 4-byte word.  */
 244
 245 #define FRAME_CHAIN(thisframe)  \
 246   ((thisframe)->pc >= first_object_file_end ? \
 247    read_memory_integer ((thisframe)->frame - 12, 4) :\
 248    0)
 249
 250 #define FRAME_CHAIN_VALID(chain, thisframe) \
 251   (chain != 0 && (FRAME_SAVED_PC (thisframe) >= first_object_file_end))
 252
 253 #define FRAME_CHAIN_COMBINE(chain, thisframe) (chain)
 254
 255 /* Define other aspects of the stack frame.  */
 256
 257 /* A macro that tells us whether the function invocation represented
 258    by FI does not have a frame on the stack associated with it.  If it
 259    does not, FRAMELESS is set to 1, else 0.  */
 260 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
 261 {                                                       \
 262   CORE_ADDR func_start, after_prologue;                 \
 263   func_start = (get_pc_function_start ((FI)->pc) +      \
 264                 FUNCTION_START_OFFSET);                 \
 265   after_prologue = func_start;                          \
 266   SKIP_PROLOGUE (after_prologue);                       \
 267   (FRAMELESS) = (after_prologue == func_start);         \
 268 }
 269
 270 /* Saved Pc.  */
 271
 272 #define FRAME_SAVED_PC(FRAME) \
 273   (read_memory_integer ((FRAME)->frame - 4, 4) & 0x03fffffc)
 274
 275 #define FRAME_ARGS_ADDRESS(fi) (fi->frame)
 276
 277 #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
 278
 279 /* Return number of args passed to a frame.
 280    Can return -1, meaning no way to tell.  */
 281
 282 #define FRAME_NUM_ARGS(numargs, fi) (numargs = -1)
 283
 284 /* Return number of bytes at start of arglist that are not really args.  */
 285
 286 #define FRAME_ARGS_SKIP 0
 287
 288 /* Put here the code to store, into a struct frame_saved_regs,
 289    the addresses of the saved registers of frame described by FRAME_INFO.
 290    This includes special registers such as pc and fp saved in special
 291    ways in the stack frame.  sp is even more special:
 292    the address we return for it IS the sp for the next frame.  */
 293
 294 #define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) \
 295 {                                                                               \
 296     register int regnum;                                                        \
 297     register int frame;                                                         \
 298     register int next_addr;                                                     \
 299     register int return_data_save;                                              \
 300     register int saved_register_mask;                                           \
 301     bzero (&frame_saved_regs, sizeof frame_saved_regs);                         \
 302     frame = (frame_info)->frame;                                                \
 303     return_data_save = read_memory_integer(frame, 4) & 0x03fffffc - 12;         \
 304     saved_register_mask =                                                       \
 305         read_memory_integer(return_data_save, 4);                               \
 306     next_addr = frame - 12;                                                     \
 307     for (regnum = 4; regnum < 10; regnum++)                                     \
 308         if (saved_register_mask & (1<<regnum)) {                                \
 309             next_addr -= 4;                                                     \
 310             (frame_saved_regs).regs[regnum] = next_addr;                        \
 311         }                                                                       \
 312     if (read_memory_integer(return_data_save + 4, 4) == 0xed6d7103) {           \
 313         next_addr -= 12;                                                        \
 314         (frame_saved_regs).regs[F0_REGNUM + 7] = next_addr;                     \
 315     }                                                                           \
 316     if (read_memory_integer(return_data_save + 8, 4) == 0xed6d6103) {           \
 317         next_addr -= 12;                                                        \
 318         (frame_saved_regs).regs[F0_REGNUM + 6] = next_addr;                     \
 319     }                                                                           \
 320     if (read_memory_integer(return_data_save + 12, 4) == 0xed6d5103) {          \
 321         next_addr -= 12;                                                        \
 322         (frame_saved_regs).regs[F0_REGNUM + 5] = next_addr;                     \
 323     }                                                                           \
 324     if (read_memory_integer(return_data_save + 16, 4) == 0xed6d4103) {          \
 325         next_addr -= 12;                                                        \
 326         (frame_saved_regs).regs[F0_REGNUM + 4] = next_addr;                     \
 327     }                                                                           \
 328     (frame_saved_regs).regs[SP_REGNUM] = next_addr;                             \
 329     (frame_saved_regs).regs[PC_REGNUM] = frame - 4;                             \
 330     (frame_saved_regs).regs[PS_REGNUM] = frame - 4;                             \
 331     (frame_saved_regs).regs[FP_REGNUM] = frame - 12;                            \
 332 }
 333 \f
 334 /* Things needed for making the inferior call functions.  */
 335
 336 /* Push an empty stack frame, to record the current PC, etc.  */
 337
 338 #define PUSH_DUMMY_FRAME \
 339 {                                                               \
 340     register CORE_ADDR sp = read_register (SP_REGNUM);          \
 341     register int regnum;                                        \
 342     /* opcode for ldmdb fp,{v1-v6,fp,ip,lr,pc}^ */              \
 343     sp = push_word(sp, 0xe92dbf0); /* dummy return_data_save ins */ \
 344     /* push a pointer to the dummy instruction minus 12 */      \
 345     sp = push_word(sp, read_register (SP_REGNUM) - 16);         \
 346     sp = push_word(sp, read_register (PS_REGNUM));              \
 347     sp = push_word(sp, read_register (SP_REGNUM));              \
 348     sp = push_word(sp, read_register (FP_REGNUM));              \
 349     for (regnum = 9; regnum >= 4; regnum --)                    \
 350         sp = push_word(sp, read_register (regnum));             \
 351     write_register (FP_REGNUM, read_register (SP_REGNUM) - 8);  \
 352     write_register (SP_REGNUM, sp); }
 353
 354 /* Discard from the stack the innermost frame, restoring all registers.  */
 355
 356 #define POP_FRAME \
 357 {                                                                       \
 358     register CORE_ADDR fp = read_register (FP_REGNUM);                  \
 359     register unsigned long return_data_save =                           \
 360         read_memory_integer ( (read_memory_integer (fp, 4) &            \
 361                                0x03fffffc)  - 12, 4);                   \
 362     register int regnum;                                                \
 363     write_register (PS_REGNUM, read_memory_integer (fp - 4, 4));        \
 364     write_register (PC_REGNUM, read_register (PS_REGNUM) & 0x03fffffc); \
 365     write_register (SP_REGNUM, read_memory_integer (fp - 8, 4));        \
 366     write_register (FP_REGNUM, read_memory_integer (fp - 12, 4));       \
 367     fp -= 12;                                                           \
 368     for (regnum = 9; regnum >= 4; regnum--)                             \
 369         if (return_data_save & (1<<regnum)) {                           \
 370             fp -= 4;                                                    \
 371             write_register (regnum, read_memory_integer(fp, 4));        \
 372         }                                                               \
 373     flush_cached_frames ();                                             \
 374     set_current_frame (create_new_frame (read_register (FP_REGNUM),     \
 375                                          read_pc ()));                  \
 376 }
 377
 378 /* This sequence of words is the instructions
 379
 380      ldmia      sp!,{a1-a4}
 381      mov        lk,pc
 382      bl         *+8
 383      swi        bkpt_swi
 384
 385    Note this is 16 bytes.  */
 386
 387 #define CALL_DUMMY {0xe8bd000f, 0xe1a0e00f, 0xeb000000, 0xef180000}
 388
 389 #define CALL_DUMMY_START_OFFSET 0  /* Start execution at beginning of dummy */
 390
 391 /* Insert the specified number of args and function address
 392    into a call sequence of the above form stored at DUMMYNAME.  */
 393
 394 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p) \
 395 {                                                                               \
 396     register enum type_code code = TYPE_CODE (type);                            \
 397     register nargs_in_registers, struct_return = 0;                             \
 398     /* fix the load-arguments mask to move the first 4 or less arguments        \
 399        into a1-a4 but make sure the structure return address in a1 is           \
 400        not disturbed if the function is returning a structure */                \
 401     if ((code == TYPE_CODE_STRUCT ||                                            \
 402          code == TYPE_CODE_UNION ||                                             \
 403          code == TYPE_CODE_ARRAY) &&                                            \
 404         TYPE_LENGTH (type) > 4) {                                               \
 405         nargs_in_registers = min(nargs + 1, 4);                                 \
 406         struct_return = 1;                                                      \
 407     } else                                                                      \
 408         nargs_in_registers = min(nargs, 4);                                     \
 409     *(char *) dummyname = (1 << nargs_in_registers) - 1 - struct_return;        \
 410     *(int *)((char *) dummyname + 8) =                                          \
 411         (((fun - (pc + 16)) / 4) & 0x00ffffff) | 0xeb000000; }