gdb/config/ns32k/tm-merlin.h

   1 /* Definitions to target GDB to a merlin under utek 2.1
   2    Copyright 1986, 1987, 1989, 1991, 1993 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 /* Offset from address of function to start of its code.
  23    Zero on most machines.  */
  24
  25 #define FUNCTION_START_OFFSET 0
  26
  27 /* Advance PC across any function entry prologue instructions
  28    to reach some "real" code.  */
  29
  30 #define SKIP_PROLOGUE(pc)                               \
  31 { register int op = read_memory_integer (pc, 1);        \
  32   if (op == 0x82)                                       \
  33     { op = read_memory_integer (pc+2,1);                \
  34       if ((op & 0x80) == 0) pc += 3;                    \
  35       else if ((op & 0xc0) == 0x80) pc += 4;            \
  36       else pc += 6;                                     \
  37     }}
  38
  39 /* Immediately after a function call, return the saved pc.
  40    Can't always go through the frames for this because on some machines
  41    the new frame is not set up until the new function executes
  42    some instructions.  */
  43
  44 #define SAVED_PC_AFTER_CALL(frame) \
  45         read_memory_integer (read_register (SP_REGNUM), 4)
  46
  47 /* Address of end of stack space.  */
  48
  49 #define STACK_END_ADDR (0x800000)
  50
  51 /* Stack grows downward.  */
  52
  53 #define INNER_THAN <
  54
  55 /* Sequence of bytes for breakpoint instruction.  */
  56
  57 #define BREAKPOINT {0xf2}
  58
  59 /* Amount PC must be decremented by after a breakpoint.
  60    This is often the number of bytes in BREAKPOINT
  61    but not always.  */
  62
  63 #define DECR_PC_AFTER_BREAK 0
  64
  65 /* Nonzero if instruction at PC is a return instruction.  */
  66
  67 #define ABOUT_TO_RETURN(pc) (read_memory_integer (pc, 1) == 0x12)
  68
  69 /* Return 1 if P points to an invalid floating point value.  */
  70
  71 #define INVALID_FLOAT(p, len) 0
  72
  73 /* Define this to say that the "svc" insn is followed by
  74    codes in memory saying which kind of system call it is.  */
  75
  76 #define NS32K_SVC_IMMED_OPERANDS
  77
  78 /* Say how long (ordinary) registers are.  This is a piece of bogosity
  79    used in push_word and a few other places; REGISTER_RAW_SIZE is the
  80    real way to know how big a register is.  */
  81
  82 #define REGISTER_SIZE 4
  83
  84 /* Number of machine registers */
  85
  86 #define NUM_REGS                25
  87
  88 #define NUM_GENERAL_REGS        8
  89
  90 /* Initializer for an array of names of registers.
  91    There should be NUM_REGS strings in this initializer.  */
  92
  93 #define REGISTER_NAMES {"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", \
  94                         "pc", "sp", "fp", "ps",                         \
  95                         "fsr",                                          \
  96                         "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", \
  97                         "l0", "l1", "l2", "l3", "l4",                   \
  98                         }
  99
 100 /* Register numbers of various important registers.
 101    Note that some of these values are "real" register numbers,
 102    and correspond to the general registers of the machine,
 103    and some are "phony" register numbers which are too large
 104    to be actual register numbers as far as the user is concerned
 105    but do serve to get the desired values when passed to read_register.  */
 106
 107 #define AP_REGNUM FP_REGNUM
 108 #define FP_REGNUM 10            /* Contains address of executing stack frame */
 109 #define SP_REGNUM 9             /* Contains address of top of stack */
 110 #define PC_REGNUM 8             /* Contains program counter */
 111 #define PS_REGNUM 11            /* Contains processor status */
 112 #define FPS_REGNUM 12           /* Floating point status register */
 113 #define FP0_REGNUM 13           /* Floating point register 0 */
 114 #define LP0_REGNUM 21           /* Double register 0 (same as FP0) */
 115
 116 /* Total amount of space needed to store our copies of the machine's
 117    register state, the array `registers'.  */
 118 #define REGISTER_BYTES ((NUM_REGS - 4) * sizeof (int) + 4 * sizeof (double))
 119
 120 /* Index within `registers' of the first byte of the space for
 121    register N.  */
 122
 123 #define REGISTER_BYTE(N) ((N) >= LP0_REGNUM ? \
 124         LP0_REGNUM * 4 + ((N) - LP0_REGNUM) * 8 : (N) * 4)
 125
 126 /* Number of bytes of storage in the actual machine representation
 127    for register N.  On the 32000, all regs are 4 bytes
 128    except for the doubled floating registers. */
 129
 130 #define REGISTER_RAW_SIZE(N) ((N) >= LP0_REGNUM ? 8 : 4)
 131
 132 /* Number of bytes of storage in the program's representation
 133    for register N.  On the 32000, all regs are 4 bytes
 134    except for the doubled floating registers. */
 135
 136 #define REGISTER_VIRTUAL_SIZE(N) ((N) >= LP0_REGNUM ? 8 : 4)
 137
 138 /* Largest value REGISTER_RAW_SIZE can have.  */
 139
 140 #define MAX_REGISTER_RAW_SIZE 8
 141
 142 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 143
 144 #define MAX_REGISTER_VIRTUAL_SIZE 8
 145
 146 /* Return the GDB type object for the "standard" data type
 147    of data in register N.  */
 148
 149 #define REGISTER_VIRTUAL_TYPE(N) \
 150   ((N) >= FP0_REGNUM ?          \
 151     ((N) >= LP0_REGNUM ?        \
 152      builtin_type_double        \
 153      : builtin_type_float)      \
 154    : builtin_type_int)
 155
 156 /* Store the address of the place in which to copy the structure the
 157    subroutine will return.  This is called from call_function.
 158
 159    On this machine this is a no-op, as gcc doesn't run on it yet.
 160    This calling convention is not used. */
 161
 162 #define STORE_STRUCT_RETURN(ADDR, SP)
 163
 164 /* Extract from an array REGBUF containing the (raw) register state
 165    a function return value of type TYPE, and copy that, in virtual format,
 166    into VALBUF.  */
 167
 168 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 169   memcpy (VALBUF, REGBUF, TYPE_LENGTH (TYPE))
 170
 171 /* Write into appropriate registers a function return value
 172    of type TYPE, given in virtual format.  */
 173
 174 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 175   write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
 176
 177 /* Extract from an array REGBUF containing the (raw) register state
 178    the address in which a function should return its structure value,
 179    as a CORE_ADDR (or an expression that can be used as one).  */
 180
 181 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(int *)(REGBUF))
 182 \f
 183 /* Describe the pointer in each stack frame to the previous stack frame
 184    (its caller).  */
 185
 186 /* FRAME_CHAIN takes a frame's nominal address
 187    and produces the frame's chain-pointer. */
 188
 189 /* In the case of the Merlin, the frame's nominal address is the FP value,
 190    and at that address is saved previous FP value as a 4-byte word.  */
 191
 192 #define FRAME_CHAIN(thisframe)  \
 193   (!inside_entry_file ((thisframe)->pc) ? \
 194    read_memory_integer ((thisframe)->frame, 4) :\
 195    0)
 196
 197 /* Define other aspects of the stack frame.  */
 198
 199 #define FRAME_SAVED_PC(FRAME) (read_memory_integer ((FRAME)->frame + 4, 4))
 200
 201 /* compute base of arguments */
 202 #define FRAME_ARGS_ADDRESS(fi) ((fi)->frame)
 203
 204 #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
 205
 206 /* Return number of args passed to a frame.
 207    Can return -1, meaning no way to tell.  */
 208
 209 #define FRAME_NUM_ARGS(numargs, fi)                     \
 210 { CORE_ADDR pc;                                         \
 211   int insn;                                             \
 212   int addr_mode;                                        \
 213   int width;                                            \
 214                                                         \
 215   pc = FRAME_SAVED_PC (fi);                             \
 216   insn = read_memory_integer (pc,2);                    \
 217   addr_mode = (insn >> 11) & 0x1f;                      \
 218   insn = insn & 0x7ff;                                  \
 219   if ((insn & 0x7fc) == 0x57c                           \
 220       && addr_mode == 0x14) /* immediate */             \
 221     { if (insn == 0x57c) /* adjspb */                   \
 222         width = 1;                                      \
 223       else if (insn == 0x57d) /* adjspw */              \
 224         width = 2;                                      \
 225       else if (insn == 0x57f) /* adjspd */              \
 226         width = 4;                                      \
 227       numargs = read_memory_integer (pc+2,width);       \
 228       if (width > 1)                                    \
 229         flip_bytes (&numargs, width);                   \
 230       numargs = - sign_extend (numargs, width*8) / 4; } \
 231   else numargs = -1;                                    \
 232 }
 233
 234 /* Return number of bytes at start of arglist that are not really args.  */
 235
 236 #define FRAME_ARGS_SKIP 8
 237
 238 /* Put here the code to store, into a struct frame_saved_regs,
 239    the addresses of the saved registers of frame described by FRAME_INFO.
 240    This includes special registers such as pc and fp saved in special
 241    ways in the stack frame.  sp is even more special:
 242    the address we return for it IS the sp for the next frame.  */
 243
 244 #define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) \
 245 { int regmask,regnum;                                           \
 246   int localcount;                                               \
 247   CORE_ADDR enter_addr;                                         \
 248   CORE_ADDR next_addr;                                          \
 249                                                                 \
 250   enter_addr = get_pc_function_start ((frame_info)->pc);        \
 251   regmask = read_memory_integer (enter_addr+1, 1);              \
 252   localcount = ns32k_localcount (enter_addr);                   \
 253   next_addr = (frame_info)->frame + localcount;                 \
 254   for (regnum = 0; regnum < 8; regnum++, regmask >>= 1)         \
 255     (frame_saved_regs).regs[regnum]                             \
 256       = (regmask & 1) ? (next_addr -= 4) : 0;                   \
 257   (frame_saved_regs).regs[SP_REGNUM] = (frame_info)->frame + 4; \
 258   (frame_saved_regs).regs[PC_REGNUM] = (frame_info)->frame + 4; \
 259   (frame_saved_regs).regs[FP_REGNUM]                            \
 260      = read_memory_integer ((frame_info)->frame, 4); }
 261
 262 \f
 263 /* Things needed for making the inferior call functions.  */
 264
 265 /* Push an empty stack frame, to record the current PC, etc.  */
 266
 267 #define PUSH_DUMMY_FRAME \
 268 { register CORE_ADDR sp = read_register (SP_REGNUM);    \
 269   register int regnum;                                  \
 270   sp = push_word (sp, read_register (PC_REGNUM));       \
 271   sp = push_word (sp, read_register (FP_REGNUM));       \
 272   write_register (FP_REGNUM, sp);                       \
 273   for (regnum = 0; regnum < 8; regnum++)                \
 274     sp = push_word (sp, read_register (regnum));        \
 275   write_register (SP_REGNUM, sp);                       \
 276 }
 277
 278 /* Discard from the stack the innermost frame, restoring all registers.  */
 279
 280 #define POP_FRAME  \
 281 { register FRAME frame = get_current_frame ();                   \
 282   register CORE_ADDR fp;                                         \
 283   register int regnum;                                           \
 284   struct frame_saved_regs fsr;                                   \
 285   struct frame_info *fi;                                                 \
 286   fi = get_frame_info (frame);                                   \
 287   fp = fi->frame;                                                \
 288   get_frame_saved_regs (fi, &fsr);                               \
 289   for (regnum = 0; regnum < 8; regnum++)                         \
 290     if (fsr.regs[regnum])                                        \
 291       write_register (regnum, read_memory_integer (fsr.regs[regnum], 4)); \
 292   write_register (FP_REGNUM, read_memory_integer (fp, 4));       \
 293   write_register (PC_REGNUM, read_memory_integer (fp + 4, 4));   \
 294   write_register (SP_REGNUM, fp + 8);                            \
 295   flush_cached_frames ();                                        \
 296   set_current_frame (create_new_frame (read_register (FP_REGNUM),\
 297                                        read_pc ()));             \
 298 }
 299
 300 /* This sequence of words is the instructions
 301      enter      0xff,0          82 ff 00
 302      jsr        @0x00010203     7f ae c0 01 02 03
 303      adjspd     0x69696969      7f a5 01 02 03 04
 304      bpt                        f2
 305    Note this is 16 bytes.  */
 306
 307 #define CALL_DUMMY { 0x7f00ff82, 0x0201c0ae, 0x01a57f03, 0xf2040302 }
 308
 309 #define CALL_DUMMY_START_OFFSET 3
 310 #define CALL_DUMMY_LENGTH       16
 311 #define CALL_DUMMY_ADDR         5
 312 #define CALL_DUMMY_NARGS        11
 313
 314 /* Insert the specified number of args and function address
 315    into a call sequence of the above form stored at DUMMYNAME.  */
 316
 317 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p)            \
 318 { int flipped = fun | 0xc0000000;                               \
 319   flip_bytes (&flipped, 4);                                     \
 320   *((int *) (((char *) dummyname)+CALL_DUMMY_ADDR)) = flipped;  \
 321   flipped = - nargs * 4;                                        \
 322   flip_bytes (&flipped, 4);                                     \
 323   *((int *) (((char *) dummyname)+CALL_DUMMY_NARGS)) = flipped; \
 324 }