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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 /* Define this to say that the "svc" insn is followed by
  70    codes in memory saying which kind of system call it is.  */
  71
  72 #define NS32K_SVC_IMMED_OPERANDS
  73
  74 /* Say how long (ordinary) registers are.  This is a piece of bogosity
  75    used in push_word and a few other places; REGISTER_RAW_SIZE is the
  76    real way to know how big a register is.  */
  77
  78 #define REGISTER_SIZE 4
  79
  80 /* Number of machine registers */
  81
  82 #define NUM_REGS                25
  83
  84 #define NUM_GENERAL_REGS        8
  85
  86 /* Initializer for an array of names of registers.
  87    There should be NUM_REGS strings in this initializer.  */
  88
  89 #define REGISTER_NAMES {"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", \
  90                         "pc", "sp", "fp", "ps",                         \
  91                         "fsr",                                          \
  92                         "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", \
  93                         "l0", "l1", "l2", "l3", "l4",                   \
  94                         }
  95
  96 /* Register numbers of various important registers.
  97    Note that some of these values are "real" register numbers,
  98    and correspond to the general registers of the machine,
  99    and some are "phony" register numbers which are too large
 100    to be actual register numbers as far as the user is concerned
 101    but do serve to get the desired values when passed to read_register.  */
 102
 103 #define AP_REGNUM FP_REGNUM
 104 #define FP_REGNUM 10            /* Contains address of executing stack frame */
 105 #define SP_REGNUM 9             /* Contains address of top of stack */
 106 #define PC_REGNUM 8             /* Contains program counter */
 107 #define PS_REGNUM 11            /* Contains processor status */
 108 #define FPS_REGNUM 12           /* Floating point status register */
 109 #define FP0_REGNUM 13           /* Floating point register 0 */
 110 #define LP0_REGNUM 21           /* Double register 0 (same as FP0) */
 111
 112 /* Total amount of space needed to store our copies of the machine's
 113    register state, the array `registers'.  */
 114 #define REGISTER_BYTES ((NUM_REGS - 4) * sizeof (int) + 4 * sizeof (double))
 115
 116 /* Index within `registers' of the first byte of the space for
 117    register N.  */
 118
 119 #define REGISTER_BYTE(N) ((N) >= LP0_REGNUM ? \
 120         LP0_REGNUM * 4 + ((N) - LP0_REGNUM) * 8 : (N) * 4)
 121
 122 /* Number of bytes of storage in the actual machine representation
 123    for register N.  On the 32000, all regs are 4 bytes
 124    except for the doubled floating registers. */
 125
 126 #define REGISTER_RAW_SIZE(N) ((N) >= LP0_REGNUM ? 8 : 4)
 127
 128 /* Number of bytes of storage in the program's representation
 129    for register N.  On the 32000, all regs are 4 bytes
 130    except for the doubled floating registers. */
 131
 132 #define REGISTER_VIRTUAL_SIZE(N) ((N) >= LP0_REGNUM ? 8 : 4)
 133
 134 /* Largest value REGISTER_RAW_SIZE can have.  */
 135
 136 #define MAX_REGISTER_RAW_SIZE 8
 137
 138 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 139
 140 #define MAX_REGISTER_VIRTUAL_SIZE 8
 141
 142 /* Return the GDB type object for the "standard" data type
 143    of data in register N.  */
 144
 145 #define REGISTER_VIRTUAL_TYPE(N) \
 146   ((N) >= FP0_REGNUM ?          \
 147     ((N) >= LP0_REGNUM ?        \
 148      builtin_type_double        \
 149      : builtin_type_float)      \
 150    : builtin_type_int)
 151
 152 /* Store the address of the place in which to copy the structure the
 153    subroutine will return.  This is called from call_function.
 154
 155    On this machine this is a no-op, as gcc doesn't run on it yet.
 156    This calling convention is not used. */
 157
 158 #define STORE_STRUCT_RETURN(ADDR, SP)
 159
 160 /* Extract from an array REGBUF containing the (raw) register state
 161    a function return value of type TYPE, and copy that, in virtual format,
 162    into VALBUF.  */
 163
 164 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 165   memcpy (VALBUF, REGBUF, TYPE_LENGTH (TYPE))
 166
 167 /* Write into appropriate registers a function return value
 168    of type TYPE, given in virtual format.  */
 169
 170 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 171   write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
 172
 173 /* Extract from an array REGBUF containing the (raw) register state
 174    the address in which a function should return its structure value,
 175    as a CORE_ADDR (or an expression that can be used as one).  */
 176
 177 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(int *)(REGBUF))
 178 \f
 179 /* Describe the pointer in each stack frame to the previous stack frame
 180    (its caller).  */
 181
 182 /* FRAME_CHAIN takes a frame's nominal address
 183    and produces the frame's chain-pointer. */
 184
 185 /* In the case of the Merlin, the frame's nominal address is the FP value,
 186    and at that address is saved previous FP value as a 4-byte word.  */
 187
 188 #define FRAME_CHAIN(thisframe)  \
 189   (!inside_entry_file ((thisframe)->pc) ? \
 190    read_memory_integer ((thisframe)->frame, 4) :\
 191    0)
 192
 193 /* Define other aspects of the stack frame.  */
 194
 195 #define FRAME_SAVED_PC(FRAME) (read_memory_integer ((FRAME)->frame + 4, 4))
 196
 197 /* compute base of arguments */
 198 #define FRAME_ARGS_ADDRESS(fi) ((fi)->frame)
 199
 200 #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
 201
 202 /* Return number of args passed to a frame.
 203    Can return -1, meaning no way to tell.  */
 204
 205 #define FRAME_NUM_ARGS(numargs, fi)                     \
 206 { CORE_ADDR pc;                                         \
 207   int insn;                                             \
 208   int addr_mode;                                        \
 209   int width;                                            \
 210                                                         \
 211   pc = FRAME_SAVED_PC (fi);                             \
 212   insn = read_memory_integer (pc,2);                    \
 213   addr_mode = (insn >> 11) & 0x1f;                      \
 214   insn = insn & 0x7ff;                                  \
 215   if ((insn & 0x7fc) == 0x57c                           \
 216       && addr_mode == 0x14) /* immediate */             \
 217     { if (insn == 0x57c) /* adjspb */                   \
 218         width = 1;                                      \
 219       else if (insn == 0x57d) /* adjspw */              \
 220         width = 2;                                      \
 221       else if (insn == 0x57f) /* adjspd */              \
 222         width = 4;                                      \
 223       numargs = read_memory_integer (pc+2,width);       \
 224       if (width > 1)                                    \
 225         flip_bytes (&numargs, width);                   \
 226       numargs = - sign_extend (numargs, width*8) / 4; } \
 227   else numargs = -1;                                    \
 228 }
 229
 230 /* Return number of bytes at start of arglist that are not really args.  */
 231
 232 #define FRAME_ARGS_SKIP 8
 233
 234 /* Put here the code to store, into a struct frame_saved_regs,
 235    the addresses of the saved registers of frame described by FRAME_INFO.
 236    This includes special registers such as pc and fp saved in special
 237    ways in the stack frame.  sp is even more special:
 238    the address we return for it IS the sp for the next frame.  */
 239
 240 #define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) \
 241 { int regmask,regnum;                                           \
 242   int localcount;                                               \
 243   CORE_ADDR enter_addr;                                         \
 244   CORE_ADDR next_addr;                                          \
 245                                                                 \
 246   enter_addr = get_pc_function_start ((frame_info)->pc);        \
 247   regmask = read_memory_integer (enter_addr+1, 1);              \
 248   localcount = ns32k_localcount (enter_addr);                   \
 249   next_addr = (frame_info)->frame + localcount;                 \
 250   for (regnum = 0; regnum < 8; regnum++, regmask >>= 1)         \
 251     (frame_saved_regs).regs[regnum]                             \
 252       = (regmask & 1) ? (next_addr -= 4) : 0;                   \
 253   (frame_saved_regs).regs[SP_REGNUM] = (frame_info)->frame + 4; \
 254   (frame_saved_regs).regs[PC_REGNUM] = (frame_info)->frame + 4; \
 255   (frame_saved_regs).regs[FP_REGNUM]                            \
 256      = read_memory_integer ((frame_info)->frame, 4); }
 257
 258 \f
 259 /* Things needed for making the inferior call functions.  */
 260
 261 /* Push an empty stack frame, to record the current PC, etc.  */
 262
 263 #define PUSH_DUMMY_FRAME \
 264 { register CORE_ADDR sp = read_register (SP_REGNUM);    \
 265   register int regnum;                                  \
 266   sp = push_word (sp, read_register (PC_REGNUM));       \
 267   sp = push_word (sp, read_register (FP_REGNUM));       \
 268   write_register (FP_REGNUM, sp);                       \
 269   for (regnum = 0; regnum < 8; regnum++)                \
 270     sp = push_word (sp, read_register (regnum));        \
 271   write_register (SP_REGNUM, sp);                       \
 272 }
 273
 274 /* Discard from the stack the innermost frame, restoring all registers.  */
 275
 276 #define POP_FRAME  \
 277 { register struct frame_info *frame = get_current_frame ();      \
 278   register CORE_ADDR fp;                                         \
 279   register int regnum;                                           \
 280   struct frame_saved_regs fsr;                                   \
 281   struct frame_info *fi;                                                 \
 282   fp = frame->frame;                                             \
 283   get_frame_saved_regs (frame, &fsr);                            \
 284   for (regnum = 0; regnum < 8; regnum++)                         \
 285     if (fsr.regs[regnum])                                        \
 286       write_register (regnum, read_memory_integer (fsr.regs[regnum], 4)); \
 287   write_register (FP_REGNUM, read_memory_integer (fp, 4));       \
 288   write_register (PC_REGNUM, read_memory_integer (fp + 4, 4));   \
 289   write_register (SP_REGNUM, fp + 8);                            \
 290   flush_cached_frames ();                                        \
 291 }
 292
 293 /* This sequence of words is the instructions
 294      enter      0xff,0          82 ff 00
 295      jsr        @0x00010203     7f ae c0 01 02 03
 296      adjspd     0x69696969      7f a5 01 02 03 04
 297      bpt                        f2
 298    Note this is 16 bytes.  */
 299
 300 #define CALL_DUMMY { 0x7f00ff82, 0x0201c0ae, 0x01a57f03, 0xf2040302 }
 301
 302 #define CALL_DUMMY_START_OFFSET 3
 303 #define CALL_DUMMY_LENGTH       16
 304 #define CALL_DUMMY_ADDR         5
 305 #define CALL_DUMMY_NARGS        11
 306
 307 /* Insert the specified number of args and function address
 308    into a call sequence of the above form stored at DUMMYNAME.  */
 309
 310 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p)            \
 311 { int flipped = fun | 0xc0000000;                               \
 312   flip_bytes (&flipped, 4);                                     \
 313   *((int *) (((char *) dummyname)+CALL_DUMMY_ADDR)) = flipped;  \
 314   flipped = - nargs * 4;                                        \
 315   flip_bytes (&flipped, 4);                                     \
 316   *((int *) (((char *) dummyname)+CALL_DUMMY_NARGS)) = flipped; \
 317 }