gdb/tm-rs6000.h

   1 /* Parameters for target execution on an RS6000, for GDB, the GNU debugger.
   2    Copyright (C) 1986, 1987, 1989, 1991 Free Software Foundation, Inc.
   3    Contributed by IBM Corporation.
   4
   5 This file is part of GDB.
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2 of the License, or
  10 (at your option) any later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program; if not, write to the Free Software
  19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21
  22 /* A successful ptrace(continue) might return errno != 0 in this particular port
  23    of rs6000. I am not sure why. We will use this kludge and ignore it until
  24    we figure out the real problem. */
  25
  26 #define AIX_BUGGY_PTRACE_CONTINUE       \
  27 { \
  28   int ret = ptrace (PT_CONTINUE, inferior_pid, \
  29                     (PTRACE_ARG3_TYPE) 1, signal, 0); \
  30   if (errno) { \
  31 /*    printf ("ret: %d, errno: %d, signal: %d\n", ret, errno, signal); */ \
  32     errno = 0; } \
  33 }
  34
  35 extern int      symtab_relocated;
  36
  37 /* Minimum possible text address in AIX */
  38
  39 #define TEXT_SEGMENT_BASE       0x10000000
  40
  41
  42 /* text addresses in a core file does not necessarily match to symbol table,
  43    if symbol table relocation wasn't done yet. */
  44
  45 #define CORE_NEEDS_RELOCATION(PC)       \
  46   if (!symtab_relocated && !inferior_pid && (PC) >  TEXT_SEGMENT_BASE)  \
  47     (PC) -= ( TEXT_SEGMENT_BASE + text_adjustment (exec_bfd));
  48
  49 /* Load segment of a given pc value. */
  50
  51 #define PC_LOAD_SEGMENT(PC)     pc_load_segment_name(PC)
  52
  53
  54 /* Conversion between a register number in stab string to actual register num. */
  55
  56 #define STAB_REG_TO_REGNUM(value)       (value)
  57
  58 /* return true if a given `pc' value is in `call dummy' function. */
  59
  60 #define PC_IN_CALL_DUMMY(STOP_PC, STOP_SP, STOP_FRAME_ADDR)     \
  61         (STOP_SP < STOP_PC && STOP_PC < STACK_END_ADDR)
  62
  63 /* For each symtab, we keep track of which BFD it came from.  */
  64 #define EXTRA_SYMTAB_INFO       \
  65         unsigned    nonreloc:1;         /* TRUE if non relocatable */
  66
  67 #define INIT_EXTRA_SYMTAB_INFO(symtab)  \
  68         symtab->nonreloc = 0;           \
  69
  70 extern unsigned int text_start, data_start;
  71 extern int inferior_pid;
  72 extern char *corefile;
  73
  74 /* setpgrp() messes up controling terminal. The other version of it
  75    requires libbsd.a. */
  76 #define setpgrp(XX,YY)          setpgid (XX, YY)
  77
  78 /* We are missing register descriptions in the system header files. Sigh! */
  79
  80 struct regs {
  81         int     gregs [32];             /* general purpose registers */
  82         int     pc;                     /* program conter       */
  83         int     ps;                     /* processor status, or machine state */
  84 };
  85
  86 struct fp_status {
  87         double  fpregs [32];            /* floating GP registers */
  88 };
  89
  90
  91 /* To be used by function_frame_info. */
  92
  93 struct aix_framedata {
  94   int   offset;                         /* # of bytes in gpr's and fpr's are saved */
  95   int   saved_gpr;                      /* smallest # of saved gpr */
  96   int   saved_fpr;                      /* smallest # of saved fpr */
  97   int   alloca_reg;                     /* alloca register number (frame ptr) */
  98   char  frameless;                      /* true if frameless functions. */
  99 };
 100
 101 void
 102 function_frame_info PARAMS ((CORE_ADDR, struct aix_framedata *));
 103
 104 /* Define the byte order of the machine.  */
 105
 106 #define TARGET_BYTE_ORDER       BIG_ENDIAN
 107
 108 /* Define this if the C compiler puts an underscore at the front
 109    of external names before giving them to the linker.  */
 110
 111 #undef NAMES_HAVE_UNDERSCORE
 112
 113 /* AIX's assembler doesn't grok dollar signs in identifiers.
 114    So we use dots instead.  This item must be coordinated with G++. */
 115 #undef CPLUS_MARKER
 116 #define CPLUS_MARKER '.'
 117
 118 /* Offset from address of function to start of its code.
 119    Zero on most machines.  */
 120
 121 #define FUNCTION_START_OFFSET 0
 122
 123 /* Advance PC across any function entry prologue instructions
 124    to reach some "real" code.  */
 125
 126 #define SKIP_PROLOGUE(pc)       pc = skip_prologue (pc)
 127
 128 /* If PC is in some function-call trampoline code, return the PC
 129    where the function itself actually starts.  If not, return NULL.  */
 130
 131 #define SKIP_TRAMPOLINE_CODE(pc)        skip_trampoline_code (pc)
 132
 133 /* When a child process is just starting, we sneak in and relocate
 134    the symbol table (and other stuff) after the dynamic linker has
 135    figured out where they go. But we want to do this relocation just
 136    once. */
 137
 138 extern int loadinfotextindex;
 139
 140 #define SOLIB_CREATE_INFERIOR_HOOK(PID) \
 141   do {                                  \
 142     if (loadinfotextindex == 0) \
 143         xcoff_relocate_symtab (PID);    \
 144   } while (0)
 145
 146
 147 /* Number of trap signals we need to skip over, once the inferior process
 148    starts running. */
 149
 150 #define START_INFERIOR_TRAPS_EXPECTED   2
 151
 152 /* AIX might return a sigtrap, with a "stop after load" status. It should
 153    be ignored by gdb, shouldn't be mixed up with breakpoint traps. */
 154
 155 /* Another little glitch  in AIX is signal 0. I have no idea why wait(2)
 156    returns with this status word. It looks harmless. */
 157
 158 #define SIGTRAP_STOP_AFTER_LOAD(W)      \
 159  if ( (W) == 0x57c || (W) == 0x7f) {    \
 160    if ((W)==0x57c && breakpoints_inserted) {    \
 161      mark_breakpoints_out ();           \
 162      insert_breakpoints ();             \
 163      insert_step_breakpoint ();         \
 164    }                                    \
 165    resume (0, 0);                       \
 166    continue;                            \
 167  }
 168
 169 /* In xcoff, we cannot process line numbers when we see them. This is
 170    mainly because we don't know the boundaries of the include files. So,
 171    we postpone that, and then enter and sort(?) the whole line table at
 172    once, when we are closing the current symbol table in end_symtab(). */
 173
 174 #define PROCESS_LINENUMBER_HOOK()       aix_process_linenos ()
 175
 176
 177 /* When a target process or core-file has been attached, we sneak in
 178    and figure out where the shared libraries have got to. In case there
 179    is no inferior_process exists (e.g. bringing up a core file), we can't
 180    attemtp to relocate symbol table, since we don't have information about
 181    load segments. */
 182
 183 #define SOLIB_ADD(a, b, c)      \
 184    if (inferior_pid)    xcoff_relocate_symtab (inferior_pid)
 185
 186 /* Immediately after a function call, return the saved pc.
 187    Can't go through the frames for this because on some machines
 188    the new frame is not set up until the new function executes
 189    some instructions.  */
 190
 191 #define SAVED_PC_AFTER_CALL(frame)      \
 192         (register_valid [LR_REGNUM] ?   \
 193           (*(int*)&registers[REGISTER_BYTE (LR_REGNUM)]) :      \
 194           read_register (LR_REGNUM))
 195
 196 /*#define SAVED_PC_AFTER_CALL(frame)    saved_pc_after_call(frame) */
 197
 198
 199 /* Address of end of stack space.  */
 200
 201 #define STACK_END_ADDR 0x2ff80000
 202
 203 /* Stack grows downward.  */
 204
 205 #define INNER_THAN <
 206
 207 #if 0
 208 /* No, we shouldn't use this. push_arguments() should leave stack in a
 209    proper alignment! */
 210 /* Stack has strict alignment. */
 211
 212 #define STACK_ALIGN(ADDR)       (((ADDR)+7)&-8)
 213 #endif
 214
 215 /* This is how argumets pushed onto stack or passed in registers. */
 216
 217 #define PUSH_ARGUMENTS(nargs, args, sp, struct_return, struct_addr) \
 218   sp = push_arguments(nargs, args, sp, struct_return, struct_addr)
 219
 220 /* Sequence of bytes for breakpoint instruction.  */
 221
 222 #define BREAKPOINT {0x7d, 0x82, 0x10, 0x08}
 223
 224 /* Amount PC must be decremented by after a breakpoint.
 225    This is often the number of bytes in BREAKPOINT
 226    but not always.  */
 227
 228 #define DECR_PC_AFTER_BREAK 0
 229
 230 /* Nonzero if instruction at PC is a return instruction.  */
 231 /* Allow any of the return instructions, including a trapv and a return
 232    from interrupt.  */
 233
 234 #define ABOUT_TO_RETURN(pc)  \
 235    ((read_memory_integer (pc, 4) & 0xfe8007ff) == 0x4e800020)
 236
 237 /* Return 1 if P points to an invalid floating point value.  */
 238
 239 #define INVALID_FLOAT(p, len) 0   /* Just a first guess; not checked */
 240
 241 /* Largest integer type */
 242
 243 #define LONGEST long
 244
 245 /* Name of the builtin type for the LONGEST type above. */
 246
 247 #define BUILTIN_TYPE_LONGEST builtin_type_long
 248
 249 /* Say how long (ordinary) registers are.  */
 250
 251 #define REGISTER_TYPE long
 252
 253 /* Number of machine registers */
 254
 255 #define NUM_REGS 71
 256
 257 /* Initializer for an array of names of registers.
 258    There should be NUM_REGS strings in this initializer.  */
 259
 260 #define REGISTER_NAMES  \
 261  {"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",  \
 262   "r8", "r9", "r10","r11","r12","r13","r14","r15", \
 263   "r16","r17","r18","r19","r20","r21","r22","r23", \
 264   "r24","r25","r26","r27","r28","r29","r30","r31", \
 265   "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",  \
 266   "f8", "f9", "f10","f11","f12","f13","f14","f15", \
 267   "f16","f17","f18","f19","f20","f21","f22","f23", \
 268   "f24","f25","f26","f27","f28","f29","f30","f31", \
 269   "pc", "ps", "cnd", "lr", "cnt", "xer", "mq" }
 270
 271 /* Register numbers of various important registers.
 272    Note that some of these values are "real" register numbers,
 273    and correspond to the general registers of the machine,
 274    and some are "phony" register numbers which are too large
 275    to be actual register numbers as far as the user is concerned
 276    but do serve to get the desired values when passed to read_register.  */
 277
 278 #define FP_REGNUM 1             /* Contains address of executing stack frame */
 279 #define SP_REGNUM 1             /* Contains address of top of stack */
 280 #define TOC_REGNUM 2            /* TOC register */
 281 #define FP0_REGNUM 32           /* Floating point register 0 */
 282 #define GP0_REGNUM 0            /* GPR register 0 */
 283 #define FP0_REGNUM 32           /* FPR (Floating point) register 0 */
 284 #define FPLAST_REGNUM 63        /* Last floating point register */
 285
 286 /* Special purpose registers... */
 287 /* P.S. keep these in the same order as in /usr/mstsave.h `mstsave' structure, for
 288    easier processing */
 289
 290 #define PC_REGNUM 64            /* Program counter (instruction address %iar) */
 291 #define PS_REGNUM 65            /* Processor (or machine) status (%msr) */
 292 #define CR_REGNUM 66            /* Condition register */
 293 #define LR_REGNUM 67            /* Link register */
 294 #define CTR_REGNUM 68           /* Count register */
 295 #define XER_REGNUM 69           /* Fixed point exception registers */
 296 #define MQ_REGNUM 70            /* Multiply/quotient register */
 297
 298 #define FIRST_SP_REGNUM 64      /* first special register number */
 299 #define LAST_SP_REGNUM  70      /* last special register number */
 300
 301 /* Total amount of space needed to store our copies of the machine's
 302    register state, the array `registers'.
 303
 304         32 4-byte gpr's
 305         32 8-byte fpr's
 306         7  4-byte special purpose registers,
 307
 308    total 416 bytes. Keep some extra space for now, in case to add more. */
 309
 310 #define REGISTER_BYTES 420
 311
 312
 313 /* Index within `registers' of the first byte of the space for
 314    register N.  */
 315
 316 #define REGISTER_BYTE(N)  \
 317  (                                                              \
 318   ((N) > FPLAST_REGNUM) ? ((((N) - FPLAST_REGNUM -1) * 4) + 384)\
 319   :((N) >= FP0_REGNUM) ? ((((N) - FP0_REGNUM) * 8) + 128)       \
 320   :((N) * 4) )
 321
 322 /* Number of bytes of storage in the actual machine representation
 323    for register N. */
 324 /* Note that the unsigned cast here forces the result of the
 325    subtractiion to very high positive values if N < FP0_REGNUM */
 326
 327 #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
 328
 329 /* Number of bytes of storage in the program's representation
 330    for register N.  On the RS6000, all regs are 4 bytes
 331    except the floating point regs which are 8-byte doubles.  */
 332
 333 #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
 334
 335 /* Largest value REGISTER_RAW_SIZE can have.  */
 336
 337 #define MAX_REGISTER_RAW_SIZE 8
 338
 339 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 340
 341 #define MAX_REGISTER_VIRTUAL_SIZE 8
 342
 343 /* convert a dbx stab register number (from `r' declaration) to a gdb REGNUM */
 344
 345 #define STAB_REG_TO_REGNUM(value)       (value)
 346
 347 /* Nonzero if register N requires conversion
 348    from raw format to virtual format.  */
 349
 350 #define REGISTER_CONVERTIBLE(N) ((N) >= FP0_REGNUM && (N) <= FPLAST_REGNUM)
 351
 352 /* Convert data from raw format for register REGNUM
 353    to virtual format for register REGNUM.  */
 354
 355 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO)     \
 356    bcopy ((FROM), (TO), REGISTER_RAW_SIZE (REGNUM))
 357
 358 /* Convert data from virtual format for register REGNUM
 359    to raw format for register REGNUM.  */
 360
 361 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
 362    bcopy ((FROM), (TO), REGISTER_RAW_SIZE (REGNUM))
 363
 364 /* Return the GDB type object for the "standard" data type
 365    of data in register N.  */
 366
 367 #define REGISTER_VIRTUAL_TYPE(N) \
 368  (((unsigned)(N) - FP0_REGNUM) < 32 ? builtin_type_double : builtin_type_int)
 369
 370 /* Store the address of the place in which to copy the structure the
 371    subroutine will return.  This is called from call_function. */
 372 /* in RS6000, struct return addresses are passed as an extra parameter in r3.
 373    In function return, callee is not responsible of returning this address back.
 374    Since gdb needs to find it, we will store in a designated variable
 375    `rs6000_struct_return_address'. */
 376
 377 extern unsigned int rs6000_struct_return_address;
 378
 379 #define STORE_STRUCT_RETURN(ADDR, SP)   \
 380   { write_register (3, (ADDR));         \
 381     rs6000_struct_return_address = (unsigned int)(ADDR); }
 382
 383 /* Extract from an array REGBUF containing the (raw) register state
 384    a function return value of type TYPE, and copy that, in virtual format,
 385    into VALBUF.  */
 386
 387 /* #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 388   bcopy (REGBUF, VALBUF, TYPE_LENGTH (TYPE)) */
 389
 390 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 391   extract_return_value(TYPE,REGBUF,VALBUF)
 392
 393 /* Write into appropriate registers a function return value
 394    of type TYPE, given in virtual format.  */
 395
 396 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 397   {                                                                     \
 398     if (TYPE_CODE (TYPE) == TYPE_CODE_FLT)                              \
 399                                                                         \
 400      /* Floating point values are returned starting from FPR1 and up.   \
 401         Say a double_double_double type could be returned in            \
 402         FPR1/FPR2/FPR3 triple. */                                       \
 403                                                                         \
 404       write_register_bytes (REGISTER_BYTE (FP0_REGNUM+1), (VALBUF),     \
 405                                                 TYPE_LENGTH (TYPE));    \
 406     else                                                                \
 407       /* Everything else is returned in GPR3 and up. */                 \
 408       write_register_bytes (REGISTER_BYTE (GP0_REGNUM+3), (VALBUF),     \
 409                                                 TYPE_LENGTH (TYPE));    \
 410   }
 411
 412
 413 /* Extract from an array REGBUF containing the (raw) register state
 414    the address in which a function should return its structure value,
 415    as a CORE_ADDR (or an expression that can be used as one).  */
 416
 417 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF)    rs6000_struct_return_address
 418 \f
 419 /* Describe the pointer in each stack frame to the previous stack frame
 420    (its caller).  */
 421
 422 /* FRAME_CHAIN takes a frame's nominal address
 423    and produces the frame's chain-pointer. */
 424
 425 /* In the case of the RS6000, the frame's nominal address
 426    is the address of a 4-byte word containing the calling frame's address.  */
 427
 428 #define FRAME_CHAIN(thisframe)  \
 429   (!inside_entry_file ((thisframe)->pc) ?       \
 430    read_memory_integer ((thisframe)->frame, 4) :\
 431    0)
 432
 433 /* Define other aspects of the stack frame.  */
 434
 435 /* A macro that tells us whether the function invocation represented
 436    by FI does not have a frame on the stack associated with it.  If it
 437    does not, FRAMELESS is set to 1, else 0.  */
 438
 439 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
 440         FRAMELESS = frameless_function_invocation (FI)
 441
 442 /* Functions calling alloca() change the value of the stack pointer. We
 443    need to use initial stack pointer (which is saved in r31 by gcc) in
 444    such cases. If a compiler emits traceback table, then we should use the
 445    alloca register specified in traceback table. FIXME. */
 446 /* Also, it is a good idea to cache information about frame's saved registers
 447    in the frame structure to speed things up. See tm-m88k.h. FIXME. */
 448
 449 #define EXTRA_FRAME_INFO        \
 450         CORE_ADDR initial_sp;                   /* initial stack pointer. */ \
 451         struct frame_saved_regs *cache_fsr;     /* saved registers        */
 452
 453 /* Frameless function invocation in IBM RS/6000 is half-done. It perfectly
 454    sets up a new frame, e.g. a new frame (in fact stack) pointer, etc, but it
 455    doesn't save the %pc. In the following, even though it is considered a
 456    frameless invocation, we still need to walk one frame up. */
 457
 458 #define INIT_EXTRA_FRAME_INFO(fromleaf, fi)     \
 459         fi->initial_sp = 0;             \
 460         fi->cache_fsr = 0;
 461
 462 #define FRAME_SAVED_PC(FRAME)           \
 463         read_memory_integer (read_memory_integer ((FRAME)->frame, 4)+8, 4)
 464
 465 #define FRAME_ARGS_ADDRESS(FI)  \
 466   (((struct frame_info*)(FI))->initial_sp ?             \
 467         ((struct frame_info*)(FI))->initial_sp :        \
 468         frame_initial_stack_address (FI))
 469
 470 #define FRAME_LOCALS_ADDRESS(FI)        FRAME_ARGS_ADDRESS(FI)
 471
 472
 473 /* Set VAL to the number of args passed to frame described by FI.
 474    Can set VAL to -1, meaning no way to tell.  */
 475
 476 /* We can't tell how many args there are
 477    now that the C compiler delays popping them.  */
 478
 479 #define FRAME_NUM_ARGS(val,fi) (val = -1)
 480
 481 /* Return number of bytes at start of arglist that are not really args.  */
 482
 483 #define FRAME_ARGS_SKIP 8       /* Not sure on this. FIXMEmgo */
 484
 485 /* Put here the code to store, into a struct frame_saved_regs,
 486    the addresses of the saved registers of frame described by FRAME_INFO.
 487    This includes special registers such as pc and fp saved in special
 488    ways in the stack frame.  sp is even more special:
 489    the address we return for it IS the sp for the next frame.  */
 490 /* In the following implementation for RS6000, we did *not* save sp. I am
 491    not sure if it will be needed. The following macro takes care of gpr's
 492    and fpr's only. */
 493
 494 #define FRAME_FIND_SAVED_REGS(FRAME_INFO, FRAME_SAVED_REGS)             \
 495 {                                                                       \
 496   int ii;                                                               \
 497   CORE_ADDR frame_addr, func_start;                                     \
 498   struct aix_framedata fdata;                                           \
 499                                                                         \
 500   /* find the start of the function and collect info about its frame. */\
 501                                                                         \
 502   func_start = get_pc_function_start ((FRAME_INFO)->pc) + FUNCTION_START_OFFSET; \
 503   function_frame_info (func_start, &fdata);                             \
 504   bzero (&(FRAME_SAVED_REGS), sizeof (FRAME_SAVED_REGS));               \
 505                                                                         \
 506   /* if there were any saved registers, figure out parent's stack pointer. */ \
 507   frame_addr = 0;                                                       \
 508   /* the following is true only if the frame doesn't have a call to alloca(), \
 509       FIXME. */                                                         \
 510   if (fdata.saved_fpr >= 0 || fdata.saved_gpr >= 0) {                   \
 511     if ((FRAME_INFO)->prev && (FRAME_INFO)->prev->frame)                \
 512       frame_addr = (FRAME_INFO)->prev->frame;                           \
 513     else                                                                \
 514       frame_addr = read_memory_integer ((FRAME_INFO)->frame, 4);        \
 515   }                                                                     \
 516                                                                         \
 517   /* if != -1, fdata.saved_fpr is the smallest number of saved_fpr. All fpr's \
 518      from saved_fpr to fp31 are saved right underneath caller stack pointer, \
 519      starting from fp31 first. */                                       \
 520                                                                         \
 521   if (fdata.saved_fpr >= 0) {                                           \
 522     for (ii=31; ii >= fdata.saved_fpr; --ii)                            \
 523       (FRAME_SAVED_REGS).regs [FP0_REGNUM + ii] = frame_addr - ((32 - ii) * 8); \
 524     frame_addr -= (32 - fdata.saved_fpr) * 8;                           \
 525   }                                                                     \
 526                                                                         \
 527   /* if != -1, fdata.saved_gpr is the smallest number of saved_gpr. All gpr's \
 528      from saved_gpr to gpr31 are saved right under saved fprs, starting \
 529      from r31 first. */                                                 \
 530                                                                         \
 531   if (fdata.saved_gpr >= 0)                                             \
 532     for (ii=31; ii >= fdata.saved_gpr; --ii)                            \
 533       (FRAME_SAVED_REGS).regs [ii] = frame_addr - ((32 - ii) * 4);      \
 534 }
 535
 536 \f
 537 /* Things needed for making the inferior call functions.  */
 538
 539 /* Push an empty stack frame, to record the current PC, etc.  */
 540 /* Change these names into rs6k_{push, pop}_frame(). FIXMEmgo. */
 541
 542 #define PUSH_DUMMY_FRAME        push_dummy_frame ()
 543
 544 /* Discard from the stack the innermost frame,
 545    restoring all saved registers.  */
 546
 547 #define POP_FRAME       pop_frame ()
 548
 549 /* This sequence of words is the instructions:
 550
 551         mflr    r0              // 0x7c0802a6
 552                                 // save fpr's
 553         stfd    r?, num(r1)     // 0xd8010000 there should be 32 of this??
 554                                 // save gpr's
 555         stm     r0, num(r1)     // 0xbc010000
 556         stu     r1, num(r1)     // 0x94210000
 557
 558         // the function we want to branch might be in a different load
 559         // segment. reset the toc register. Note that the actual toc address
 560         // will be fix by fix_call_dummy () along with function address.
 561
 562         st      r2, 0x14(r1)    // 0x90410014 save toc register
 563         liu     r2, 0x1234      // 0x3c401234 reset a new toc value 0x12345678
 564         oril    r2, r2,0x5678   // 0x60425678
 565
 566                                 // load absolute address 0x12345678 to r0
 567         liu     r0, 0x1234      // 0x3c001234
 568         oril    r0, r0,0x5678   // 0x60005678
 569         mtctr   r0              // 0x7c0903a6 ctr <- r0
 570         bctrl                   // 0x4e800421 jump subroutine 0x12345678 (%ctr)
 571         cror    0xf, 0xf, 0xf   // 0x4def7b82
 572         brpt                    // 0x7d821008, breakpoint
 573         cror    0xf, 0xf, 0xf   // 0x4def7b82 (for 8 byte alignment)
 574
 575
 576   We actually start executing by saving the toc register first, since the pushing
 577   of the registers is done by PUSH_DUMMY_FRAME.  If this were real code,
 578   the arguments for the function called by the `bctrl' would be pushed
 579   between the `stu' and the `bctrl', and we could allow it to execute through.
 580   But the arguments have to be pushed by GDB after the PUSH_DUMMY_FRAME is done,
 581   and we cannot allow to push the registers again.
 582 */
 583
 584 #define CALL_DUMMY {0x7c0802a6, 0xd8010000, 0xbc010000, 0x94210000, \
 585                     0x90410014, 0x3c401234, 0x60425678,             \
 586                     0x3c001234, 0x60005678, 0x7c0903a6, 0x4e800421, \
 587                     0x4def7b82, 0x7d821008, 0x4def7b82 }
 588
 589
 590 /* keep this as multiple of 8 (%sp requires 8 byte alignment) */
 591 #define CALL_DUMMY_LENGTH 56
 592
 593 #define CALL_DUMMY_START_OFFSET 16
 594
 595 /* Insert the specified number of args and function address
 596    into a call sequence of the above form stored at DUMMYNAME.  */
 597
 598 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, using_gcc) \
 599         fix_call_dummy(dummyname, pc, fun, nargs, type)
 600
 601
 602 /* Signal handler for SIGWINCH `window size changed'. */
 603
 604 #define SIGWINCH_HANDLER  aix_resizewindow
 605 extern  void    aix_resizewindow ();
 606
 607 /* `lines_per_page' and `chars_per_line' are local to utils.c. Rectify this. */
 608
 609 #define SIGWINCH_HANDLER_BODY   \
 610                                                                         \
 611 /* Respond to SIGWINCH `window size changed' signal, and reset GDB's    \
 612    window settings approproatelt. */                                    \
 613                                                                         \
 614 void                                            \
 615 aix_resizewindow ()                             \
 616 {                                               \
 617   int fd = fileno (stdout);                     \
 618   if (isatty (fd)) {                            \
 619     int val;                                    \
 620                                                 \
 621     val = atoi (termdef (fd, 'l'));             \
 622     if (val > 0)                                \
 623       lines_per_page = val;                     \
 624     val = atoi (termdef (fd, 'c'));             \
 625     if (val > 0)                                \
 626       chars_per_line = val;                     \
 627   }                                             \
 628 }
 629
 630
 631 /* Flag for machine-specific stuff in shared files.  FIXME */
 632 #define IBM6000_TARGET
 633
 634 /* RS6000/AIX does not support PT_STEP.  Has to be simulated.  */
 635
 636 #define NO_SINGLE_STEP