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