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 /* AIX's assembler doesn't grok dollar signs in identifiers.
 111    So we use dots instead.  This item must be coordinated with G++. */
 112 #undef CPLUS_MARKER
 113 #define CPLUS_MARKER '.'
 114
 115 /* Offset from address of function to start of its code.
 116    Zero on most machines.  */
 117
 118 #define FUNCTION_START_OFFSET 0
 119
 120 /* Advance PC across any function entry prologue instructions
 121    to reach some "real" code.  */
 122
 123 #define SKIP_PROLOGUE(pc)       pc = skip_prologue (pc)
 124
 125 /* If PC is in some function-call trampoline code, return the PC
 126    where the function itself actually starts.  If not, return NULL.  */
 127
 128 #define SKIP_TRAMPOLINE_CODE(pc)        skip_trampoline_code (pc)
 129
 130 /* When a child process is just starting, we sneak in and relocate
 131    the symbol table (and other stuff) after the dynamic linker has
 132    figured out where they go. But we want to do this relocation just
 133    once. */
 134
 135 extern int aix_loadInfoTextIndex;
 136
 137 #define SOLIB_CREATE_INFERIOR_HOOK(PID) \
 138   do {                                  \
 139     if (aix_loadInfoTextIndex == 0)     \
 140         aixcoff_relocate_symtab (PID);  \
 141   } while (0)
 142
 143
 144 /* Number of trap signals we need to skip over, once the inferior process
 145    starts running. */
 146
 147 #define START_INFERIOR_TRAPS_EXPECTED   2
 148
 149 /* AIX might return a sigtrap, with a "stop after load" status. It should
 150    be ignored by gdb, shouldn't be mixed up with breakpoint traps. */
 151
 152 /* Another little glitch  in AIX is signal 0. I have no idea why wait(2)
 153    returns with this status word. It looks harmless. */
 154
 155 #define SIGTRAP_STOP_AFTER_LOAD(W)      \
 156  if ( (W) == 0x57c || (W) == 0x7f) {    \
 157    if ((W)==0x57c && breakpoints_inserted) {    \
 158      mark_breakpoints_out ();           \
 159      insert_breakpoints ();             \
 160      insert_step_breakpoint ();         \
 161    }                                    \
 162    resume (0, 0);                       \
 163    continue;                            \
 164  }
 165
 166 /* In aixcoff, we cannot process line numbers when we see them. This is
 167    mainly because we don't know the boundaries of the include files. So,
 168    we postpone that, and then enter and sort(?) the whole line table at
 169    once, when we are closing the current symbol table in end_symtab(). */
 170
 171 #define PROCESS_LINENUMBER_HOOK()       aix_process_linenos ()
 172
 173
 174 /* When a target process or core-file has been attached, we sneak in
 175    and figure out where the shared libraries have got to. In case there
 176    is no inferior_process exists (e.g. bringing up a core file), we can't
 177    attemtp to relocate symbol table, since we don't have information about
 178    load segments. */
 179
 180 #define SOLIB_ADD(a, b, c)      \
 181    if (inferior_pid)    aixcoff_relocate_symtab (inferior_pid)
 182
 183 /* Immediately after a function call, return the saved pc.
 184    Can't go through the frames for this because on some machines
 185    the new frame is not set up until the new function executes
 186    some instructions.  */
 187
 188 #include "inferior.h"   /* For registers[] and register_valid[]. */
 189
 190 #define SAVED_PC_AFTER_CALL(frame)      \
 191         (register_valid [LR_REGNUM] ?   \
 192           (*(int*)&registers[REGISTER_BYTE (LR_REGNUM)]) :      \
 193           read_register (LR_REGNUM))
 194
 195 /*#define SAVED_PC_AFTER_CALL(frame)    saved_pc_after_call(frame) */
 196
 197
 198 /* Address of end of stack space.  */
 199
 200 #define STACK_END_ADDR 0x2ff80000
 201
 202 /* Stack grows downward.  */
 203
 204 #define INNER_THAN <
 205
 206 #if 0
 207 /* No, we shouldn't use this. push_arguments() should leave stack in a
 208    proper alignment! */
 209 /* Stack has strict alignment. */
 210
 211 #define STACK_ALIGN(ADDR)       (((ADDR)+7)&-8)
 212 #endif
 213
 214 /* This is how argumets pushed onto stack or passed in registers. */
 215
 216 #define PUSH_ARGUMENTS(nargs, args, sp, struct_return, struct_addr) \
 217   sp = push_arguments(nargs, args, sp, struct_return, struct_addr)
 218
 219 /* Sequence of bytes for breakpoint instruction.  */
 220
 221 #define BREAKPOINT {0x7d, 0x82, 0x10, 0x08}
 222
 223 /* Amount PC must be decremented by after a breakpoint.
 224    This is often the number of bytes in BREAKPOINT
 225    but not always.  */
 226
 227 #define DECR_PC_AFTER_BREAK 0
 228
 229 /* Nonzero if instruction at PC is a return instruction.  */
 230 /* Allow any of the return instructions, including a trapv and a return
 231    from interrupt.  */
 232
 233 #define ABOUT_TO_RETURN(pc)  \
 234    ((read_memory_integer (pc, 4) & 0xfe8007ff) == 0x4e800020)
 235
 236 /* Return 1 if P points to an invalid floating point value.  */
 237
 238 #define INVALID_FLOAT(p, len) 0   /* Just a first guess; not checked */
 239
 240 /* Largest integer type */
 241
 242 #define LONGEST long
 243
 244 /* Name of the builtin type for the LONGEST type above. */
 245
 246 #define BUILTIN_TYPE_LONGEST builtin_type_long
 247
 248 /* Say how long (ordinary) registers are.  */
 249
 250 #define REGISTER_TYPE long
 251
 252 /* Number of machine registers */
 253
 254 #define NUM_REGS 71
 255
 256 /* Initializer for an array of names of registers.
 257    There should be NUM_REGS strings in this initializer.  */
 258
 259 #define REGISTER_NAMES  \
 260  {"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",  \
 261   "r8", "r9", "r10","r11","r12","r13","r14","r15", \
 262   "r16","r17","r18","r19","r20","r21","r22","r23", \
 263   "r24","r25","r26","r27","r28","r29","r30","r31", \
 264   "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",  \
 265   "f8", "f9", "f10","f11","f12","f13","f14","f15", \
 266   "f16","f17","f18","f19","f20","f21","f22","f23", \
 267   "f24","f25","f26","f27","f28","f29","f30","f31", \
 268   "pc", "ps", "cnd", "lr", "cnt", "xer", "mq" }
 269
 270 /* Register numbers of various important registers.
 271    Note that some of these values are "real" register numbers,
 272    and correspond to the general registers of the machine,
 273    and some are "phony" register numbers which are too large
 274    to be actual register numbers as far as the user is concerned
 275    but do serve to get the desired values when passed to read_register.  */
 276
 277 #define FP_REGNUM 1             /* Contains address of executing stack frame */
 278 #define SP_REGNUM 1             /* Contains address of top of stack */
 279 #define TOC_REGNUM 2            /* TOC register */
 280 #define FP0_REGNUM 32           /* Floating point register 0 */
 281 #define GP0_REGNUM 0            /* GPR register 0 */
 282 #define FP0_REGNUM 32           /* FPR (Floating point) register 0 */
 283 #define FPLAST_REGNUM 63        /* Last floating point register */
 284
 285 /* Special purpose registers... */
 286 /* P.S. keep these in the same order as in /usr/mstsave.h `mstsave' structure, for
 287    easier processing */
 288
 289 #define PC_REGNUM 64            /* Program counter (instruction address %iar) */
 290 #define PS_REGNUM 65            /* Processor (or machine) status (%msr) */
 291 #define CR_REGNUM 66            /* Condition register */
 292 #define LR_REGNUM 67            /* Link register */
 293 #define CTR_REGNUM 68           /* Count register */
 294 #define XER_REGNUM 69           /* Fixed point exception registers */
 295 #define MQ_REGNUM 70            /* Multiply/quotient register */
 296
 297 #define FIRST_SP_REGNUM 64      /* first special register number */
 298 #define LAST_SP_REGNUM  70      /* last special register number */
 299
 300 /* Total amount of space needed to store our copies of the machine's
 301    register state, the array `registers'.
 302
 303         32 4-byte gpr's
 304         32 8-byte fpr's
 305         7  4-byte special purpose registers,
 306
 307    total 416 bytes. Keep some extra space for now, in case to add more. */
 308
 309 #define REGISTER_BYTES 420
 310
 311
 312 /* Index within `registers' of the first byte of the space for
 313    register N.  */
 314
 315 #define REGISTER_BYTE(N)  \
 316  (                                                              \
 317   ((N) > FPLAST_REGNUM) ? ((((N) - FPLAST_REGNUM -1) * 4) + 384)\
 318   :((N) >= FP0_REGNUM) ? ((((N) - FP0_REGNUM) * 8) + 128)       \
 319   :((N) * 4) )
 320
 321 /* Number of bytes of storage in the actual machine representation
 322    for register N. */
 323 /* Note that the unsigned cast here forces the result of the
 324    subtractiion to very high positive values if N < FP0_REGNUM */
 325
 326 #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
 327
 328 /* Number of bytes of storage in the program's representation
 329    for register N.  On the RS6000, all regs are 4 bytes
 330    except the floating point regs which are 8-byte doubles.  */
 331
 332 #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
 333
 334 /* Largest value REGISTER_RAW_SIZE can have.  */
 335
 336 #define MAX_REGISTER_RAW_SIZE 8
 337
 338 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 339
 340 #define MAX_REGISTER_VIRTUAL_SIZE 8
 341
 342 /* convert a dbx stab register number (from `r' declaration) to a gdb REGNUM */
 343
 344 #define STAB_REG_TO_REGNUM(value)       (value)
 345
 346 /* Nonzero if register N requires conversion
 347    from raw format to virtual format.  */
 348
 349 #define REGISTER_CONVERTIBLE(N) ((N) >= FP0_REGNUM && (N) <= FPLAST_REGNUM)
 350
 351 /* Convert data from raw format for register REGNUM
 352    to virtual format for register REGNUM.  */
 353
 354 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO)     \
 355    bcopy ((FROM), (TO), REGISTER_RAW_SIZE (REGNUM))
 356
 357 /* Convert data from virtual format for register REGNUM
 358    to raw format for register REGNUM.  */
 359
 360 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
 361    bcopy ((FROM), (TO), REGISTER_RAW_SIZE (REGNUM))
 362
 363 /* Return the GDB type object for the "standard" data type
 364    of data in register N.  */
 365
 366 #define REGISTER_VIRTUAL_TYPE(N) \
 367  (((unsigned)(N) - FP0_REGNUM) < 32 ? builtin_type_double : builtin_type_int)
 368
 369 /* Store the address of the place in which to copy the structure the
 370    subroutine will return.  This is called from call_function. */
 371 /* in RS6000, struct return addresses are passed as an extra parameter in r3.
 372    In function return, callee is not responsible of returning this address back.
 373    Since gdb needs to find it, we will store in a designated variable
 374    `rs6000_struct_return_address'. */
 375
 376 extern unsigned int rs6000_struct_return_address;
 377
 378 #define STORE_STRUCT_RETURN(ADDR, SP)   \
 379   { write_register (3, (ADDR));         \
 380     rs6000_struct_return_address = (unsigned int)(ADDR); }
 381
 382 /* Extract from an array REGBUF containing the (raw) register state
 383    a function return value of type TYPE, and copy that, in virtual format,
 384    into VALBUF.  */
 385
 386 /* #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 387   bcopy (REGBUF, VALBUF, TYPE_LENGTH (TYPE)) */
 388
 389 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 390   extract_return_value(TYPE,REGBUF,VALBUF)
 391
 392 /* Write into appropriate registers a function return value
 393    of type TYPE, given in virtual format.  */
 394
 395 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 396   {                                                                     \
 397     if (TYPE_CODE (TYPE) == TYPE_CODE_FLT)                              \
 398                                                                         \
 399      /* Floating point values are returned starting from FPR1 and up.   \
 400         Say a double_double_double type could be returned in            \
 401         FPR1/FPR2/FPR3 triple. */                                       \
 402                                                                         \
 403       write_register_bytes (REGISTER_BYTE (FP0_REGNUM+1), (VALBUF),     \
 404                                                 TYPE_LENGTH (TYPE));    \
 405     else                                                                \
 406       /* Everything else is returned in GPR3 and up. */                 \
 407       write_register_bytes (REGISTER_BYTE (GP0_REGNUM+3), (VALBUF),     \
 408                                                 TYPE_LENGTH (TYPE));    \
 409   }
 410
 411
 412 /* Extract from an array REGBUF containing the (raw) register state
 413    the address in which a function should return its structure value,
 414    as a CORE_ADDR (or an expression that can be used as one).  */
 415
 416 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF)    rs6000_struct_return_address
 417
 418
 419 /* Do implement the attach and detach commands.  */
 420
 421 #define ATTACH_DETACH
 422
 423 /* infptrace.c requires those. */
 424
 425 #define PTRACE_ATTACH 30
 426 #define PTRACE_DETACH 31
 427
 428 \f
 429 /* Describe the pointer in each stack frame to the previous stack frame
 430    (its caller).  */
 431
 432 /* FRAME_CHAIN takes a frame's nominal address
 433    and produces the frame's chain-pointer. */
 434
 435 /* In the case of the RS6000, the frame's nominal address
 436    is the address of a 4-byte word containing the calling frame's address.  */
 437
 438 #define FRAME_CHAIN(thisframe)  \
 439   (!inside_entry_file ((thisframe)->pc) ?       \
 440    read_memory_integer ((thisframe)->frame, 4) :\
 441    0)
 442
 443 /* Define other aspects of the stack frame.  */
 444
 445 /* A macro that tells us whether the function invocation represented
 446    by FI does not have a frame on the stack associated with it.  If it
 447    does not, FRAMELESS is set to 1, else 0.  */
 448
 449 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
 450         FRAMELESS = frameless_function_invocation (FI)
 451
 452 /* Functions calling alloca() change the value of the stack pointer. We
 453    need to use initial stack pointer (which is saved in r31 by gcc) in
 454    such cases. If a compiler emits traceback table, then we should use the
 455    alloca register specified in traceback table. FIXME. */
 456 /* Also, it is a good idea to cache information about frame's saved registers
 457    in the frame structure to speed things up. See tm-m88k.h. FIXME. */
 458
 459 #define EXTRA_FRAME_INFO        \
 460         CORE_ADDR initial_sp;                   /* initial stack pointer. */ \
 461         struct frame_saved_regs *cache_fsr;     /* saved registers        */
 462
 463 /* Frameless function invocation in IBM RS/6000 is half-done. It perfectly
 464    sets up a new frame, e.g. a new frame (in fact stack) pointer, etc, but it
 465    doesn't save the %pc. In the following, even though it is considered a
 466    frameless invocation, we still need to walk one frame up. */
 467
 468 #define INIT_EXTRA_FRAME_INFO(fromleaf, fi)     \
 469         fi->initial_sp = 0;             \
 470         fi->cache_fsr = 0;
 471
 472 #define FRAME_SAVED_PC(FRAME)           \
 473         read_memory_integer (read_memory_integer ((FRAME)->frame, 4)+8, 4)
 474
 475 #define FRAME_ARGS_ADDRESS(FI)  \
 476   (((struct frame_info*)(FI))->initial_sp ?             \
 477         ((struct frame_info*)(FI))->initial_sp :        \
 478         frame_initial_stack_address (FI))
 479
 480 #define FRAME_LOCALS_ADDRESS(FI)        FRAME_ARGS_ADDRESS(FI)
 481
 482
 483 /* Set VAL to the number of args passed to frame described by FI.
 484    Can set VAL to -1, meaning no way to tell.  */
 485
 486 /* We can't tell how many args there are
 487    now that the C compiler delays popping them.  */
 488
 489 #define FRAME_NUM_ARGS(val,fi) (val = -1)
 490
 491 /* Return number of bytes at start of arglist that are not really args.  */
 492
 493 #define FRAME_ARGS_SKIP 8       /* Not sure on this. FIXMEmgo */
 494
 495 /* Put here the code to store, into a struct frame_saved_regs,
 496    the addresses of the saved registers of frame described by FRAME_INFO.
 497    This includes special registers such as pc and fp saved in special
 498    ways in the stack frame.  sp is even more special:
 499    the address we return for it IS the sp for the next frame.  */
 500 /* In the following implementation for RS6000, we did *not* save sp. I am
 501    not sure if it will be needed. The following macro takes care of gpr's
 502    and fpr's only. */
 503
 504 #define FRAME_FIND_SAVED_REGS(FRAME_INFO, FRAME_SAVED_REGS)             \
 505 {                                                                       \
 506   int ii, frame_addr, func_start;                                       \
 507   struct aix_framedata fdata;                                                   \
 508                                                                                 \
 509   /* find the start of the function and collect info about its frame. */        \
 510                                                                                 \
 511   func_start = get_pc_function_start ((FRAME_INFO)->pc) + FUNCTION_START_OFFSET;\
 512   function_frame_info (func_start, &fdata);                                     \
 513   bzero (&(FRAME_SAVED_REGS), sizeof (FRAME_SAVED_REGS));                       \
 514                                                                                 \
 515   /* if there were any saved registers, figure out parent's stack pointer. */   \
 516   frame_addr = 0;                                                               \
 517   /* the following is true only if the frame doesn't have a call to alloca(),   \
 518       FIXME. */                                                                 \
 519   if (fdata.saved_fpr >= 0 || fdata.saved_gpr >= 0) {                           \
 520     if ((FRAME_INFO)->prev && (FRAME_INFO)->prev->frame)                        \
 521       frame_addr = (FRAME_INFO)->prev->frame;                                   \
 522     else                                                                        \
 523       frame_addr = read_memory_integer ((FRAME_INFO)->frame, 4);                \
 524   }                                                                             \
 525                                                                                 \
 526   /* if != -1, fdata.saved_fpr is the smallest number of saved_fpr. All fpr's   \
 527      from saved_fpr to fp31 are saved right underneath caller stack pointer,    \
 528      starting from fp31 first. */                                               \
 529                                                                                 \
 530   if (fdata.saved_fpr >= 0) {                                                   \
 531     for (ii=31; ii >= fdata.saved_fpr; --ii)                                    \
 532       (FRAME_SAVED_REGS).regs [FP0_REGNUM + ii] = frame_addr - ((32 - ii) * 8); \
 533     frame_addr -= (32 - fdata.saved_fpr) * 8;                                   \
 534   }                                                                             \
 535                                                                                 \
 536   /* if != -1, fdata.saved_gpr is the smallest number of saved_gpr. All gpr's   \
 537      from saved_gpr to gpr31 are saved right under saved fprs, starting         \
 538      from r31 first. */                                                         \
 539                                                                                 \
 540   if (fdata.saved_gpr >= 0)                                                     \
 541     for (ii=31; ii >= fdata.saved_gpr; --ii)                                    \
 542       (FRAME_SAVED_REGS).regs [ii] = frame_addr - ((32 - ii) * 4);              \
 543 }
 544
 545 \f
 546 /* Things needed for making the inferior call functions.  */
 547
 548 /* Push an empty stack frame, to record the current PC, etc.  */
 549 /* Change these names into rs6k_{push, pop}_frame(). FIXMEmgo. */
 550
 551 #define PUSH_DUMMY_FRAME        push_dummy_frame ()
 552
 553 /* Discard from the stack the innermost frame,
 554    restoring all saved registers.  */
 555
 556 #define POP_FRAME       pop_frame ()
 557
 558 /* This sequence of words is the instructions:
 559
 560         mflr    r0              // 0x7c0802a6
 561                                 // save fpr's
 562         stfd    r?, num(r1)     // 0xd8010000 there should be 32 of this??
 563                                 // save gpr's
 564         stm     r0, num(r1)     // 0xbc010000
 565         stu     r1, num(r1)     // 0x94210000
 566
 567         // the function we want to branch might be in a different load
 568         // segment. reset the toc register. Note that the actual toc address
 569         // will be fix by fix_call_dummy () along with function address.
 570
 571         st      r2, 0x14(r1)    // 0x90410014 save toc register
 572         liu     r2, 0x1234      // 0x3c401234 reset a new toc value 0x12345678
 573         oril    r2, r2,0x5678   // 0x60425678
 574
 575                                 // load absolute address 0x12345678 to r0
 576         liu     r0, 0x1234      // 0x3c001234
 577         oril    r0, r0,0x5678   // 0x60005678
 578         mtctr   r0              // 0x7c0903a6 ctr <- r0
 579         bctrl                   // 0x4e800421 jump subroutine 0x12345678 (%ctr)
 580         cror    0xf, 0xf, 0xf   // 0x4def7b82
 581         brpt                    // 0x7d821008, breakpoint
 582         cror    0xf, 0xf, 0xf   // 0x4def7b82 (for 8 byte alignment)
 583
 584
 585   We actually start executing by saving the toc register first, since the pushing
 586   of the registers is done by PUSH_DUMMY_FRAME.  If this were real code,
 587   the arguments for the function called by the `bctrl' would be pushed
 588   between the `stu' and the `bctrl', and we could allow it to execute through.
 589   But the arguments have to be pushed by GDB after the PUSH_DUMMY_FRAME is done,
 590   and we cannot allow to push the registers again.
 591 */
 592
 593 #define CALL_DUMMY {0x7c0802a6, 0xd8010000, 0xbc010000, 0x94210000, \
 594                     0x90410014, 0x3c401234, 0x60425678,             \
 595                     0x3c001234, 0x60005678, 0x7c0903a6, 0x4e800421, \
 596                     0x4def7b82, 0x7d821008, 0x4def7b82 }
 597
 598
 599 /* keep this as multiple of 8 (%sp requires 8 byte alignment) */
 600 #define CALL_DUMMY_LENGTH 56
 601
 602 #define CALL_DUMMY_START_OFFSET 16
 603
 604 /* Insert the specified number of args and function address
 605    into a call sequence of the above form stored at DUMMYNAME.  */
 606
 607 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, using_gcc) \
 608         fix_call_dummy(dummyname, pc, fun, nargs, type)
 609
 610
 611 /* Signal handler for SIGWINCH `window size changed'. */
 612
 613 #define SIGWINCH_HANDLER  aix_resizewindow
 614 extern  void    aix_resizewindow ();
 615
 616 /* `lines_per_page' and `chars_per_line' are local to utils.c. Rectify this. */
 617
 618 #define SIGWINCH_HANDLER_BODY   \
 619                                                                         \
 620 /* Respond to SIGWINCH `window size changed' signal, and reset GDB's    \
 621    window settings approproatelt. */                                    \
 622                                                                         \
 623 void                                            \
 624 aix_resizewindow ()                             \
 625 {                                               \
 626   int fd = fileno (stdout);                     \
 627   if (isatty (fd)) {                            \
 628     int val;                                    \
 629                                                 \
 630     val = atoi (termdef (fd, 'l'));             \
 631     if (val > 0)                                \
 632       lines_per_page = val;                     \
 633     val = atoi (termdef (fd, 'c'));             \
 634     if (val > 0)                                \
 635       chars_per_line = val;                     \
 636   }                                             \
 637 }
 638
 639
 640 /* Flag for machine-specific stuff in shared files.  FIXME */
 641 #define IBM6000_TARGET