gdb/tm-29k.h

   1 /* Parameters for target machine of AMD 29000, for GDB, the GNU debugger.
   2    Copyright 1990, 1991 Free Software Foundation, Inc.
   3    Contributed by Cygnus Support.  Written by Jim Kingdon.
   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 /* Parameters for an EB29K (a board which plugs into a PC and is
  22    accessed through EBMON software running on the PC, which we
  23    use as we'd use a remote stub (see remote-eb.c).
  24
  25    If gdb is ported to other 29k machines/systems, the
  26    machine/system-specific parts should be removed from this file (a
  27    la tm-68k.h).  */
  28
  29 /* Byte order is configurable, but this machine runs big-endian.  */
  30 #define TARGET_BYTE_ORDER BIG_ENDIAN
  31
  32 /* Floating point uses IEEE representations.  */
  33 #define IEEE_FLOAT
  34
  35 /* Recognize our magic number.  */
  36 #define BADMAG(x) ((x).f_magic != 0572)
  37
  38 /* Define this if the C compiler puts an underscore at the front
  39    of external names before giving them to the linker.  */
  40
  41 #define NAMES_HAVE_UNDERSCORE
  42
  43 /* Offset from address of function to start of its code.
  44    Zero on most machines.  */
  45
  46 #define FUNCTION_START_OFFSET 0
  47
  48 /* Advance PC across any function entry prologue instructions
  49    to reach some "real" code.  */
  50
  51 #define SKIP_PROLOGUE(pc) \
  52   { pc = skip_prologue (pc); }
  53 CORE_ADDR skip_prologue ();
  54
  55 /* Immediately after a function call, return the saved pc.
  56    Can't go through the frames for this because on some machines
  57    the new frame is not set up until the new function executes
  58    some instructions.  */
  59
  60 #define SAVED_PC_AFTER_CALL(frame) (read_register (LR0_REGNUM))
  61
  62 /* I'm not sure about the exact value of this, but based on looking
  63    at the stack pointer when we get to main this seems to be right.
  64
  65    This is the register stack; We call it "CONTROL" in GDB for consistency
  66    with Pyramid.  */
  67 #define CONTROL_END_ADDR 0x80200000
  68
  69 /* Memory stack.  This is for the default register stack size, which is
  70    only 0x800 bytes.  Perhaps we should let the user specify stack sizes
  71    (and tell EBMON with the "ZS" command).  */
  72 #define STACK_END_ADDR 0x801ff800
  73
  74 /* Stack grows downward.  */
  75
  76 #define INNER_THAN <
  77
  78 /* Stack must be aligned on 32-bit word boundaries.  */
  79 #define STACK_ALIGN(ADDR) (((ADDR) + 3) & ~3)
  80
  81 /* Sequence of bytes for breakpoint instruction.  */
  82 /* ASNEQ 0x50, gr1, gr1
  83    The trap number 0x50 is chosen arbitrarily.  */
  84 #if TARGET_BYTE_ORDER == BIG_ENDIAN
  85 #define BREAKPOINT {0x72, 0x50, 0x01, 0x01}
  86 #else /* Target is little-endian.  */
  87 #define BREAKPOINT {0x01, 0x01, 0x50, 0x72}
  88 #endif /* Target is little-endian.  */
  89
  90 /* Amount PC must be decremented by after a breakpoint.
  91    This is often the number of bytes in BREAKPOINT
  92    but not always.  */
  93
  94 #define DECR_PC_AFTER_BREAK 4
  95
  96 /* Nonzero if instruction at PC is a return instruction.
  97    On the 29k, this is a "jmpi l0" instruction.  */
  98
  99 #define ABOUT_TO_RETURN(pc) \
 100   ((read_memory_integer (pc, 4) & 0xff0000ff) == 0xc0000080)
 101
 102 /* Return 1 if P points to an invalid floating point value.  */
 103
 104 #define INVALID_FLOAT(p, len) 0   /* Just a first guess; not checked */
 105
 106 /* Say how long (ordinary) registers are.  */
 107
 108 #define REGISTER_TYPE long
 109
 110 /* Allow the register declarations here to be overridden for remote
 111    kernel debugging.  */
 112 #if !defined (REGISTER_NAMES)
 113
 114 /* Number of machine registers */
 115
 116 #define NUM_REGS 205
 117
 118 /* Initializer for an array of names of registers.
 119    There should be NUM_REGS strings in this initializer.
 120
 121    FIXME, add floating point registers and support here.
 122
 123    Also note that this list does not attempt to deal with kernel
 124    debugging (in which the first 32 registers are gr64-gr95).  */
 125
 126 #define REGISTER_NAMES \
 127 {"gr96", "gr97", "gr98", "gr99", "gr100", "gr101", "gr102", "gr103", "gr104", \
 128  "gr105", "gr106", "gr107", "gr108", "gr109", "gr110", "gr111", "gr112", \
 129  "gr113", "gr114", "gr115", "gr116", "gr117", "gr118", "gr119", "gr120", \
 130  "gr121", "gr122", "gr123", "gr124", "gr125", "gr126", "gr127",          \
 131  "lr0", "lr1", "lr2", "lr3", "lr4", "lr5", "lr6", "lr7", "lr8", "lr9",   \
 132  "lr10", "lr11", "lr12", "lr13", "lr14", "lr15", "lr16", "lr17", "lr18", \
 133  "lr19", "lr20", "lr21", "lr22", "lr23", "lr24", "lr25", "lr26", "lr27", \
 134  "lr28", "lr29", "lr30", "lr31", "lr32", "lr33", "lr34", "lr35", "lr36", \
 135  "lr37", "lr38", "lr39", "lr40", "lr41", "lr42", "lr43", "lr44", "lr45", \
 136  "lr46", "lr47", "lr48", "lr49", "lr50", "lr51", "lr52", "lr53", "lr54", \
 137  "lr55", "lr56", "lr57", "lr58", "lr59", "lr60", "lr61", "lr62", "lr63", \
 138  "lr64", "lr65", "lr66", "lr67", "lr68", "lr69", "lr70", "lr71", "lr72", \
 139  "lr73", "lr74", "lr75", "lr76", "lr77", "lr78", "lr79", "lr80", "lr81", \
 140  "lr82", "lr83", "lr84", "lr85", "lr86", "lr87", "lr88", "lr89", "lr90", \
 141  "lr91", "lr92", "lr93", "lr94", "lr95", "lr96", "lr97", "lr98", "lr99", \
 142  "lr100", "lr101", "lr102", "lr103", "lr104", "lr105", "lr106", "lr107", \
 143  "lr108", "lr109", "lr110", "lr111", "lr112", "lr113", "lr114", "lr115", \
 144  "lr116", "lr117", "lr118", "lr119", "lr120", "lr121", "lr122", "lr123", \
 145  "lr124", "lr125", "lr126", "lr127",                                     \
 146   "AI0", "AI1", "AI2", "AI3", "AI4", "AI5", "AI6", "AI7", "AI8", "AI9",  \
 147   "AI10", "AI11", "AI12", "AI13", "AI14", "AI15", "FP",                  \
 148   "bp", "fc", "cr", "q",                                                 \
 149   "vab", "ops", "cps", "cfg", "cha", "chd", "chc", "rbp", "tmc", "tmr",  \
 150   "pc0", "pc1", "pc2", "mmu", "lru", "fpe", "int", "fps", "exo", "gr1",  \
 151   "alu", "ipc", "ipa", "ipb" }
 152
 153 /* Convert Processor Special register #x to REGISTER_NAMES register # */
 154 #define SR_REGNUM(x) \
 155   ((x) < 15  ? VAB_REGNUM + (x)                                  \
 156    : (x) >= 128 && (x) < 131 ? IPC_REGNUM + (x) - 128            \
 157    : (x) == 131 ? Q_REGNUM                                       \
 158    : (x) == 132 ? ALU_REGNUM                                     \
 159    : (x) >= 133 && (x) < 136 ? BP_REGNUM + (x) - 133             \
 160    : (x) >= 160 && (x) < 163 ? FPE_REGNUM + (x) - 160            \
 161    : (x) == 164 ? EXO_REGNUM                                     \
 162    : (error ("Internal error in SR_REGNUM"), 0))
 163 #define GR96_REGNUM 0
 164 /* Define the return register separately, so it can be overridden for
 165    kernel procedure calling conventions. */
 166 #define RETURN_REGNUM   GR96_REGNUM
 167 #define GR1_REGNUM 200
 168 /* This needs to be the memory stack pointer, not the register stack pointer,
 169    to make call_function work right.  */
 170 #define SP_REGNUM MSP_REGNUM
 171 #define FP_REGNUM 33 /* lr1 */
 172 /* Large Return Pointer (gr123).  */
 173 #define LRP_REGNUM (123 - 96 + GR96_REGNUM)
 174 /* Static link pointer (gr124).  */
 175 #define SLP_REGNUM (124 - 96 + GR96_REGNUM)
 176 /* Memory Stack Pointer (gr125).  */
 177 #define MSP_REGNUM (125 - 96 + GR96_REGNUM)
 178 /* Register allocate bound (gr126).  */
 179 #define RAB_REGNUM (126 - 96 + GR96_REGNUM)
 180 /* Register Free Bound (gr127).  */
 181 #define RFB_REGNUM (127 - 96 + GR96_REGNUM)
 182 /* Register Stack Pointer.  */
 183 #define RSP_REGNUM GR1_REGNUM
 184 #define LR0_REGNUM 32
 185 #define BP_REGNUM 177
 186 #define FC_REGNUM 178
 187 #define CR_REGNUM 179
 188 #define Q_REGNUM 180
 189 #define VAB_REGNUM 181
 190 #define OPS_REGNUM (VAB_REGNUM + 1)
 191 #define CPS_REGNUM (VAB_REGNUM + 2)
 192 #define CFG_REGNUM (VAB_REGNUM + 3)
 193 #define CHA_REGNUM (VAB_REGNUM + 4)
 194 #define CHD_REGNUM (VAB_REGNUM + 5)
 195 #define CHC_REGNUM (VAB_REGNUM + 6)
 196 #define RBP_REGNUM (VAB_REGNUM + 7)
 197 #define TMC_REGNUM (VAB_REGNUM + 8)
 198 #define TMR_REGNUM (VAB_REGNUM + 9)
 199 #define NPC_REGNUM (VAB_REGNUM + 10)  /* pc0 */
 200 #define PC_REGNUM  (VAB_REGNUM + 11)  /* pc1 */
 201 #define PC2_REGNUM (VAB_REGNUM + 12)
 202 #define MMU_REGNUM (VAB_REGNUM + 13)
 203 #define LRU_REGNUM (VAB_REGNUM + 14)
 204 #define FPE_REGNUM (VAB_REGNUM + 15)
 205 #define INT_REGNUM (VAB_REGNUM + 16)
 206 #define FPS_REGNUM (VAB_REGNUM + 17)
 207 #define EXO_REGNUM (VAB_REGNUM + 18)
 208 /* gr1 is defined above as 200 = VAB_REGNUM + 19 */
 209 #define ALU_REGNUM (VAB_REGNUM + 20)
 210 #define PS_REGNUM  ALU_REGNUM
 211 #define IPC_REGNUM (VAB_REGNUM + 21)
 212 #define IPA_REGNUM (VAB_REGNUM + 22)
 213 #define IPB_REGNUM (VAB_REGNUM + 23)
 214
 215 #endif  /* !defined(REGISTER_NAMES) */
 216
 217 /* Total amount of space needed to store our copies of the machine's
 218    register state, the array `registers'.  */
 219 #define REGISTER_BYTES (NUM_REGS * 4)
 220
 221 /* Index within `registers' of the first byte of the space for
 222    register N.  */
 223 #define REGISTER_BYTE(N)  ((N)*4)
 224
 225 /* Number of bytes of storage in the actual machine representation
 226    for register N.  */
 227
 228 /* All regs are 4 bytes.  */
 229
 230 #define REGISTER_RAW_SIZE(N) (4)
 231
 232 /* Number of bytes of storage in the program's representation
 233    for register N.  */
 234
 235 /* All regs are 4 bytes.  */
 236
 237 #define REGISTER_VIRTUAL_SIZE(N) (4)
 238
 239 /* Largest value REGISTER_RAW_SIZE can have.  */
 240
 241 #define MAX_REGISTER_RAW_SIZE (4)
 242
 243 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 244
 245 #define MAX_REGISTER_VIRTUAL_SIZE (4)
 246
 247 /* Nonzero if register N requires conversion
 248    from raw format to virtual format.  */
 249
 250 #define REGISTER_CONVERTIBLE(N) (0)
 251
 252 /* Convert data from raw format for register REGNUM
 253    to virtual format for register REGNUM.  */
 254
 255 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO) \
 256 { bcopy ((FROM), (TO), 4); }
 257
 258 /* Convert data from virtual format for register REGNUM
 259    to raw format for register REGNUM.  */
 260
 261 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
 262 { bcopy ((FROM), (TO), 4); }
 263
 264 /* Return the GDB type object for the "standard" data type
 265    of data in register N.  */
 266
 267 #define REGISTER_VIRTUAL_TYPE(N) \
 268   (((N) == PC_REGNUM || (N) == LRP_REGNUM || (N) == SLP_REGNUM         \
 269     || (N) == MSP_REGNUM || (N) == RAB_REGNUM || (N) == RFB_REGNUM     \
 270     || (N) == GR1_REGNUM || (N) == FP_REGNUM || (N) == LR0_REGNUM       \
 271     || (N) == NPC_REGNUM || (N) == PC2_REGNUM)                           \
 272    ? lookup_pointer_type (builtin_type_void) : builtin_type_int)
 273 \f
 274 /* Store the address of the place in which to copy the structure the
 275    subroutine will return.  This is called from call_function. */
 276 /* On the 29k the LRP points to the part of the structure beyond the first
 277    16 words.  */
 278 #define STORE_STRUCT_RETURN(ADDR, SP) \
 279   write_register (LRP_REGNUM, (ADDR) + 16 * 4);
 280
 281 /* Should call_function allocate stack space for a struct return?  */
 282 /* On the 29k objects over 16 words require the caller to allocate space.  */
 283 #define USE_STRUCT_CONVENTION(gcc_p, type) (TYPE_LENGTH (type) > 16 * 4)
 284
 285 /* Extract from an array REGBUF containing the (raw) register state
 286    a function return value of type TYPE, and copy that, in virtual format,
 287    into VALBUF.  */
 288
 289 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF)              \
 290   {                                                                        \
 291     int reg_length = TYPE_LENGTH (TYPE);                                   \
 292     if (reg_length > 16 * 4)                                               \
 293       {                                                                    \
 294         reg_length = 16 * 4;                                               \
 295         read_memory (*((int *)(REGBUF) + LRP_REGNUM), (VALBUF) + 16 * 4,   \
 296                      TYPE_LENGTH (TYPE) - 16 * 4);                         \
 297       }                                                                    \
 298     bcopy (((int *)(REGBUF))+RETURN_REGNUM, (VALBUF), reg_length);         \
 299   }
 300
 301 /* Write into appropriate registers a function return value
 302    of type TYPE, given in virtual format.  */
 303
 304 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 305   {                                                                       \
 306     int reg_length = TYPE_LENGTH (TYPE);                                  \
 307     if (reg_length > 16 * 4)                                              \
 308       {                                                                   \
 309         reg_length = 16 * 4;                                              \
 310         write_memory (read_register (LRP_REGNUM),                         \
 311                       (char *)(VALBUF) + 16 * 4,                          \
 312                       TYPE_LENGTH (TYPE) - 16 * 4);                       \
 313       }                                                                   \
 314     write_register_bytes (REGISTER_BYTE (RETURN_REGNUM), (char *)(VALBUF),  \
 315                           TYPE_LENGTH (TYPE));                            \
 316   }
 317 \f
 318 /* The am29k user's guide documents well what the stacks look like.
 319    But what isn't so clear there is how this interracts with the
 320    symbols, or with GDB.
 321    In the following saved_msp, saved memory stack pointer (which functions
 322    as a memory frame pointer), means either
 323    a register containing the memory frame pointer or, in the case of
 324    functions with fixed size memory frames (i.e. those who don't use
 325    alloca()), the result of the calculation msp + msize.
 326
 327    LOC_ARG, LOC_LOCAL - For GCC, these are relative to saved_msp.
 328      For high C, these are relative to msp (making alloca impossible).
 329    LOC_REGISTER, LOC_REGPARM - The register number is the number at the
 330      time the function is running (after the prologue), or in the case
 331      of LOC_REGPARM, may be a register number in the range 160-175.
 332
 333    The compilers do things like store an argument into memory, and then put out
 334    a LOC_ARG for it, or put it into global registers and put out a
 335    LOC_REGPARM.  Thus is it important to execute the first line of
 336    code (i.e. the line of the open brace, i.e. the prologue) of a function
 337    before trying to print arguments or anything.
 338
 339    The following diagram attempts to depict what is going on in memory
 340    (see also the _am29k user's guide_) and also how that interacts with
 341    GDB frames.  We arbitrarily pick fci->frame to point the same place
 342    as the register stack pointer; since we set it ourself in
 343    INIT_EXTRA_FRAME_INFO, and access it only through the FRAME_*
 344    macros, it doesn't really matter exactly how we
 345    do it.  However, note that FRAME_FP is used in two ways in GDB:
 346    (1) as a "magic cookie" which uniquely identifies frames (even over
 347    calls to the inferior), (2) (in PC_IN_CALL_DUMMY [ON_STACK])
 348    as the value of SP_REGNUM before the dummy frame was pushed.  These
 349    two meanings would be incompatible for the 29k if we defined
 350    CALL_DUMMY_LOCATION == ON_STACK (but we don't, so don't worry about it).
 351    Also note that "lr1" below, while called a frame pointer
 352    in the user's guide, has only one function:  To determine whether
 353    registers need to be filled in the function epilogue.
 354
 355    Consider the code:
 356               < call bar>
 357         loc1: . . .
 358         bar:  sub gr1,gr1,rsize_b
 359               . . .
 360               add mfp,msp,0
 361               sub msp,msp,msize_b
 362               . . .
 363               < call foo >
 364         loc2: . . .
 365         foo:  sub gr1,gr1,rsize_f
 366               . . .
 367               add mfp,msp,0
 368               sub msp,msp,msize_f
 369               . . .
 370         loc3: < suppose the inferior stops here >
 371
 372                    memory stack      register stack
 373                    |           |     |____________|
 374                    |           |     |____loc1____|
 375           +------->|___________|     |            |   ^
 376           |        | ^         |     |  locals_b  |   |
 377           |        | |         |     |____________|   |
 378           |        | |         |     |            |   | rsize_b
 379           |        | | msize_b |     | args_to_f  |   |
 380           |        | |         |     |____________|   |
 381           |        | |         |     |____lr1_____|   V
 382           |        | V         |     |____loc2____|<----------------+
 383           |   +--->|___________|<---------mfp     |   ^             |
 384           |   |    | ^         |     |  locals_f  |   |             |
 385           |   |    | | msize_f |     |____________|   |             |
 386           |   |    | |         |     |            |   | rsize_f     |
 387           |   |    | V         |     |   args     |   |             |
 388           |   |    |___________|<msp |____________|   |             |
 389           |   |                      |_____lr1____|   V             |
 390           |   |                      |___garbage__| <- gr1 <----+   |
 391           |   |                                                 |   |
 392           |   |                                                 |   |
 393           |   |                      pc=loc3                    |   |
 394           |   |                                                 |   |
 395           |   |                                                 |   |
 396           |   |            frame cache                          |   |
 397           |   |       |_________________|                       |   |
 398           |   |       |rsize=rsize_b    |                       |   |
 399           |   |       |msize=msize_b    |                       |   |
 400           +---|--------saved_msp        |                       |   |
 401               |       |frame------------------------------------|---+
 402               |       |pc=loc2          |                       |
 403               |       |_________________|                       |
 404               |       |rsize=rsize_f    |                       |
 405               |       |msize=msize_f    |                       |
 406               +--------saved_msp        |                       |
 407                       |frame------------------------------------+
 408                       |pc=loc3          |
 409                       |_________________|
 410
 411    So, is that sufficiently confusing?  Welcome to the 29000.
 412    Notes:
 413    * The frame for foo uses a memory frame pointer but the frame for
 414      bar does not.  In the latter case the saved_msp is
 415      computed by adding msize to the saved_msp of the
 416      next frame.
 417    * msize is in the frame cache only for high C's sake.  */
 418
 419 void read_register_stack ();
 420 long read_register_stack_integer ();
 421 \f
 422 #define EXTRA_FRAME_INFO  \
 423   CORE_ADDR saved_msp;    \
 424   unsigned int rsize;     \
 425   unsigned int msize;
 426
 427 /* Because INIT_FRAME_PC gets passed fromleaf, that's where we init
 428    not only ->pc and ->frame, but all the extra stuff, when called from
 429    get_prev_frame_info, that is.  */
 430 #define INIT_EXTRA_FRAME_INFO(fromleaf, fci) \
 431   init_extra_frame_info(fci);
 432 void init_extra_frame_info ();
 433 #define INIT_FRAME_PC(fromleaf, fci) \
 434   init_frame_pc(fromleaf, fci);
 435 void init_frame_pc ();
 436 \f
 437 /* FRAME_CHAIN takes a FRAME
 438    and produces the frame's chain-pointer.
 439
 440    FRAME_CHAIN_COMBINE takes the chain pointer and the frame's nominal address
 441    and produces the nominal address of the caller frame.
 442
 443    However, if FRAME_CHAIN_VALID returns zero,
 444    it means the given frame is the outermost one and has no caller.
 445    In that case, FRAME_CHAIN_COMBINE is not used.  */
 446
 447 /* On the 29k, the nominal address of a frame is the address on the
 448    register stack of the return address (the one next to the incoming
 449    arguments, not down at the bottom so nominal address == stack pointer).
 450
 451    GDB expects "nominal address" to equal contents of FP_REGNUM,
 452    at least when it comes time to create the innermost frame.
 453    However, that doesn't work for us, so when creating the innermost
 454    frame we set ->frame ourselves in INIT_EXTRA_FRAME_INFO.  */
 455
 456 /* These are mostly dummies for the 29k because INIT_FRAME_PC
 457    sets prev->frame instead.  */
 458 #define FRAME_CHAIN(thisframe) (0)
 459
 460 /* Not sure how to figure out where the bottom frame is.  There is
 461    no frame for start.  In my tests so far the
 462    pc has been outside the text segment, though, so check for that.
 463    FIXME!!!
 464    However, allow a pc in a call dummy.  */
 465 #define FRAME_CHAIN_VALID(chain, thisframe) \
 466   (outside_startup_file (FRAME_SAVED_PC (thisframe)))
 467
 468 #define FRAME_CHAIN_COMBINE(chain, thisframe) (0)
 469
 470 /* Define other aspects of the stack frame.  */
 471
 472 /* A macro that tells us whether the function invocation represented
 473    by FI does not have a frame on the stack associated with it.  If it
 474    does not, FRAMELESS is set to 1, else 0.  */
 475 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
 476   (FRAMELESS) = frameless_look_for_prologue(FI)
 477
 478 /* Saved pc (i.e. return address).  */
 479 #define FRAME_SAVED_PC(fraim) \
 480   (read_register_stack_integer ((fraim)->frame + (fraim)->rsize, 4))
 481
 482 /* Local variables (i.e. LOC_LOCAL) are on the memory stack, with their
 483    offsets being relative to the memory stack pointer (high C) or
 484    saved_msp (gcc).  */
 485
 486 #define FRAME_LOCALS_ADDRESS(fi) frame_locals_address (fi)
 487 extern CORE_ADDR frame_locals_address ();
 488
 489 /* Return number of args passed to a frame.
 490    Can return -1, meaning no way to tell.  */
 491 /* While we could go the effort of finding the tags word and getting
 492    the argcount field from it,
 493    (1) It only counts arguments in registers, i.e. the first 16 words
 494        of arguments
 495    (2) It gives the number of arguments the function was declared with
 496        not how many it was called with (or some variation, like all 16
 497        words for varadic functions).  This makes argcount pretty much
 498        redundant with -g info, even for varadic functions.
 499    So don't bother.  */
 500 #define FRAME_NUM_ARGS(numargs, fi) ((numargs) = -1)
 501
 502 #define FRAME_ARGS_ADDRESS(fi) FRAME_LOCALS_ADDRESS (fi)
 503
 504 /* Return number of bytes at start of arglist that are not really args.  */
 505
 506 #define FRAME_ARGS_SKIP 0
 507
 508 /* Provide our own get_saved_register.  HAVE_REGISTER_WINDOWS is insufficient
 509    because registers get renumbered on the 29k without getting saved.  */
 510
 511 #define GET_SAVED_REGISTER
 512 \f
 513 /* Call function stuff.  */
 514
 515 /* The dummy frame looks like this (see also the general frame picture
 516    above):
 517
 518                                         register stack
 519
 520                                       |                |  frame for function
 521                                       |   locals_sproc |  executing at time
 522                                       |________________|  of call_function.
 523                                       |                |  We must not disturb
 524                                       | args_out_sproc |  it.
 525         memory stack                  |________________|
 526                                       |____lr1_sproc___|
 527        |            |                 |__retaddr_sproc_| <- gr1 (at start)
 528        |____________|<-msp 0 <-----------mfp_dummy_____|
 529        |            |  (at start)     |                |
 530        | arg_slop   |                 |  saved regs    |
 531        | (16 words) |                 | gr96-gr124     |
 532        |____________|<-msp 1--after   | sr128-sr135    |
 533        |            | PUSH_DUMMY_FRAME|                |
 534        | struct ret |                 |________________|
 535        | 17+        |                 |                |
 536        |____________|<- lrp           | args_out_dummy |
 537        | struct ret |                 |  (16 words)    |
 538        | 16         |                 |________________|
 539        | (16 words) |                 |____lr1_dummy___|
 540        |____________|<- msp 2--after  |_retaddr_dummy__|<- gr1 after
 541        |            | struct ret      |                |   PUSH_DUMMY_FRAME
 542        | margs17+   | area allocated  |  locals_inf    |
 543        |            |                 |________________|    called
 544        |____________|<- msp 4--when   |                |    function's
 545        |            |   inf called    | args_out_inf   |    frame (set up
 546        | margs16    |                 |________________|    by called
 547        | (16 words) |                 |_____lr1_inf____|    function).
 548        |____________|<- msp 3--after  |       .        |
 549        |            |   args pushed   |       .        |
 550        |            |                 |       .        |
 551                                       |                |
 552
 553    arg_slop: This area is so that when the call dummy adds 16 words to
 554       the msp, it won't end up larger than mfp_dummy (it is needed in the
 555       case where margs and struct_ret do not add up to at least 16 words).
 556    struct ret:  This area is allocated by GDB if the return value is more
 557       than 16 words.  struct ret_16 is not used on the 29k.
 558    margs:  Pushed by GDB.  The call dummy copies the first 16 words to
 559       args_out_dummy.
 560    retaddr_sproc:  Contains the PC at the time we call the function.
 561       set by PUSH_DUMMY_FRAME and read by POP_FRAME.
 562    retaddr_dummy:  This points to a breakpoint instruction in the dummy.  */
 563 \f
 564 /* Rsize for dummy frame, in bytes.  */
 565
 566 /* Bytes for outgoing args, lr1, and retaddr.  */
 567 #define DUMMY_ARG (2 * 4 + 16 * 4)
 568
 569 /* Number of special registers (sr128-) to save.  */
 570 #define DUMMY_SAVE_SR128 8
 571 /* Number of general (gr96- or gr64-) registers to save.  */
 572 #define DUMMY_SAVE_GREGS 29
 573
 574 #define DUMMY_FRAME_RSIZE \
 575 (4 /* mfp_dummy */                                 \
 576  + DUMMY_SAVE_GREGS * 4                             \
 577  + DUMMY_SAVE_SR128 * 4                            \
 578  + DUMMY_ARG                                       \
 579  )
 580
 581 /* Push an empty stack frame, to record the current PC, etc.  */
 582
 583 #define PUSH_DUMMY_FRAME push_dummy_frame();
 584 extern void push_dummy_frame ();
 585
 586 /* Discard from the stack the innermost frame,
 587    restoring all saved registers.  */
 588
 589 #define POP_FRAME pop_frame ();
 590 extern void pop_frame ();
 591
 592 /* This sequence of words is the instructions
 593    mtsrim cr, 15
 594    loadm 0, 0, lr2, msp     ; load first 16 words of arguments into registers
 595    add msp, msp, 16 * 4     ; point to the remaining arguments
 596   CONST_INSN:
 597    const gr96,inf
 598    consth gr96,inf
 599    calli lr0, gr96
 600    aseq 0x40,gr1,gr1   ; nop
 601    asneq 0x50,gr1,gr1  ; breakpoint
 602    */
 603
 604 /* Position of the "const" instruction within CALL_DUMMY in bytes.  */
 605 #define CONST_INSN (3 * 4)
 606 #if TARGET_BYTE_ORDER == HOST_BYTE_ORDER
 607 #define CALL_DUMMY {0x0400870f, 0x3600827d, 0x157d7d40, 0x03ff60ff,    \
 608                     0x02ff60ff, 0xc8008060, 0x70400101, 0x72500101}
 609 #else /* Byte order differs.  */
 610   you lose
 611 #endif /* Byte order differs.  */
 612 #define CALL_DUMMY_LENGTH (8 * 4)
 613
 614 #define CALL_DUMMY_START_OFFSET 0  /* Start execution at beginning of dummy */
 615
 616 /* Helper macro for FIX_CALL_DUMMY.  WORDP is a long * which points to a
 617    word in target byte order; bits 0-7 and 16-23 of *WORDP are replaced with
 618    bits 0-7 and 8-15 of DATA (which is in host byte order).  */
 619
 620 #if TARGET_BYTE_ORDER == BIG_ENDIAN
 621 #define STUFF_I16(WORDP, DATA) \
 622   { \
 623     *((char *)(WORDP) + 3) = ((DATA) & 0xff);\
 624     *((char *)(WORDP) + 1) = (((DATA) >> 8) & 0xff);\
 625   }
 626 #else /* Target is little endian.  */
 627 #define STUFF_I16(WORDP, DATA) \
 628   {
 629     *(char *)(WORDP) = ((DATA) & 0xff);
 630     *((char *)(WORDP) + 2) = (((DATA) >> 8) & 0xff);
 631   }
 632 #endif /* Target is little endian.  */
 633
 634 /* Insert the specified number of args and function address
 635    into a call sequence of the above form stored at DUMMYNAME.  */
 636
 637 /* Currently this stuffs in the address of the function that we are calling.
 638    If different 29k systems use different breakpoint instructions, it
 639    could also stuff BREAKPOINT in the right place (to avoid having to
 640    duplicate CALL_DUMMY in each tm-*.h file).  */
 641
 642 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p)   \
 643   {\
 644     STUFF_I16((char *)dummyname + CONST_INSN, fun);\
 645     STUFF_I16((char *)dummyname + CONST_INSN + 4, fun >> 16);\
 646   }
 647
 648 /* 29k architecture has separate data & instruction memories -- wired to
 649    different pins on the chip -- and can't execute the data memory.
 650    Also, there should be space after text_end;
 651    we won't get a SIGSEGV or scribble on data space.  */
 652
 653 #define CALL_DUMMY_LOCATION AFTER_TEXT_END
 654
 655 /* Because of this, we need (as a kludge) to know the addresses of the
 656    text section.  */
 657
 658 #define NEED_TEXT_START_END
 659
 660 /* How to translate register numbers in the .stab's into gdb's internal register
 661    numbers.  We don't translate them, but we warn if an invalid register
 662    number is seen.  Note that FIXME, we use the value "sym" as an implicit
 663    argument in printing the error message.  It happens to be available where
 664    this macro is used.  (This macro definition appeared in a late revision
 665    of gdb-3.91.6 and is not well tested.  Also, it should be a "complaint".) */
 666
 667 #define STAB_REG_TO_REGNUM(num) \
 668         (((num) > LR0_REGNUM + 127) \
 669            ? fprintf(stderr,    \
 670                 "Invalid register number %d in symbol table entry for %s\n", \
 671                  (num), SYMBOL_NAME (sym)), (num)       \
 672            : (num))