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 0
  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", "inte", "fps", "exo", "gr1",  \
 151   "alu", "ipc", "ipa", "ipb" }
 152
 153 /*
 154  * Converts an sdb register number to an internal gdb register number.
 155  * Currently under epi, gr96->0...gr127->31...lr0->32...lr127->159, or...
 156  *                      gr64->0...gr95->31, lr0->32...lr127->159.
 157  */
 158 #define SDB_REG_TO_REGNUM(value) \
 159   (((value) >= 96 && (value) <= 127) ? ((value) - 96) : \
 160    ((value) >= 128 && (value) <=  255) ? ((value) - 128 + LR0_REGNUM) : \
 161    (value))
 162
 163 /*
 164  * Provide the processor register numbers of some registers that are
 165  * expected/written in instructions that might change under different
 166  * register sets.  Namely, gcc can compile (-mkernel-registers) so that
 167  * it uses gr64-gr95 in stead of gr96-gr127.
 168  */
 169 #define MSP_HW_REGNUM   125             /* gr125 */
 170 #define RAB_HW_REGNUM   126             /* gr126 */
 171
 172 /* Convert Processor Special register #x to REGISTER_NAMES register # */
 173 #define SR_REGNUM(x) \
 174   ((x) < 15  ? VAB_REGNUM + (x)                                  \
 175    : (x) >= 128 && (x) < 131 ? IPC_REGNUM + (x) - 128            \
 176    : (x) == 131 ? Q_REGNUM                                       \
 177    : (x) == 132 ? ALU_REGNUM                                     \
 178    : (x) >= 133 && (x) < 136 ? BP_REGNUM + (x) - 133             \
 179    : (x) >= 160 && (x) < 163 ? FPE_REGNUM + (x) - 160            \
 180    : (x) == 164 ? EXO_REGNUM                                     \
 181    : (error ("Internal error in SR_REGNUM"), 0))
 182 #define GR96_REGNUM 0
 183 /* Define the return register separately, so it can be overridden for
 184    kernel procedure calling conventions. */
 185 #define RETURN_REGNUM   GR96_REGNUM
 186 #define GR1_REGNUM 200
 187 /* This needs to be the memory stack pointer, not the register stack pointer,
 188    to make call_function work right.  */
 189 #define SP_REGNUM MSP_REGNUM
 190 #define FP_REGNUM 33 /* lr1 */
 191 /* Large Return Pointer (gr123).  */
 192 #define LRP_REGNUM (123 - 96 + GR96_REGNUM)
 193 /* Static link pointer (gr124).  */
 194 #define SLP_REGNUM (124 - 96 + GR96_REGNUM)
 195 /* Memory Stack Pointer (gr125).  */
 196 #define MSP_REGNUM (125 - 96 + GR96_REGNUM)
 197 /* Register allocate bound (gr126).  */
 198 #define RAB_REGNUM (126 - 96 + GR96_REGNUM)
 199 /* Register Free Bound (gr127).  */
 200 #define RFB_REGNUM (127 - 96 + GR96_REGNUM)
 201 /* Register Stack Pointer.  */
 202 #define RSP_REGNUM GR1_REGNUM
 203 #define LR0_REGNUM 32
 204 #define BP_REGNUM 177
 205 #define FC_REGNUM 178
 206 #define CR_REGNUM 179
 207 #define Q_REGNUM 180
 208 #define VAB_REGNUM 181
 209 #define OPS_REGNUM (VAB_REGNUM + 1)
 210 #define CPS_REGNUM (VAB_REGNUM + 2)
 211 #define CFG_REGNUM (VAB_REGNUM + 3)
 212 #define CHA_REGNUM (VAB_REGNUM + 4)
 213 #define CHD_REGNUM (VAB_REGNUM + 5)
 214 #define CHC_REGNUM (VAB_REGNUM + 6)
 215 #define RBP_REGNUM (VAB_REGNUM + 7)
 216 #define TMC_REGNUM (VAB_REGNUM + 8)
 217 #define TMR_REGNUM (VAB_REGNUM + 9)
 218 #define NPC_REGNUM (VAB_REGNUM + 10)  /* pc0 */
 219 #define PC_REGNUM  (VAB_REGNUM + 11)  /* pc1 */
 220 #define PC2_REGNUM (VAB_REGNUM + 12)
 221 #define MMU_REGNUM (VAB_REGNUM + 13)
 222 #define LRU_REGNUM (VAB_REGNUM + 14)
 223 #define FPE_REGNUM (VAB_REGNUM + 15)
 224 #define INTE_REGNUM (VAB_REGNUM + 16)
 225 #define FPS_REGNUM (VAB_REGNUM + 17)
 226 #define EXO_REGNUM (VAB_REGNUM + 18)
 227 /* gr1 is defined above as 200 = VAB_REGNUM + 19 */
 228 #define ALU_REGNUM (VAB_REGNUM + 20)
 229 #define PS_REGNUM  ALU_REGNUM
 230 #define IPC_REGNUM (VAB_REGNUM + 21)
 231 #define IPA_REGNUM (VAB_REGNUM + 22)
 232 #define IPB_REGNUM (VAB_REGNUM + 23)
 233
 234 #endif  /* !defined(REGISTER_NAMES) */
 235
 236 /* Total amount of space needed to store our copies of the machine's
 237    register state, the array `registers'.  */
 238 #define REGISTER_BYTES (NUM_REGS * 4)
 239
 240 /* Index within `registers' of the first byte of the space for
 241    register N.  */
 242 #define REGISTER_BYTE(N)  ((N)*4)
 243
 244 /* Number of bytes of storage in the actual machine representation
 245    for register N.  */
 246
 247 /* All regs are 4 bytes.  */
 248
 249 #define REGISTER_RAW_SIZE(N) (4)
 250
 251 /* Number of bytes of storage in the program's representation
 252    for register N.  */
 253
 254 /* All regs are 4 bytes.  */
 255
 256 #define REGISTER_VIRTUAL_SIZE(N) (4)
 257
 258 /* Largest value REGISTER_RAW_SIZE can have.  */
 259
 260 #define MAX_REGISTER_RAW_SIZE (4)
 261
 262 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 263
 264 #define MAX_REGISTER_VIRTUAL_SIZE (4)
 265
 266 /* Nonzero if register N requires conversion
 267    from raw format to virtual format.  */
 268
 269 #define REGISTER_CONVERTIBLE(N) (0)
 270
 271 /* Convert data from raw format for register REGNUM
 272    to virtual format for register REGNUM.  */
 273
 274 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO) \
 275 { bcopy ((FROM), (TO), 4); }
 276
 277 /* Convert data from virtual format for register REGNUM
 278    to raw format for register REGNUM.  */
 279
 280 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
 281 { bcopy ((FROM), (TO), 4); }
 282
 283 /* Return the GDB type object for the "standard" data type
 284    of data in register N.  */
 285
 286 #define REGISTER_VIRTUAL_TYPE(N) \
 287   (((N) == PC_REGNUM || (N) == LRP_REGNUM || (N) == SLP_REGNUM         \
 288     || (N) == MSP_REGNUM || (N) == RAB_REGNUM || (N) == RFB_REGNUM     \
 289     || (N) == GR1_REGNUM || (N) == FP_REGNUM || (N) == LR0_REGNUM       \
 290     || (N) == NPC_REGNUM || (N) == PC2_REGNUM)                           \
 291    ? lookup_pointer_type (builtin_type_void) : builtin_type_int)
 292 \f
 293 /* Store the address of the place in which to copy the structure the
 294    subroutine will return.  This is called from call_function. */
 295 /* On the 29k the LRP points to the part of the structure beyond the first
 296    16 words.  */
 297 #define STORE_STRUCT_RETURN(ADDR, SP) \
 298   write_register (LRP_REGNUM, (ADDR) + 16 * 4);
 299
 300 /* Should call_function allocate stack space for a struct return?  */
 301 /* On the 29k objects over 16 words require the caller to allocate space.  */
 302 #define USE_STRUCT_CONVENTION(gcc_p, type) (TYPE_LENGTH (type) > 16 * 4)
 303
 304 /* Extract from an array REGBUF containing the (raw) register state
 305    a function return value of type TYPE, and copy that, in virtual format,
 306    into VALBUF.  */
 307
 308 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF)              \
 309   {                                                                        \
 310     int reg_length = TYPE_LENGTH (TYPE);                                   \
 311     if (reg_length > 16 * 4)                                               \
 312       {                                                                    \
 313         reg_length = 16 * 4;                                               \
 314         read_memory (*((int *)(REGBUF) + LRP_REGNUM), (VALBUF) + 16 * 4,   \
 315                      TYPE_LENGTH (TYPE) - 16 * 4);                         \
 316       }                                                                    \
 317     bcopy (((int *)(REGBUF))+RETURN_REGNUM, (VALBUF), reg_length);         \
 318   }
 319
 320 /* Write into appropriate registers a function return value
 321    of type TYPE, given in virtual format.  */
 322
 323 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 324   {                                                                       \
 325     int reg_length = TYPE_LENGTH (TYPE);                                  \
 326     if (reg_length > 16 * 4)                                              \
 327       {                                                                   \
 328         reg_length = 16 * 4;                                              \
 329         write_memory (read_register (LRP_REGNUM),                         \
 330                       (char *)(VALBUF) + 16 * 4,                          \
 331                       TYPE_LENGTH (TYPE) - 16 * 4);                       \
 332       }                                                                   \
 333     write_register_bytes (REGISTER_BYTE (RETURN_REGNUM), (char *)(VALBUF),  \
 334                           TYPE_LENGTH (TYPE));                            \
 335   }
 336 \f
 337 /* The am29k user's guide documents well what the stacks look like.
 338    But what isn't so clear there is how this interracts with the
 339    symbols, or with GDB.
 340    In the following saved_msp, saved memory stack pointer (which functions
 341    as a memory frame pointer), means either
 342    a register containing the memory frame pointer or, in the case of
 343    functions with fixed size memory frames (i.e. those who don't use
 344    alloca()), the result of the calculation msp + msize.
 345
 346    LOC_ARG, LOC_LOCAL - For GCC, these are relative to saved_msp.
 347      For high C, these are relative to msp (making alloca impossible).
 348    LOC_REGISTER, LOC_REGPARM - The register number is the number at the
 349      time the function is running (after the prologue), or in the case
 350      of LOC_REGPARM, may be a register number in the range 160-175.
 351
 352    The compilers do things like store an argument into memory, and then put out
 353    a LOC_ARG for it, or put it into global registers and put out a
 354    LOC_REGPARM.  Thus is it important to execute the first line of
 355    code (i.e. the line of the open brace, i.e. the prologue) of a function
 356    before trying to print arguments or anything.
 357
 358    The following diagram attempts to depict what is going on in memory
 359    (see also the _am29k user's guide_) and also how that interacts with
 360    GDB frames.  We arbitrarily pick fci->frame to point the same place
 361    as the register stack pointer; since we set it ourself in
 362    INIT_EXTRA_FRAME_INFO, and access it only through the FRAME_*
 363    macros, it doesn't really matter exactly how we
 364    do it.  However, note that FRAME_FP is used in two ways in GDB:
 365    (1) as a "magic cookie" which uniquely identifies frames (even over
 366    calls to the inferior), (2) (in PC_IN_CALL_DUMMY [ON_STACK])
 367    as the value of SP_REGNUM before the dummy frame was pushed.  These
 368    two meanings would be incompatible for the 29k if we defined
 369    CALL_DUMMY_LOCATION == ON_STACK (but we don't, so don't worry about it).
 370    Also note that "lr1" below, while called a frame pointer
 371    in the user's guide, has only one function:  To determine whether
 372    registers need to be filled in the function epilogue.
 373
 374    Consider the code:
 375               < call bar>
 376         loc1: . . .
 377         bar:  sub gr1,gr1,rsize_b
 378               . . .
 379               add mfp,msp,0
 380               sub msp,msp,msize_b
 381               . . .
 382               < call foo >
 383         loc2: . . .
 384         foo:  sub gr1,gr1,rsize_f
 385               . . .
 386               add mfp,msp,0
 387               sub msp,msp,msize_f
 388               . . .
 389         loc3: < suppose the inferior stops here >
 390
 391                    memory stack      register stack
 392                    |           |     |____________|
 393                    |           |     |____loc1____|
 394           +------->|___________|     |            |   ^
 395           |        | ^         |     |  locals_b  |   |
 396           |        | |         |     |____________|   |
 397           |        | |         |     |            |   | rsize_b
 398           |        | | msize_b |     | args_to_f  |   |
 399           |        | |         |     |____________|   |
 400           |        | |         |     |____lr1_____|   V
 401           |        | V         |     |____loc2____|<----------------+
 402           |   +--->|___________|<---------mfp     |   ^             |
 403           |   |    | ^         |     |  locals_f  |   |             |
 404           |   |    | | msize_f |     |____________|   |             |
 405           |   |    | |         |     |            |   | rsize_f     |
 406           |   |    | V         |     |   args     |   |             |
 407           |   |    |___________|<msp |____________|   |             |
 408           |   |                      |_____lr1____|   V             |
 409           |   |                      |___garbage__| <- gr1 <----+   |
 410           |   |                                                 |   |
 411           |   |                                                 |   |
 412           |   |                      pc=loc3                    |   |
 413           |   |                                                 |   |
 414           |   |                                                 |   |
 415           |   |            frame cache                          |   |
 416           |   |       |_________________|                       |   |
 417           |   |       |rsize=rsize_b    |                       |   |
 418           |   |       |msize=msize_b    |                       |   |
 419           +---|--------saved_msp        |                       |   |
 420               |       |frame------------------------------------|---+
 421               |       |pc=loc2          |                       |
 422               |       |_________________|                       |
 423               |       |rsize=rsize_f    |                       |
 424               |       |msize=msize_f    |                       |
 425               +--------saved_msp        |                       |
 426                       |frame------------------------------------+
 427                       |pc=loc3          |
 428                       |_________________|
 429
 430    So, is that sufficiently confusing?  Welcome to the 29000.
 431    Notes:
 432    * The frame for foo uses a memory frame pointer but the frame for
 433      bar does not.  In the latter case the saved_msp is
 434      computed by adding msize to the saved_msp of the
 435      next frame.
 436    * msize is in the frame cache only for high C's sake.  */
 437
 438 void read_register_stack ();
 439 long read_register_stack_integer ();
 440 \f
 441 #define EXTRA_FRAME_INFO  \
 442   CORE_ADDR saved_msp;    \
 443   unsigned int rsize;     \
 444   unsigned int msize;     \
 445   unsigned char flags;
 446
 447 /* Bits for flags in EXTRA_FRAME_INFO */
 448 #define TRANSPARENT     0x1             /* This is a transparent frame */
 449 #define MFP_USED        0x2             /* A memory frame pointer is used */
 450
 451 /* Because INIT_FRAME_PC gets passed fromleaf, that's where we init
 452    not only ->pc and ->frame, but all the extra stuff, when called from
 453    get_prev_frame_info, that is.  */
 454 #define INIT_EXTRA_FRAME_INFO(fromleaf, fci)  init_extra_frame_info(fci)
 455 void init_extra_frame_info ();
 456
 457 #define INIT_FRAME_PC(fromleaf, fci) init_frame_pc(fromleaf, fci)
 458 void init_frame_pc ();
 459
 460 \f
 461 /* FRAME_CHAIN takes a FRAME
 462    and produces the frame's chain-pointer.
 463
 464    However, if FRAME_CHAIN_VALID returns zero,
 465    it means the given frame is the outermost one and has no caller.  */
 466
 467 /* On the 29k, the nominal address of a frame is the address on the
 468    register stack of the return address (the one next to the incoming
 469    arguments, not down at the bottom so nominal address == stack pointer).
 470
 471    GDB expects "nominal address" to equal contents of FP_REGNUM,
 472    at least when it comes time to create the innermost frame.
 473    However, that doesn't work for us, so when creating the innermost
 474    frame we set ->frame ourselves in INIT_EXTRA_FRAME_INFO.  */
 475
 476 /* These are mostly dummies for the 29k because INIT_FRAME_PC
 477    sets prev->frame instead.  */
 478 #define FRAME_CHAIN(thisframe) ((thisframe)->frame + (thisframe)->rsize)
 479
 480 /* Determine if the frame has a 'previous' and back-traceable frame. */
 481 #define FRAME_IS_UNCHAINED(frame)       ((frame)->flags & TRANSPARENT)
 482
 483 /* Find the previous frame of a transparent routine.
 484  * For now lets not try and trace through a transparent routine (we might
 485  * have to assume that all transparent routines are traps).
 486  */
 487 #define FIND_PREV_UNCHAINED_FRAME(frame)        0
 488
 489 /* Define other aspects of the stack frame.  */
 490
 491 /* A macro that tells us whether the function invocation represented
 492    by FI does not have a frame on the stack associated with it.  If it
 493    does not, FRAMELESS is set to 1, else 0.  */
 494 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
 495   (FRAMELESS) = frameless_look_for_prologue(FI)
 496
 497 /* Saved pc (i.e. return address).  */
 498 #define FRAME_SAVED_PC(fraim) \
 499   (read_register_stack_integer ((fraim)->frame + (fraim)->rsize, 4))
 500
 501 /* Local variables (i.e. LOC_LOCAL) are on the memory stack, with their
 502    offsets being relative to the memory stack pointer (high C) or
 503    saved_msp (gcc).  */
 504
 505 #define FRAME_LOCALS_ADDRESS(fi) frame_locals_address (fi)
 506 extern CORE_ADDR frame_locals_address ();
 507
 508 /* Return number of args passed to a frame.
 509    Can return -1, meaning no way to tell.  */
 510 /* While we could go the effort of finding the tags word and getting
 511    the argcount field from it,
 512    (1) It only counts arguments in registers, i.e. the first 16 words
 513        of arguments
 514    (2) It gives the number of arguments the function was declared with
 515        not how many it was called with (or some variation, like all 16
 516        words for varadic functions).  This makes argcount pretty much
 517        redundant with -g info, even for varadic functions.
 518    So don't bother.  */
 519 #define FRAME_NUM_ARGS(numargs, fi) ((numargs) = -1)
 520
 521 #define FRAME_ARGS_ADDRESS(fi) FRAME_LOCALS_ADDRESS (fi)
 522
 523 /* Return number of bytes at start of arglist that are not really args.  */
 524
 525 #define FRAME_ARGS_SKIP 0
 526
 527 /* Provide our own get_saved_register.  HAVE_REGISTER_WINDOWS is insufficient
 528    because registers get renumbered on the 29k without getting saved.  */
 529
 530 #define GET_SAVED_REGISTER
 531 \f
 532 /* Call function stuff.  */
 533
 534 /* The dummy frame looks like this (see also the general frame picture
 535    above):
 536
 537                                         register stack
 538
 539                                       |                |  frame for function
 540                                       |   locals_sproc |  executing at time
 541                                       |________________|  of call_function.
 542                                       |                |  We must not disturb
 543                                       | args_out_sproc |  it.
 544         memory stack                  |________________|
 545                                       |____lr1_sproc___|<-+
 546        |            |                 |__retaddr_sproc_|  | <-- gr1 (at start)
 547        |____________|<-msp 0 <-----------mfp_dummy_____|  |
 548        |            |  (at start)     |  save regs     |  |
 549        | arg_slop   |                 |  pc0,pc1       |  |
 550        | (16 words) |                 | gr96-gr124     |  |
 551        |____________|<-msp 1--after   | sr160-sr162    |  |
 552        |            | PUSH_DUMMY_FRAME| sr128-sr135    |  |
 553        | struct ret |                 |________________|  |
 554        | 17+        |                 |                |  |
 555        |____________|<- lrp           | args_out_dummy |  |
 556        | struct ret |                 |  (16 words)    |  |
 557        | 16         |                 |________________|  |
 558        | (16 words) |                 |____lr1_dummy___|--+
 559        |____________|<- msp 2--after  |_retaddr_dummy__|<- gr1 after
 560        |            | struct ret      |                |   PUSH_DUMMY_FRAME
 561        | margs17+   | area allocated  |  locals_inf    |
 562        |            |                 |________________|    called
 563        |____________|<- msp 4--when   |                |    function's
 564        |            |   inf called    | args_out_inf   |    frame (set up
 565        | margs16    |                 |________________|    by called
 566        | (16 words) |                 |_____lr1_inf____|    function).
 567        |____________|<- msp 3--after  |       .        |
 568        |            |   args pushed   |       .        |
 569        |            |                 |       .        |
 570                                       |                |
 571
 572    arg_slop: This area is so that when the call dummy adds 16 words to
 573       the msp, it won't end up larger than mfp_dummy (it is needed in the
 574       case where margs and struct_ret do not add up to at least 16 words).
 575    struct ret:  This area is allocated by GDB if the return value is more
 576       than 16 words.  struct ret_16 is not used on the 29k.
 577    margs:  Pushed by GDB.  The call dummy copies the first 16 words to
 578       args_out_dummy.
 579    retaddr_sproc:  Contains the PC at the time we call the function.
 580       set by PUSH_DUMMY_FRAME and read by POP_FRAME.
 581    retaddr_dummy:  This points to a breakpoint instruction in the dummy.  */
 582 \f
 583 /* Rsize for dummy frame, in bytes.  */
 584
 585 /* Bytes for outgoing args, lr1, and retaddr.  */
 586 #define DUMMY_ARG (2 * 4 + 16 * 4)
 587
 588 /* Number of special registers (sr128-) to save.  */
 589 #define DUMMY_SAVE_SR128 8
 590 /* Number of special registers (sr160-) to save.  */
 591 #define DUMMY_SAVE_SR160 3
 592 /* Number of general (gr96- or gr64-) registers to save.  */
 593 #define DUMMY_SAVE_GREGS 29
 594
 595 #define DUMMY_FRAME_RSIZE \
 596 (4 /* mfp_dummy */        \
 597  + 2 * 4  /* pc0, pc1 */  \
 598  + DUMMY_SAVE_GREGS * 4   \
 599  + DUMMY_SAVE_SR160 * 4   \
 600  + DUMMY_SAVE_SR128 * 4   \
 601  + DUMMY_ARG              \
 602  )
 603
 604 /* Push an empty stack frame, to record the current PC, etc.  */
 605
 606 #define PUSH_DUMMY_FRAME push_dummy_frame()
 607 extern void push_dummy_frame ();
 608
 609 /* Discard from the stack the innermost frame,
 610    restoring all saved registers.  */
 611
 612 #define POP_FRAME pop_frame()
 613 extern void pop_frame ();
 614
 615 /* This sequence of words is the instructions
 616    mtsrim cr, 15
 617    loadm 0, 0, lr2, msp     ; load first 16 words of arguments into registers
 618    add msp, msp, 16 * 4     ; point to the remaining arguments
 619   CONST_INSN:
 620    const lr0,inf
 621    consth lr0,inf
 622    calli lr0, lr0
 623    aseq 0x40,gr1,gr1   ; nop
 624    asneq 0x50,gr1,gr1  ; breakpoint
 625    */
 626
 627 /* Position of the "const" instruction within CALL_DUMMY in bytes.  */
 628 #define CONST_INSN (3 * 4)
 629 #if TARGET_BYTE_ORDER == HOST_BYTE_ORDER
 630 #define CALL_DUMMY {0x0400870f,\
 631                 0x36008200|(MSP_HW_REGNUM), \
 632                 0x15000040|(MSP_HW_REGNUM<<8)|(MSP_HW_REGNUM<<16), \
 633                 0x03ff80ff, 0x02ff80ff, 0xc8008080, 0x70400101, 0x72500101}
 634 #else /* Byte order differs.  */
 635   you lose
 636 #endif /* Byte order differs.  */
 637 #define CALL_DUMMY_LENGTH (8 * 4)
 638
 639 #define CALL_DUMMY_START_OFFSET 0  /* Start execution at beginning of dummy */
 640
 641 /* Helper macro for FIX_CALL_DUMMY.  WORDP is a long * which points to a
 642    word in target byte order; bits 0-7 and 16-23 of *WORDP are replaced with
 643    bits 0-7 and 8-15 of DATA (which is in host byte order).  */
 644
 645 #if TARGET_BYTE_ORDER == BIG_ENDIAN
 646 #define STUFF_I16(WORDP, DATA) \
 647   { \
 648     *((char *)(WORDP) + 3) = ((DATA) & 0xff);\
 649     *((char *)(WORDP) + 1) = (((DATA) >> 8) & 0xff);\
 650   }
 651 #else /* Target is little endian.  */
 652 #define STUFF_I16(WORDP, DATA) \
 653   {
 654     *(char *)(WORDP) = ((DATA) & 0xff);
 655     *((char *)(WORDP) + 2) = (((DATA) >> 8) & 0xff);
 656   }
 657 #endif /* Target is little endian.  */
 658
 659 /* Insert the specified number of args and function address
 660    into a call sequence of the above form stored at DUMMYNAME.  */
 661
 662 /* Currently this stuffs in the address of the function that we are calling.
 663    If different 29k systems use different breakpoint instructions, it
 664    could also stuff BREAKPOINT in the right place (to avoid having to
 665    duplicate CALL_DUMMY in each tm-*.h file).  */
 666
 667 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p)   \
 668   {\
 669     STUFF_I16((char *)dummyname + CONST_INSN, fun);\
 670     STUFF_I16((char *)dummyname + CONST_INSN + 4, fun >> 16);\
 671   }
 672
 673 /* 29k architecture has separate data & instruction memories -- wired to
 674    different pins on the chip -- and can't execute the data memory.
 675    Also, there should be space after text_end;
 676    we won't get a SIGSEGV or scribble on data space.  */
 677
 678 #define CALL_DUMMY_LOCATION AFTER_TEXT_END
 679
 680 /* Because of this, we need (as a kludge) to know the addresses of the
 681    text section.  */
 682
 683 #define NEED_TEXT_START_END
 684
 685 /* How to translate register numbers in the .stab's into gdb's internal register
 686    numbers.  We don't translate them, but we warn if an invalid register
 687    number is seen.  Note that FIXME, we use the value "sym" as an implicit
 688    argument in printing the error message.  It happens to be available where
 689    this macro is used.  (This macro definition appeared in a late revision
 690    of gdb-3.91.6 and is not well tested.  Also, it should be a "complaint".) */
 691
 692 #define STAB_REG_TO_REGNUM(num) \
 693         (((num) > LR0_REGNUM + 127) \
 694            ? fprintf(stderr,    \
 695                 "Invalid register number %d in symbol table entry for %s\n", \
 696                  (num), SYMBOL_NAME (sym)), (num)       \
 697            : (num))