gdb/config/a29k/tm-a29k.h

   1 /* Parameters for target machine of AMD 29000, for GDB, the GNU debugger.
   2    Copyright 1990, 1991, 1993 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 a29k machines/systems, the
  26    machine/system-specific parts should be removed from this file (a
  27    la tm-m68k.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 /* Offset from address of function to start of its code.
  39    Zero on most machines.  */
  40
  41 #define FUNCTION_START_OFFSET 0
  42
  43 /* Advance PC across any function entry prologue instructions
  44    to reach some "real" code.  */
  45
  46 #define SKIP_PROLOGUE(pc) \
  47   { pc = skip_prologue (pc); }
  48 CORE_ADDR skip_prologue ();
  49
  50 /* Immediately after a function call, return the saved pc.
  51    Can't go through the frames for this because on some machines
  52    the new frame is not set up until the new function executes
  53    some instructions.  */
  54
  55 #define SAVED_PC_AFTER_CALL(frame) ((frame->flags & TRANSPARENT) \
  56                                     ? read_register (TPC_REGNUM) \
  57                                     : read_register (LR0_REGNUM))
  58
  59 /* I'm not sure about the exact value of this, but based on looking
  60    at the stack pointer when we get to main this seems to be right.
  61
  62    This is the register stack; We call it "CONTROL" in GDB for consistency
  63    with Pyramid.  */
  64 /* I suspect this is obsolete, just like STACK_END_ADDR.  */
  65 #define CONTROL_END_ADDR 0x80200000
  66
  67 /* Stack grows downward.  */
  68
  69 #define INNER_THAN <
  70
  71 /* Stack must be aligned on 32-bit word boundaries.  */
  72 #define STACK_ALIGN(ADDR) (((ADDR) + 3) & ~3)
  73
  74 /* Sequence of bytes for breakpoint instruction.  */
  75 /* ASNEQ 0x50, gr1, gr1
  76    The trap number 0x50 is chosen arbitrarily.
  77    We let the command line (or previously included files) override this
  78    setting.  */
  79 #ifndef BREAKPOINT
  80 #if TARGET_BYTE_ORDER == BIG_ENDIAN
  81 #define BREAKPOINT {0x72, 0x50, 0x01, 0x01}
  82 #else /* Target is little-endian.  */
  83 #define BREAKPOINT {0x01, 0x01, 0x50, 0x72}
  84 #endif /* Target is little-endian.  */
  85 #endif /* BREAKPOINT */
  86
  87 /* Amount PC must be decremented by after a breakpoint.
  88    This is often the number of bytes in BREAKPOINT
  89    but not always.  */
  90
  91 #define DECR_PC_AFTER_BREAK 0
  92
  93 /* Nonzero if instruction at PC is a return instruction.
  94    On the a29k, this is a "jmpi l0" instruction.  */
  95
  96 #define ABOUT_TO_RETURN(pc) \
  97   ((read_memory_integer (pc, 4) & 0xff0000ff) == 0xc0000080)
  98
  99 /* Return 1 if P points to an invalid floating point value.  */
 100
 101 #define INVALID_FLOAT(p, len) 0   /* Just a first guess; not checked */
 102
 103 /* Say how long (ordinary) registers are.  */
 104
 105 #define REGISTER_TYPE long
 106
 107 /* Allow the register declarations here to be overridden for remote
 108    kernel debugging.  */
 109 #if !defined (REGISTER_NAMES)
 110
 111 /* Number of machine registers */
 112
 113 #define NUM_REGS 205
 114
 115 /* Initializer for an array of names of registers.
 116    There should be NUM_REGS strings in this initializer.
 117
 118    FIXME, add floating point registers and support here.
 119
 120    Also note that this list does not attempt to deal with kernel
 121    debugging (in which the first 32 registers are gr64-gr95).  */
 122
 123 #define REGISTER_NAMES \
 124 {"gr96", "gr97", "gr98", "gr99", "gr100", "gr101", "gr102", "gr103", "gr104", \
 125  "gr105", "gr106", "gr107", "gr108", "gr109", "gr110", "gr111", "gr112", \
 126  "gr113", "gr114", "gr115", "gr116", "gr117", "gr118", "gr119", "gr120", \
 127  "gr121", "gr122", "gr123", "gr124", "gr125", "gr126", "gr127",          \
 128  "lr0", "lr1", "lr2", "lr3", "lr4", "lr5", "lr6", "lr7", "lr8", "lr9",   \
 129  "lr10", "lr11", "lr12", "lr13", "lr14", "lr15", "lr16", "lr17", "lr18", \
 130  "lr19", "lr20", "lr21", "lr22", "lr23", "lr24", "lr25", "lr26", "lr27", \
 131  "lr28", "lr29", "lr30", "lr31", "lr32", "lr33", "lr34", "lr35", "lr36", \
 132  "lr37", "lr38", "lr39", "lr40", "lr41", "lr42", "lr43", "lr44", "lr45", \
 133  "lr46", "lr47", "lr48", "lr49", "lr50", "lr51", "lr52", "lr53", "lr54", \
 134  "lr55", "lr56", "lr57", "lr58", "lr59", "lr60", "lr61", "lr62", "lr63", \
 135  "lr64", "lr65", "lr66", "lr67", "lr68", "lr69", "lr70", "lr71", "lr72", \
 136  "lr73", "lr74", "lr75", "lr76", "lr77", "lr78", "lr79", "lr80", "lr81", \
 137  "lr82", "lr83", "lr84", "lr85", "lr86", "lr87", "lr88", "lr89", "lr90", \
 138  "lr91", "lr92", "lr93", "lr94", "lr95", "lr96", "lr97", "lr98", "lr99", \
 139  "lr100", "lr101", "lr102", "lr103", "lr104", "lr105", "lr106", "lr107", \
 140  "lr108", "lr109", "lr110", "lr111", "lr112", "lr113", "lr114", "lr115", \
 141  "lr116", "lr117", "lr118", "lr119", "lr120", "lr121", "lr122", "lr123", \
 142  "lr124", "lr125", "lr126", "lr127",                                     \
 143   "AI0", "AI1", "AI2", "AI3", "AI4", "AI5", "AI6", "AI7", "AI8", "AI9",  \
 144   "AI10", "AI11", "AI12", "AI13", "AI14", "AI15", "FP",                  \
 145   "bp", "fc", "cr", "q",                                                 \
 146   "vab", "ops", "cps", "cfg", "cha", "chd", "chc", "rbp", "tmc", "tmr",  \
 147   "pc0", "pc1", "pc2", "mmu", "lru", "fpe", "inte", "fps", "exo", "gr1",  \
 148   "alu", "ipc", "ipa", "ipb" }
 149
 150 /*
 151  * Converts an sdb register number to an internal gdb register number.
 152  * Currently under epi, gr96->0...gr127->31...lr0->32...lr127->159, or...
 153  *                      gr64->0...gr95->31, lr0->32...lr127->159.
 154  */
 155 #define SDB_REG_TO_REGNUM(value) \
 156   (((value) >= 96 && (value) <= 127) ? ((value) - 96) : \
 157    ((value) >= 128 && (value) <=  255) ? ((value) - 128 + LR0_REGNUM) : \
 158    (value))
 159
 160 /*
 161  * Provide the processor register numbers of some registers that are
 162  * expected/written in instructions that might change under different
 163  * register sets.  Namely, gcc can compile (-mkernel-registers) so that
 164  * it uses gr64-gr95 in stead of gr96-gr127.
 165  */
 166 #define MSP_HW_REGNUM   125             /* gr125 */
 167 #define RAB_HW_REGNUM   126             /* gr126 */
 168
 169 /* Convert Processor Special register #x to REGISTER_NAMES register # */
 170 #define SR_REGNUM(x) \
 171   ((x) < 15  ? VAB_REGNUM + (x)                                  \
 172    : (x) >= 128 && (x) < 131 ? IPC_REGNUM + (x) - 128            \
 173    : (x) == 131 ? Q_REGNUM                                       \
 174    : (x) == 132 ? ALU_REGNUM                                     \
 175    : (x) >= 133 && (x) < 136 ? BP_REGNUM + (x) - 133             \
 176    : (x) >= 160 && (x) < 163 ? FPE_REGNUM + (x) - 160            \
 177    : (x) == 164 ? EXO_REGNUM                                     \
 178    : (error ("Internal error in SR_REGNUM"), 0))
 179 #define GR96_REGNUM 0
 180
 181 /* Define the return register separately, so it can be overridden for
 182    kernel procedure calling conventions. */
 183 #define RETURN_REGNUM   GR96_REGNUM
 184 #define GR1_REGNUM 200
 185 /* This needs to be the memory stack pointer, not the register stack pointer,
 186    to make call_function work right.  */
 187 #define SP_REGNUM MSP_REGNUM
 188 #define FP_REGNUM 33 /* lr1 */
 189
 190 /* Return register for transparent calling convention (gr122).  */
 191 #define TPC_REGNUM (122 - 96 + GR96_REGNUM)
 192
 193 /* Large Return Pointer (gr123).  */
 194 #define LRP_REGNUM (123 - 96 + GR96_REGNUM)
 195
 196 /* Static link pointer (gr124).  */
 197 #define SLP_REGNUM (124 - 96 + GR96_REGNUM)
 198
 199 /* Memory Stack Pointer (gr125).  */
 200 #define MSP_REGNUM (125 - 96 + GR96_REGNUM)
 201
 202 /* Register allocate bound (gr126).  */
 203 #define RAB_REGNUM (126 - 96 + GR96_REGNUM)
 204
 205 /* Register Free Bound (gr127).  */
 206 #define RFB_REGNUM (127 - 96 + GR96_REGNUM)
 207
 208 /* Register Stack Pointer.  */
 209 #define RSP_REGNUM GR1_REGNUM
 210 #define LR0_REGNUM 32
 211 #define BP_REGNUM 177
 212 #define FC_REGNUM 178
 213 #define CR_REGNUM 179
 214 #define Q_REGNUM 180
 215 #define VAB_REGNUM 181
 216 #define OPS_REGNUM (VAB_REGNUM + 1)
 217 #define CPS_REGNUM (VAB_REGNUM + 2)
 218 #define CFG_REGNUM (VAB_REGNUM + 3)
 219 #define CHA_REGNUM (VAB_REGNUM + 4)
 220 #define CHD_REGNUM (VAB_REGNUM + 5)
 221 #define CHC_REGNUM (VAB_REGNUM + 6)
 222 #define RBP_REGNUM (VAB_REGNUM + 7)
 223 #define TMC_REGNUM (VAB_REGNUM + 8)
 224 #define TMR_REGNUM (VAB_REGNUM + 9)
 225 #define NPC_REGNUM (VAB_REGNUM + 10)  /* pc0 */
 226 #define PC_REGNUM  (VAB_REGNUM + 11)  /* pc1 */
 227 #define PC2_REGNUM (VAB_REGNUM + 12)
 228 #define MMU_REGNUM (VAB_REGNUM + 13)
 229 #define LRU_REGNUM (VAB_REGNUM + 14)
 230 #define FPE_REGNUM (VAB_REGNUM + 15)
 231 #define INTE_REGNUM (VAB_REGNUM + 16)
 232 #define FPS_REGNUM (VAB_REGNUM + 17)
 233 #define EXO_REGNUM (VAB_REGNUM + 18)
 234 /* gr1 is defined above as 200 = VAB_REGNUM + 19 */
 235 #define ALU_REGNUM (VAB_REGNUM + 20)
 236 #define PS_REGNUM  ALU_REGNUM
 237 #define IPC_REGNUM (VAB_REGNUM + 21)
 238 #define IPA_REGNUM (VAB_REGNUM + 22)
 239 #define IPB_REGNUM (VAB_REGNUM + 23)
 240
 241 #endif  /* !defined(REGISTER_NAMES) */
 242
 243 /* Total amount of space needed to store our copies of the machine's
 244    register state, the array `registers'.  */
 245 #define REGISTER_BYTES (NUM_REGS * 4)
 246
 247 /* Index within `registers' of the first byte of the space for
 248    register N.  */
 249 #define REGISTER_BYTE(N)  ((N)*4)
 250
 251 /* Number of bytes of storage in the actual machine representation
 252    for register N.  */
 253
 254 /* All regs are 4 bytes.  */
 255
 256 #define REGISTER_RAW_SIZE(N) (4)
 257
 258 /* Number of bytes of storage in the program's representation
 259    for register N.  */
 260
 261 /* All regs are 4 bytes.  */
 262
 263 #define REGISTER_VIRTUAL_SIZE(N) (4)
 264
 265 /* Largest value REGISTER_RAW_SIZE can have.  */
 266
 267 #define MAX_REGISTER_RAW_SIZE (4)
 268
 269 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 270
 271 #define MAX_REGISTER_VIRTUAL_SIZE (4)
 272
 273 /* Return the GDB type object for the "standard" data type
 274    of data in register N.  */
 275
 276 #define REGISTER_VIRTUAL_TYPE(N) \
 277   (((N) == PC_REGNUM || (N) == LRP_REGNUM || (N) == SLP_REGNUM         \
 278     || (N) == MSP_REGNUM || (N) == RAB_REGNUM || (N) == RFB_REGNUM     \
 279     || (N) == GR1_REGNUM || (N) == FP_REGNUM || (N) == LR0_REGNUM       \
 280     || (N) == NPC_REGNUM || (N) == PC2_REGNUM)                           \
 281    ? lookup_pointer_type (builtin_type_void) : builtin_type_int)
 282 \f
 283 /* Store the address of the place in which to copy the structure the
 284    subroutine will return.  This is called from call_function. */
 285 /* On the a29k the LRP points to the part of the structure beyond the first
 286    16 words.  */
 287 #define STORE_STRUCT_RETURN(ADDR, SP) \
 288   write_register (LRP_REGNUM, (ADDR) + 16 * 4);
 289
 290 /* Should call_function allocate stack space for a struct return?  */
 291 /* On the a29k objects over 16 words require the caller to allocate space.  */
 292 #define USE_STRUCT_CONVENTION(gcc_p, type) (TYPE_LENGTH (type) > 16 * 4)
 293
 294 /* Extract from an array REGBUF containing the (raw) register state
 295    a function return value of type TYPE, and copy that, in virtual format,
 296    into VALBUF.  */
 297
 298 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF)              \
 299   {                                                                        \
 300     int reg_length = TYPE_LENGTH (TYPE);                                   \
 301     if (reg_length > 16 * 4)                                               \
 302       {                                                                    \
 303         reg_length = 16 * 4;                                               \
 304         read_memory (*((int *)(REGBUF) + LRP_REGNUM), (VALBUF) + 16 * 4,   \
 305                      TYPE_LENGTH (TYPE) - 16 * 4);                         \
 306       }                                                                    \
 307     memcpy ((VALBUF), ((int *)(REGBUF))+RETURN_REGNUM, reg_length);        \
 308   }
 309
 310 /* Write into appropriate registers a function return value
 311    of type TYPE, given in virtual format.  */
 312
 313 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 314   {                                                                       \
 315     int reg_length = TYPE_LENGTH (TYPE);                                  \
 316     if (reg_length > 16 * 4)                                              \
 317       {                                                                   \
 318         reg_length = 16 * 4;                                              \
 319         write_memory (read_register (LRP_REGNUM),                         \
 320                       (char *)(VALBUF) + 16 * 4,                          \
 321                       TYPE_LENGTH (TYPE) - 16 * 4);                       \
 322       }                                                                   \
 323     write_register_bytes (REGISTER_BYTE (RETURN_REGNUM), (char *)(VALBUF),  \
 324                           TYPE_LENGTH (TYPE));                            \
 325   }
 326 \f
 327 /* The a29k user's guide documents well what the stacks look like.
 328    But what isn't so clear there is how this interracts with the
 329    symbols, or with GDB.
 330    In the following saved_msp, saved memory stack pointer (which functions
 331    as a memory frame pointer), means either
 332    a register containing the memory frame pointer or, in the case of
 333    functions with fixed size memory frames (i.e. those who don't use
 334    alloca()), the result of the calculation msp + msize.
 335
 336    LOC_ARG, LOC_LOCAL - For GCC, these are relative to saved_msp.
 337      For high C, these are relative to msp (making alloca impossible).
 338    LOC_REGISTER, LOC_REGPARM - The register number is the number at the
 339      time the function is running (after the prologue), or in the case
 340      of LOC_REGPARM, may be a register number in the range 160-175.
 341
 342    The compilers do things like store an argument into memory, and then put out
 343    a LOC_ARG for it, or put it into global registers and put out a
 344    LOC_REGPARM.  Thus is it important to execute the first line of
 345    code (i.e. the line of the open brace, i.e. the prologue) of a function
 346    before trying to print arguments or anything.
 347
 348    The following diagram attempts to depict what is going on in memory
 349    (see also the _a29k user's guide_) and also how that interacts with
 350    GDB frames.  We arbitrarily pick fci->frame to point the same place
 351    as the register stack pointer; since we set it ourself in
 352    INIT_EXTRA_FRAME_INFO, and access it only through the FRAME_*
 353    macros, it doesn't really matter exactly how we
 354    do it.  However, note that FRAME_FP is used in two ways in GDB:
 355    (1) as a "magic cookie" which uniquely identifies frames (even over
 356    calls to the inferior), (2) (in PC_IN_CALL_DUMMY [ON_STACK])
 357    as the value of SP_REGNUM before the dummy frame was pushed.  These
 358    two meanings would be incompatible for the a29k if we defined
 359    CALL_DUMMY_LOCATION == ON_STACK (but we don't, so don't worry about it).
 360    Also note that "lr1" below, while called a frame pointer
 361    in the user's guide, has only one function:  To determine whether
 362    registers need to be filled in the function epilogue.
 363
 364    Consider the code:
 365               < call bar>
 366         loc1: . . .
 367         bar:  sub gr1,gr1,rsize_b
 368               . . .
 369               add mfp,msp,0
 370               sub msp,msp,msize_b
 371               . . .
 372               < call foo >
 373         loc2: . . .
 374         foo:  sub gr1,gr1,rsize_f
 375               . . .
 376               add mfp,msp,0
 377               sub msp,msp,msize_f
 378               . . .
 379         loc3: < suppose the inferior stops here >
 380
 381                    memory stack      register stack
 382                    |           |     |____________|
 383                    |           |     |____loc1____|
 384           +------->|___________|     |            |   ^
 385           |        | ^         |     |  locals_b  |   |
 386           |        | |         |     |____________|   |
 387           |        | |         |     |            |   | rsize_b
 388           |        | | msize_b |     | args_to_f  |   |
 389           |        | |         |     |____________|   |
 390           |        | |         |     |____lr1_____|   V
 391           |        | V         |     |____loc2____|<----------------+
 392           |   +--->|___________|<---------mfp     |   ^             |
 393           |   |    | ^         |     |  locals_f  |   |             |
 394           |   |    | | msize_f |     |____________|   |             |
 395           |   |    | |         |     |            |   | rsize_f     |
 396           |   |    | V         |     |   args     |   |             |
 397           |   |    |___________|<msp |____________|   |             |
 398           |   |                      |_____lr1____|   V             |
 399           |   |                      |___garbage__| <- gr1 <----+   |
 400           |   |                                                 |   |
 401           |   |                                                 |   |
 402           |   |                      pc=loc3                    |   |
 403           |   |                                                 |   |
 404           |   |                                                 |   |
 405           |   |            frame cache                          |   |
 406           |   |       |_________________|                       |   |
 407           |   |       |rsize=rsize_b    |                       |   |
 408           |   |       |msize=msize_b    |                       |   |
 409           +---|--------saved_msp        |                       |   |
 410               |       |frame------------------------------------|---+
 411               |       |pc=loc2          |                       |
 412               |       |_________________|                       |
 413               |       |rsize=rsize_f    |                       |
 414               |       |msize=msize_f    |                       |
 415               +--------saved_msp        |                       |
 416                       |frame------------------------------------+
 417                       |pc=loc3          |
 418                       |_________________|
 419
 420    So, is that sufficiently confusing?  Welcome to the 29000.
 421    Notes:
 422    * The frame for foo uses a memory frame pointer but the frame for
 423      bar does not.  In the latter case the saved_msp is
 424      computed by adding msize to the saved_msp of the
 425      next frame.
 426    * msize is in the frame cache only for high C's sake.  */
 427
 428 void read_register_stack ();
 429 long read_register_stack_integer ();
 430 \f
 431 #define EXTRA_FRAME_INFO  \
 432   CORE_ADDR saved_msp;    \
 433   unsigned int rsize;     \
 434   unsigned int msize;     \
 435   unsigned char flags;
 436
 437 /* Bits for flags in EXTRA_FRAME_INFO */
 438 #define TRANSPARENT     0x1             /* This is a transparent frame */
 439 #define MFP_USED        0x2             /* A memory frame pointer is used */
 440
 441 /* Because INIT_FRAME_PC gets passed fromleaf, that's where we init
 442    not only ->pc and ->frame, but all the extra stuff, when called from
 443    get_prev_frame_info, that is.  */
 444 #define INIT_EXTRA_FRAME_INFO(fromleaf, fci)  init_extra_frame_info(fci)
 445 void init_extra_frame_info ();
 446
 447 #define INIT_FRAME_PC(fromleaf, fci) init_frame_pc(fromleaf, fci)
 448 void init_frame_pc ();
 449
 450 \f
 451 /* FRAME_CHAIN takes a FRAME
 452    and produces the frame's chain-pointer.
 453
 454    However, if FRAME_CHAIN_VALID returns zero,
 455    it means the given frame is the outermost one and has no caller.  */
 456
 457 /* On the a29k, the nominal address of a frame is the address on the
 458    register stack of the return address (the one next to the incoming
 459    arguments, not down at the bottom so nominal address == stack pointer).
 460
 461    GDB expects "nominal address" to equal contents of FP_REGNUM,
 462    at least when it comes time to create the innermost frame.
 463    However, that doesn't work for us, so when creating the innermost
 464    frame we set ->frame ourselves in INIT_EXTRA_FRAME_INFO.  */
 465
 466 /* These are mostly dummies for the a29k because INIT_FRAME_PC
 467    sets prev->frame instead.  */
 468 /* If rsize is zero, we must be at end of stack (or otherwise hosed).
 469    If we don't check rsize, we loop forever if we see rsize == 0.  */
 470 #define FRAME_CHAIN(thisframe) \
 471   ((thisframe)->rsize == 0 \
 472    ? 0 \
 473    : (thisframe)->frame + (thisframe)->rsize)
 474
 475 /* Determine if the frame has a 'previous' and back-traceable frame. */
 476 #define FRAME_IS_UNCHAINED(frame)       ((frame)->flags & TRANSPARENT)
 477
 478 /* Find the previous frame of a transparent routine.
 479  * For now lets not try and trace through a transparent routine (we might
 480  * have to assume that all transparent routines are traps).
 481  */
 482 #define FIND_PREV_UNCHAINED_FRAME(frame)        0
 483
 484 /* Define other aspects of the stack frame.  */
 485
 486 /* A macro that tells us whether the function invocation represented
 487    by FI does not have a frame on the stack associated with it.  If it
 488    does not, FRAMELESS is set to 1, else 0.  */
 489 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
 490   (FRAMELESS) = frameless_look_for_prologue(FI)
 491
 492 /* Saved pc (i.e. return address).  */
 493 #define FRAME_SAVED_PC(fraim) \
 494   (read_register_stack_integer ((fraim)->frame + (fraim)->rsize, 4))
 495
 496 /* Local variables (i.e. LOC_LOCAL) are on the memory stack, with their
 497    offsets being relative to the memory stack pointer (high C) or
 498    saved_msp (gcc).  */
 499
 500 #define FRAME_LOCALS_ADDRESS(fi) frame_locals_address (fi)
 501 extern CORE_ADDR frame_locals_address ();
 502
 503 /* Return number of args passed to a frame.
 504    Can return -1, meaning no way to tell.  */
 505 /* While we could go the effort of finding the tags word and getting
 506    the argcount field from it,
 507    (1) It only counts arguments in registers, i.e. the first 16 words
 508        of arguments
 509    (2) It gives the number of arguments the function was declared with
 510        not how many it was called with (or some variation, like all 16
 511        words for varadic functions).  This makes argcount pretty much
 512        redundant with -g info, even for varadic functions.
 513    So don't bother.  */
 514 #define FRAME_NUM_ARGS(numargs, fi) ((numargs) = -1)
 515
 516 #define FRAME_ARGS_ADDRESS(fi) FRAME_LOCALS_ADDRESS (fi)
 517
 518 /* Return number of bytes at start of arglist that are not really args.  */
 519
 520 #define FRAME_ARGS_SKIP 0
 521
 522 /* Provide our own get_saved_register.  HAVE_REGISTER_WINDOWS is insufficient
 523    because registers get renumbered on the a29k without getting saved.  */
 524
 525 #define GET_SAVED_REGISTER
 526 \f
 527 /* Call function stuff.  */
 528
 529 /* The dummy frame looks like this (see also the general frame picture
 530    above):
 531
 532                                         register stack
 533
 534                                       |                |  frame for function
 535                                       |   locals_sproc |  executing at time
 536                                       |________________|  of call_function.
 537                                       |                |  We must not disturb
 538                                       | args_out_sproc |  it.
 539         memory stack                  |________________|
 540                                       |____lr1_sproc___|<-+
 541        |            |                 |__retaddr_sproc_|  | <-- gr1 (at start)
 542        |____________|<-msp 0 <-----------mfp_dummy_____|  |
 543        |            |  (at start)     |  save regs     |  |
 544        | arg_slop   |                 |  pc0,pc1       |  |
 545        | (16 words) |                 | gr96-gr124     |  |
 546        |____________|<-msp 1--after   | sr160-sr162    |  |
 547        |            | PUSH_DUMMY_FRAME| sr128-sr135    |  |
 548        | struct ret |                 |________________|  |
 549        | 17+        |                 |                |  |
 550        |____________|<- lrp           | args_out_dummy |  |
 551        | struct ret |                 |  (16 words)    |  |
 552        | 16         |                 |________________|  |
 553        | (16 words) |                 |____lr1_dummy___|--+
 554        |____________|<- msp 2--after  |_retaddr_dummy__|<- gr1 after
 555        |            | struct ret      |                |   PUSH_DUMMY_FRAME
 556        | margs17+   | area allocated  |  locals_inf    |
 557        |            |                 |________________|    called
 558        |____________|<- msp 4--when   |                |    function's
 559        |            |   inf called    | args_out_inf   |    frame (set up
 560        | margs16    |                 |________________|    by called
 561        | (16 words) |                 |_____lr1_inf____|    function).
 562        |____________|<- msp 3--after  |       .        |
 563        |            |   args pushed   |       .        |
 564        |            |                 |       .        |
 565                                       |                |
 566
 567    arg_slop: This area is so that when the call dummy adds 16 words to
 568       the msp, it won't end up larger than mfp_dummy (it is needed in the
 569       case where margs and struct_ret do not add up to at least 16 words).
 570    struct ret:  This area is allocated by GDB if the return value is more
 571       than 16 words.  struct ret_16 is not used on the a29k.
 572    margs:  Pushed by GDB.  The call dummy copies the first 16 words to
 573       args_out_dummy.
 574    retaddr_sproc:  Contains the PC at the time we call the function.
 575       set by PUSH_DUMMY_FRAME and read by POP_FRAME.
 576    retaddr_dummy:  This points to a breakpoint instruction in the dummy.  */
 577 \f
 578 /* Rsize for dummy frame, in bytes.  */
 579
 580 /* Bytes for outgoing args, lr1, and retaddr.  */
 581 #define DUMMY_ARG (2 * 4 + 16 * 4)
 582
 583 /* Number of special registers (sr128-) to save.  */
 584 #define DUMMY_SAVE_SR128 8
 585 /* Number of special registers (sr160-) to save.  */
 586 #define DUMMY_SAVE_SR160 3
 587 /* Number of general (gr96- or gr64-) registers to save.  */
 588 #define DUMMY_SAVE_GREGS 29
 589
 590 #define DUMMY_FRAME_RSIZE \
 591 (4 /* mfp_dummy */        \
 592  + 2 * 4  /* pc0, pc1 */  \
 593  + DUMMY_SAVE_GREGS * 4   \
 594  + DUMMY_SAVE_SR160 * 4   \
 595  + DUMMY_SAVE_SR128 * 4   \
 596  + DUMMY_ARG              \
 597  + 4 /* pad to doubleword */ )
 598
 599 /* Push an empty stack frame, to record the current PC, etc.  */
 600
 601 #define PUSH_DUMMY_FRAME push_dummy_frame()
 602 extern void push_dummy_frame ();
 603
 604 /* Discard from the stack the innermost frame,
 605    restoring all saved registers.  */
 606
 607 #define POP_FRAME pop_frame()
 608 extern void pop_frame ();
 609
 610 /* This sequence of words is the instructions
 611    mtsrim cr, 15
 612    loadm 0, 0, lr2, msp     ; load first 16 words of arguments into registers
 613    add msp, msp, 16 * 4     ; point to the remaining arguments
 614  CONST_INSN:
 615    const lr0,inf                ; (replaced by       half of target addr)
 616    consth lr0,inf               ; (replaced by other half of target addr)
 617    calli lr0, lr0
 618    aseq 0x40,gr1,gr1   ; nop
 619  BREAKPT_INSN:
 620    asneq 0x50,gr1,gr1  ; breakpoint     (replaced by local breakpoint insn)
 621    */
 622
 623 #if TARGET_BYTE_ORDER == HOST_BYTE_ORDER
 624 #define BS(const)       const
 625 #else
 626 #define BS(const)       (((const) & 0xff) << 24) |      \
 627                         (((const) & 0xff00) << 8) |     \
 628                         (((const) & 0xff0000) >> 8) |   \
 629                         (((const) & 0xff000000) >> 24)
 630 #endif
 631
 632 /* Position of the "const" and blkt instructions within CALL_DUMMY in bytes. */
 633 #define CONST_INSN (3 * 4)
 634 #define BREAKPT_INSN (7 * 4)
 635 #define CALL_DUMMY {    \
 636                 BS(0x0400870f),\
 637                 BS(0x36008200|(MSP_HW_REGNUM)), \
 638                 BS(0x15000040|(MSP_HW_REGNUM<<8)|(MSP_HW_REGNUM<<16)), \
 639                 BS(0x03ff80ff), \
 640                 BS(0x02ff80ff), \
 641                 BS(0xc8008080), \
 642                 BS(0x70400101), \
 643                 BS(0x72500101)}
 644 #define CALL_DUMMY_LENGTH (8 * 4)
 645
 646 #define CALL_DUMMY_START_OFFSET 0  /* Start execution at beginning of dummy */
 647
 648 /* Helper macro for FIX_CALL_DUMMY.  WORDP is a long * which points to a
 649    word in target byte order; bits 0-7 and 16-23 of *WORDP are replaced with
 650    bits 0-7 and 8-15 of DATA (which is in host byte order).  */
 651
 652 #if TARGET_BYTE_ORDER == BIG_ENDIAN
 653 #define STUFF_I16(WORDP, DATA) \
 654   { \
 655     *((char *)(WORDP) + 3) = ((DATA) & 0xff);\
 656     *((char *)(WORDP) + 1) = (((DATA) >> 8) & 0xff);\
 657   }
 658 #else /* Target is little endian.  */
 659 #define STUFF_I16(WORDP, DATA) \
 660   {
 661     *(char *)(WORDP) = ((DATA) & 0xff);
 662     *((char *)(WORDP) + 2) = (((DATA) >> 8) & 0xff);
 663   }
 664 #endif /* Target is little endian.  */
 665
 666 /* Insert the specified number of args and function address
 667    into a call sequence of the above form stored at DUMMYNAME.  */
 668
 669 /* Currently this stuffs in the address of the function that we are calling.
 670    Since different a29k systems use different breakpoint instructions, it
 671    also stuffs BREAKPOINT in the right place (to avoid having to
 672    duplicate CALL_DUMMY in each tm-*.h file).  */
 673
 674 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p)   \
 675   {\
 676     STUFF_I16((char *)dummyname + CONST_INSN, fun);             \
 677     STUFF_I16((char *)dummyname + CONST_INSN + 4, fun >> 16);   \
 678   /* FIXME  memcpy ((char *)(dummyname) + BREAKPT_INSN, break_insn, 4); */ \
 679   }
 680
 681 /* a29k architecture has separate data & instruction memories -- wired to
 682    different pins on the chip -- and can't execute the data memory.
 683    Also, there should be space after text_end;
 684    we won't get a SIGSEGV or scribble on data space.  */
 685
 686 #define CALL_DUMMY_LOCATION AFTER_TEXT_END
 687
 688 /* Because of this, we need (as a kludge) to know the addresses of the
 689    text section.  */
 690
 691 #define NEED_TEXT_START_END
 692
 693 /* How to translate register numbers in the .stab's into gdb's internal register
 694    numbers.  We don't translate them, but we warn if an invalid register
 695    number is seen.  Note that FIXME, we use the value "sym" as an implicit
 696    argument in printing the error message.  It happens to be available where
 697    this macro is used.  (This macro definition appeared in a late revision
 698    of gdb-3.91.6 and is not well tested.  Also, it should be a "complaint".) */
 699
 700 #define STAB_REG_TO_REGNUM(num) \
 701         (((num) > LR0_REGNUM + 127) \
 702            ? fprintf(stderr,    \
 703                 "Invalid register number %d in symbol table entry for %s\n", \
 704                  (num), SYMBOL_SOURCE_NAME (sym)), (num)        \
 705            : (num))
 706
 707 extern enum a29k_processor_types {
 708   a29k_unknown,
 709
 710   /* Bit 0x400 of the CPS does *not* identify freeze mode, i.e. 29000,
 711      29030, etc.  */
 712   a29k_no_freeze_mode,
 713
 714   /* Bit 0x400 of the CPS does identify freeze mode, i.e. 29050.  */
 715   a29k_freeze_mode
 716 } processor_type;