gdb/config/m88k/tm-m88k.h

   1 /* Target machine description for generic Motorola 88000, for GDB.
   2    Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1993
   3    Free Software Foundation, Inc.
   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 /* g++ support is not yet included.  */
  22
  23 #define TARGET_BYTE_ORDER BIG_ENDIAN
  24
  25 /* We cache information about saved registers in the frame structure,
  26    to save us from having to re-scan function prologues every time
  27    a register in a non-current frame is accessed.  */
  28
  29 #define EXTRA_FRAME_INFO        \
  30         struct frame_saved_regs *fsr;   \
  31         CORE_ADDR locals_pointer;       \
  32         CORE_ADDR args_pointer;
  33
  34 /* Zero the frame_saved_regs pointer when the frame is initialized,
  35    so that FRAME_FIND_SAVED_REGS () will know to allocate and
  36    initialize a frame_saved_regs struct the first time it is called.
  37    Set the arg_pointer to -1, which is not valid; 0 and other values
  38    indicate real, cached values.  */
  39
  40 #define INIT_EXTRA_FRAME_INFO(fromleaf, fi) \
  41         init_extra_frame_info (fromleaf, fi)
  42 extern void init_extra_frame_info ();
  43
  44 #define IEEE_FLOAT
  45
  46 /* Offset from address of function to start of its code.
  47    Zero on most machines.  */
  48
  49 #define FUNCTION_START_OFFSET 0
  50
  51 /* Advance PC across any function entry prologue instructions
  52    to reach some "real" code.  */
  53
  54 #define SKIP_PROLOGUE(frompc)   \
  55         skip_prologue (frompc)
  56 extern CORE_ADDR skip_prologue ();
  57
  58 /* The m88k kernel aligns all instructions on 4-byte boundaries.  The
  59    kernel also uses the least significant two bits for its own hocus
  60    pocus.  When gdb receives an address from the kernel, it needs to
  61    preserve those right-most two bits, but gdb also needs to be careful
  62    to realize that those two bits are not really a part of the address
  63    of an instruction.  Shrug.  */
  64
  65 #define ADDR_BITS_REMOVE(addr) ((addr) & ~3)
  66 #define ADDR_BITS_SET(addr) (((addr) | 0x00000002) - 4)
  67
  68 /* Immediately after a function call, return the saved pc.
  69    Can't always go through the frames for this because on some machines
  70    the new frame is not set up until the new function executes
  71    some instructions.  */
  72
  73 #define SAVED_PC_AFTER_CALL(frame) \
  74   (ADDR_BITS_REMOVE (read_register (SRP_REGNUM)))
  75
  76 /* Stack grows downward.  */
  77
  78 #define INNER_THAN <
  79
  80 /* Sequence of bytes for breakpoint instruction.  */
  81
  82 /* instruction 0xF000D1FF is 'tb0 0,r0,511'
  83    If Bit bit 0 of r0 is clear (always true),
  84    initiate exception processing (trap).
  85  */
  86 #define BREAKPOINT {0xF0, 0x00, 0xD1, 0xFF}
  87
  88 /* Amount PC must be decremented by after a breakpoint.
  89    This is often the number of bytes in BREAKPOINT
  90    but not always.  */
  91
  92 #define DECR_PC_AFTER_BREAK 0
  93
  94 /* Nonzero if instruction at PC is a return instruction.  */
  95 /* 'jmp r1' or 'jmp.n r1' is used to return from a subroutine. */
  96
  97 #define ABOUT_TO_RETURN(pc) (read_memory_integer (pc, 2) == 0xF800)
  98
  99 /* Return 1 if P points to an invalid floating point value.
 100    LEN is the length in bytes.  */
 101
 102 #define INVALID_FLOAT(p, len) IEEE_isNAN(p,len)
 103
 104 /* Say how long (ordinary) registers are.  */
 105
 106 #define REGISTER_TYPE long
 107
 108 /* Number of machine registers */
 109
 110 #define NUM_REGS 38
 111
 112 /* Initializer for an array of names of registers.
 113    There should be NUM_REGS strings in this initializer.  */
 114
 115 #define REGISTER_NAMES {\
 116         "r0",\
 117         "r1",\
 118         "r2",\
 119         "r3",\
 120         "r4",\
 121         "r5",\
 122         "r6",\
 123         "r7",\
 124         "r8",\
 125         "r9",\
 126         "r10",\
 127         "r11",\
 128         "r12",\
 129         "r13",\
 130         "r14",\
 131         "r15",\
 132         "r16",\
 133         "r17",\
 134         "r18",\
 135         "r19",\
 136         "r20",\
 137         "r21",\
 138         "r22",\
 139         "r23",\
 140         "r24",\
 141         "r25",\
 142         "r26",\
 143         "r27",\
 144         "r28",\
 145         "r29",\
 146         "r30",\
 147         "r31",\
 148         "psr",\
 149         "fpsr",\
 150         "fpcr",\
 151         "sxip",\
 152         "snip",\
 153         "sfip",\
 154         "vbr",\
 155         "dmt0",\
 156         "dmd0",\
 157         "dma0",\
 158         "dmt1",\
 159         "dmd1",\
 160         "dma1",\
 161         "dmt2",\
 162         "dmd2",\
 163         "dma2",\
 164         "sr0",\
 165         "sr1",\
 166         "sr2",\
 167         "sr3",\
 168         "fpecr",\
 169         "fphs1",\
 170         "fpls1",\
 171         "fphs2",\
 172         "fpls2",\
 173         "fppt",\
 174         "fprh",\
 175         "fprl",\
 176         "fpit",\
 177         "fpsr",\
 178         "fpcr",\
 179         }
 180
 181
 182 /* Register numbers of various important registers.
 183    Note that some of these values are "real" register numbers,
 184    and correspond to the general registers of the machine,
 185    and some are "phony" register numbers which are too large
 186    to be actual register numbers as far as the user is concerned
 187    but do serve to get the desired values when passed to read_register.  */
 188
 189 #define SRP_REGNUM 1            /* Contains subroutine return pointer */
 190 #define RV_REGNUM 2             /* Contains simple return values */
 191 #define SRA_REGNUM 12           /* Contains address of struct return values */
 192 #define FP_REGNUM 31            /* Reg fetched to locate frame when pgm stops */
 193 #define SP_REGNUM 31            /* Contains address of top of stack */
 194 #define SXIP_REGNUM 35          /* Contains Shadow Execute Instruction Pointer */
 195 #define SNIP_REGNUM 36          /* Contains Shadow Next Instruction Pointer */
 196 #define PC_REGNUM SXIP_REGNUM   /* Program Counter */
 197 #define NPC_REGNUM SNIP_REGNUM  /* Next Program Counter */
 198 #define PSR_REGNUM 32           /* Processor Status Register */
 199 #define FPSR_REGNUM 33          /* Floating Point Status Register */
 200 #define FPCR_REGNUM 34          /* Floating Point Control Register */
 201 #define SFIP_REGNUM 37          /* Contains Shadow Fetched Intruction pointer */
 202 #define NNPC_REGNUM SFIP_REGNUM /* Next Next Program Counter */
 203
 204 /* PSR status bit definitions.  */
 205
 206 #define PSR_MODE                0x80000000
 207 #define PSR_BYTE_ORDER          0x40000000
 208 #define PSR_SERIAL_MODE         0x20000000
 209 #define PSR_CARRY               0x10000000
 210 #define PSR_SFU_DISABLE         0x000003f0
 211 #define PSR_SFU1_DISABLE        0x00000008
 212 #define PSR_MXM                 0x00000004
 213 #define PSR_IND                 0x00000002
 214 #define PSR_SFRZ                0x00000001
 215
 216 /* BCS requires that the SXIP_REGNUM (or PC_REGNUM) contain the address
 217    of the next instr to be executed when a breakpoint occurs.  Because
 218    the kernel gets the next instr (SNIP_REGNUM), the instr in SNIP needs
 219    to be put back into SFIP, and the instr in SXIP should be shifted
 220    to SNIP */
 221
 222 /* Are you sitting down?  It turns out that the 88K BCS (binary compatibility
 223   standard) folks originally felt that the debugger should be responsible
 224   for backing up the IPs, not the kernel (as is usually done).  Well, they
 225   have reversed their decision, and in future releases our kernel will be
 226   handling the backing up of the IPs.  So, eventually, we won't need to
 227   do the SHIFT_INST_REGS stuff.  But, for now, since there are 88K systems out
 228   there that do need the debugger to do the IP shifting, and since there
 229   will be systems where the kernel does the shifting, the code is a little
 230   more complex than perhaps it needs to be (we still go inside SHIFT_INST_REGS,
 231   and if the shifting hasn't occurred then gdb goes ahead and shifts).  */
 232
 233 #define SHIFT_INST_REGS
 234
 235 /* Number of bytes of storage in the actual machine representation
 236    for register N.  */
 237
 238 #define REGISTER_RAW_SIZE(N) 4
 239
 240 /* Total amount of space needed to store our copies of the machine's
 241    register state, the array `registers'.  */
 242
 243 #define REGISTER_BYTES (NUM_REGS * REGISTER_RAW_SIZE(0))
 244
 245 /* Index within `registers' of the first byte of the space for
 246    register N.  */
 247
 248 #define REGISTER_BYTE(N) ((N)*REGISTER_RAW_SIZE(0))
 249
 250 /* Number of bytes of storage in the program's representation
 251    for register N. */
 252
 253 #define REGISTER_VIRTUAL_SIZE(N) (REGISTER_RAW_SIZE(N))
 254
 255 /* Largest value REGISTER_RAW_SIZE can have.  */
 256
 257 #define MAX_REGISTER_RAW_SIZE (REGISTER_RAW_SIZE(0))
 258
 259 /* Largest value REGISTER_VIRTUAL_SIZE can have.
 260 /* Are FPS1, FPS2, FPR "virtual" regisers? */
 261
 262 #define MAX_REGISTER_VIRTUAL_SIZE (REGISTER_RAW_SIZE(0))
 263
 264 /* Nonzero if register N requires conversion
 265    from raw format to virtual format.  */
 266
 267 #define REGISTER_CONVERTIBLE(N) (0)
 268
 269 /* Convert data from raw format for register REGNUM
 270    to virtual format for register REGNUM.  */
 271
 272 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO) \
 273   {bcopy ((FROM), (TO), REGISTER_RAW_SIZE (REGNUM));}
 274
 275 /* Convert data from virtual format for register REGNUM
 276    to raw format for register REGNUM.  */
 277
 278 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
 279   {bcopy ((FROM), (TO), REGISTER_RAW_SIZE (REGNUM));}
 280
 281 /* Return the GDB type object for the "standard" data type
 282    of data in register N.  */
 283
 284 #define REGISTER_VIRTUAL_TYPE(N) (builtin_type_int)
 285
 286 /* The 88k call/return conventions call for "small" values to be returned
 287    into consecutive registers starting from r2.  */
 288
 289 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 290   bcopy (&(((char *)REGBUF)[REGISTER_BYTE(RV_REGNUM)]), (VALBUF), TYPE_LENGTH (TYPE))
 291
 292 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(int *)(REGBUF))
 293
 294 /* Write into appropriate registers a function return value
 295    of type TYPE, given in virtual format.  */
 296
 297 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 298   write_register_bytes (2*REGISTER_RAW_SIZE(0), (VALBUF), TYPE_LENGTH (TYPE))
 299
 300 /* In COFF, if PCC says a parameter is a short or a char, do not
 301    change it to int (it seems the convention is to change it). */
 302
 303 #define BELIEVE_PCC_PROMOTION 1
 304
 305 /* Describe the pointer in each stack frame to the previous stack frame
 306    (its caller).  */
 307
 308 /* FRAME_CHAIN takes a frame's nominal address
 309    and produces the frame's chain-pointer.
 310
 311    However, if FRAME_CHAIN_VALID returns zero,
 312    it means the given frame is the outermost one and has no caller.  */
 313
 314 extern CORE_ADDR frame_chain ();
 315 extern int frame_chain_valid ();
 316 extern int frameless_function_invocation ();
 317
 318 #define FRAME_CHAIN(thisframe) \
 319         frame_chain (thisframe)
 320
 321 #define FRAME_CHAIN_VALID(chain, thisframe)     \
 322         frame_chain_valid (chain, thisframe)
 323
 324 #define FRAMELESS_FUNCTION_INVOCATION(frame, fromleaf)  \
 325         fromleaf = frameless_function_invocation (frame)
 326
 327 /* Define other aspects of the stack frame.  */
 328
 329 #define FRAME_SAVED_PC(FRAME)   \
 330         frame_saved_pc (FRAME)
 331 extern CORE_ADDR frame_saved_pc ();
 332
 333 #define FRAME_ARGS_ADDRESS(fi)  \
 334         frame_args_address (fi)
 335 extern CORE_ADDR frame_args_address ();
 336
 337 #define FRAME_LOCALS_ADDRESS(fi) \
 338         frame_locals_address (fi)
 339 extern CORE_ADDR frame_locals_address ();
 340
 341 /* Return number of args passed to a frame.
 342    Can return -1, meaning no way to tell.  */
 343
 344 #define FRAME_NUM_ARGS(numargs, fi)  ((numargs) = -1)
 345
 346 /* Return number of bytes at start of arglist that are not really args.  */
 347
 348 #define FRAME_ARGS_SKIP 0
 349
 350 /* Put here the code to store, into a struct frame_saved_regs,
 351    the addresses of the saved registers of frame described by FRAME_INFO.
 352    This includes special registers such as pc and fp saved in special
 353    ways in the stack frame.  sp is even more special:
 354    the address we return for it IS the sp for the next frame.  */
 355
 356 /* On the 88k, parameter registers get stored into the so called "homing"
 357    area.  This *always* happens when you compiled with GCC and use -g.
 358    Also, (with GCC and -g) the saving of the parameter register values
 359    always happens right within the function prologue code, so these register
 360    values can generally be relied upon to be already copied into their
 361    respective homing slots by the time you will normally try to look at
 362    them (we hope).
 363
 364    Note that homing area stack slots are always at *positive* offsets from
 365    the frame pointer.  Thus, the homing area stack slots for the parameter
 366    registers (passed values) for a given function are actually part of the
 367    frame area of the caller.  This is unusual, but it should not present
 368    any special problems for GDB.
 369
 370    Note also that on the 88k, we are only interested in finding the
 371    registers that might have been saved in memory.  This is a subset of
 372    the whole set of registers because the standard calling sequence allows
 373    the called routine to clobber many registers.
 374
 375    We could manage to locate values for all of the so called "preserved"
 376    registers (some of which may get saved within any particular frame) but
 377    that would require decoding all of the tdesc information.  Tht would be
 378    nice information for GDB to have, but it is not strictly manditory if we
 379    can live without the ability to look at values within (or backup to)
 380    previous frames.
 381 */
 382
 383 #define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) \
 384         frame_find_saved_regs (frame_info, &frame_saved_regs)
 385
 386 \f
 387 /* There is not currently a functioning way to call functions in the
 388    inferior.  */
 389
 390 /* But if there was this is where we'd put the call dummy.  */
 391 /* #define CALL_DUMMY_LOCATION AFTER_TEXT_END */
 392
 393 /* When popping a frame on the 88k (say when doing a return command), the
 394    calling function only expects to have the "preserved" registers restored.
 395    Thus, those are the only ones that we even try to restore here.   */
 396
 397 #define POP_FRAME pop_frame ()
 398 extern void pop_frame ();