gdb/tm-mips.h

   1 /* Definitions to make GDB run on a mips box under 4.3bsd.
   2    Copyright (C) 1986, 1987, 1989, 1991, 1992 Free Software Foundation, Inc.
   3    Contributed by Per Bothner (bothner@cs.wisc.edu) at U.Wisconsin
   4    and by Alessandro Forin (af@cs.cmu.edu) at CMU.
   5
   6 This file is part of GDB.
   7
   8 This program is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 2 of the License, or
  11 (at your option) any later version.
  12
  13 This program is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with this program; if not, write to the Free Software
  20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  21
  22 #include "coff/sym.h"           /* Needed for PDR below.  */
  23 #include "coff/symconst.h"
  24
  25 #if !defined (TARGET_BYTE_ORDER)
  26 #define TARGET_BYTE_ORDER LITTLE_ENDIAN
  27 #endif
  28
  29 /* FIXME, this triggers host-and-target (``native'') dependent code
  30    which currently sits in mips-xdep.c.  Needs to be moved out to
  31    mips-nat.c or some such.  */
  32 #define GDB_TARGET_IS_MIPS
  33
  34 /* Floating point is IEEE compliant */
  35 #define IEEE_FLOAT
  36
  37 /* Define this if the C compiler puts an underscore at the front
  38    of external names before giving them to the linker.  */
  39
  40 /*#define NAMES_HAVE_UNDERSCORE*/
  41
  42 /* Offset from address of function to start of its code.
  43    Zero on most machines.  */
  44
  45 #define FUNCTION_START_OFFSET 0
  46
  47 /* Advance PC across any function entry prologue instructions
  48    to reach some "real" code.  */
  49
  50 #define SKIP_PROLOGUE(pc)       pc = mips_skip_prologue(pc)
  51
  52 /* Immediately after a function call, return the saved pc.
  53    Can't always go through the frames for this because on some machines
  54    the new frame is not set up until the new function executes
  55    some instructions.  */
  56
  57 #define SAVED_PC_AFTER_CALL(frame)      read_register(RA_REGNUM)
  58
  59 /* Are we currently handling a signal */
  60
  61 #define IN_SIGTRAMP(pc, name)   in_sigtramp(pc, name)
  62
  63 /* Address of end of stack space.  */
  64
  65 #define STACK_END_ADDR (0x7ffff000)
  66
  67 /* Stack grows downward.  */
  68
  69 #define INNER_THAN <
  70
  71 #define BIG_ENDIAN 4321
  72 #if TARGET_BYTE_ORDER == BIG_ENDIAN
  73 #define BREAKPOINT {0, 0x5, 0, 0xd}
  74 #else
  75 #define BREAKPOINT {0xd, 0, 0x5, 0}
  76 #endif
  77
  78 /* Amount PC must be decremented by after a breakpoint.
  79    This is often the number of bytes in BREAKPOINT
  80    but not always.  */
  81
  82 #define DECR_PC_AFTER_BREAK 0
  83
  84 /* Nonzero if instruction at PC is a return instruction. "j ra" on mips. */
  85
  86 #define ABOUT_TO_RETURN(pc) (read_memory_integer (pc, 4) == 0x3e00008)
  87
  88 /* Return 1 if P points to an invalid floating point value. */
  89
  90 #define INVALID_FLOAT(p,l)      isa_NAN(p,l)
  91
  92 /* Say how long (all) registers are.  */
  93
  94 #define REGISTER_TYPE long
  95
  96 /* Number of machine registers */
  97
  98 #define NUM_REGS 80
  99
 100 /* Initializer for an array of names of registers.
 101    There should be NUM_REGS strings in this initializer.  */
 102
 103 #define REGISTER_NAMES  \
 104     {   "zero", "at",   "v0",   "v1",   "a0",   "a1",   "a2",   "a3", \
 105         "t0",   "t1",   "t2",   "t3",   "t4",   "t5",   "t6",   "t7", \
 106         "s0",   "s1",   "s2",   "s3",   "s4",   "s5",   "s6",   "s7", \
 107         "t8",   "t9",   "k0",   "k1",   "gp",   "sp",   "s8",   "ra", \
 108         "sr",   "lo",   "hi",   "bad",  "cause","pc",    \
 109         "f0",   "f1",   "f2",   "f3",   "f4",   "f5",   "f6",   "f7", \
 110         "f8",   "f9",   "f10",  "f11",  "f12",  "f13",  "f14",  "f15", \
 111         "f16",  "f17",  "f18",  "f19",  "f20",  "f21",  "f22",  "f23",\
 112         "f24",  "f25",  "f26",  "f27",  "f28",  "f29",  "f30",  "f31",\
 113         "fsr",  "fir",  "fp",   "inx",  "rand", "tlblo","ctxt", "tlbhi",\
 114         "epc",  "prid"\
 115     }
 116
 117 /* Register numbers of various important registers.
 118    Note that some of these values are "real" register numbers,
 119    and correspond to the general registers of the machine,
 120    and some are "phony" register numbers which are too large
 121    to be actual register numbers as far as the user is concerned
 122    but do serve to get the desired values when passed to read_register.  */
 123
 124 #define ZERO_REGNUM 0           /* read-only register, always 0 */
 125 #define A0_REGNUM 4             /* Loc of first arg during a subr call */
 126 #define SP_REGNUM 29            /* Contains address of top of stack */
 127 #define RA_REGNUM 31            /* Contains return address value */
 128 #define PS_REGNUM 32            /* Contains processor status */
 129 #define HI_REGNUM 34            /* Multiple/divide temp */
 130 #define LO_REGNUM 33            /* ... */
 131 #define BADVADDR_REGNUM 35      /* bad vaddr for addressing exception */
 132 #define CAUSE_REGNUM 36         /* describes last exception */
 133 #define PC_REGNUM 37            /* Contains program counter */
 134 #define FP0_REGNUM 38           /* Floating point register 0 (single float) */
 135 #define FCRCS_REGNUM 70         /* FP control/status */
 136 #define FCRIR_REGNUM 71         /* FP implementation/revision */
 137 #define FP_REGNUM 72            /* Pseudo register that contains true address of executing stack frame */
 138 #define FIRST_EMBED_REGNUM 73   /* First supervisor register for embedded use */
 139 #define LAST_EMBED_REGNUM 79    /* Last one */
 140
 141 /* Define DO_REGISTERS_INFO() to do machine-specific formatting
 142    of register dumps. */
 143
 144 #define DO_REGISTERS_INFO(_regnum, fp) mips_do_registers_info(_regnum, fp)
 145
 146 /* Total amount of space needed to store our copies of the machine's
 147    register state, the array `registers'.  */
 148 #define REGISTER_BYTES (NUM_REGS*4)
 149
 150 /* Index within `registers' of the first byte of the space for
 151    register N.  */
 152
 153 #define REGISTER_BYTE(N) ((N) * 4)
 154
 155 /* Number of bytes of storage in the actual machine representation
 156    for register N.  On mips, all regs are 4 bytes.  */
 157
 158 #define REGISTER_RAW_SIZE(N) 4
 159
 160 /* Number of bytes of storage in the program's representation
 161    for register N.  On mips, all regs are 4 bytes.  */
 162
 163 #define REGISTER_VIRTUAL_SIZE(N) 4
 164
 165 /* Largest value REGISTER_RAW_SIZE can have.  */
 166
 167 #define MAX_REGISTER_RAW_SIZE 4
 168
 169 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 170
 171 #define MAX_REGISTER_VIRTUAL_SIZE 4
 172
 173 /* Nonzero if register N requires conversion
 174    from raw format to virtual format.  */
 175
 176 #define REGISTER_CONVERTIBLE(N) 0
 177
 178 /* Convert data from raw format for register REGNUM
 179    to virtual format for register REGNUM.  */
 180
 181 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO)     \
 182   bcopy ((FROM), (TO), 4);
 183
 184 /* Convert data from virtual format for register REGNUM
 185    to raw format for register REGNUM.  */
 186
 187 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
 188   bcopy ((FROM), (TO), 4);
 189
 190 /* Return the GDB type object for the "standard" data type
 191    of data in register N.  */
 192
 193 #define REGISTER_VIRTUAL_TYPE(N) \
 194         (((N) >= FP0_REGNUM && (N) < FP0_REGNUM+32)  \
 195          ? builtin_type_float : builtin_type_int) \
 196
 197 /* Store the address of the place in which to copy the structure the
 198    subroutine will return.  This is called from call_function. */
 199
 200 #define STORE_STRUCT_RETURN(addr, sp) \
 201   { sp = push_word(sp, addr);}
 202
 203 /* Extract from an array REGBUF containing the (raw) register state
 204    a function return value of type TYPE, and copy that, in virtual format,
 205    into VALBUF.  XXX floats */
 206
 207 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 208   bcopy (REGBUF+REGISTER_BYTE (TYPE_CODE (TYPE) == TYPE_CODE_FLT ? FP0_REGNUM : 2), VALBUF, TYPE_LENGTH (TYPE))
 209
 210 /* Write into appropriate registers a function return value
 211    of type TYPE, given in virtual format.  */
 212
 213 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 214   write_register_bytes (REGISTER_BYTE (TYPE_CODE (TYPE) == TYPE_CODE_FLT ? FP0_REGNUM : 2), VALBUF, TYPE_LENGTH (TYPE))
 215
 216 /* Extract from an array REGBUF containing the (raw) register state
 217    the address in which a function should return its structure value,
 218    as a CORE_ADDR (or an expression that can be used as one).  */
 219
 220 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(int *)(REGBUF+16))
 221
 222 /* Structures are returned by ref in extra arg0 */
 223 #define USE_STRUCT_CONVENTION(gcc_p, type)      1
 224
 225 \f
 226 /* Describe the pointer in each stack frame to the previous stack frame
 227    (its caller).  */
 228
 229 /* FRAME_CHAIN takes a frame's nominal address
 230    and produces the frame's chain-pointer. */
 231
 232 #define FRAME_CHAIN(thisframe) (FRAME_ADDR)mips_frame_chain(thisframe)
 233
 234 /* Define other aspects of the stack frame.  */
 235
 236
 237 /* A macro that tells us whether the function invocation represented
 238    by FI does not have a frame on the stack associated with it.  If it
 239    does not, FRAMELESS is set to 1, else 0.  */
 240 /* We handle this differently for mips, and maybe we should not */
 241
 242 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS)  {(FRAMELESS) = 0;}
 243
 244 /* Saved Pc.  */
 245
 246 #define FRAME_SAVED_PC(FRAME)   (mips_frame_saved_pc(FRAME))
 247
 248 #define FRAME_ARGS_ADDRESS(fi)  (fi)->frame
 249
 250 #define FRAME_LOCALS_ADDRESS(fi) (fi)->frame
 251
 252 /* Return number of args passed to a frame.
 253    Can return -1, meaning no way to tell.  */
 254
 255 #define FRAME_NUM_ARGS(num, fi) (num = mips_frame_num_args(fi))
 256
 257 /* Return number of bytes at start of arglist that are not really args.  */
 258
 259 #define FRAME_ARGS_SKIP 0
 260
 261 /* Put here the code to store, into a struct frame_saved_regs,
 262    the addresses of the saved registers of frame described by FRAME_INFO.
 263    This includes special registers such as pc and fp saved in special
 264    ways in the stack frame.  sp is even more special:
 265    the address we return for it IS the sp for the next frame.  */
 266
 267 #define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) ( \
 268   (frame_saved_regs) = *(frame_info)->saved_regs, \
 269   (frame_saved_regs).regs[SP_REGNUM] = (frame_info)->frame)
 270
 271 \f
 272 /* Things needed for making the inferior call functions.  */
 273
 274 /* Stack has strict alignment. However, use PUSH_ARGUMENTS
 275    to take care of it. */
 276 /*#define STACK_ALIGN(addr)     (((addr)+3)&~3)*/
 277
 278 #define PUSH_ARGUMENTS(nargs, args, sp, struct_return, struct_addr) \
 279     sp = mips_push_arguments(nargs, args, sp, struct_return, struct_addr)
 280
 281 /* Push an empty stack frame, to record the current PC, etc.  */
 282
 283 #define PUSH_DUMMY_FRAME        mips_push_dummy_frame()
 284
 285 /* Discard from the stack the innermost frame, restoring all registers.  */
 286
 287 #define POP_FRAME               mips_pop_frame()
 288
 289 #define MK_OP(op,rs,rt,offset) (((op)<<26)|((rs)<<21)|((rt)<<16)|(offset))
 290 #define CALL_DUMMY_SIZE (16*4)
 291 #define Dest_Reg 2
 292 #define CALL_DUMMY {\
 293  MK_OP(0,RA_REGNUM,0,8),        /* jr $ra # Fake ABOUT_TO_RETURN ...*/\
 294  0,                             /* nop    #  ... to stop raw backtrace*/\
 295  0x27bd0000,                    /* addu sp,?0 # Pseudo prologue */\
 296 /* Start here: */\
 297  MK_OP(061,SP_REGNUM,12,0),     /* lwc1 $f12,0(sp) # Reload first 4 args*/\
 298  MK_OP(061,SP_REGNUM,13,4),     /* lwc1 $f13,4(sp) */\
 299  MK_OP(061,SP_REGNUM,14,8),     /* lwc1 $f14,8(sp) */\
 300  MK_OP(061,SP_REGNUM,15,12),    /* lwc1 $f15,12(sp) */\
 301  MK_OP(043,SP_REGNUM,4,0),      /* lw $r4,0(sp) # Re-load FP regs*/\
 302  MK_OP(043,SP_REGNUM,5,4),      /* lw $r5,4(sp) */\
 303  MK_OP(043,SP_REGNUM,6,8),      /* lw $r6,8(sp) */\
 304  MK_OP(043,SP_REGNUM,7,12),     /* lw $r7,12(sp) */\
 305  (017<<26)| (Dest_Reg << 16),   /* lui $r31,<target upper 16 bits>*/\
 306  MK_OP(13,Dest_Reg,Dest_Reg,0), /* ori $r31,$r31,<lower 16 bits>*/ \
 307  (Dest_Reg<<21) | (31<<11) | 9, /* jalr $r31 */\
 308  MK_OP(043,SP_REGNUM,7,12),     /* lw $r7,12(sp) */\
 309  0x5000d,                       /* bpt */\
 310 }
 311
 312 #define CALL_DUMMY_START_OFFSET 12
 313
 314 /* Insert the specified number of args and function address
 315    into a call sequence of the above form stored at DUMMYNAME.  */
 316
 317 #define FIX_CALL_DUMMY(dummyname, start_sp, fun, nargs, args, rettype, gcc_p)\
 318   (((int*)dummyname)[11] |= (((unsigned long)(fun)) >> 16), \
 319    ((int*)dummyname)[12] |= (unsigned short)(fun))
 320
 321 /* There's a mess in stack frame creation.  See comments in blockframe.c
 322    near reference to INIT_FRAME_PC_FIRST.  */
 323
 324 #define INIT_FRAME_PC(fromleaf, prev) /* nada */
 325
 326 #define INIT_FRAME_PC_FIRST(fromleaf, prev) \
 327   (prev)->pc = ((fromleaf) ? SAVED_PC_AFTER_CALL ((prev)->next) : \
 328               (prev)->next ? FRAME_SAVED_PC ((prev)->next) : read_pc ());
 329
 330 /* Specific information about a procedure.
 331    This overlays the MIPS's PDR records,
 332    mipsread.c (ab)uses this to save memory */
 333
 334 typedef struct mips_extra_func_info {
 335         long    numargs;        /* number of args to procedure (was iopt) */
 336         PDR     pdr;            /* Procedure descriptor record */
 337 } *mips_extra_func_info_t;
 338
 339 #define EXTRA_FRAME_INFO \
 340   mips_extra_func_info_t proc_desc; \
 341   int num_args;\
 342   struct frame_saved_regs *saved_regs;
 343
 344 #define INIT_EXTRA_FRAME_INFO(fromleaf, fci) init_extra_frame_info(fci)
 345
 346 #define PRINT_EXTRA_FRAME_INFO(fi) \
 347   { \
 348     if (fi && fi->proc_desc && fi->proc_desc->pdr.framereg < NUM_REGS) \
 349       printf_filtered (" frame pointer is at %s+%d\n", \
 350                        reg_names[fi->proc_desc->pdr.framereg], \
 351                                  fi->proc_desc->pdr.frameoffset); \
 352   }
 353
 354 /* It takes two values to specify a frame (at least!) on the MIPS.  Sigh.
 355
 356    In fact, at the moment, the *PC* is the primary value that sets up
 357    a frame.  The PC is looked up to see what function it's in; symbol
 358    information from that function tells us which register is the frame
 359    pointer base, and what offset from there is the "virtual frame pointer".
 360    (This is usually an offset from SP.)  FIXME -- this should be cleaned
 361    up so that the primary value is the SP, and the PC is used to disambiguate
 362    multiple functions with the same SP that are at different stack levels. */
 363 #define FRAME_SPECIFICATION_DYADIC
 364
 365 #define STAB_REG_TO_REGNUM(num) ((num) < 32 ? (num) : (num)+FP0_REGNUM-32)
 366
 367 /* Size of elements in jmpbuf */
 368
 369 #define JB_ELEMENT_SIZE 4
 370
 371 /* Figure out where the longjmp will land.  We expect that we have just entered
 372    longjmp and haven't yet setup the stack frame, so the args are still in the
 373    argument regs.  a0 (CALL_ARG0) points at the jmp_buf structure from which we
 374    extract the pc (JB_PC) that we will land at.  The pc is copied into ADDR.
 375    This routine returns true on success */
 376
 377 /* Note that caller must #include <setjmp.h> in order to get def of JB_* */
 378 #define GET_LONGJMP_TARGET(ADDR) get_longjmp_target(ADDR)