gdb/config/m68k/tm-isi.h

   1 /* Definitions to target GDB on an ISI Optimum V (3.05) under 4.3bsd.
   2    Copyright (C) 1987, 1989, 1991, 1993 Free Software Foundation, Inc.
   3
   4 This file is part of GDB.
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or
   9 (at your option) any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  19
  20 /* This has not been tested on ISI's running BSD 4.2, but it will probably
  21    work.  */
  22
  23 /* Data segment starts at etext rounded up to DATAROUND in {N,Z}MAGIC files */
  24
  25 #define DATAROUND       0x20000
  26 #define N_DATADDR(hdr)  (hdr.a_magic != OMAGIC ? \
  27         (hdr.a_text + DATAROUND) & ~(DATAROUND-1) : hdr.a_text)
  28
  29 /* Text segment starts at sizeof (struct exec) in {N,Z}MAGIC files */
  30
  31 #define N_TXTADDR(hdr)  (hdr.a_magic != OMAGIC ? sizeof (struct exec) : 0)
  32
  33 /* Amount PC must be decremented by after a breakpoint.
  34    This is often the number of bytes in BREAKPOINT
  35    but not always.
  36    On the ISI, the kernel resets the pc to the trap instr */
  37
  38 #define DECR_PC_AFTER_BREAK 0
  39
  40 \f
  41 /* Return number of args passed to a frame.
  42    Can return -1, meaning no way to tell.  */
  43
  44 #define FRAME_NUM_ARGS(val, fi)  \
  45 { register CORE_ADDR pc = FRAME_SAVED_PC (fi);                  \
  46   register int insn = 0177777 & read_memory_integer (pc, 2);    \
  47   val = 0;                                                      \
  48   if (insn == 0047757 || insn == 0157374)  /* lea W(sp),sp or addaw #W,sp */ \
  49     val = read_memory_integer (pc + 2, 2);                      \
  50   else if ((insn & 0170777) == 0050217 /* addql #N, sp */       \
  51            || (insn & 0170777) == 0050117)  /* addqw */         \
  52     { val = (insn >> 9) & 7; if (val == 0) val = 8; }           \
  53   else if (insn == 0157774) /* addal #WW, sp */                 \
  54     val = read_memory_integer (pc + 2, 4);                      \
  55   val >>= 2; }
  56
  57 /* Put here the code to store, into a struct frame_saved_regs,
  58    the addresses of the saved registers of frame described by FRAME_INFO.
  59    This includes special registers such as pc and fp saved in special
  60    ways in the stack frame.  sp is even more special:
  61    the address we return for it IS the sp for the next frame.  */
  62
  63 #define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs)             \
  64 { register int regnum;                                                  \
  65   register int regmask;                                                 \
  66   register CORE_ADDR next_addr;                                         \
  67   register CORE_ADDR pc;                                                \
  68   register int insn;                                                    \
  69   register int offset;                                                  \
  70   memset (&frame_saved_regs, '\0', sizeof frame_saved_regs);                    \
  71   if ((frame_info)->pc >= (frame_info)->frame - CALL_DUMMY_LENGTH - FP_REGNUM*4 - 8*12 - 4 \
  72       && (frame_info)->pc <= (frame_info)->frame)                               \
  73     { next_addr = (frame_info)->frame;                                  \
  74       pc = (frame_info)->frame - CALL_DUMMY_LENGTH - FP_REGNUM * 4 - 8*12 - 4; }\
  75   else                                                                  \
  76     { pc = get_pc_function_start ((frame_info)->pc);                    \
  77       /* Verify we have a link a6 instruction next,                     \
  78          or a branch followed by a link a6 instruction;                 \
  79          if not we lose.  If we win, find the address above the saved   \
  80          regs using the amount of storage from the link instruction.  */\
  81 retry:                                                                  \
  82       insn = read_memory_integer (pc, 2);                               \
  83       if (insn == 044016)                                               \
  84         next_addr = (frame_info)->frame - read_memory_integer (pc += 2, 4), pc+=4; \
  85       else if (insn == 047126)                                          \
  86         next_addr = (frame_info)->frame - read_memory_integer (pc += 2, 2), pc+=2; \
  87       else if ((insn & 0177400) == 060000)      /* bra insn */          \
  88         { offset = insn & 0377;                                         \
  89           pc += 2;                              /* advance past bra */  \
  90           if (offset == 0)                      /* bra #word */         \
  91             offset = read_memory_integer (pc, 2), pc += 2;              \
  92           else if (offset == 0377)              /* bra #long */         \
  93             offset = read_memory_integer (pc, 4), pc += 4;              \
  94           pc += offset;                                                 \
  95           goto retry;                                                   \
  96       } else goto lose;                                                 \
  97       /* If have an addal #-n, sp next, adjust next_addr.  */           \
  98       if ((0177777 & read_memory_integer (pc, 2)) == 0157774)           \
  99         next_addr += read_memory_integer (pc += 2, 4), pc += 4;         \
 100     }                                                                   \
 101   /* next should be a moveml to (sp) or -(sp) or a movl r,-(sp) */      \
 102   insn = read_memory_integer (pc, 2), pc += 2;                          \
 103   regmask = read_memory_integer (pc, 2);                                \
 104   if ((insn & 0177760) == 022700)       /* movl rn, (sp) */             \
 105     (frame_saved_regs).regs[(insn&7) + ((insn&010)?8:0)] = next_addr;   \
 106   else if ((insn & 0177760) == 024700)  /* movl rn, -(sp) */            \
 107     (frame_saved_regs).regs[(insn&7) + ((insn&010)?8:0)] = next_addr-=4; \
 108   else if (insn == 0044327)             /* moveml mask, (sp) */         \
 109     { pc += 2;                                                          \
 110       /* Regmask's low bit is for register 0, the first written */      \
 111       next_addr -= 4;                                                   \
 112       for (regnum = 0; regnum < 16; regnum++, regmask >>= 1)            \
 113         if (regmask & 1)                                                \
 114           (frame_saved_regs).regs[regnum] = (next_addr += 4);           \
 115   } else if (insn == 0044347)           /* moveml mask, -(sp) */        \
 116     { pc += 2;                                                          \
 117       /* Regmask's low bit is for register 15, the first pushed */      \
 118       for (regnum = 15; regnum >= 0; regnum--, regmask >>= 1)           \
 119         if (regmask & 1)                                                \
 120           (frame_saved_regs).regs[regnum] = (next_addr -= 4); }         \
 121   /* clrw -(sp); movw ccr,-(sp) may follow.  */                         \
 122   if (read_memory_integer (pc, 2) == 041147                             \
 123       && read_memory_integer (pc+2, 2) == 042347)                       \
 124     (frame_saved_regs).regs[PS_REGNUM] = (next_addr -= 4);              \
 125   lose: ;                                                               \
 126   (frame_saved_regs).regs[SP_REGNUM] = (frame_info)->frame + 8;         \
 127   (frame_saved_regs).regs[FP_REGNUM] = (frame_info)->frame;             \
 128   (frame_saved_regs).regs[PC_REGNUM] = (frame_info)->frame + 4;         \
 129 }
 130
 131 /* The only reason this is here is the tm-isi.h reference below.  It
 132    was moved back here from tm-m68k.h.  FIXME? */
 133
 134 #define SKIP_PROLOGUE(pc)   \
 135 { register int op = read_memory_integer (pc, 2);        \
 136   if (op == 0047126)                                    \
 137     pc += 4;   /* Skip link #word */                    \
 138   else if (op == 0044016)                               \
 139     pc += 6;   /* Skip link #long */                    \
 140   /* Not sure why branches are here.  */                \
 141   /* From tm-isi.h, tm-altos.h */                       \
 142   else if (op == 0060000)                               \
 143     pc += 4;   /* Skip bra #word */                     \
 144   else if (op == 00600377)                              \
 145     pc += 6;   /* skip bra #long */                     \
 146   else if ((op & 0177400) == 0060000)                   \
 147     pc += 2;   /* skip bra #char */                     \
 148 }
 149
 150 #include "m68k/tm-m68k.h"