sdcc-extra/emu/rrgb/z80.c

   1 /* Emulation of the Z80 CPU with hooks into the other parts of Z81.
   2  * Copyright (C) 1994 Ian Collier.
   3  * Z81 changes (C) 1995 Russell Marks.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20 #include <math.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <time.h>
  24 #include "z80.h"
  25 #include "debugger.h"
  26 #include "parse_map.h"
  27 #include "disgb.h"
  28
  29 pmfunction fun_first;
  30
  31 unsigned short breakpoints[5];
  32 unsigned short callback_stack[100];
  33
  34 int callback_stack_pos;
  35 extern unsigned long tstates;
  36
  37 void push_callback( unsigned short addr )
  38 {
  39         pmfunction walk;
  40         int done = 0;
  41
  42         walk=fun_first;
  43         while ((walk!=NULL)&&(!done)) {
  44                 if (walk->addr==addr) {
  45                         walk->start = tstates;
  46                         walk->num_calls++;
  47                         done=1;
  48                 }
  49                 else
  50                         walk = walk->next;
  51         }
  52         if (!done) {
  53                 /* New one */
  54                 walk=fun_first;
  55                 fun_first=malloc(sizeof(mfunction));
  56                 fun_first->next=walk;
  57                 fun_first->num_calls=1;
  58                 fun_first->tstates=0;
  59                 fun_first->addr=addr;
  60                 fun_first->start=tstates;
  61         }
  62         callback_stack[callback_stack_pos++] = addr;
  63 }
  64
  65 void pop_callback(void)
  66 {
  67         pmfunction walk;
  68
  69         if (callback_stack_pos > 0) {
  70                 callback_stack_pos--;
  71                 walk=fun_first;
  72                 while (walk) {
  73                         if (walk->addr==callback_stack[callback_stack_pos]) {
  74                                 walk->tstates+=tstates- walk->start;
  75                                 walk = NULL;
  76                         }
  77                         else
  78                                 walk = walk->next;
  79                 }
  80         }
  81 }
  82
  83 int mainloop(int flags)
  84 {
  85         unsigned char a, f, b, c, d, e, h, l;
  86         unsigned char r, i, iff1, iff2, im;
  87         unsigned short pc;
  88         unsigned short sp;
  89         extern unsigned long tstates;
  90         unsigned int radjust;
  91         unsigned char intsample;
  92         unsigned char op;
  93         int     states_until_timerint;
  94         unsigned long last_tstates;
  95         unsigned startTime = tstates;
  96         int cpuRunning = 1;
  97         clock_t max_run_time = clock() + CLOCKS_PER_SEC*30;
  98         unsigned run_time_check_mod = 0;
  99
 100         int j, runOne = 0;
 101
 102         struct sregs regs =
 103         {
 104           &a, &f, &b, &c, &d, &e, &h, &l, &pc, &sp, &cpuRunning
 105         };
 106         a = f = b = c = d = e = h = l = i = r = iff1 = iff2 = im = 0;
 107         fun_first = NULL;
 108         sp = pc = 0;
 109         sp = 0xdfff;
 110         pc = 0x100;             /* GB start address */
 111         tstates = 0;
 112         last_tstates=0;
 113         callback_stack_pos = 0;
 114         states_until_timerint = 40000;
 115
 116         for (j = 0; j < 5; j++)
 117                 breakpoints[j] = 0;
 118
 119         if (flags&DSTARTDEBUG)
 120                 breakpoints[0] = 0x100;
 121
 122         while (cpuRunning) {
 123                 if (runOne) {
 124                         if (enterDebugger(&regs))
 125                                 runOne = 1;
 126                         else
 127                                 runOne = 0;
 128                 }
 129                 j = 0;
 130                 while (j < 5) {
 131                         if (breakpoints[j] == pc) {
 132                                 if (enterDebugger(&regs))
 133                                         runOne = 1;
 134                                 break;
 135                         }
 136                         j++;
 137                 }
 138                 op = fetch(pc);
 139                 pc++;
 140                 switch (op) {
 141 #include "z80ops.c"
 142                 default:
 143                         printf("\nrrgb: warning - invalid opcode %02x at %04x.\n", op, pc - 1);
 144                         enterDebugger(&regs);
 145                         break;
 146                 }
 147                 if (flags&DTIMERINT) {
 148                         states_until_timerint-=tstates-last_tstates;
 149                         last_tstates=tstates;
 150                         if (states_until_timerint<0) {
 151                                 states_until_timerint=40000;
 152                                 push2(pc);
 153                                 pc=0x50;
 154                         }
 155                 }
 156                 if (flags&DLIMITEDRUN && (++run_time_check_mod) == 100) {
 157                   if (clock() > max_run_time) {
 158                         printf("Error: Maximum runtime exceeded\n");
 159                         cpuRunning = 0;
 160                   }
 161                   run_time_check_mod = 0;
 162                 }
 163         }
 164         return 0;
 165 }