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-rw-r--r--src/z80.c366
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diff --git a/src/z80.c b/src/z80.c
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+/*
+
+ z80 - Z80 Emulator
+
+ Copyright (C) 2006 Ian Cowburn <ianc@noddybox.co.uk>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+ -------------------------------------------------------------------------
+
+ $Id$
+
+ Z80
+
+*/
+#include <stdlib.h>
+#include <string.h>
+
+#include "z80.h"
+#include "z80_private.h"
+
+static const char ident[]="$Id$";
+static const char ident_z80_header[]=Z80_H;
+static const char ident_z80_private_header[]=Z80_PRIVATE_H;
+
+Z80Label *z80_labels=NULL;
+
+/* ---------------------------------------- PRIVATE FUNCTIONS
+*/
+static void InitTables()
+{
+ static int init=FALSE;
+
+ if (init)
+ return;
+
+ init=TRUE;
+
+ Z80_InitialiseInternals();
+}
+
+static void Z80_CheckInterrupt(Z80 *cpu)
+{
+ /* Check interrupts
+ */
+ if (cpu->raise)
+ {
+ if (cpu->nmi)
+ {
+ if (cpu->halt)
+ {
+ cpu->halt=FALSE;
+ CALLBACK(eZ80_Halt,0);
+ cpu->PC++;
+ }
+
+ TSTATE(2);
+ cpu->IFF1=0;
+ cpu->nmi=FALSE;
+ PUSH(cpu->PC);
+ cpu->PC=0x66;
+ }
+ else if (cpu->IFF1)
+ {
+ if (cpu->halt)
+ {
+ cpu->halt=FALSE;
+ CALLBACK(eZ80_Halt,0);
+ cpu->PC++;
+ }
+
+ TSTATE(2);
+
+ switch(cpu->IM)
+ {
+ default:
+ case 0:
+ INC_R;
+ Z80_Decode(cpu,cpu->devbyte);
+ return;
+ break;
+
+ case 1:
+ PUSH(cpu->PC);
+ cpu->PC=0x38;
+ break;
+
+ case 2:
+ PUSH(cpu->PC);
+ cpu->PC=(Z80Word)cpu->I*256+cpu->devbyte;
+ break;
+ }
+ }
+
+ cpu->raise=FALSE;
+ }
+}
+
+
+/* ---------------------------------------- INTERFACES
+*/
+
+Z80 *Z80Init(Z80ReadMemory read_memory,
+ Z80WriteMemory write_memory,
+ Z80ReadPort read_port,
+ Z80WritePort write_port,
+ Z80ReadMemory read_disassem)
+{
+ Z80 *cpu;
+ int f;
+ int r;
+
+ InitTables();
+
+ if (!read_memory || !write_memory)
+ return NULL;
+
+ cpu=malloc(sizeof *cpu);
+
+ if (cpu)
+ {
+ cpu->mread=read_memory;
+ cpu->mwrite=write_memory;
+ cpu->pread=read_port;
+ cpu->pwrite=write_port;
+ cpu->disread=read_disassem;
+
+ for(f=0;f<eZ80_NO_CALLBACK;f++)
+ for(r=0;r<MAX_PER_CALLBACK;r++)
+ cpu->callback[f][r]=NULL;
+
+ Z80Reset(cpu);
+ }
+
+ return cpu;
+}
+
+
+void Z80Reset(Z80 *cpu)
+{
+ cpu->cycle=0;
+ cpu->PC=0;
+
+ cpu->AF.w=0xffff;
+ cpu->BC.w=0xffff;
+ cpu->DE.w=0xffff;
+ cpu->HL.w=0xffff;
+ cpu->AF_=0xffff;
+ cpu->BC_=0xffff;
+ cpu->DE_=0xffff;
+ cpu->HL_=0xffff;
+
+ cpu->IX.w=0xffff;
+ cpu->IY.w=0xffff;
+
+ cpu->SP=0xffff;
+ cpu->IFF1=0;
+ cpu->IFF2=0;
+ cpu->IM=0;
+ cpu->I=0;
+ cpu->R=0;
+ cpu->halt=0;
+
+ cpu->raise=FALSE;
+ cpu->nmi=FALSE;
+}
+
+
+void Z80SetPC(Z80 *cpu,Z80Word PC)
+{
+ cpu->PC=PC;
+}
+
+
+Z80Word Z80GetPC(Z80 *cpu)
+{
+ return cpu->PC;
+}
+
+
+void Z80ResetCycles(Z80 *cpu, Z80Val cycles)
+{
+ cpu->cycle=cycles;
+}
+
+
+int Z80LodgeCallback(Z80 *cpu, Z80CallbackReason reason, Z80Callback callback)
+{
+ int f;
+
+ for(f=0;f<MAX_PER_CALLBACK;f++)
+ {
+ if (!cpu->callback[reason][f])
+ {
+ cpu->callback[reason][f]=callback;
+ return TRUE;
+ }
+ }
+
+ return FALSE;
+}
+
+
+void Z80RemoveCallback(Z80 *cpu, Z80CallbackReason reason, Z80Callback callback)
+{
+ int f;
+
+ for(f=0;f<MAX_PER_CALLBACK;f++)
+ if (cpu->callback[reason][f]==callback)
+ cpu->callback[reason][f]=NULL;
+}
+
+
+void Z80Interrupt(Z80 *cpu, Z80Byte devbyte)
+{
+ cpu->raise=TRUE;
+ cpu->devbyte=devbyte;
+ cpu->nmi=FALSE;
+}
+
+
+void Z80NMI(Z80 *cpu)
+{
+ cpu->raise=TRUE;
+ cpu->nmi=TRUE;
+}
+
+
+int Z80SingleStep(Z80 *cpu)
+{
+ Z80Byte opcode;
+
+ cpu->last_cb=TRUE;
+ cpu->shift=0;
+
+ Z80_CheckInterrupt(cpu);
+
+ CALLBACK(eZ80_Instruction,cpu->cycle);
+
+ INC_R;
+
+ opcode=FETCH_BYTE;
+
+ Z80_Decode(cpu,opcode);
+
+ return cpu->last_cb;
+}
+
+
+void Z80Exec(Z80 *cpu)
+{
+ while (Z80SingleStep(cpu));
+}
+
+
+void Z80GetState(Z80 *cpu, Z80State *state)
+{
+ state->cycle= cpu->cycle;
+
+ state->AF = cpu->AF.w;
+ state->BC = cpu->BC.w;
+ state->DE = cpu->DE.w;
+ state->HL = cpu->HL.w;
+
+ state->AF_ = cpu->AF_;
+ state->BC_ = cpu->BC_;
+ state->DE_ = cpu->DE_;
+ state->HL_ = cpu->HL_;
+
+ state->IX = cpu->IX.w;
+ state->IY = cpu->IY.w;
+
+ state->SP = cpu->SP;
+ state->PC = cpu->PC;
+
+ state->IFF1 = cpu->IFF1;
+ state->IFF2 = cpu->IFF2;
+ state->IM = cpu->IM;
+ state->I = cpu->I;
+ state->R = cpu->R;
+}
+
+
+void Z80SetState(Z80 *cpu, const Z80State *state)
+{
+ cpu->cycle = state->cycle;
+
+ cpu->AF.w = state->AF;
+ cpu->BC.w = state->BC;
+ cpu->DE.w = state->DE;
+ cpu->HL.w = state->HL;
+
+ cpu->AF_ = state->AF_;
+ cpu->BC_ = state->BC_;
+ cpu->DE_ = state->DE_;
+ cpu->HL_ = state->HL_;
+
+ cpu->IX.w = state->IX;
+ cpu->IY.w = state->IY;
+
+ cpu->SP = state->SP;
+ cpu->PC = state->PC;
+
+ cpu->IFF1 = state->IFF1;
+ cpu->IFF2 = state->IFF2;
+ cpu->IM = state->IM;
+ cpu->I = state->I;
+ cpu->R = state->R;
+}
+
+
+Z80Val Z80Cycles(Z80 *cpu)
+{
+ return cpu->cycle;
+}
+
+
+void Z80SetLabels(Z80Label labels[])
+{
+ z80_labels=labels;
+}
+
+
+const char *Z80Disassemble(Z80 *cpu, Z80Word *pc)
+{
+#ifdef ENABLE_DISASSEM
+ static char s[80];
+ Z80Word opc,npc;
+ Z80Byte op;
+ int f;
+
+ opc=*pc;
+ op=Z80_Dis_FetchByte(cpu,pc);
+ dis_opcode_z80[op](cpu,op,pc);
+ npc=*pc;
+
+ strcpy(s,Z80_Dis_Printf("%-5s",Z80_Dis_GetOp()));
+ strcat(s,Z80_Dis_Printf("%-40s ;",Z80_Dis_GetArg()));
+
+ for(f=0;f<5 && opc!=npc;f++)
+ strcat(s,Z80_Dis_Printf(" %.2x",(int)cpu->disread(cpu,opc++)));
+
+ if (opc!=npc)
+ for(f=1;f<3;f++)
+ s[strlen(s)-f]='.';
+
+ return s;
+#else
+ (*pc)+=4;
+ return "NO DISASSEMBLER";
+#endif
+}
+
+/* END OF FILE */
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