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Diffstat (limited to 'arm9/source/z80.c')
| -rw-r--r-- | arm9/source/z80.c | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/arm9/source/z80.c b/arm9/source/z80.c new file mode 100644 index 0000000..b841b39 --- /dev/null +++ b/arm9/source/z80.c @@ -0,0 +1,331 @@ +/* + + z80 - Z80 Emulator + + Copyright (C) 2007 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 (PRIV->raise) + { + if (PRIV->nmi) + { + if (PRIV->halt) + { + PRIV->halt=FALSE; + CALLBACK(eZ80_Halt,0); + cpu->PC++; + } + + TSTATE(2); + cpu->IFF1=0; + PRIV->nmi=FALSE; + PUSH(cpu->PC); + cpu->PC=0x66; + } + else if (cpu->IFF1) + { + if (PRIV->halt) + { + PRIV->halt=FALSE; + CALLBACK(eZ80_Halt,0); + cpu->PC++; + } + + TSTATE(2); + + cpu->IFF1=0; + cpu->IFF2=0; + + switch(cpu->IM) + { + default: + case 0: + INC_R; + Z80_Decode(cpu,PRIV->devbyte); + return; + break; + + case 1: + PUSH(cpu->PC); + cpu->PC=0x38; + break; + + case 2: + PUSH(cpu->PC); + cpu->PC=(Z80Word)cpu->I*256+PRIV->devbyte; + break; + } + } + + PRIV->raise=FALSE; + } +} + + +/* ---------------------------------------- INTERFACES +*/ + +#ifdef ENABLE_ARRAY_MEMORY +Z80 *Z80Init(Z80ReadPort read_port, + Z80WritePort write_port) +#else +Z80 *Z80Init(Z80ReadMemory read_memory, + Z80WriteMemory write_memory, + Z80ReadPort read_port, + Z80WritePort write_port, + Z80ReadMemory read_for_disassem) +#endif +{ + Z80 *cpu; + int f; + int r; + + InitTables(); + +#ifndef ENABLE_ARRAY_MEMORY + if (!read_memory || !write_memory) + return NULL; +#endif + + cpu=malloc(sizeof *cpu); + + if (cpu) + { + cpu->priv=malloc(sizeof *cpu->priv); + + if (cpu->priv) + { +#ifndef ENABLE_ARRAY_MEMORY + PRIV->mread=read_memory; + PRIV->mwrite=write_memory; + PRIV->disread=read_for_disassem; +#endif + PRIV->pread=read_port; + PRIV->pwrite=write_port; + + for(f=0;f<eZ80_NO_CALLBACK;f++) + for(r=0;r<MAX_PER_CALLBACK;r++) + PRIV->callback[f][r]=NULL; + + Z80Reset(cpu); + } + else + { + free(cpu); + cpu=NULL; + } + } + + return cpu; +} + + +void Z80Reset(Z80 *cpu) +{ + PRIV->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; + PRIV->halt=0; + + PRIV->raise=FALSE; + PRIV->nmi=FALSE; +} + + +Z80Val Z80Cycles(Z80 *cpu) +{ + return PRIV->cycle; +} + + +void Z80ResetCycles(Z80 *cpu, Z80Val cycles) +{ + PRIV->cycle=cycles; +} + + +int Z80LodgeCallback(Z80 *cpu, Z80CallbackReason reason, Z80Callback callback) +{ + int f; + + for(f=0;f<MAX_PER_CALLBACK;f++) + { + if (!PRIV->callback[reason][f]) + { + PRIV->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 (PRIV->callback[reason][f]==callback) + { + PRIV->callback[reason][f]=NULL; + } + } +} + + +void Z80Interrupt(Z80 *cpu, Z80Byte devbyte) +{ + PRIV->raise=TRUE; + PRIV->devbyte=devbyte; + PRIV->nmi=FALSE; +} + + +void Z80NMI(Z80 *cpu) +{ + PRIV->raise=TRUE; + PRIV->nmi=TRUE; +} + + +int Z80SingleStep(Z80 *cpu) +{ + Z80Byte opcode; + + PRIV->last_cb=TRUE; + PRIV->shift=0; + + Z80_CheckInterrupt(cpu); + + CALLBACK(eZ80_Instruction,PRIV->cycle); + + INC_R; + + opcode=FETCH_BYTE; + + Z80_Decode(cpu,opcode); + + return PRIV->last_cb; +} + + +void Z80Exec(Z80 *cpu) +{ + while (Z80SingleStep(cpu)); +} + + +void Z80SetLabels(Z80Label labels[]) +{ + z80_labels=labels; +} + + +const char *Z80Disassemble(Z80 *cpu, Z80Word *pc) +{ +#ifdef ENABLE_DISASSEM + Z80Byte Z80_Dis_FetchByte(Z80 *cpu, Z80Word *pc); + 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++) + { +#ifdef ENABLE_ARRAY_MEMORY + strcat(s,Z80_Dis_Printf(" %.2x",(int)Z80_MEMORY[opc++])); +#else + strcat(s,Z80_Dis_Printf(" %.2x",(int)PRIV->disread(cpu,opc++))); +#endif + } + + 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 */ |