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/*
6502 - 6502 emulation
Copyright (C) 2025 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 3 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, see <http://www.gnu.org/licenses/>
-------------------------------------------------------------------------
6502
*/
#include <stdlib.h>
#include <string.h>
#include "6502.h"
/* ---------------------------------------- MACROS
*/
#define PRIV cpu->priv
#define MAX_PER_CALLBACK 10
#define TRUE 1
#define FALSE 0
#define CALLBACK(r,d) do \
{ \
int f; \
\
for(f = 0; f < MAX_PER_CALLBACK; f++) \
if (PRIV->callback[r][f]) \
PRIV->last_cb &= \
PRIV->callback[r][f](cpu,d);\
} while(0)
/* ---------------------------------------- PRIVATE DATA AND TYPES
*/
struct C6502Private
{
C6502Val cycles;
C6502Val timer[e6502_NO_TIMERS];
C6502ReadMemory mread;
C6502WriteMemory mwrite;
C6502ReadMemory disread;
C6502Callback callback[e6502_NO_CALLBACK][MAX_PER_CALLBACK];
C6502Label *labels;
int last_cb;
};
/* ---------------------------------------- PRIVATE FUNCTIONS
*/
static void InitTables()
{
static int init=FALSE;
if (init)
return;
init=TRUE;
/* TODO */
}
static void C6502_CheckInterrupt(C6502 *cpu)
{
/* TODO */
}
/* ---------------------------------------- INTERFACES
*/
C6502 *C6502Init(C6502ReadMemory read_memory,
C6502WriteMemory write_memory,
C6502ReadMemory read_for_disassem)
{
C6502 *cpu;
int f;
int r;
InitTables();
cpu = malloc(sizeof *cpu);
if (cpu)
{
PRIV = malloc(sizeof *cpu->priv);
if (PRIV)
{
PRIV->mread = read_memory;
PRIV->mwrite = write_memory;
PRIV->disread = read_for_disassem;
for(f = 0; f < eC6502_NO_CALLBACK; f++)
for(r = 0; r < MAX_PER_CALLBACK; r++)
PRIV->callback[f][r] = NULL;
C6502Reset(cpu);
}
else
{
free(cpu);
cpu = NULL;
}
}
return cpu;
}
void Z80Reset(Z80 *cpu)
{
PRIV->cycle = 0;
PRIV->timer[e6502_TIMER_1] = 0;
PRIV->timer[e6502_TIMER_2] = 0;
PRIV->timer[e6502_TIMER_3] = 0;
cpu->PC = 0;
/* TODO */
}
C6502Val C6502Cycles(C6502 *cpu)
{
return PRIV->cycle;
}
void C6502ResetCycles(C6502 *cpu, C6502Val cycles)
{
PRIV->cycle = cycles;
}
C6502Val C6502GetTimer(C6502 *cpu, C6502Timer timer)
{
return PRIV->timer[timer];
}
void C6502SetTimer(C6502 *cpu, C6502Timer timer, C6502Val cycles)
{
PRIV->timer[timer] = cycles;
}
int C6502LodgeCallback(C6502 *cpu,
C6502CallbackReason reason,
C6502Callback 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 C6502RemoveCallback(C6502 *cpu,
C6502CallbackReason reason,
C6502Callback callback)
{
int f;
for(f = 0; f < MAX_PER_CALLBACK; f++)
{
if (PRIV->callback[reason][f] == callback)
{
PRIV->callback[reason][f] = NULL;
}
}
}
void C6502Interrupt(C6502 *cpu)
{
PRIV->raise = TRUE;
PRIV->nmi = FALSE;
}
void C6502NMI(C6502 *cpu)
{
PRIV->raise = TRUE;
PRIV->nmi = TRUE;
}
int C6502SingleStep(C6502 *cpu)
{
C6502_CheckInterrupt(cpu);
CALLBACK(eC6502_Instruction, PRIV->cycle);
INC_R;
opcode=FETCH_BYTE;
C6502_Decode(cpu,opcode);
return PRIV->last_cb;
}
void C6502Exec(C6502 *cpu)
{
while (C6502SingleStep(cpu));
}
void C6502SetLabels(C6502 *cpu, C6502Label labels[])
{
PRIV->labels = labels;
}
const char *C6502Disassemble(C6502 *cpu, C6502Word *pc)
{
#ifdef ENABLE_DISASSEM
C6502Byte C6502_Dis_FetchByte(C6502 *cpu, C6502Word *pc);
static char s[80];
C6502Word opc,npc;
C6502Byte op;
int f;
opc=*pc;
op=C6502_Dis_FetchByte(cpu,pc);
dis_opcode_z80[op](cpu,op,pc);
npc=*pc;
strcpy(s,C6502_Dis_Printf("%-5s",C6502_Dis_GetOp()));
strcat(s,C6502_Dis_Printf("%-40s ;",C6502_Dis_GetArg()));
for(f=0;f<5 && opc!=npc;f++)
{
#ifdef ENABLE_ARRAY_MEMORY
strcat(s,C6502_Dis_Printf(" %.2x",(int)C6502_MEMORY[opc++]));
#else
strcat(s,C6502_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 */
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