0dc63c1b71
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@8262 a1c6a512-1295-4272-9138-f99709370657
1304 lines
37 KiB
C
1304 lines
37 KiB
C
/***************************************************************************
|
|
* __________ __ ___.
|
|
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
|
|
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
|
|
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
|
|
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
|
|
* \/ \/ \/ \/ \/
|
|
* $Id$
|
|
*
|
|
* Orginal from Vision-8 Emulator / Copyright (C) 1997-1999 Marcel de Kogel
|
|
* Modified for Archos by Blueloop (a.wenger@gmx.de)
|
|
*
|
|
* All files in this archive are subject to the GNU General Public License.
|
|
* See the file COPYING in the source tree root for full license agreement.
|
|
*
|
|
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
|
|
* KIND, either express or implied.
|
|
*
|
|
****************************************************************************/
|
|
#include "plugin.h"
|
|
|
|
/* Only build for (correct) target */
|
|
#ifdef HAVE_LCD_BITMAP
|
|
|
|
static struct plugin_api* rb; /* here is a global api struct pointer */
|
|
|
|
#define EXTERN static
|
|
#define STATIC static
|
|
#define memset rb->memset
|
|
#define memcpy rb->memcpy
|
|
#define printf DEBUGF
|
|
#define rand rb->rand
|
|
/* #define CHIP8_DEBUG */
|
|
|
|
#if (LCD_WIDTH >= 112) && (LCD_HEIGHT >= 64)
|
|
#define CHIP8_SUPER /* SCHIP even on the archos recorder (112x64) */
|
|
#endif
|
|
|
|
/****************************************************************************/
|
|
/** (S)CHIP-8 core emulation, from Vision-8 + mods by Fdy **/
|
|
/** The core is completely generic and can be used outside of Rockbox, **/
|
|
/** thus the STATIC, EXTERN etc. Please do not modify. **/
|
|
/****************************************************************************/
|
|
/** Vision8: CHIP8 emulator *************************************************/
|
|
/** **/
|
|
/** CHIP8.h **/
|
|
/** **/
|
|
/** This file contains the portable CHIP8 emulation engine definitions **/
|
|
/** **/
|
|
/** Copyright (C) Marcel de Kogel 1997 **/
|
|
/** You are not allowed to distribute this software commercially **/
|
|
/** Please, notify me, if you make any changes to this file **/
|
|
/****************************************************************************/
|
|
|
|
#ifndef __CHIP8_H
|
|
#define __CHIP8_H
|
|
|
|
#ifndef EXTERN
|
|
#define EXTERN extern
|
|
#endif
|
|
|
|
typedef unsigned char byte; /* sizeof(byte)==1 */
|
|
typedef unsigned short word; /* sizeof(word)>=2 */
|
|
|
|
struct chip8_regs_struct
|
|
{
|
|
byte alg[16]; /* 16 general registers */
|
|
byte delay,sound; /* delay and sound timer */
|
|
word i; /* index register */
|
|
word pc; /* program counter */
|
|
word sp; /* stack pointer */
|
|
};
|
|
|
|
EXTERN struct chip8_regs_struct chip8_regs;
|
|
|
|
#ifdef CHIP8_SUPER
|
|
#define CHIP8_WIDTH 128
|
|
#define CHIP8_HEIGHT 64
|
|
EXTERN byte chip8_super; /* != 0 if in SCHIP display mode */
|
|
#else
|
|
#define CHIP8_WIDTH 64
|
|
#define CHIP8_HEIGHT 32
|
|
#endif
|
|
|
|
EXTERN byte chip8_iperiod; /* number of opcodes per */
|
|
/* timeslice (1/50sec.) */
|
|
EXTERN byte chip8_keys[16]; /* if 1, key is held down */
|
|
EXTERN byte chip8_display[CHIP8_WIDTH*CHIP8_HEIGHT];/* 0xff if pixel is set, */
|
|
/* 0x00 otherwise */
|
|
EXTERN byte chip8_mem[4096]; /* machine memory. program */
|
|
/* is loaded at 0x200 */
|
|
EXTERN byte chip8_running; /* if 0, emulation stops */
|
|
|
|
EXTERN void chip8_execute (void); /* execute chip8_iperiod */
|
|
/* opcodes */
|
|
EXTERN void chip8_reset (void); /* reset virtual machine */
|
|
EXTERN void chip8 (void); /* start chip8 emulation */
|
|
|
|
EXTERN void chip8_sound_on (void); /* turn sound on */
|
|
EXTERN void chip8_sound_off (void); /* turn sound off */
|
|
EXTERN void chip8_interrupt (void); /* update keyboard, */
|
|
/* display, etc. */
|
|
|
|
#ifdef CHIP8_DEBUG
|
|
EXTERN byte chip8_trace; /* if 1, call debugger */
|
|
/* every opcode */
|
|
EXTERN word chip8_trap; /* if pc==trap, set trace */
|
|
/* flag */
|
|
EXTERN void chip8_debug (word opcode,struct chip8_regs_struct *regs);
|
|
#endif
|
|
|
|
#endif /* __CHIP8_H */
|
|
|
|
/** Vision8: CHIP8 emulator *************************************************/
|
|
/** **/
|
|
/** CHIP8.c **/
|
|
/** **/
|
|
/** This file contains the portable CHIP8 emulation engine **/
|
|
/** SCHIP emulation (C) Frederic Devernay 2005 **/
|
|
/** **/
|
|
/** Copyright (C) Marcel de Kogel 1997 **/
|
|
/** You are not allowed to distribute this software commercially **/
|
|
/** Please, notify me, if you make any changes to this file **/
|
|
/****************************************************************************/
|
|
|
|
/* you can
|
|
#define STATIC static
|
|
#define EXTERN static
|
|
and include this file for single-object generation
|
|
*/
|
|
|
|
#ifndef STATIC
|
|
#include <stdlib.h> /* for memset, etc. */
|
|
#include <string.h>
|
|
#define STATIC
|
|
#endif
|
|
|
|
#ifdef CHIP8_DEBUG
|
|
#include <stdio.h>
|
|
#define DBG_(_x) ((void)(_x))
|
|
#else
|
|
#define DBG_(_x) ((void)0)
|
|
#endif
|
|
|
|
STATIC struct chip8_regs_struct chip8_regs;
|
|
|
|
static byte chip8_key_pressed;
|
|
STATIC byte chip8_keys[16]; /* if 1, key is held down */
|
|
STATIC byte chip8_display[CHIP8_WIDTH*CHIP8_HEIGHT]; /* 0xff if pixel is set, */
|
|
/* 0x00 otherwise */
|
|
#ifdef CHIP8_SUPER
|
|
STATIC byte chip8_super; /* != 0 if in SCHIP display mode */
|
|
#endif
|
|
STATIC byte chip8_mem[4096]; /* machine memory. program */
|
|
/* is loaded at 0x200 */
|
|
|
|
#define read_mem(a) (chip8_mem[(a)&4095])
|
|
#define write_mem(a,v) (chip8_mem[(a)&4095]=(v))
|
|
|
|
STATIC byte chip8_iperiod;
|
|
|
|
STATIC byte chip8_running; /* Flag for End-of-Emulation */
|
|
|
|
#define get_reg_offset(opcode) (chip8_regs.alg+(opcode>>8))
|
|
#define get_reg_value(opcode) (*get_reg_offset(opcode))
|
|
#define get_reg_offset_2(opcode) (chip8_regs.alg+((opcode>>4)&0x0f))
|
|
#define get_reg_value_2(opcode) (*get_reg_offset_2(opcode))
|
|
|
|
typedef void (*opcode_fn) (word opcode);
|
|
typedef void (*math_fn) (byte *reg1,byte reg2);
|
|
|
|
|
|
|
|
static void op_call (word opcode)
|
|
{
|
|
chip8_regs.sp--;
|
|
write_mem (chip8_regs.sp,chip8_regs.pc&0xff);
|
|
chip8_regs.sp--;
|
|
write_mem (chip8_regs.sp,chip8_regs.pc>>8);
|
|
chip8_regs.pc=opcode;
|
|
#ifdef CHIP8_DEBUG
|
|
if(chip8_regs.sp < 0x1c0)
|
|
printf("warning: more than 16 subroutine calls, sp=%x\n", chip8_regs.sp);
|
|
#endif
|
|
}
|
|
|
|
static void op_jmp (word opcode)
|
|
{
|
|
chip8_regs.pc=opcode;
|
|
}
|
|
|
|
static void op_key (word opcode)
|
|
{
|
|
#ifdef CHIP8_DEBUG
|
|
static byte tested[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
|
|
#endif
|
|
byte key, key_value,cp_value;
|
|
if ((opcode&0xff)==0x9e) /* skp */
|
|
cp_value=1;
|
|
else if ((opcode&0xff)==0xa1) /* sknp */
|
|
cp_value=0;
|
|
else {
|
|
DBG_(printf("unhandled key opcode 0x%x\n", opcode));
|
|
return;
|
|
}
|
|
key = get_reg_value(opcode)&0x0f;
|
|
#ifdef CHIP8_DEBUG
|
|
if (!tested[key]) {
|
|
tested[key] = 1;
|
|
DBG_(printf("testing key %d\n", key));
|
|
}
|
|
#endif
|
|
key_value=chip8_keys[key];
|
|
if (cp_value==key_value)
|
|
chip8_regs.pc+=2;
|
|
}
|
|
|
|
static void op_skeq_const (word opcode)
|
|
{
|
|
if (get_reg_value(opcode)==(opcode&0xff))
|
|
chip8_regs.pc+=2;
|
|
}
|
|
|
|
static void op_skne_const (word opcode)
|
|
{
|
|
if (get_reg_value(opcode)!=(opcode&0xff))
|
|
chip8_regs.pc+=2;
|
|
}
|
|
|
|
static void op_skeq_reg (word opcode)
|
|
{
|
|
if (get_reg_value(opcode)==get_reg_value_2(opcode))
|
|
chip8_regs.pc+=2;
|
|
}
|
|
|
|
static void op_skne_reg (word opcode)
|
|
{
|
|
if (get_reg_value(opcode)!=get_reg_value_2(opcode))
|
|
chip8_regs.pc+=2;
|
|
}
|
|
|
|
static void op_mov_const (word opcode)
|
|
{
|
|
*get_reg_offset(opcode)=opcode&0xff;
|
|
}
|
|
|
|
static void op_add_const (word opcode)
|
|
{
|
|
*get_reg_offset(opcode)+=opcode&0xff;
|
|
}
|
|
|
|
static void op_mvi (word opcode)
|
|
{
|
|
chip8_regs.i=opcode;
|
|
}
|
|
|
|
static void op_jmi (word opcode)
|
|
{
|
|
chip8_regs.pc=opcode+chip8_regs.alg[0];
|
|
}
|
|
|
|
static void op_rand (word opcode)
|
|
{
|
|
*get_reg_offset(opcode)=rand()&(opcode&0xff);
|
|
}
|
|
|
|
static void math_or (byte *reg1,byte reg2)
|
|
{
|
|
*reg1|=reg2;
|
|
}
|
|
|
|
static void math_mov (byte *reg1,byte reg2)
|
|
{
|
|
*reg1=reg2;
|
|
}
|
|
|
|
static void math_nop (byte *reg1,byte reg2)
|
|
{
|
|
(void)reg1;
|
|
(void)reg2;
|
|
DBG_(printf("Warning: math nop!\n"));
|
|
}
|
|
|
|
static void math_and (byte *reg1,byte reg2)
|
|
{
|
|
*reg1&=reg2;
|
|
}
|
|
|
|
static void math_xor (byte *reg1,byte reg2)
|
|
{
|
|
*reg1^=reg2;
|
|
}
|
|
|
|
static void math_add (byte *reg1,byte reg2)
|
|
{
|
|
word tmp;
|
|
tmp=*reg1+reg2;
|
|
*reg1=(byte)tmp;
|
|
chip8_regs.alg[15]=tmp>>8;
|
|
}
|
|
|
|
static void math_sub (byte *reg1,byte reg2)
|
|
{
|
|
word tmp;
|
|
tmp=*reg1-reg2;
|
|
*reg1=(byte)tmp;
|
|
chip8_regs.alg[15]=((byte)(tmp>>8))+1;
|
|
}
|
|
|
|
static void math_shr (byte *reg1,byte reg2)
|
|
{
|
|
(void)reg2;
|
|
chip8_regs.alg[15]=*reg1&1;
|
|
*reg1>>=1;
|
|
}
|
|
|
|
static void math_shl (byte *reg1,byte reg2)
|
|
{
|
|
(void)reg2;
|
|
chip8_regs.alg[15]=*reg1>>7;
|
|
*reg1<<=1;
|
|
}
|
|
|
|
static void math_rsb (byte *reg1,byte reg2)
|
|
{
|
|
word tmp;
|
|
tmp=reg2-*reg1;
|
|
*reg1=(byte)tmp;
|
|
chip8_regs.alg[15]=((byte)(tmp>>8))+1;
|
|
}
|
|
|
|
#ifdef CHIP8_SUPER
|
|
/* SUPER: scroll down n lines (or half in CHIP8 mode) */
|
|
static void scroll_down(word opcode)
|
|
{
|
|
int n = opcode & 0xf;
|
|
byte *dst = chip8_display + CHIP8_WIDTH*CHIP8_HEIGHT -1;
|
|
byte *src = dst - n*CHIP8_WIDTH;
|
|
while(src >= chip8_display) {
|
|
*dst-- = *src--;
|
|
}
|
|
while(dst >= chip8_display) {
|
|
*dst-- = 0;
|
|
}
|
|
}
|
|
/* SUPER: scroll 4 pixels left! */
|
|
static void scroll_left(void)
|
|
{
|
|
byte *dst = chip8_display;
|
|
byte *src = dst;
|
|
byte *eol = chip8_display + CHIP8_WIDTH;
|
|
byte *eoi = chip8_display + CHIP8_WIDTH*CHIP8_HEIGHT;
|
|
while(eol <= eoi) {
|
|
src+=4;
|
|
while(src < eol) {
|
|
*dst++ = *src++;
|
|
}
|
|
*dst++ = 0;
|
|
*dst++ = 0;
|
|
*dst++ = 0;
|
|
*dst++ = 0;
|
|
eol += CHIP8_WIDTH;
|
|
}
|
|
}
|
|
static void scroll_right(void)
|
|
{
|
|
byte *dst = chip8_display + CHIP8_WIDTH*CHIP8_HEIGHT -1;
|
|
byte *src = dst;
|
|
byte *bol = chip8_display + CHIP8_WIDTH*(CHIP8_HEIGHT-1);
|
|
while(bol >= chip8_display) {
|
|
src-=4;
|
|
while(src >= bol) {
|
|
*dst-- = *src--;
|
|
}
|
|
*dst-- = 0;
|
|
*dst-- = 0;
|
|
*dst-- = 0;
|
|
*dst-- = 0;
|
|
bol -= CHIP8_WIDTH;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
static void op_system (word opcode)
|
|
{
|
|
switch ((byte)opcode)
|
|
{
|
|
#ifdef CHIP8_SUPER
|
|
case 0xfb:
|
|
scroll_right();
|
|
break;
|
|
case 0xfc:
|
|
scroll_left();
|
|
break;
|
|
case 0xfd:
|
|
DBG_(printf("SUPER: quit the emulator\n"));
|
|
chip8_reset();
|
|
break;
|
|
case 0xfe:
|
|
DBG_(printf("SUPER: set CHIP-8 graphic mode\n"));
|
|
memset (chip8_display,0,sizeof(chip8_display));
|
|
chip8_super = 0;
|
|
break;
|
|
case 0xff:
|
|
DBG_(printf("SUPER: set SCHIP graphic mode\n"));
|
|
memset (chip8_display,0,sizeof(chip8_display));
|
|
chip8_super = 1;
|
|
break;
|
|
#endif
|
|
case 0xe0:
|
|
memset (chip8_display,0,sizeof(chip8_display));
|
|
break;
|
|
case 0xee:
|
|
chip8_regs.pc=read_mem(chip8_regs.sp)<<8;
|
|
chip8_regs.sp++;
|
|
chip8_regs.pc+=read_mem(chip8_regs.sp);
|
|
chip8_regs.sp++;
|
|
break;
|
|
default:
|
|
#ifdef CHIP8_SUPER
|
|
if ((opcode & 0xF0) == 0xC0)
|
|
scroll_down(opcode);
|
|
else
|
|
#endif
|
|
{
|
|
DBG_(printf("unhandled system opcode 0x%x\n", opcode));
|
|
chip8_running = 3;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void op_misc (word opcode)
|
|
{
|
|
byte *reg,i,j;
|
|
#ifdef CHIP8_DEBUG
|
|
static byte firstwait = 1;
|
|
#endif
|
|
reg=get_reg_offset(opcode);
|
|
switch ((byte)opcode)
|
|
{
|
|
case 0x07: /* gdelay */
|
|
*reg=chip8_regs.delay;
|
|
break;
|
|
case 0x0a: /* key */
|
|
#ifdef CHIP8_DEBUG
|
|
if(firstwait) {
|
|
printf("waiting for key press\n");
|
|
firstwait = 0;
|
|
}
|
|
#endif
|
|
if (chip8_key_pressed)
|
|
*reg=chip8_key_pressed-1;
|
|
else
|
|
chip8_regs.pc-=2;
|
|
break;
|
|
case 0x15: /* sdelay */
|
|
chip8_regs.delay=*reg;
|
|
break;
|
|
case 0x18: /* ssound */
|
|
chip8_regs.sound=*reg;
|
|
if (chip8_regs.sound)
|
|
chip8_sound_on();
|
|
break;
|
|
case 0x1e: /* adi */
|
|
chip8_regs.i+=(*reg);
|
|
break;
|
|
case 0x29: /* font */
|
|
chip8_regs.i=((word)(*reg&0x0f))*5;
|
|
break;
|
|
#ifdef CHIP8_SUPER
|
|
case 0x30: /* xfont */
|
|
chip8_regs.i=((word)(*reg&0x0f))*10+0x50;
|
|
break;
|
|
#endif
|
|
case 0x33: /* bcd */
|
|
i=*reg;
|
|
for (j=0;i>=100;i-=100)
|
|
j++;
|
|
write_mem (chip8_regs.i,j);
|
|
for (j=0;i>=10;i-=10)
|
|
j++;
|
|
write_mem (chip8_regs.i+1,j);
|
|
write_mem (chip8_regs.i+2,i);
|
|
break;
|
|
case 0x55: /* str */
|
|
for (i=0,j=(opcode>>8)&0x0f; i<=j; ++i)
|
|
write_mem(chip8_regs.i+i,chip8_regs.alg[i]);
|
|
break;
|
|
case 0x65: /* ldr */
|
|
for (i=0,j=(opcode>>8)&0x0f; i<=j; ++i)
|
|
chip8_regs.alg[i]=read_mem(chip8_regs.i+i);
|
|
break;
|
|
#ifdef CHIP8_SUPER
|
|
case 0x75:
|
|
DBG_(printf("SUPER: save V0..V%x (X<8) in the HP48 flags\n", (opcode>>8)&0x0f));
|
|
break;
|
|
case 0x85:
|
|
DBG_(printf("SUPER: load V0..V%x (X<8) from the HP48 flags\n", (opcode>>8)&0x0f));
|
|
break;
|
|
#endif
|
|
default:
|
|
DBG_(printf("unhandled misc opcode 0x%x\n", opcode));
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void op_sprite (word opcode)
|
|
{
|
|
byte *q;
|
|
byte n,x,x2,y,collision;
|
|
word p;
|
|
x=get_reg_value(opcode);
|
|
y=get_reg_value_2(opcode);
|
|
p=chip8_regs.i;
|
|
n=opcode&0x0f;
|
|
#ifdef CHIP8_SUPER
|
|
if (chip8_super) {
|
|
/*printf("SUPER: sprite(%x)\n", opcode);*/
|
|
x &= 128-1;
|
|
y &= 64-1;
|
|
q=chip8_display+y*CHIP8_WIDTH;
|
|
if(n == 0)
|
|
{ /* 16x16 sprite */
|
|
n = 16;
|
|
if (n+y>64)
|
|
n=64-y;
|
|
for (collision=1;n;--n,q+=CHIP8_WIDTH)
|
|
{
|
|
/* first 8 bits */
|
|
for (y=read_mem(p++),x2=x;y;y<<=1,x2=(x2+1)&(CHIP8_WIDTH-1))
|
|
if (y&0x80)
|
|
collision&=(q[x2]^=0xff);
|
|
x2=(x+8)&(CHIP8_WIDTH-1);
|
|
/* last 8 bits */
|
|
for (y=read_mem(p++);y;y<<=1,x2=(x2+1)&(CHIP8_WIDTH-1))
|
|
if (y&0x80)
|
|
collision&=(q[x2]^=0xff);
|
|
}
|
|
}
|
|
else {
|
|
/* 8xn sprite */
|
|
if (n+y>64)
|
|
n=64-y;
|
|
for (collision=1;n;--n,q+=CHIP8_WIDTH)
|
|
{
|
|
for (y=read_mem(p++),x2=x;y;y<<=1,x2=(x2+1)&(CHIP8_WIDTH-1))
|
|
if (y&0x80)
|
|
collision&=(q[x2]^=0xff);
|
|
}
|
|
}
|
|
}
|
|
else {
|
|
x &= 64-1;
|
|
y &= 32-1;
|
|
q=chip8_display+y*CHIP8_WIDTH*2;
|
|
if(n == 0)
|
|
n = 16;
|
|
if (n+y>32)
|
|
n=32-y;
|
|
for (collision=1;n;--n,q+=CHIP8_WIDTH*2)
|
|
{
|
|
for (y=read_mem(p++),x2=x*2;y;y<<=1,x2=(x2+2)&(CHIP8_WIDTH-1))
|
|
if (y&0x80) {
|
|
q[x2]^=0xff;
|
|
q[x2+1]^=0xff;
|
|
q[x2+CHIP8_WIDTH]^=0xff;
|
|
q[x2+CHIP8_WIDTH+1]^=0xff;
|
|
collision &= q[x2]|q[x2+1]|q[x2+CHIP8_WIDTH]|q[x2+CHIP8_WIDTH+1];
|
|
}
|
|
}
|
|
}
|
|
#else
|
|
x &= 64-1;
|
|
y &= 32-1;
|
|
q=chip8_display+y*CHIP8_WIDTH;
|
|
if (n+y>32)
|
|
n=32-y;
|
|
for (collision=1;n;--n,q+=CHIP8_WIDTH)
|
|
{
|
|
for (y=read_mem(p++),x2=x;y;y<<=1,x2=(x2+1)&(CHIP8_WIDTH-1))
|
|
if (y&0x80)
|
|
collision&=(q[x2]^=0xff);
|
|
}
|
|
#endif
|
|
chip8_regs.alg[15]=collision^1;
|
|
}
|
|
|
|
static math_fn math_opcodes[16]=
|
|
{
|
|
math_mov,
|
|
math_or,
|
|
math_and,
|
|
math_xor,
|
|
math_add,
|
|
math_sub,
|
|
math_shr,
|
|
math_rsb,
|
|
math_nop,
|
|
math_nop,
|
|
math_nop,
|
|
math_nop,
|
|
math_nop,
|
|
math_nop,
|
|
math_shl,
|
|
math_nop
|
|
};
|
|
|
|
static void op_math (word opcode)
|
|
{
|
|
(*(math_opcodes[opcode&0x0f]))
|
|
(get_reg_offset(opcode),get_reg_value_2(opcode));
|
|
}
|
|
|
|
static opcode_fn main_opcodes[16]=
|
|
{
|
|
op_system,
|
|
op_jmp,
|
|
op_call,
|
|
op_skeq_const,
|
|
op_skne_const,
|
|
op_skeq_reg,
|
|
op_mov_const,
|
|
op_add_const,
|
|
op_math,
|
|
op_skne_reg,
|
|
op_mvi,
|
|
op_jmi,
|
|
op_rand,
|
|
op_sprite,
|
|
op_key,
|
|
op_misc
|
|
};
|
|
|
|
#ifdef CHIP8_DEBUG
|
|
STATIC byte chip8_trace;
|
|
STATIC word chip8_trap;
|
|
|
|
/****************************************************************************/
|
|
/* This routine is called every opcode when chip8_trace==1. It prints the */
|
|
/* current register contents and the opcode being executed */
|
|
/****************************************************************************/
|
|
STATIC void chip8_debug (word opcode,struct chip8_regs_struct *regs)
|
|
{
|
|
int i;
|
|
byte hextable[16] = "0123456789ABCDEF";
|
|
byte v1[3] = "Vx\0";
|
|
byte v2[3] = "Vx\0";
|
|
v1[1] = hextable[(opcode>>8)&0x0f];
|
|
v2[1] = hextable[(opcode>>8)&0x0f];
|
|
printf ("PC=%04X: %04X - ",regs->pc,opcode);
|
|
switch (opcode>>12) {
|
|
case 0:
|
|
if ((opcode&0xff0) == 0xc0) {
|
|
printf ("SCD %01X ; Scroll down n lines",opcode&0xf);
|
|
}
|
|
else switch (opcode&0xfff) {
|
|
case 0xe0:
|
|
printf ("CLS ; Clear screen");
|
|
break;
|
|
case 0xee:
|
|
printf ("RET ; Return from subroutine call");
|
|
break;
|
|
case 0xfb:
|
|
printf("SCR ; Scroll right");
|
|
break;
|
|
case 0xfc:
|
|
printf("SCL ; Scroll left");
|
|
break;
|
|
case 0xfd:
|
|
printf("EXIT ; Terminate the interpreter");
|
|
break;
|
|
case 0xfe:
|
|
printf("LOW ; Disable extended screen mode");
|
|
break;
|
|
case 0xff:
|
|
printf("HIGH ; Enable extended screen mode");
|
|
break;
|
|
default:
|
|
printf ("SYS %03X ; Unknown system call",opcode&0xff);
|
|
}
|
|
break;
|
|
case 1:
|
|
printf ("JP %03X ; Jump to address",opcode&0xfff);
|
|
break;
|
|
case 2:
|
|
printf ("CALL %03X ; Call subroutine",opcode&0xfff);
|
|
break;
|
|
case 3:
|
|
printf ("SE %s,%02X ; Skip if register == constant",v1,opcode&0xff);
|
|
break;
|
|
case 4:
|
|
printf ("SNE %s,%02X ; Skip if register <> constant",v1,opcode&0xff);
|
|
break;
|
|
case 5:
|
|
printf ("SE %s,%s ; Skip if register == register",v1,v2);
|
|
break;
|
|
case 6:
|
|
printf ("LD %s,%02X ; Set VX = Byte",v1,opcode&0xff);
|
|
break;
|
|
case 7:
|
|
printf ("ADD %s,%02X ; Set VX = VX + Byte",v1,opcode&0xff);
|
|
break;
|
|
case 8:
|
|
switch (opcode&0x0f) {
|
|
case 0:
|
|
printf ("LD %s,%s ; Set VX = VY, VF updates",v1,v2);
|
|
break;
|
|
case 1:
|
|
printf ("OR %s,%s ; Set VX = VX | VY, VF updates",v1,v2);
|
|
break;
|
|
case 2:
|
|
printf ("AND %s,%s ; Set VX = VX & VY, VF updates",v1,v2);
|
|
break;
|
|
case 3:
|
|
printf ("XOR %s,%s ; Set VX = VX ^ VY, VF updates",v1,v2);
|
|
break;
|
|
case 4:
|
|
printf ("ADD %s,%s ; Set VX = VX + VY, VF = carry",v1,v2);
|
|
break;
|
|
case 5:
|
|
printf ("SUB %s,%s ; Set VX = VX - VY, VF = !borrow",v1,v2);
|
|
break;
|
|
case 6:
|
|
printf ("SHR %s,%s ; Set VX = VX >> 1, VF = carry",v1,v2);
|
|
break;
|
|
case 7:
|
|
printf ("SUBN %s,%s ; Set VX = VY - VX, VF = !borrow",v1,v2);
|
|
break;
|
|
case 14:
|
|
printf ("SHL %s,%s ; Set VX = VX << 1, VF = carry",v1,v2);
|
|
break;
|
|
default:
|
|
printf ("Illegal opcode");
|
|
}
|
|
break;
|
|
case 9:
|
|
printf ("SNE %s,%s ; Skip next instruction iv VX!=VY",v1,v2);
|
|
break;
|
|
case 10:
|
|
printf ("LD I,%03X ; Set I = Addr",opcode&0xfff);
|
|
break;
|
|
case 11:
|
|
printf ("JP V0,%03X ; Jump to Addr + V0",opcode&0xfff);
|
|
break;
|
|
case 12:
|
|
printf ("RND %s,%02X ; Set VX = random & Byte",v1,opcode&0xff);
|
|
break;
|
|
case 13:
|
|
printf ("DRW %s,%s,%X ; Draw n byte sprite stored at [i] at VX,VY. Set VF = collision",v1,v2,opcode&0x0f);
|
|
break;
|
|
case 14:
|
|
switch (opcode&0xff) {
|
|
case 0x9e:
|
|
printf ("SKP %s ; Skip next instruction if key VX down",v1);
|
|
break;
|
|
case 0xa1:
|
|
printf ("SKNP %s ; Skip next instruction if key VX up",v1);
|
|
break;
|
|
default:
|
|
printf ("%04X ; Illegal opcode", opcode);
|
|
}
|
|
break;
|
|
case 15:
|
|
switch (opcode&0xff) {
|
|
case 0x07:
|
|
printf ("LD %s,DT ; Set VX = delaytimer",v1);
|
|
break;
|
|
case 0x0a:
|
|
printf ("LD %s,K ; Set VX = key, wait for keypress",v1);
|
|
break;
|
|
case 0x15:
|
|
printf ("LD DT,%s ; Set delaytimer = VX",v1);
|
|
break;
|
|
case 0x18:
|
|
printf ("LD ST,%s ; Set soundtimer = VX",v1);
|
|
break;
|
|
case 0x1e:
|
|
printf ("ADD I,%s ; Set I = I + VX",v1);
|
|
break;
|
|
case 0x29:
|
|
printf ("LD LF,%s ; Point I to 5 byte numeric sprite for value in VX",v1);
|
|
break;
|
|
case 0x30:
|
|
printf ("LD HF,%s ; Point I to 10 byte numeric sprite for value in VX",v1);
|
|
break;
|
|
case 0x33:
|
|
printf ("LD B,%s ; Store BCD of VX in [I], [I+1], [I+2]",v1);
|
|
break;
|
|
case 0x55:
|
|
printf ("LD [I],%s ; Store V0..VX in [I]..[I+X]",v1);
|
|
break;
|
|
case 0x65:
|
|
printf ("LD %s,[I] ; Read V0..VX from [I]..[I+X]",v1);
|
|
break;
|
|
case 0x75:
|
|
printf ("LD R,%s ; Store V0..VX in RPL user flags (X<=7)",v1);
|
|
break;
|
|
case 0x85:
|
|
printf ("LD %s,R ; Read V0..VX from RPL user flags (X<=7)",v1);
|
|
break;
|
|
default:
|
|
printf ("%04X ; Illegal opcode", opcode);
|
|
}
|
|
break;
|
|
}
|
|
printf ("\n; Registers: ");
|
|
for (i=0;i<16;++i) printf ("%02x ",(regs->alg[i])&0xff);
|
|
printf ("\n; Index: %03x Stack:%03x Delay:%02x Sound:%02x\n",
|
|
regs->i&0xfff,regs->sp&0xfff,regs->delay&0xff,regs->sound&0xff);
|
|
}
|
|
#endif
|
|
|
|
/****************************************************************************/
|
|
/* Execute chip8_iperiod opcodes */
|
|
/****************************************************************************/
|
|
STATIC void chip8_execute(void)
|
|
{
|
|
byte i;
|
|
byte key_pressed=0;
|
|
word opcode;
|
|
for (i = chip8_iperiod ; i ;--i)
|
|
{
|
|
/* Fetch the opcode */
|
|
opcode=(read_mem(chip8_regs.pc)<<8)+read_mem(chip8_regs.pc+1);
|
|
#ifdef CHIP8_DEBUG
|
|
/* Check if trap address has been reached */
|
|
if ((chip8_regs.pc&4095)==chip8_trap)
|
|
chip8_trace=1;
|
|
/* Call the debugger if chip8_trace!=0 */
|
|
if (chip8_trace)
|
|
chip8_debug (opcode,&chip8_regs);
|
|
#endif
|
|
chip8_regs.pc+=2;
|
|
(*(main_opcodes[opcode>>12]))(opcode&0x0fff); /* Emulate this opcode */
|
|
}
|
|
/* Update timers */
|
|
if (chip8_regs.delay)
|
|
--chip8_regs.delay;
|
|
if (chip8_regs.sound)
|
|
if (--chip8_regs.sound == 0)
|
|
chip8_sound_off();
|
|
|
|
/* Update the machine status */
|
|
chip8_interrupt ();
|
|
|
|
for (i=key_pressed=0;i<16;++i) /* check if a key was first */
|
|
if (chip8_keys[i]) /* pressed */
|
|
key_pressed=i+1;
|
|
if (key_pressed && key_pressed!=chip8_key_pressed)
|
|
chip8_key_pressed=key_pressed;
|
|
else
|
|
chip8_key_pressed=0;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
/* Reset the virtual chip8 machine */
|
|
/****************************************************************************/
|
|
STATIC void chip8_reset(void)
|
|
{
|
|
static byte chip8_sprites[0x50]=
|
|
{
|
|
0xf9,0x99,0xf2,0x62,0x27,
|
|
0xf1,0xf8,0xff,0x1f,0x1f,
|
|
0x99,0xf1,0x1f,0x8f,0x1f,
|
|
0xf8,0xf9,0xff,0x12,0x44,
|
|
0xf9,0xf9,0xff,0x9f,0x1f,
|
|
0xf9,0xf9,0x9e,0x9e,0x9e,
|
|
0xf8,0x88,0xfe,0x99,0x9e,
|
|
0xf8,0xf8,0xff,0x8f,0x88,
|
|
}; /* 4x5 pixel hexadecimal character font patterns */
|
|
#ifdef CHIP8_SUPER
|
|
static byte schip_sprites[10*10]=
|
|
{
|
|
0x3C, 0x7E, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0x7E, 0x3C, /* 0 */
|
|
0x18, 0x38, 0x58, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x3C, /* 1 */
|
|
0x3E, 0x7F, 0xC3, 0x06, 0x0C, 0x18, 0x30, 0x60, 0xFF, 0xFF, /* 2 */
|
|
0x3C, 0x7E, 0xC3, 0x03, 0x0E, 0x0E, 0x03, 0xC3, 0x7E, 0x3C, /* 3 */
|
|
0x06, 0x0E, 0x1E, 0x36, 0x66, 0xC6, 0xFF, 0xFF, 0x06, 0x06, /* 4 */
|
|
0xFF, 0xFF, 0xC0, 0xC0, 0xFC, 0xFE, 0x03, 0xC3, 0x7E, 0x3C, /* 5 */
|
|
0x3E, 0x7C, 0xC0, 0xC0, 0xFC, 0xFE, 0xC3, 0xC3, 0x7E, 0x3C, /* 6 */
|
|
0xFF, 0xFF, 0x03, 0x06, 0x0C, 0x18, 0x30, 0x60, 0x60, 0x60, /* 7 */
|
|
0x3C, 0x7E, 0xC3, 0xC3, 0x7E, 0x7E, 0xC3, 0xC3, 0x7E, 0x3C, /* 8 */
|
|
0x3C, 0x7E, 0xC3, 0xC3, 0x7F, 0x3F, 0x03, 0x03, 0x3E, 0x7C, /* 9 */
|
|
}; /* 8x10 pixel font patterns (only 10) */
|
|
#endif
|
|
byte i;
|
|
for (i=0;i<16*5;++i)
|
|
{
|
|
write_mem (i<<1,chip8_sprites[i]&0xf0);
|
|
write_mem ((i<<1)+1,chip8_sprites[i]<<4);
|
|
}
|
|
#ifdef CHIP8_SUPER
|
|
/*
|
|
for (i=0; i<100; i++)
|
|
write_mem (i+0x50,schip_sprites[i]);
|
|
*/
|
|
memcpy(chip8_mem+0x50, schip_sprites, 100);
|
|
chip8_super = 0;
|
|
#endif
|
|
memset (chip8_regs.alg,0,sizeof(chip8_regs.alg));
|
|
memset (chip8_keys,0,sizeof(chip8_keys));
|
|
chip8_key_pressed=0;
|
|
memset (chip8_display,0,sizeof(chip8_display));
|
|
chip8_regs.delay=chip8_regs.sound=chip8_regs.i=0;
|
|
chip8_regs.sp=0x1e0;
|
|
chip8_regs.pc=0x200;
|
|
chip8_sound_off ();
|
|
chip8_running=1;
|
|
#ifdef CHIP8_DEBUG
|
|
chip8_trace=0;
|
|
#endif
|
|
}
|
|
|
|
|
|
/****************************************************************************/
|
|
/* Start CHIP8 emulation */
|
|
/****************************************************************************/
|
|
STATIC void chip8 (void)
|
|
{
|
|
chip8_reset ();
|
|
while (chip8_running==1) chip8_execute ();
|
|
}
|
|
|
|
/****************************************************************************/
|
|
/** END OF (S)CHIP-8 core emulation, from Vision-8 + mods by Fdy **/
|
|
/****************************************************************************/
|
|
|
|
/* size of the displayed area */
|
|
#if (CHIP8_WIDTH == 128) && (LCD_WIDTH < 128)
|
|
#define CHIP8_LCDWIDTH 112
|
|
#else
|
|
#define CHIP8_LCDWIDTH CHIP8_WIDTH
|
|
#endif
|
|
|
|
#if (LCD_WIDTH > CHIP8_LCDWIDTH)
|
|
#define CHIP8_X ((LCD_WIDTH - CHIP8_LCDWIDTH)/2)
|
|
#else
|
|
#define CHIP8_X 0
|
|
#endif
|
|
#if (LCD_HEIGHT > CHIP8_HEIGHT)
|
|
#define CHIP8_Y (((LCD_HEIGHT - CHIP8_HEIGHT)>>4)<<3)
|
|
#else
|
|
#define CHIP8_Y 0
|
|
#endif
|
|
|
|
/* variable button definitions */
|
|
#if CONFIG_KEYPAD == RECORDER_PAD /* only 9 out of 16 chip8 buttons */
|
|
#define CHIP8_OFF BUTTON_OFF
|
|
#define CHIP8_KEY1 BUTTON_F1
|
|
#define CHIP8_KEY2 BUTTON_UP
|
|
#define CHIP8_KEY3 BUTTON_F3
|
|
#define CHIP8_KEY4 BUTTON_LEFT
|
|
#define CHIP8_KEY5 BUTTON_PLAY
|
|
#define CHIP8_KEY6 BUTTON_RIGHT
|
|
#define CHIP8_KEY7 BUTTON_F2
|
|
#define CHIP8_KEY8 BUTTON_DOWN
|
|
#define CHIP8_KEY9 BUTTON_ON
|
|
|
|
#elif CONFIG_KEYPAD == ONDIO_PAD /* even more limited */
|
|
#define CHIP8_OFF BUTTON_OFF
|
|
#define CHIP8_KEY2 BUTTON_UP
|
|
#define CHIP8_KEY4 BUTTON_LEFT
|
|
#define CHIP8_KEY5 BUTTON_MENU
|
|
#define CHIP8_KEY6 BUTTON_RIGHT
|
|
#define CHIP8_KEY8 BUTTON_DOWN
|
|
|
|
#elif (CONFIG_KEYPAD == IRIVER_H100_PAD) || \
|
|
(CONFIG_KEYPAD == IRIVER_H300_PAD)
|
|
#define CHIP8_OFF BUTTON_OFF
|
|
#define CHIP8_KEY2 BUTTON_UP
|
|
#define CHIP8_KEY4 BUTTON_LEFT
|
|
#define CHIP8_KEY5 BUTTON_SELECT
|
|
#define CHIP8_KEY6 BUTTON_RIGHT
|
|
#define CHIP8_KEY8 BUTTON_DOWN
|
|
|
|
#elif (CONFIG_KEYPAD == IPOD_4G_PAD)
|
|
#define CHIP8_OFF BUTTON_MENU
|
|
#define CHIP8_KEY2 BUTTON_SCROLL_BACK
|
|
#define CHIP8_KEY4 BUTTON_LEFT
|
|
#define CHIP8_KEY5 BUTTON_PLAY
|
|
#define CHIP8_KEY6 BUTTON_RIGHT
|
|
#define CHIP8_KEY8 BUTTON_SCROLL_FWD
|
|
|
|
#endif
|
|
|
|
static byte chip8_virtual_keys[16];
|
|
static byte chip8_keymap[16];
|
|
|
|
static unsigned long starttimer; /* Timer value at the beginning */
|
|
static unsigned long cycles; /* Number of update cycles (50Hz) */
|
|
|
|
#ifndef SIMULATOR
|
|
static bool is_playing;
|
|
#endif
|
|
|
|
/* one frame of bitswapped mp3 data */
|
|
static unsigned char beep[]={255,
|
|
223, 28, 35, 0,192,210, 35,226, 72,188,242, 1,128,166, 16, 68,146,252,151, 19,
|
|
10,180,245,127, 96,184, 3,184, 30, 0,118, 59,128,121,102, 6,212, 0, 97, 6,
|
|
42, 65, 28,134,192,145, 57, 38,136, 73, 29, 38,132, 15, 21, 70, 91,185, 99,198,
|
|
15,192, 83, 6, 33,129, 20, 6, 97, 33, 4, 6,245,128, 92, 6, 24, 0, 86, 6,
|
|
56,129, 44, 24,224, 25, 13, 48, 50, 82,180, 11,251,106,249, 59, 24, 82,175,223,
|
|
252,119, 76,134,120,236,149,250,247,115,254,145,173,174,168,180,255,107,195, 89,
|
|
24, 25, 48,131,192, 61, 48, 64, 10,176, 49, 64, 1,152, 50, 32, 8,140, 48, 16,
|
|
5,129, 51,196,187, 41,177, 23,138, 70, 50, 8, 10,242, 48,192, 3,248,226, 0,
|
|
20,100, 18, 96, 41, 96, 78,102, 7,201,122, 76,119, 20,137, 37,177, 15,132,224,
|
|
20, 17,191, 67,147,187,116,211, 41,169, 63,172,182,186,217,155,111,140,104,254,
|
|
111,181,184,144, 17,148, 21,101,166,227,100, 86, 85, 85, 85};
|
|
|
|
/* callback to request more mp3 data */
|
|
void callback(unsigned char** start, int* size)
|
|
{
|
|
*start = beep; /* give it the same frame again */
|
|
*size = sizeof(beep);
|
|
}
|
|
|
|
/****************************************************************************/
|
|
/* Turn sound on */
|
|
/****************************************************************************/
|
|
static void chip8_sound_on (void)
|
|
{
|
|
#ifndef SIMULATOR
|
|
if (!is_playing)
|
|
rb->mp3_play_pause(true); /* kickoff audio */
|
|
#endif
|
|
}
|
|
|
|
/****************************************************************************/
|
|
/* Turn sound off */
|
|
/****************************************************************************/
|
|
static void chip8_sound_off (void)
|
|
{
|
|
#ifndef SIMULATOR
|
|
if (!is_playing)
|
|
rb->mp3_play_pause(false); /* pause audio */
|
|
#endif
|
|
}
|
|
|
|
/****************************************************************************/
|
|
/* Update the display */
|
|
/****************************************************************************/
|
|
static void chip8_update_display(void)
|
|
{
|
|
int x, lcd_x, y, i;
|
|
byte w;
|
|
byte* row;
|
|
/* frame buffer in hardware fomat */
|
|
unsigned char lcd_framebuf[CHIP8_HEIGHT/8][CHIP8_LCDWIDTH];
|
|
|
|
for (y=0;y<CHIP8_HEIGHT/8;++y)
|
|
{
|
|
row = lcd_framebuf[y];
|
|
for (x=0, lcd_x=0;x<CHIP8_WIDTH;++x,++lcd_x)
|
|
{
|
|
w = 0;
|
|
for (i=0;i<8;i++)
|
|
{
|
|
w = w >> 1;
|
|
if (chip8_display[x+(y*8+i)*CHIP8_WIDTH] != 0)
|
|
{
|
|
w += 128;
|
|
}
|
|
}
|
|
#if (CHIP8_LCDWIDTH < 128) /* LCD_WIDTH between 112 and 127 */
|
|
if (x%8 == 1) {
|
|
row[-1] |= w; /* overlay on */
|
|
}
|
|
else
|
|
#endif
|
|
*row++ = w;
|
|
}
|
|
}
|
|
#if defined(SIMULATOR) || (LCD_DEPTH > 1)
|
|
rb->lcd_set_drawmode(DRMODE_SOLID);
|
|
rb->lcd_mono_bitmap(lcd_framebuf[0], CHIP8_X, CHIP8_Y, CHIP8_LCDWIDTH, CHIP8_HEIGHT);
|
|
rb->lcd_update();
|
|
#else
|
|
rb->lcd_blit(lcd_framebuf[0], CHIP8_X, CHIP8_Y>>3, CHIP8_LCDWIDTH, CHIP8_HEIGHT>>3
|
|
, CHIP8_LCDWIDTH);
|
|
#endif
|
|
}
|
|
|
|
static void chip8_keyboard(void)
|
|
{
|
|
int i;
|
|
int button = rb->button_get(false);
|
|
switch (button)
|
|
{
|
|
case CHIP8_OFF: /* Abort Emulator */
|
|
chip8_running = 0;
|
|
break;
|
|
|
|
case CHIP8_KEY2: chip8_virtual_keys[2] = 1; break;
|
|
case CHIP8_KEY2 | BUTTON_REL: chip8_virtual_keys[2] = 0; break;
|
|
case CHIP8_KEY4: chip8_virtual_keys[4] = 1; break;
|
|
case CHIP8_KEY4 | BUTTON_REL: chip8_virtual_keys[4] = 0; break;
|
|
case CHIP8_KEY6: chip8_virtual_keys[6] = 1; break;
|
|
case CHIP8_KEY6 | BUTTON_REL: chip8_virtual_keys[6] = 0; break;
|
|
case CHIP8_KEY8: chip8_virtual_keys[8] = 1; break;
|
|
case CHIP8_KEY8 | BUTTON_REL: chip8_virtual_keys[8] = 0; break;
|
|
case CHIP8_KEY5: chip8_virtual_keys[5] = 1; break;
|
|
case CHIP8_KEY5 | BUTTON_REL: chip8_virtual_keys[5] = 0; break;
|
|
#ifdef CHIP8_KEY1
|
|
case CHIP8_KEY1: chip8_virtual_keys[1] = 1; break;
|
|
case CHIP8_KEY1 | BUTTON_REL: chip8_virtual_keys[1] = 0; break;
|
|
#endif
|
|
#ifdef CHIP8_KEY3
|
|
case CHIP8_KEY3: chip8_virtual_keys[3] = 1; break;
|
|
case CHIP8_KEY3 | BUTTON_REL: chip8_virtual_keys[3] = 0; break;
|
|
#endif
|
|
#ifdef CHIP8_KEY7
|
|
case CHIP8_KEY7: chip8_virtual_keys[7] = 1; break;
|
|
case CHIP8_KEY7 | BUTTON_REL: chip8_virtual_keys[7] = 0; break;
|
|
#endif
|
|
#ifdef CHIP8_KEY9
|
|
case CHIP8_KEY9: chip8_virtual_keys[9] = 1; break;
|
|
case CHIP8_KEY9 | BUTTON_REL: chip8_virtual_keys[9] = 0; break;
|
|
#endif
|
|
|
|
default:
|
|
if (rb->default_event_handler(button) == SYS_USB_CONNECTED)
|
|
chip8_running = 2; /* indicates stopped because of USB */
|
|
break;
|
|
}
|
|
for(i=0; i<16; i++) {
|
|
chip8_keys[i] = chip8_virtual_keys[chip8_keymap[i]];
|
|
}
|
|
}
|
|
|
|
/****************************************************************************/
|
|
/* Update keyboard and display, sync emulation with VDP clock */
|
|
/****************************************************************************/
|
|
static void chip8_interrupt (void)
|
|
{
|
|
unsigned long newtimer;
|
|
unsigned long timer, runtime;
|
|
|
|
chip8_update_display();
|
|
chip8_keyboard();
|
|
cycles ++;
|
|
runtime = cycles * HZ / 50;
|
|
timer = starttimer + runtime;
|
|
newtimer = *rb->current_tick;
|
|
if (TIME_AFTER(timer, newtimer))
|
|
{
|
|
rb->sleep(timer - newtimer);
|
|
}
|
|
else
|
|
{
|
|
rb->yield();
|
|
}
|
|
starttimer = newtimer - runtime;
|
|
}
|
|
|
|
static bool chip8_init(char* file)
|
|
{
|
|
int numread;
|
|
int fd;
|
|
int len;
|
|
int i;
|
|
|
|
fd = rb->open(file, O_RDONLY);
|
|
if (fd==-1) {
|
|
rb->lcd_puts(0, 6, "File Error.");
|
|
return false;
|
|
}
|
|
numread = rb->read(fd, chip8_mem+0x200, 4096-0x200);
|
|
if (numread==-1) {
|
|
rb->lcd_puts(0, 6, "I/O Error.");
|
|
return false;
|
|
}
|
|
|
|
rb->close(fd);
|
|
/* is there a c8k file (chip8 keys) ? */
|
|
for(i=0; i<16; i++) {
|
|
chip8_virtual_keys[i] = 0;
|
|
chip8_keymap[i] = i;
|
|
}
|
|
len = rb->strlen(file);
|
|
file[len-2] = '8';
|
|
file[len-1] = 'k';
|
|
fd = rb->open(file, O_RDONLY);
|
|
if (fd!=-1) {
|
|
rb->lcd_puts(0, 6, "File&Keymap OK.");
|
|
numread = rb->read(fd, chip8_keymap, 16);
|
|
rb->close(fd);
|
|
}
|
|
else
|
|
{
|
|
rb->lcd_puts(0, 6, "File OK.");
|
|
}
|
|
for(i=0; i<16; i++) {
|
|
if (chip8_keymap[i] >= '0'
|
|
&& chip8_keymap[i] <= '9')
|
|
chip8_keymap[i] -= '0';
|
|
else if (chip8_keymap[i] >= 'A'
|
|
&& chip8_keymap[i] <= 'F')
|
|
chip8_keymap[i] -= 'A' - 10;
|
|
else if (chip8_keymap[i] >= 'a'
|
|
&& chip8_keymap[i] <= 'f')
|
|
chip8_keymap[i] -= 'a' - 10;
|
|
else
|
|
chip8_keymap[i] %= 16;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool chip8_run(char* file)
|
|
{
|
|
int ok;
|
|
|
|
rb->lcd_clear_display();
|
|
rb->lcd_puts(0, 0, "SChip8 Emulator");
|
|
rb->lcd_puts(0, 1, " (c) by ");
|
|
rb->lcd_puts(0, 2, "Marcel de Kogel");
|
|
rb->lcd_puts(0, 3, " Rockbox: ");
|
|
rb->lcd_puts(0, 4, " Blueloop/Fdy ");
|
|
rb->lcd_puts(0, 5, "---------------");
|
|
ok = chip8_init(file);
|
|
rb->lcd_update();
|
|
rb->sleep(HZ*1);
|
|
if (!ok)
|
|
return false;
|
|
rb->lcd_clear_display();
|
|
#if (CHIP8_X > 0) && (CHIP8_Y > 0)
|
|
rb->lcd_drawrect(CHIP8_X-1,CHIP8_Y-1,CHIP8_LCDWIDTH+2,CHIP8_HEIGHT+2);
|
|
#endif
|
|
rb->lcd_update();
|
|
|
|
#ifndef SIMULATOR
|
|
/* init sound */
|
|
is_playing = rb->mp3_is_playing(); /* would we disturb playback? */
|
|
if (!is_playing) /* no? then we can make sound */
|
|
{ /* prepare */
|
|
rb->mp3_play_data(beep, sizeof(beep), callback);
|
|
}
|
|
#endif
|
|
starttimer = *rb->current_tick;
|
|
|
|
chip8_iperiod=15;
|
|
cycles = 0;
|
|
chip8();
|
|
|
|
if (!ok) {
|
|
rb->splash(HZ, true, "Error");
|
|
return false;
|
|
}
|
|
|
|
#ifndef SIMULATOR
|
|
if (!is_playing)
|
|
{ /* stop it if we used audio */
|
|
rb->mp3_play_stop(); /* Stop audio playback */
|
|
}
|
|
#endif
|
|
|
|
if (chip8_running == 3) {
|
|
/* unsupported instruction */
|
|
rb->splash(HZ, true, "Error: Unsupported"
|
|
#ifndef CHIP8_SUPER
|
|
" CHIP-8 instruction. (maybe S-CHIP)"
|
|
#else
|
|
" (S)CHIP-8 instruction."
|
|
#endif
|
|
);
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
|
|
/***************** Plugin Entry Point *****************/
|
|
|
|
enum plugin_status plugin_start(struct plugin_api* api, void* parameter)
|
|
{
|
|
char* filename;
|
|
|
|
/* this macro should be called as the first thing you do in the plugin.
|
|
it test that the api version and model the plugin was compiled for
|
|
matches the machine it is running on */
|
|
TEST_PLUGIN_API(api);
|
|
rb = api; /* copy to global api pointer */
|
|
|
|
if (parameter == NULL)
|
|
{
|
|
rb->splash(HZ, true, "Play a .ch8 file!");
|
|
return PLUGIN_ERROR;
|
|
}
|
|
else
|
|
{
|
|
filename = (char*) parameter;
|
|
}
|
|
|
|
/* now go ahead and have fun! */
|
|
if (chip8_run(filename))
|
|
if (chip8_running == 0)
|
|
return PLUGIN_OK;
|
|
else
|
|
return PLUGIN_USB_CONNECTED;
|
|
else
|
|
return PLUGIN_ERROR;
|
|
}
|
|
#endif /* #ifdef HAVE_LCD_BITMAP */
|