ref: c881e33e8ed668f4d5a2102c113e3edb1ea80d44
dir: /sys/src/games/gb/gb.c/
#include <u.h>
#include <libc.h>
#include <thread.h>
#include <draw.h>
#include <keyboard.h>
#include "../eui.h"
#include "dat.h"
#include "fns.h"
int cpuhalt;
int backup;
int savefd = -1, saveframes;
ulong clock;
u8int mbc, feat, mode;
extern MBC3Timer timer, timerl;
extern double TAU;
void
tauup(void)
{
TAU += 5000;
}
void
taudn(void)
{
TAU -= 5000;
}
void
writeback(void)
{
if(saveframes == 0)
saveframes = 15;
}
void
timerload(uchar *buf)
{
timer.ns = buf[0] | buf[1] << 8 | buf[2] << 16 | buf[3] << 24 | (uvlong)buf[4] << 32 | (uvlong)buf[5] << 40 | (uvlong)buf[6] << 48LL | (uvlong)buf[7] << 56LL;
timer.sec = buf[8];
timer.min = buf[9];
timer.hr = buf[10];
timer.dl = buf[11];
timer.dh = buf[12];
timerl.sec = buf[13];
timerl.min = buf[14];
timerl.hr = buf[15];
timerl.dl = buf[16];
timerl.dh = buf[17];
}
void
timersave(uchar *buf)
{
buf[0] = timer.ns;
buf[1] = timer.ns >> 8;
buf[2] = timer.ns >> 16;
buf[3] = timer.ns >> 24;
buf[4] = timer.ns >> 32;
buf[5] = timer.ns >> 40;
buf[6] = timer.ns >> 48;
buf[7] = timer.ns >> 56;
buf[8] = timer.sec;
buf[9] = timer.min;
buf[10] = timer.hr;
buf[11] = timer.dl;
buf[12] = timer.dh;
buf[13] = timerl.sec;
buf[14] = timerl.min;
buf[15] = timerl.hr;
buf[16] = timerl.dl;
buf[17] = timerl.dh;
}
void
flushback(void)
{
uchar buf[TIMERSIZ];
if(savefd >= 0){
pwrite(savefd, back, nback, 0);
timersave(buf);
pwrite(savefd, buf, TIMERSIZ, nback);
}
saveframes = 0;
}
void
loadsave(char *file)
{
char *buf, *p;
uchar tim[TIMERSIZ];
buf = emalloc(strlen(file) + 4);
strcpy(buf, file);
p = strrchr(buf, '.');
if(p == nil)
p = buf + strlen(buf);
strcpy(p, ".sav");
savefd = open(buf, ORDWR);
if(savefd < 0){
savefd = create(buf, OWRITE, 0664);
if(savefd < 0){
fprint(2, "create: %r");
free(buf);
return;
}
back = emalloc(nback);
memset(back, 0, nback);
write(savefd, back, nback);
free(buf);
if((feat & FEATTIM) != 0){
timer.ns = nsec();
timersave(tim);
write(savefd, tim, TIMERSIZ);
}
atexit(flushback);
return;
}
back = emalloc(nback);
readn(savefd, back, nback);
if((feat & FEATTIM) != 0){
readn(savefd, tim, TIMERSIZ);
timerload(tim);
}
atexit(flushback);
free(buf);
}
void
loadrom(char *file)
{
int fd;
vlong sz;
static uchar nintendo[24] = {
0xCE, 0xED, 0x66, 0x66, 0xCC, 0x0D, 0x00, 0x0B, 0x03, 0x73, 0x00, 0x83,
0x00, 0x0C, 0x00, 0x0D, 0x00, 0x08, 0x11, 0x1F, 0x88, 0x89, 0x00, 0x0E
};
static u8int mbctab[31] = {
0, 1, 1, 1, -1, 2, 2, -1,
0, 0, -1, 6, 6, 6, -1, 3,
3, 3, 3, 3, -1, 4, 4, 4,
-1, 5, 5, 5, 5, 5, 5};
static u8int feattab[31] = {
0, 0, FEATRAM, FEATRAM|FEATBAT, 0, FEATRAM, FEATRAM|FEATBAT, 0,
FEATRAM, FEATRAM|FEATBAT, 0, 0, FEATRAM, FEATRAM|FEATBAT, 0, FEATTIM|FEATBAT,
FEATTIM|FEATRAM|FEATBAT, 0, FEATRAM, FEATRAM|FEATBAT, 0, 0, FEATRAM, FEATRAM|FEATBAT,
0, 0, FEATRAM, FEATRAM|FEATBAT, 0, FEATRAM, FEATRAM|FEATBAT
};
fd = open(file, OREAD);
if(fd < 0)
sysfatal("open: %r");
sz = seek(fd, 0, 2);
if(sz <= 0 || sz > 32*1024*1024)
sysfatal("invalid file size");
seek(fd, 0, 0);
nrom = sz;
rom = emalloc(nrom);
if(readn(fd, rom, sz) < sz)
sysfatal("read: %r");
close(fd);
if(memcmp(rom + 0x104, nintendo, 24) != 0)
sysfatal("not a gameboy rom");
if(rom[0x147] > 0x1f)
sysfatal("unsupported mapper ([0x147] = %.2ux)", rom[0x147]);
mbc = mbctab[rom[0x147]];
feat = feattab[rom[0x147]];
if((feat & FEATRAM) != 0){
switch(rom[0x149]){
case 0:
if(mbc == 2)
nback = 512;
else
feat &= ~FEATRAM;
break;
case 1: nback = 2048; break;
case 2: nback = 8192; break;
case 3: nback = 32768; break;
default: sysfatal("invalid ram size");
}
}
if(nback == 0)
nbackbank = 1;
else
nbackbank = nback + 8191 >> 13;
if((feat & (FEATRAM|FEATTIM)) == 0)
feat &= ~FEATBAT;
if((rom[0x143] & 0x80) != 0 && (mode & FORCEDMG) == 0)
mode = CGB|COL;
if((feat & FEATBAT) != 0)
loadsave(file);
switch(mbc){
case 0: case 1: case 2: case 3: case 5: break;
default: sysfatal("unsupported mbc %d", mbc);
}
}
void
flush(void)
{
extern uchar pic[];
static vlong old, delta;
flushmouse(1);
flushscreen();
flushaudio(audioout);
if(saveframes > 0 && --saveframes == 0)
flushback();
if(savereq){
savestate("gb.save");
savereq = 0;
}
if(loadreq){
loadstate("gb.save");
loadreq = 0;
}
}
void
usage(void)
{
fprint(2, "usage: %s [-aTcd] [-C col0,col1,col2,col3] [-x scale] rom\n", argv0);
exits("usage");
}
void
colinit(void)
{
int i;
union { u8int c[4]; u32int l; } c;
c.c[3] = 0;
for(i = 0; i < 4; i++){
c.c[0] = c.c[1] = c.c[2] = i * 0x55;
moncols[i] = c.l;
}
}
void
colparse(char *p)
{
int i;
union { u8int c[4]; u32int l; } c;
u32int l;
c.c[3] = 0;
for(i = 0; i < 4; i++){
l = strtol(p, &p, 16);
if(*p != (i == 3 ? 0 : ',') || l > 0xffffff)
usage();
p++;
c.c[0] = l;
c.c[1] = l >> 8;
c.c[2] = l >> 16;
moncols[i] = c.l;
}
}
void
threadmain(int argc, char **argv)
{
int t;
colinit();
ARGBEGIN {
case 'a':
audioinit();
break;
case 'c':
mode |= CGB;
break;
case 'd':
mode |= FORCEDMG;
break;
case 'C':
colparse(EARGF(usage()));
break;
case 'x':
fixscale = strtol(EARGF(usage()), nil, 0);
break;
default:
usage();
} ARGEND;
if(argc < 1)
usage();
loadrom(argv[0]);
initemu(PICW, PICH, 4, XRGB32, 1, nil);
regkey("b", 'z', 1<<5);
regkey("a", 'x', 1<<4);
regkey("control", Kshift, 1<<6);
regkey("start", '\n', 1<<7);
regkey("up", Kup, 1<<2);
regkey("down", Kdown, 1<<3);
regkey("left", Kleft, 1<<1);
regkey("right", Kright, 1<<0);
regkeyfn(KF|9, tauup);
regkeyfn(KF|10, taudn);
eventinit();
meminit();
ppuinit();
reset();
for(;;){
if(paused){
qlock(&pauselock);
qunlock(&pauselock);
}
if(dma > 0)
t = dmastep();
else
t = step();
if((mode & TURBO) == 0)
t += t;
clock += t;
if((elist->time -= t) <= 0)
popevent();
}
}