BizHawk/waterbox/picodrive/pico/pico.c

346 lines
9.0 KiB
C

/*
* PicoDrive
* (c) Copyright Dave, 2004
* (C) notaz, 2006-2010
*
* This work is licensed under the terms of MAME license.
* See COPYING file in the top-level directory.
*/
#include "pico_int.h"
#include "sound/ym2612.h"
struct Pico Pico;
int PicoOpt;
int PicoSkipFrame; // skip rendering frame?
int PicoPad[2]; // Joypads, format is MXYZ SACB RLDU
int PicoPadInt[2]; // internal copy
int PicoAHW; // active addon hardware: PAHW_*
int PicoQuirks; // game-specific quirks
int PicoRegionOverride; // override the region detection 0: Auto, 1: Japan NTSC, 2: Japan PAL, 4: US, 8: Europe
int PicoAutoRgnOrder;
struct PicoSRAM SRam;
int emustatus; // rapid_ym2612, multi_ym_updates
int scanlines_total;
void (*PicoWriteSound)(int len) = NULL; // called at the best time to send sound buffer (PsndOut) to hardware
void (*PicoResetHook)(void) = NULL;
void (*PicoLineHook)(void) = NULL;
// to be called once on emu init
void PicoInit(void)
{
// Blank space for state:
memset(&Pico,0,sizeof(Pico));
memset(&PicoPad,0,sizeof(PicoPad));
memset(&PicoPadInt,0,sizeof(PicoPadInt));
// Init CPUs:
SekInit();
z80_init(); // init even if we aren't going to use it
PicoInitMCD();
PicoSVPInit();
Pico32xInit();
}
void PicoPower(void)
{
Pico.m.frame_count = 0;
SekCycleCnt = SekCycleAim = 0;
// clear all memory of the emulated machine
memset(&Pico.ram,0,(unsigned char *)&Pico.rom - Pico.ram);
memset(&Pico.video,0,sizeof(Pico.video));
memset(&Pico.m,0,sizeof(Pico.m));
Pico.video.pending_ints=0;
z80_reset();
// my MD1 VA6 console has this in IO
Pico.ioports[1] = Pico.ioports[2] = Pico.ioports[3] = 0xff;
// default VDP register values (based on Fusion)
Pico.video.reg[0] = Pico.video.reg[1] = 0x04;
Pico.video.reg[0xc] = 0x81;
Pico.video.reg[0xf] = 0x02;
if (PicoAHW & PAHW_MCD)
PicoPowerMCD();
if (PicoOpt & POPT_EN_32X)
PicoPower32x();
PicoReset();
}
PICO_INTERNAL void PicoDetectRegion(void)
{
int support=0, hw=0, i;
unsigned char pal=0;
if (PicoRegionOverride)
{
support = PicoRegionOverride;
}
else
{
// Read cartridge region data:
unsigned short *rd = (unsigned short *)(Pico.rom + 0x1f0);
int region = (rd[0] << 16) | rd[1];
for (i = 0; i < 4; i++)
{
int c;
c = region >> (i<<3);
c &= 0xff;
if (c <= ' ') continue;
if (c=='J') support|=1;
else if (c=='U') support|=4;
else if (c=='E') support|=8;
else if (c=='j') {support|=1; break; }
else if (c=='u') {support|=4; break; }
else if (c=='e') {support|=8; break; }
else
{
// New style code:
char s[2]={0,0};
s[0]=(char)c;
support|=strtol(s,NULL,16);
}
}
}
// auto detection order override
if (PicoAutoRgnOrder) {
if (((PicoAutoRgnOrder>>0)&0xf) & support) support = (PicoAutoRgnOrder>>0)&0xf;
else if (((PicoAutoRgnOrder>>4)&0xf) & support) support = (PicoAutoRgnOrder>>4)&0xf;
else if (((PicoAutoRgnOrder>>8)&0xf) & support) support = (PicoAutoRgnOrder>>8)&0xf;
}
// Try to pick the best hardware value for English/50hz:
if (support&8) { hw=0xc0; pal=1; } // Europe
else if (support&4) hw=0x80; // USA
else if (support&2) { hw=0x40; pal=1; } // Japan PAL
else if (support&1) hw=0x00; // Japan NTSC
else hw=0x80; // USA
Pico.m.hardware=(unsigned char)(hw|0x20); // No disk attached
Pico.m.pal=pal;
}
int PicoReset(void)
{
if (Pico.romsize <= 0)
return 1;
#if defined(CPU_CMP_R) || defined(CPU_CMP_W) || defined(DRC_CMP)
PicoOpt |= POPT_DIS_VDP_FIFO|POPT_DIS_IDLE_DET;
#endif
/* must call now, so that banking is reset, and correct vectors get fetched */
if (PicoResetHook)
PicoResetHook();
memset(&PicoPadInt,0,sizeof(PicoPadInt));
emustatus = 0;
if (PicoAHW & PAHW_SMS) {
PicoResetMS();
return 0;
}
SekReset();
// ..but do not reset SekCycle* to not desync with addons
// s68k doesn't have the TAS quirk, so we just globally set normal TAS handler in MCD mode (used by Batman games).
SekSetRealTAS(PicoAHW & PAHW_MCD);
Pico.m.dirtyPal = 1;
Pico.m.z80_bank68k = 0;
Pico.m.z80_reset = 1;
PicoDetectRegion();
Pico.video.status = 0x3428 | Pico.m.pal; // 'always set' bits | vblank | collision | pal
PsndReset(); // pal must be known here
// create an empty "dma" to cause 68k exec start at random frame location
if (Pico.m.dma_xfers == 0 && !(PicoOpt & POPT_DIS_VDP_FIFO))
Pico.m.dma_xfers = rand() & 0x1fff;
SekFinishIdleDet();
if (PicoAHW & PAHW_MCD) {
PicoResetMCD();
return 0;
}
// reinit, so that checksum checks pass
if (!(PicoOpt & POPT_DIS_IDLE_DET))
SekInitIdleDet();
if (PicoOpt & POPT_EN_32X)
PicoReset32x();
// reset sram state; enable sram access by default if it doesn't overlap with ROM
Pico.m.sram_reg = 0;
if ((SRam.flags & SRF_EEPROM) || Pico.romsize <= SRam.start)
Pico.m.sram_reg |= SRR_MAPPED;
if (SRam.flags & SRF_ENABLED)
elprintf(EL_STATUS, "sram: %06x - %06x; eeprom: %i", SRam.start, SRam.end,
!!(SRam.flags & SRF_EEPROM));
return 0;
}
// flush config changes before emu loop starts
void PicoLoopPrepare(void)
{
if (PicoRegionOverride)
// force setting possibly changed..
Pico.m.pal = (PicoRegionOverride == 2 || PicoRegionOverride == 8) ? 1 : 0;
// FIXME: PAL has 313 scanlines..
scanlines_total = Pico.m.pal ? 312 : 262;
Pico.m.dirtyPal = 1;
rendstatus_old = -1;
}
// dma2vram settings are just hacks to unglitch Legend of Galahad (needs <= 104 to work)
// same for Outrunners (92-121, when active is set to 24)
// 96 is VR hack
static const int dma_timings[] = {
167, 167, 166, 83, // vblank: 32cell: dma2vram dma2[vs|c]ram vram_fill vram_copy
102, 205, 204, 102, // vblank: 40cell:
16, 16, 15, 8, // active: 32cell:
24, 18, 17, 9 // ...
};
static const int dma_bsycles[] = {
(488<<8)/167, (488<<8)/167, (488<<8)/166, (488<<8)/83,
(488<<8)/102, (488<<8)/233, (488<<8)/204, (488<<8)/102,
(488<<8)/16, (488<<8)/16, (488<<8)/15, (488<<8)/8,
(488<<8)/24, (488<<8)/18, (488<<8)/17, (488<<8)/9
};
// grossly inaccurate.. FIXME FIXXXMEE
PICO_INTERNAL int CheckDMA(void)
{
int burn = 0, xfers_can, dma_op = Pico.video.reg[0x17]>>6; // see gens for 00 and 01 modes
int xfers = Pico.m.dma_xfers;
int dma_op1;
if(!(dma_op&2)) dma_op = (Pico.video.type==1) ? 0 : 1; // setting dma_timings offset here according to Gens
dma_op1 = dma_op;
if(Pico.video.reg[12] & 1) dma_op |= 4; // 40 cell mode?
if(!(Pico.video.status&8)&&(Pico.video.reg[1]&0x40)) dma_op|=8; // active display?
xfers_can = dma_timings[dma_op];
if(xfers <= xfers_can)
{
if(dma_op&2) Pico.video.status&=~2; // dma no longer busy
else {
burn = xfers * dma_bsycles[dma_op] >> 8; // have to be approximate because can't afford division..
}
Pico.m.dma_xfers = 0;
} else {
if(!(dma_op&2)) burn = 488;
Pico.m.dma_xfers -= xfers_can;
}
elprintf(EL_VDPDMA, "~Dma %i op=%i can=%i burn=%i [%i]", Pico.m.dma_xfers, dma_op1, xfers_can, burn, SekCyclesDone());
//dprintf("~aim: %i, cnt: %i", SekCycleAim, SekCycleCnt);
return burn;
}
#include "pico_cmn.inc"
unsigned int last_z80_sync; /* in 68k cycles */
int z80_cycle_cnt;
int z80_cycle_aim;
int z80_scanline;
int z80_scanline_cycles; /* cycles done until z80_scanline */
/* sync z80 to 68k */
PICO_INTERNAL void PicoSyncZ80(unsigned int m68k_cycles_done)
{
int m68k_cnt;
int cnt;
m68k_cnt = m68k_cycles_done - last_z80_sync;
z80_cycle_aim += cycles_68k_to_z80(m68k_cnt);
cnt = z80_cycle_aim - z80_cycle_cnt;
last_z80_sync = m68k_cycles_done;
pprof_start(z80);
elprintf(EL_BUSREQ, "z80 sync %i (%u|%u -> %u|%u)", cnt,
z80_cycle_cnt, z80_cycle_cnt / 288,
z80_cycle_aim, z80_cycle_aim / 288);
if (cnt > 0)
z80_cycle_cnt += z80_run(cnt);
pprof_end(z80);
}
void PicoFrame(void)
{
pprof_start(frame);
Pico.m.frame_count++;
if (PicoAHW & PAHW_SMS) {
PicoFrameMS();
goto end;
}
if (PicoAHW & PAHW_32X) {
PicoFrame32x(); // also does MCD+32X
goto end;
}
if (PicoAHW & PAHW_MCD) {
PicoFrameMCD();
goto end;
}
//if(Pico.video.reg[12]&0x2) Pico.video.status ^= 0x10; // change odd bit in interlace mode
PicoFrameStart();
PicoFrameHints();
end:
pprof_end(frame);
}
void PicoFrameDrawOnly(void)
{
if (!(PicoAHW & PAHW_SMS)) {
PicoFrameStart();
PicoDrawSync(223, 0);
} else {
PicoFrameDrawOnlyMS();
}
}
void PicoGetInternal(pint_t which, pint_ret_t *r)
{
switch (which)
{
case PI_ROM: r->vptr = Pico.rom; break;
case PI_ISPAL: r->vint = Pico.m.pal; break;
case PI_IS40_CELL: r->vint = Pico.video.reg[12]&1; break;
case PI_IS240_LINES: r->vint = Pico.m.pal && (Pico.video.reg[1]&8); break;
}
}