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bahamut/Snes.HC
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Alec Murphy d4588bba42 Add files to repository
2020-02-16 18:17:17 -05:00

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extern I64 mem_read(I64 adr, Bool dma=FALSE);
extern U0 mem_write(I64 adr, I64 value, Bool dma = FALSE);
extern I64 readBBus(I64 adr);
extern U0 writeBBus(I64 adr, I64 value);
extern U0 cpu_cycle();
extern U0 renderLine(I32 line);
class ROMHeader
{
U8 *name;
I64 type;
I64 speed;
I64 chips;
I64 romSize;
I64 ramSize;
Bool hasSram;
I64 banks;
I64 sramSize;
};
ROMHeader header;
U8 *ram = MAlloc(0x20000);
U8 *sram;
U8 *rom;
// ppu variables
I64 cgramAdr;
Bool cgramSecond;
I64 cgramBuffer = 0;
I64 vramInc;
I64 vramRemap;
Bool vramIncOnHigh;
I64 vramAdr;
I64 vramReadBuffer;
Bool tilemapWider[4];
Bool tilemapHigher[4];
I64 tilemapAdr[4];
I64 tileAdr[4];
I64 bgHoff[5];
I64 bgVoff[5];
I64 offPrev1;
I64 offPrev2;
I64 mode;
Bool layer3Prio;
Bool bigTiles[4];
Bool mosaicEnabled[5];
I64 mosaicSize;
I64 mosaicStartLine;
Bool mainScreenEnabled[5];
Bool subScreenEnabled[5];
Bool forcedBlank;
I64 brightness;
I64 oamAdr;
I64 oamRegAdr;
Bool oamInHigh;
Bool oamRegInHigh;
Bool objPriority;
Bool oamSecond;
U16 oamBuffer;
I64 sprAdr1;
I64 sprAdr2;
I64 objSize;
Bool rangeOver;
Bool timeOver;
Bool mode7ExBg;
Bool pseudoHires;
Bool overscan;
Bool objInterlace;
Bool interlace;
Bool frameOverscan;
Bool frameInterlace;
Bool evenFrame;
I64 latchedHpos;
I64 latchedVpos;
Bool latchHsecond;
Bool latchVsecond;
Bool countersLatched;
I64 mode7Hoff;
I64 mode7Voff;
I64 mode7A;
I64 mode7B;
I64 mode7C;
I64 mode7D;
I64 mode7X;
I64 mode7Y;
I64 mode7Prev;
I64 multResult;
Bool mode7LargeField;
Bool mode7Char0fill;
Bool mode7FlipX;
Bool mode7FlipY;
Bool window1Inversed[6];
Bool window1Enabled[6];
Bool window2Inversed[6];
Bool window2Enabled[6];
I64 windowMaskLogic[6];
I64 window1Left;
I64 window1Right;
I64 window2Left;
I64 window2Right;
Bool mainScreenWindow[6];
Bool subScreenWindow[6];
I64 colorClip;
I64 preventMath;
Bool addSub;
Bool directColor;
Bool subtractColors;
Bool halfColors;
Bool mathEnabled[6];
I64 fixedColorB;
I64 fixedColorG;
I64 fixedColorR;
I64 tilemapBuffer[4];
I64 tileBufferP1[4];
I64 tileBufferP2[4];
I64 tileBufferP3[4];
I64 tileBufferP4[4];
I64 lastTileFetchedX[4];
I64 lastTileFetchedY[4];
I64 optHorBuffer[2];
I64 optVerBuffer[2];
I64 lastOrigTileX[2];
I64 dmaOffs[32] = {
0, 0, 0, 0,
0, 1, 0, 1,
0, 0, 0, 0,
0, 0, 1, 1,
0, 1, 2, 3,
0, 1, 0, 1,
0, 0, 0, 0,
0, 0, 1, 1
};
I64 dmaOffLengths[8] = {1, 2, 2, 4, 4, 4, 2, 4};
I64 apuCyclesPerMaster = (32040 * 32) / (1364 * 262 * 60);
U8 spcWritePorts[4];
U8 spcReadPorts[6];
// for dma
U8 dmaBadr[8];
U16 dmaAadr[8];
U8 dmaAadrBank[8];
U16 dmaSize[8];
U8 hdmaIndBank[8];
U16 hdmaTableAdr[8];
U8 hdmaRepCount[8];
I64 xPos = 0;
I64 yPos = 0;
I64 frames = 0;
I64 cpuCyclesLeft = 5 * 8 + 12; // reset: 5 read cycles + 2 IO cycles
I64 cpuMemOps = 0;
I64 apuCatchCycles = 0;
I64 cyclesLeft; // moved from CPU.HC
Bool irqWanted; // moved from CPU.HC
Bool nmiWanted; // moved from CPU.HC
// for cpu-ports
I64 ramAdr = 0;
Bool hIrqEnabled = FALSE;
Bool vIrqEnabled = FALSE;
Bool nmiEnabled = FALSE;
I64 hTimer = 0x1ff;
I64 vTimer = 0x1ff;
Bool inNmi = FALSE;
Bool inIrq = FALSE;
Bool inHblank = FALSE;
Bool inVblank = FALSE;
Bool autoJoyRead = FALSE;
Bool autoJoyBusy = FALSE;
I64 autoJoyTimer = 0;
Bool ppuLatch = FALSE;
I64 joypad1Val = 0;
I64 joypad2Val = 0;
I64 joypad1AutoRead = 0;
I64 joypad2AutoRead = 0;
Bool joypadStrobe = FALSE;
I64 joypad1State = 0; // current button state
I64 joypad2State = 0; // current button state
I64 multiplyA = 0xff;
I64 divA = 0xffff;
I64 divResult = 0x101;
I64 mulResult = 0xfe01;
Bool fastMem = FALSE;
// dma and hdma
I64 dmaTimer = 0;
I64 hdmaTimer = 0;
Bool dmaBusy = FALSE;
Bool dmaActive[8] = {FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE};
Bool hdmaActive[8] = {FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE};
I64 dmaMode[8] = {0, 0, 0, 0, 0, 0, 0, 0};
Bool dmaFixed[8] = {FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE};
Bool dmaDec[8] = {FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE};
Bool hdmaInd[8] = {FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE};
Bool dmaFromB[8] = {FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE};
Bool hdmaDoTransfer[8] = {
FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE
};
Bool hdmaTerminated[8] = {
FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE
};
I64 dmaOffIndex = 0;
I64 openBus = 0;
I64 getAccessTime(I64 adr) {
adr &= 0xffffff;
I64 bank = adr >> 16;
adr &= 0xffff;
if(bank >= 0x40 && bank < 0x80) {
// banks 0x40-0x7f, all slow
return 8;
}
if(bank >= 0xc0) {
// banks 0xc0-0xff, depends on speed
return cond(fastMem, 6, 8);
}
// banks 0x00-0x3f and 0x80-0xbf
if(adr < 0x2000) {
return 8; // slow
}
if(adr < 0x4000) {
return 6; // fast
}
if(adr < 0x4200) {
return 12; // extra slow
}
if(adr < 0x6000) {
return 6; // fast
}
if(adr < 0x8000) {
return 8; // slow
}
// 0x8000-0xffff, depends on fastrom setting if in banks 0x80+
return cond((fastMem && bank >= 0x80), 6, 8);
}
U0 catchUpApu() {
I64 i;
I64 catchUpCycles = apuCatchCycles & 0xffffffff;
for(i = 0; i < catchUpCycles; i++) {
//apu_cycle;
}
apuCatchCycles -= catchUpCycles;
}
U0 handleDma() {
I64 i, tableOff;
if(dmaTimer > 0) {
dmaTimer -= 2;
return;
}
// loop over each dma channel to find the first active one
for(i = 0; i < 8; i++) {
if(dmaActive[i]) {
break;
}
}
if(i == 8) {
// no active channel left, dma is done
dmaBusy = FALSE;
dmaOffIndex = 0;
//log("Finished DMA");
return;
}
tableOff = dmaMode[i] * 4 + dmaOffIndex++;
dmaOffIndex &= 0x3;
if(dmaFromB[i]) {
mem_write(
(dmaAadrBank[i] << 16) | dmaAadr[i],
readBBus(
(dmaBadr[i] + dmaOffs[tableOff]) & 0xff
), TRUE
);
} else {
writeBBus(
(dmaBadr[i] + dmaOffs[tableOff]) & 0xff,
mem_read((dmaAadrBank[i] << 16) | dmaAadr[i], TRUE)
);
}
dmaTimer += 6;
// because this run through the function itself also costs 2 master cycles,
// we have to wait 6 more to get to 8 per byte transferred
if(!dmaFixed[i]) {
if(dmaDec[i]) {
dmaAadr[i]--;
} else {
dmaAadr[i]++;
}
}
dmaSize[i]--;
if(dmaSize[i] == 0) {
dmaOffIndex = 0;
dmaActive[i] = FALSE;
dmaTimer += 8; // 8 extra cycles overhead per channel
}
}
U0 initHdma() {
hdmaTimer = 18;
I64 i;
for(i = 0; i < 8; i++) {
if(hdmaActive[i]) {
// terminate DMA if it was busy for this channel
dmaActive[i] = FALSE;
hdmaTableAdr[i] = dmaAadr[i];
hdmaRepCount[i] = mem_read(
(dmaAadrBank[i] << 16) | hdmaTableAdr[i]++, TRUE
);
hdmaTimer += 8;
if(hdmaInd[i]) {
dmaSize[i] = mem_read(
(dmaAadrBank[i] << 16) | hdmaTableAdr[i]++, TRUE
);
dmaSize[i] |= mem_read(
(dmaAadrBank[i] << 16) | hdmaTableAdr[i]++, TRUE
) << 8;
hdmaTimer += 16;
}
hdmaDoTransfer[i] = TRUE;
} else {
hdmaDoTransfer[i] = FALSE;
}
hdmaTerminated[i] = FALSE;
}
}
U0 handleHdma() {
I64 i, j, tableOff;
hdmaTimer = 18;
for(i = 0; i < 8; i++) {
if(hdmaActive[i] && !hdmaTerminated[i]) {
// terminate dma if it is busy on this channel
dmaActive[i] = FALSE;
hdmaTimer += 8;
if(hdmaDoTransfer[i]) {
for(j = 0; j < dmaOffLengths[dmaMode[i]]; j++) {
tableOff = dmaMode[i] * 4 + j;
hdmaTimer += 8;
if(hdmaInd[i]) {
if(dmaFromB[i]) {
mem_write(
(hdmaIndBank[i] << 16) | dmaSize[i],
readBBus(
(dmaBadr[i] + dmaOffs[tableOff]) & 0xff
), TRUE
);
} else {
writeBBus(
(dmaBadr[i] + dmaOffs[tableOff]) & 0xff,
mem_read((hdmaIndBank[i] << 16) | dmaSize[i], TRUE)
);
}
dmaSize[i]++;
} else {
if(dmaFromB[i]) {
mem_write(
(dmaAadrBank[i] << 16) | hdmaTableAdr[i],
readBBus(
(dmaBadr[i] + dmaOffs[tableOff]) & 0xff
), TRUE
);
} else {
writeBBus(
(dmaBadr[i] + dmaOffs[tableOff]) & 0xff,
mem_read(
(dmaAadrBank[i] << 16) | hdmaTableAdr[i], TRUE
)
);
}
hdmaTableAdr[i]++;
}
}
}
hdmaRepCount[i]--;
hdmaDoTransfer[i] = (hdmaRepCount[i] & 0x80) > 0;
if((hdmaRepCount[i] & 0x7f) == 0) {
hdmaRepCount[i] = mem_read(
(dmaAadrBank[i] << 16) | hdmaTableAdr[i]++, TRUE
);
if(hdmaInd[i]) {
dmaSize[i] = mem_read(
(dmaAadrBank[i] << 16) | hdmaTableAdr[i]++, TRUE
);
dmaSize[i] |= mem_read(
(dmaAadrBank[i] << 16) | hdmaTableAdr[i]++, TRUE
) << 8;
hdmaTimer += 16;
}
if(hdmaRepCount[i] == 0) {
hdmaTerminated[i] = TRUE;
}
hdmaDoTransfer[i] = TRUE;
}
}
}
}
U0 doAutoJoyRead() {
I64 i, bit;
joypad1AutoRead = 0;
joypad2AutoRead = 0;
joypad1Val = joypad1State;
joypad2Val = joypad2State;
for(i = 0; i < 16; i++) {
bit = joypad1Val & 0x1;
joypad1Val >>= 1;
joypad1Val |= 0x8000;
joypad1AutoRead |= (bit << (15 - i));
bit = joypad2Val & 0x1;
joypad2Val >>= 1;
joypad2Val |= 0x8000;
joypad2AutoRead |= (bit << (15 - i));
}
}
U0 cpuCycle() {
if(cpuCyclesLeft == 0) {
cyclesLeft = 0;
cpuMemOps = 0;
cpu_cycle;
cpuCyclesLeft += (cyclesLeft + 1 - cpuMemOps) * 6;
}
cpuCyclesLeft -= 2;
}
U0 cycle(Bool noPpu)
{
apuCatchCycles += (apuCyclesPerMaster * 2);
if(joypadStrobe) {
joypad1Val = joypad1State;
joypad2Val = joypad2State;
}
if(hdmaTimer > 0) {
hdmaTimer -= 2;
} else if(dmaBusy) {
handleDma;
} else if (xPos < 536 || xPos >= 576) {
// the cpu is paused for 40 cycles starting around dot 536
cpuCycle;
}
if(yPos == vTimer && vIrqEnabled) {
if(!hIrqEnabled) {
// only v irq enabed
if(xPos == 0) {
inIrq = TRUE;
irqWanted = TRUE;
}
} else {
// v and h irq enabled
if(xPos == (hTimer * 4)) {
inIrq = TRUE;
irqWanted = TRUE;
}
}
} else if (
xPos == (hTimer * 4)
&& hIrqEnabled && !vIrqEnabled
) {
// only h irq enabled
inIrq = TRUE;
irqWanted = TRUE;
}
if(xPos == 1024) {
// start of hblank
inHblank = TRUE;
if(!inVblank) {
handleHdma;
}
} else if(xPos == 0) {
// end of hblank
inHblank = FALSE;
} else if(xPos == 512 && !noPpu) {
// render line at cycle 512 for better support
renderLine(yPos);
}
//renderLine(yPos);
if(yPos == cond(frameOverscan, 240, 225) && xPos == 0) {
// start of vblank
inNmi = TRUE;
inVblank = TRUE;
if(autoJoyRead) {
autoJoyBusy = TRUE;
autoJoyTimer = 4224;
doAutoJoyRead;
}
if(nmiEnabled) {
nmiWanted = TRUE;
}
} else if(yPos == 0 && xPos == 0) {
// end of vblank
inNmi = FALSE;
inVblank = FALSE;
initHdma;
}
if(autoJoyBusy) {
autoJoyTimer -= 2; // loop only runs every second master cycle
if(autoJoyTimer == 0) {
autoJoyBusy = FALSE;
}
}
// TODO: in non-intelace mode, line 240 on every odd frame is 1360 cycles
// and in interlace mode, every even frame is 263 lines
xPos += 2;
if(xPos == 1364) {
xPos = 0;
yPos++;
if(yPos == 262) {
// when finishing a frame, also catch up the apu
catchUpApu;
yPos = 0;
frames++;
}
}
}
#define JPAD_Y 0
#define JPAD_B 1
#define JPAD_SELECT 2
#define JPAD_START 3
#define JPAD_UP 4
#define JPAD_DOWN 5
#define JPAD_LEFT 6
#define JPAD_RIGHT 7
#define JPAD_A 8
#define JPAD_X 9
#define JPAD_L 10
#define JPAD_R 11
U0 setPad1Button(I64 num, I64 sc)
{
switch (KeyDown(sc))
{
case 0:
joypad1State &= (~(1 << num)) & 0xfff;
break;
case 1:
joypad1State |= (1 << num);
break;
}
}
U0 Joypad1Update()
{
setPad1Button(JPAD_Y, Char2ScanCode('z'));
setPad1Button(JPAD_B, Char2ScanCode('a'));
setPad1Button(JPAD_X, Char2ScanCode('s'));
setPad1Button(JPAD_A, Char2ScanCode('x'));
setPad1Button(JPAD_L, Char2ScanCode('d'));
setPad1Button(JPAD_R, Char2ScanCode('c'));
setPad1Button(JPAD_SELECT, SC_SHIFT);
setPad1Button(JPAD_START, SC_ENTER);
setPad1Button(JPAD_UP, SC_CURSOR_UP);
setPad1Button(JPAD_DOWN, SC_CURSOR_DOWN);
setPad1Button(JPAD_LEFT, SC_CURSOR_LEFT);
setPad1Button(JPAD_RIGHT, SC_CURSOR_RIGHT);
}
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