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emulate DMA timings.

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keeps games from overflowing the GXFIFO... when they aren't fucking dumb.
This commit is contained in:
StapleButter
2017-02-17 05:33:37 +01:00
parent abd2cb444b
commit cca0a71d81
7 changed files with 176 additions and 34 deletions
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118
DMA.cpp
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@ -34,6 +34,66 @@ DMA::DMA(u32 cpu, u32 num)
CPU = cpu;
Num = num;
if (cpu == 0)
CountMask = 0x001FFFFF;
else
CountMask = (num==3 ? 0x0000FFFF : 0x00003FFF);
// TODO: merge with the one in ARM.cpp, somewhere
for (int i = 0; i < 16; i++)
{
Waitstates[0][i] = 1;
Waitstates[1][i] = 1;
}
if (!num)
{
// ARM9
// note: 33MHz cycles
Waitstates[0][0x2] = 1;
Waitstates[0][0x3] = 1;
Waitstates[0][0x4] = 1;
Waitstates[0][0x5] = 1;
Waitstates[0][0x6] = 1;
Waitstates[0][0x7] = 1;
Waitstates[0][0x8] = 6;
Waitstates[0][0x9] = 6;
Waitstates[0][0xA] = 10;
Waitstates[0][0xF] = 1;
Waitstates[1][0x2] = 2;
Waitstates[1][0x3] = 1;
Waitstates[1][0x4] = 1;
Waitstates[1][0x5] = 2;
Waitstates[1][0x6] = 2;
Waitstates[1][0x7] = 1;
Waitstates[1][0x8] = 12;
Waitstates[1][0x9] = 12;
Waitstates[1][0xA] = 10;
Waitstates[1][0xF] = 1;
}
else
{
// ARM7
Waitstates[0][0x0] = 1;
Waitstates[0][0x2] = 1;
Waitstates[0][0x3] = 1;
Waitstates[0][0x4] = 1;
Waitstates[0][0x6] = 1;
Waitstates[0][0x8] = 6;
Waitstates[0][0x9] = 6;
Waitstates[0][0xA] = 10;
Waitstates[1][0x0] = 1;
Waitstates[1][0x2] = 2;
Waitstates[1][0x3] = 1;
Waitstates[1][0x4] = 1;
Waitstates[1][0x6] = 2;
Waitstates[1][0x8] = 12;
Waitstates[1][0x9] = 12;
Waitstates[1][0xA] = 10;
}
Reset();
}
@ -51,8 +111,11 @@ void DMA::Reset()
CurSrcAddr = 0;
CurDstAddr = 0;
RemCount = 0;
IterCount = 0;
SrcAddrInc = 0;
DstAddrInc = 0;
Running = false;
}
void DMA::WriteCnt(u32 val)
@ -90,16 +153,16 @@ void DMA::WriteCnt(u32 val)
Start();
else if (StartMode == 0x07)
GPU3D::CheckFIFODMA();
//else
// printf("SPECIAL ARM%d DMA%d START MODE %02X\n", CPU?7:9, Num, StartMode);
if ((StartMode&7)!=0x00 && (StartMode&7)!=0x1 && StartMode!=2 && StartMode!=0x05 && StartMode!=0x12 && StartMode!=0x07)
printf("UNIMPLEMENTED ARM%d DMA%d START MODE %02X\n", CPU?7:9, Num, StartMode);
//if (StartMode==2)printf("HBLANK DMA %08X -> %08X\n", SrcAddr, DstAddr);
}
}
void DMA::Start()
{
if (Running) return;
u32 countmask;
if (CPU == 0)
countmask = 0x001FFFFF;
@ -110,6 +173,11 @@ void DMA::Start()
if (!RemCount)
RemCount = countmask+1;
if (StartMode == 0x07 && RemCount > 112)
IterCount = 112;
else
IterCount = RemCount;
if ((Cnt & 0x00600000) == 0x00600000)
CurDstAddr = DstAddr;
@ -126,24 +194,33 @@ void DMA::Start()
NDS::TriggerIRQ(CPU, NDS::IRQ_DMA0 + Num);
return;
}
//if (StartMode == 0x07)printf("GXFIFO DMA %08X %08X\n", Cnt, CurSrcAddr);
u32 num = RemCount;
if (StartMode == 0x07 && num > 112)
num = 112;
// TODO: NOT MAKE THE DMA INSTANT!!
// TODO eventually: not stop if we're running code in ITCM
Running = true;
NDS::StopCPU(CPU, true);
}
s32 DMA::Run(s32 cycles)
{
if (!Running)
return cycles;
u32 zorp = IterCount;
if (!(Cnt & 0x04000000))
{
u16 (*readfn)(u32) = CPU ? NDS::ARM7Read16 : NDS::ARM9Read16;
void (*writefn)(u32,u16) = CPU ? NDS::ARM7Write16 : NDS::ARM9Write16;
while (num > 0)
while (IterCount > 0 && cycles > 0)
{
writefn(CurDstAddr, readfn(CurSrcAddr));
cycles -= (Waitstates[0][(CurSrcAddr >> 24) & 0xF] + Waitstates[0][(CurDstAddr >> 24) & 0xF]);
CurSrcAddr += SrcAddrInc<<1;
CurDstAddr += DstAddrInc<<1;
num--;
IterCount--;
RemCount--;
}
}
@ -152,22 +229,30 @@ void DMA::Start()
u32 (*readfn)(u32) = CPU ? NDS::ARM7Read32 : NDS::ARM9Read32;
void (*writefn)(u32,u32) = CPU ? NDS::ARM7Write32 : NDS::ARM9Write32;
while (num > 0)
while (IterCount > 0 && cycles > 0)
{
writefn(CurDstAddr, readfn(CurSrcAddr));
cycles -= (Waitstates[1][(CurSrcAddr >> 24) & 0xF] + Waitstates[1][(CurDstAddr >> 24) & 0xF]);
CurSrcAddr += SrcAddrInc<<2;
CurDstAddr += DstAddrInc<<2;
num--;
IterCount--;
RemCount--;
}
}
if (RemCount)
{
Cnt &= ~countmask;
Cnt &= ~CountMask;
Cnt |= RemCount;
return;
if (IterCount == 0)
{
Running = false;
NDS::StopCPU(CPU, false);
}
return cycles;
}
if (!(Cnt & 0x02000000))
@ -175,4 +260,9 @@ void DMA::Start()
if (Cnt & 0x40000000)
NDS::TriggerIRQ(CPU, NDS::IRQ_DMA0 + Num);
Running = false;
NDS::StopCPU(CPU, false);
return cycles - 2;
}