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#include "global.h"
#include "dma3.h"
IWRAM_DATA struct {
/* 0x00 */ const u8 *src;
/* 0x04 */ u8 *dest;
/* 0x08 */ u16 size;
/* 0x0A */ u16 mode;
/* 0x0C */ u32 value;
} gDma3Requests[128];
static bool8 gDma3ManagerLocked;
static u8 gDma3RequestCursor;
void ClearDma3Requests(void)
{
int i;
gDma3ManagerLocked = TRUE;
gDma3RequestCursor = 0;
for(i = 0; i < (u8)ARRAY_COUNT(gDma3Requests); i++)
{
gDma3Requests[i].size = 0;
gDma3Requests[i].src = 0;
gDma3Requests[i].dest = 0;
}
gDma3ManagerLocked = FALSE;
}
// Maximum amount of data will will transfer in one operation
#define DMA_MAX_BLOCK_SIZE 0x1000
#define Dma3CopyLarge_(src, dest, size, bit) \
{ \
const void *_src = src; \
void *_dest = dest; \
u32 _size = size; \
while (1) \
{ \
if (_size <= DMA_MAX_BLOCK_SIZE) \
{ \
DmaCopy##bit(3, _src, _dest, _size); \
break; \
} \
DmaCopy##bit(3, _src, _dest, DMA_MAX_BLOCK_SIZE); \
_src += DMA_MAX_BLOCK_SIZE; \
_dest += DMA_MAX_BLOCK_SIZE; \
_size -= DMA_MAX_BLOCK_SIZE; \
} \
}
#define Dma3CopyLarge16_(src, dest, size) Dma3CopyLarge_(src, dest, size, 16)
#define Dma3CopyLarge32_(src, dest, size) Dma3CopyLarge_(src, dest, size, 32)
#define Dma3FillLarge_(value, dest, size, bit) \
{ \
void *_dest = dest; \
u32 _size = size; \
while (1) \
{ \
if (_size <= DMA_MAX_BLOCK_SIZE) \
{ \
DmaFill##bit(3, value, _dest, _size); \
break; \
} \
DmaFill##bit(3, value, _dest, DMA_MAX_BLOCK_SIZE); \
_dest += DMA_MAX_BLOCK_SIZE; \
_size -= DMA_MAX_BLOCK_SIZE; \
} \
}
#define Dma3FillLarge16_(value, dest, size) Dma3FillLarge_(value, dest, size, 16)
#define Dma3FillLarge32_(value, dest, size) Dma3FillLarge_(value, dest, size, 32)
void ProcessDma3Requests(void)
{
u16 totalSize;
if (gDma3ManagerLocked)
return;
totalSize = 0;
// as long as there are DMA requests to process (unless size or vblank is an issue), do not exit
while (gDma3Requests[gDma3RequestCursor].size != 0)
{
totalSize += gDma3Requests[gDma3RequestCursor].size;
if (totalSize > 0xA000)
return; // don't do too much at once
if (*(u8 *)REG_ADDR_VCOUNT > 224)
return; // we're about to leave vblank, stop
switch (gDma3Requests[gDma3RequestCursor].mode)
{
case 1: // regular 32-bit copy
Dma3CopyLarge32_(gDma3Requests[gDma3RequestCursor].src,
gDma3Requests[gDma3RequestCursor].dest,
gDma3Requests[gDma3RequestCursor].size);
break;
case 2: // repeat a single 32-bit value across RAM
Dma3FillLarge32_(gDma3Requests[gDma3RequestCursor].value,
gDma3Requests[gDma3RequestCursor].dest,
gDma3Requests[gDma3RequestCursor].size);
break;
case 3: // regular 16-bit copy
Dma3CopyLarge16_(gDma3Requests[gDma3RequestCursor].src,
gDma3Requests[gDma3RequestCursor].dest,
gDma3Requests[gDma3RequestCursor].size);
break;
case 4: // repeat a single 16-bit value across RAM
Dma3FillLarge16_(gDma3Requests[gDma3RequestCursor].value,
gDma3Requests[gDma3RequestCursor].dest,
gDma3Requests[gDma3RequestCursor].size);
break;
}
gDma3Requests[gDma3RequestCursor].src = NULL;
gDma3Requests[gDma3RequestCursor].dest = NULL;
gDma3Requests[gDma3RequestCursor].size = 0;
gDma3Requests[gDma3RequestCursor].mode = 0;
gDma3Requests[gDma3RequestCursor].value = 0;
gDma3RequestCursor++;
if (gDma3RequestCursor >= 128) // loop back to the first DMA request
gDma3RequestCursor = 0;
}
}
int RequestDma3Copy(const void *src, void *dest, u16 size, u8 mode)
{
int cursor;
int var = 0;
gDma3ManagerLocked = 1;
cursor = gDma3RequestCursor;
while(1)
{
if(!gDma3Requests[cursor].size) // an empty copy was found and the current cursor will be returned.
{
gDma3Requests[cursor].src = src;
gDma3Requests[cursor].dest = dest;
gDma3Requests[cursor].size = size;
if(mode == 1)
gDma3Requests[cursor].mode = mode;
else
gDma3Requests[cursor].mode = 3;
gDma3ManagerLocked = FALSE;
return (s16)cursor;
}
if(++cursor >= 0x80) // loop back to start.
{
cursor = 0;
}
if(++var >= 0x80) // max checks were made. all resulted in failure.
{
break;
}
}
gDma3ManagerLocked = FALSE;
return -1;
}
int RequestDma3Fill(s32 value, void *dest, u16 size, u8 mode)
{
int cursor;
int var = 0;
cursor = gDma3RequestCursor;
gDma3ManagerLocked = 1;
while(1)
{
if(!gDma3Requests[cursor].size)
{
gDma3Requests[cursor].dest = dest;
gDma3Requests[cursor].size = size;
gDma3Requests[cursor].mode = mode;
gDma3Requests[cursor].value = value;
if(mode == 1)
gDma3Requests[cursor].mode = 2;
else
gDma3Requests[cursor].mode = 4;
gDma3ManagerLocked = FALSE;
return (s16)cursor;
}
if(++cursor >= 0x80) // loop back to start.
{
cursor = 0;
}
if(++var >= 0x80) // max checks were made. all resulted in failure.
{
break;
}
}
gDma3ManagerLocked = FALSE;
return -1;
}
int CheckForSpaceForDma3Request(s16 index)
{
int current = 0;
if (index == -1)
{
for (; current < 0x80; current ++)
if (gDma3Requests[current].size)
return -1;
return 0;
}
if (gDma3Requests[index].size)
return -1;
return 0;
}
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