Added preliminary Adaptec 154x emulation, needs fixing in the Read 10 command.

Made ATAPI derived from SCSI.
Added proper S/G emulation for SCSI DMA.
Added SCSI CD-ROM emulation, preserving all the former ATAPI commands as well.

src/scattergather.c

@@ -0,0 +1,128 @@
+/* Copyright holders: SA1988
+   see COPYING for more details
+*/
+/*Scatter/Gather emulation*/
+#include <stdlib.h>
+#include <string.h>
+#include "ibm.h"
+
+#include "scattergather.h"
+
+static uint8_t *SegmentBufferGet(SGBUF *SegmentBuf, uint32_t Data)
+{
+	uint32_t DataSize;
+	uint8_t *Buffer;
+	
+	if (SegmentBuf->SegmentIndex == SegmentBuf->SegmentNum
+				&& !SegmentBuf->SegmentLeft)
+	{
+		Data = 0;
+		return NULL;
+	}
+	
+	DataSize = MIN(Data, SegmentBuf->SegmentLeft);
+	Buffer = SegmentBuf->SegmentPtrCur;
+	SegmentBuf->SegmentLeft -= Data;
+	
+	if (!SegmentBuf->SegmentLeft)
+	{
+		SegmentBuf->SegmentIndex++;
+		
+		if (SegmentBuf->SegmentIndex < SegmentBuf->SegmentNum)
+		{
+			SegmentBuf->SegmentPtrCur = SegmentBuf->SegmentPtr[SegmentBuf->SegmentIndex].Address;
+			SegmentBuf->SegmentLeft = SegmentBuf->SegmentPtr[SegmentBuf->SegmentIndex].Length;			
+		}
+		
+		Data = DataSize;
+	}
+	else
+		SegmentBuf->SegmentPtrCur = (uint8_t *)SegmentBuf->SegmentPtrCur + DataSize;
+	
+	return Buffer;
+}
+
+uint8_t *SegmentBufferGetNextSegment(SGBUF *SegmentBuf, uint32_t Segment)
+{
+	if (!Segment)
+		Segment = SegmentBuf->SegmentLeft;
+	
+	return SegmentBufferGet(SegmentBuf, Segment);
+}
+
+uint32_t SegmentBufferCopy(SGBUF *SegmentDst, SGBUF *SegmentSrc, uint32_t Copy)
+{
+	uint32_t Left = Copy;
+	while (Left)
+	{
+		uint32_t ThisCopy = MIN(MIN(SegmentDst->SegmentLeft, Left), SegmentSrc->SegmentLeft);
+		if (!ThisCopy)
+			break;
+		
+		uint32_t Tmp = ThisCopy;
+		uint8_t *BufDst = SegmentBufferGet(SegmentDst, Tmp);
+		uint8_t *BufSrc = SegmentBufferGet(SegmentSrc, Tmp);
+
+		memcpy(BufSrc, BufDst, ThisCopy);
+		
+		BufDst += ThisCopy;
+		BufSrc -= ThisCopy;
+		Left -= ThisCopy;
+	}
+	
+	return Copy - Left;
+}
+
+uint32_t SegmentBufferCopyFromBuf(SGBUF *SegmentBuf, uint8_t *BufSrc, uint32_t Copy)
+{
+	uint32_t Left = Copy;
+	
+	while (Left)
+	{
+		uint32_t ThisCopy = Left;
+		uint8_t *BufDst = SegmentBufferGet(SegmentBuf, ThisCopy);
+		
+		if (!ThisCopy)
+			break;
+		
+		BufDst += ThisCopy;
+		Left -= ThisCopy;
+		BufSrc = (void *)((uintptr_t)BufSrc + ThisCopy);
+	}
+	
+	return Copy - Left;
+}
+
+uint32_t SegmentBufferAdvance(SGBUF *SegmentBuf, uint32_t Advance)
+{
+	uint32_t Left = Advance;
+	while (Left)
+	{
+		uint32_t ThisAdvance = Left;
+		SegmentBufferGet(SegmentBuf, ThisAdvance);
+		if (!ThisAdvance)
+			break;
+		
+		Left -= ThisAdvance;
+	}
+	
+	return Advance - Left;
+}
+
+void SegmentBufferInit(SGBUF *SegmentBuf, const SGSEG *SegmentPtr, uint32_t Segments)
+{
+	SegmentBuf->SegmentPtr = SegmentPtr;
+	SegmentBuf->SegmentNum = (unsigned)Segments;
+	SegmentBuf->SegmentIndex = 0;
+	
+	if (Segments && SegmentPtr)
+	{
+		SegmentBuf->SegmentPtrCur = SegmentPtr[0].Address;
+		SegmentBuf->SegmentLeft = SegmentPtr[0].Length;
+	}
+	else
+	{
+		SegmentBuf->SegmentPtrCur = NULL;
+		SegmentBuf->SegmentLeft = 0;		
+	}
+}