X-Git-Url: http://www.aleph1.co.uk/gitweb/?p=yaffs2.git;a=blobdiff_plain;f=direct%2Fyaffs_ramdisk.c;fp=direct%2Fyaffs_ramdisk.c;h=b19d6cb2d12f57b083a6c6d77da0ea8eae7c5758;hp=0000000000000000000000000000000000000000;hb=2e51ed27a28a076ee9eb870ba8c0eb09b8114b01;hpb=363520161b021b7ac870c269064606e3f16feeeb

diff --git a/direct/yaffs_ramdisk.c b/direct/yaffs_ramdisk.c
new file mode 100644
index 0000000..b19d6cb
--- /dev/null
+++ b/direct/yaffs_ramdisk.c
@@ -0,0 +1,232 @@
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system. 
+ * yaffs_ramdisk.c: yaffs ram disk component
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+// This provides a rma disk under yaffs.
+// NB this is not intended for NAND emulation.
+// Use this with dev->useNANDECC enabled, then ECC overheads are not required.
+
+const char *yaffs_ramdisk_c_version = "$Id: yaffs_ramdisk.c,v 1.1 2004-11-03 08:29:28 charles Exp $";
+
+
+#include "yportenv.h"
+
+#include "yaffs_ramdisk.h"
+#include "yaffs_guts.h"
+#include "devextras.h"
+#include "yaffs_packedtags.h"
+
+
+
+#define SIZE_IN_MB 2
+
+#define BLOCK_SIZE (32 * 528)
+#define BLOCKS_PER_MEG ((1024*1024)/(32 * 512))
+
+
+
+
+
+typedef struct 
+{
+	__u8 data[528]; // Data + spare
+} yramdisk_Page;
+
+typedef struct
+{
+	yramdisk_Page page[32]; // The pages in the block
+	
+} yramdisk_Block;
+
+
+
+typedef struct
+{
+	yramdisk_Block **block;
+	int nBlocks;
+} yramdisk_Device;
+
+static yramdisk_Device ramdisk;
+
+static int  CheckInit(yaffs_Device *dev)
+{
+	static int initialised = 0;
+	
+	int i;
+	int fail = 0;
+	//int nBlocks; 
+	int nAllocated = 0;
+	
+	if(initialised) 
+	{
+		return YAFFS_OK;
+	}
+
+	initialised = 1;
+	
+	
+	ramdisk.nBlocks = (SIZE_IN_MB * 1024 * 1024)/(16 * 1024);
+	
+	ramdisk.block = YMALLOC(sizeof(yramdisk_Block *) * ramdisk.nBlocks);
+	
+	if(!ramdisk.block) return 0;
+	
+	for(i=0; i <ramdisk.nBlocks; i++)
+	{
+		ramdisk.block[i] = NULL;
+	}
+	
+	for(i=0; i <ramdisk.nBlocks && !fail; i++)
+	{
+		if((ramdisk.block[i] = YMALLOC(sizeof(yramdisk_Block))) == 0)
+		{
+			fail = 1;
+		}
+		else
+		{
+			yramdisk_EraseBlockInNAND(dev,i);
+			nAllocated++;
+		}
+	}
+	
+	if(fail)
+	{
+		for(i = 0; i < nAllocated; i++)
+		{
+			YFREE(ramdisk.block[i]);
+		}
+		YFREE(ramdisk.block);
+		
+		T(YAFFS_TRACE_ALWAYS,("Allocation failed, could only allocate %dMB of %dMB requested.\n",
+		   nAllocated/64,ramdisk.nBlocks * 528));
+		return 0;
+	}
+	
+	
+	return 1;
+}
+
+int yramdisk_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_ExtendedTags *tags)
+{
+	int blk;
+	int pg;
+	
+
+	CheckInit(dev);
+	
+	blk = chunkInNAND/32;
+	pg = chunkInNAND%32;
+	
+	
+	if(data)
+	{
+		memcpy(ramdisk.block[blk]->page[pg].data,data,512);
+	}
+	
+	
+	if(tags)
+	{
+		yaffs_PackedTags pt;
+		
+		yaffs_PackTags(&pt,tags);
+		memcpy(&ramdisk.block[blk]->page[pg].data[512],&pt,sizeof(pt));
+	}
+
+	return YAFFS_OK;	
+
+}
+
+
+int yramdisk_ReadChunkWithTagsFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_ExtendedTags *tags)
+{
+	int blk;
+	int pg;
+
+	
+	CheckInit(dev);
+	
+	blk = chunkInNAND/32;
+	pg = chunkInNAND%32;
+	
+	
+	if(data)
+	{
+		memcpy(data,ramdisk.block[blk]->page[pg].data,512);
+	}
+	
+	
+	if(tags)
+	{
+		yaffs_PackedTags pt;
+		
+		memcpy(&pt,&ramdisk.block[blk]->page[pg].data[512],sizeof(pt));
+		yaffs_UnpackTags(tags,&pt);
+		
+	}
+
+	return YAFFS_OK;
+}
+
+
+int yramdisk_CheckChunkErased(yaffs_Device *dev,int chunkInNAND)
+{
+	int blk;
+	int pg;
+	int i;
+
+	
+	CheckInit(dev);
+	
+	blk = chunkInNAND/32;
+	pg = chunkInNAND%32;
+	
+	
+	for(i = 0; i < 528; i++)
+	{
+		if(ramdisk.block[blk]->page[pg].data[i] != 0xFF)
+		{
+			return YAFFS_FAIL;
+		}
+	}
+
+	return YAFFS_OK;
+
+}
+
+int yramdisk_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
+{
+	
+	CheckInit(dev);
+	
+	if(blockNumber < 0 || blockNumber >= ramdisk.nBlocks)
+	{
+		T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));
+		return YAFFS_FAIL;
+	}
+	else
+	{
+		memset(ramdisk.block[blockNumber],0xFF,sizeof(yramdisk_Block));
+		return YAFFS_OK;
+	}
+	
+}
+
+int yramdisk_InitialiseNAND(yaffs_Device *dev)
+{
+	//dev->useNANDECC = 1; // force on useNANDECC which gets faked. 
+						 // This saves us doing ECC checks.
+	
+	return YAFFS_OK;
+}
+
+