*** empty log message ***
authorcharles <charles>
Tue, 9 Aug 2005 01:00:37 +0000 (01:00 +0000)
committercharles <charles>
Tue, 9 Aug 2005 01:00:37 +0000 (01:00 +0000)
direct/yaffs_ramem2k.c [new file with mode: 0644]

diff --git a/direct/yaffs_ramem2k.c b/direct/yaffs_ramem2k.c
new file mode 100644 (file)
index 0000000..7ce6a3e
--- /dev/null
@@ -0,0 +1,362 @@
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system. 
+ * yaffs_ramem.c  NAND emulation on top of a chunk of RAM
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * 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.
+ *
+ */
+ //yaffs_ramem2k.c: RAM emulation in-kernel for 2K pages (YAFFS2)
+
+
+const char *yaffs_ramem2k_c_version = "$Id: yaffs_ramem2k.c,v 1.1 2005-08-09 01:00:37 charles Exp $";
+
+#ifndef __KERNEL__
+#define CONFIG_YAFFS_RAM_ENABLED
+#else
+#include <linux/config.h>
+#endif
+
+#ifdef CONFIG_YAFFS_RAM_ENABLED
+
+#include "yportenv.h"
+
+#include "yaffs_nandemul2k.h"
+#include "yaffs_guts.h"
+#include "yaffsinterface.h"
+#include "devextras.h"
+#include "yaffs_packedtags2.h"
+
+
+
+#define EM_SIZE_IN_MEG (32)
+#define PAGE_DATA_SIZE  (2048)
+#define PAGE_SPARE_SIZE (64)
+#define PAGES_PER_BLOCK (64)
+
+
+
+#define EM_SIZE_IN_BYTES (EM_SIZE_IN_MEG * (1<<20))
+
+#define PAGE_TOTAL_SIZE (PAGE_DATA_SIZE+PAGE_SPARE_SIZE)
+
+#define BLOCK_TOTAL_SIZE (PAGES_PER_BLOCK * PAGE_TOTAL_SIZE)
+
+#define BLOCKS_PER_MEG ((1<<20)/(PAGES_PER_BLOCK * PAGE_DATA_SIZE))
+
+
+typedef struct 
+{
+       __u8 data[PAGE_TOTAL_SIZE]; // Data + spare
+       int empty;      // is this empty?
+} nandemul_Page;
+
+
+typedef struct
+{
+       nandemul_Page *page[PAGES_PER_BLOCK];
+       int damaged;    
+} nandemul_Block;
+
+
+
+typedef struct
+{
+       nandemul_Block**block;
+       int nBlocks;
+} nandemul_Device;
+
+static nandemul_Device ned;
+
+static int sizeInMB = EM_SIZE_IN_MEG;
+
+
+static void nandemul_yield(int n)
+{
+#ifdef __KERNEL__
+       if(n > 0) schedule_timeout(n);
+#endif
+
+}
+
+
+static void nandemul_ReallyEraseBlock(int blockNumber)
+{
+       int i;
+       
+       nandemul_Block *blk;
+       
+       if(blockNumber < 0 || blockNumber >= ned.nBlocks)
+       {
+               return;
+       }
+       
+       blk = ned.block[blockNumber];
+       
+       for(i = 0; i < PAGES_PER_BLOCK; i++)
+       {
+               memset(blk->page[i],0xff,sizeof(nandemul_Page));
+               blk->page[i]->empty = 1;
+       }
+       nandemul_yield(2);
+}
+
+
+static int nandemul2k_CalcNBlocks(void)
+{
+       return EM_SIZE_IN_MEG * BLOCKS_PER_MEG;
+}
+
+
+
+static int  CheckInit(void)
+{
+       static int initialised = 0;
+       
+       int i,j;
+       
+       int fail = 0;
+       int nBlocks; 
+
+       int nAllocated = 0;
+       
+       if(initialised) 
+       {
+               return YAFFS_OK;
+       }
+       
+       
+       ned.nBlocks = nBlocks = nandemul2k_CalcNBlocks();
+
+       
+       ned.block = YMALLOC(sizeof(nandemul_Block*) * nBlocks );
+       
+       if(!ned.block) return YAFFS_FAIL;
+       
+       
+       
+
+               
+       for(i=fail=0; i <nBlocks; i++)
+       {
+               
+               nandemul_Block *blk;
+               
+               if(!(blk = ned.block[i] = YMALLOC(sizeof(nandemul_Block))))
+               {
+                fail = 1;
+               }  
+               else
+               {
+                       for(j = 0; j < PAGES_PER_BLOCK; j++)
+                       {
+                               if((blk->page[j] = YMALLOC(sizeof(nandemul_Page))) == 0)
+                               {
+                                       fail = 1;
+                               }
+                       }
+                       nandemul_ReallyEraseBlock(i);
+                       ned.block[i]->damaged = 0;
+                       nAllocated++;
+               }
+       }
+       
+       if(fail)
+       {
+               //Todo thump pages
+               
+               for(i = 0; i < nAllocated; i++)
+               {
+                       YFREE(ned.block[i]);
+               }
+               YFREE(ned.block);
+               
+               T(YAFFS_TRACE_ALWAYS,("Allocation failed, could only allocate %dMB of %dMB requested.\n",
+                  nAllocated/64,sizeInMB));
+               return 0;
+       }
+       
+       ned.nBlocks = nBlocks;
+       
+       initialised = 1;
+       
+       return 1;
+}
+
+int nandemul2k_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_ExtendedTags *tags)
+{
+       int blk;
+       int pg;
+       int i;
+       
+       __u8 *x;
+
+       
+       blk = chunkInNAND/PAGES_PER_BLOCK;
+       pg = chunkInNAND%PAGES_PER_BLOCK;
+       
+       
+       if(data)
+       {
+               x = ned.block[blk]->page[pg]->data;
+               
+               for(i = 0; i < PAGE_DATA_SIZE; i++)
+               {
+                       x[i] &=data[i];
+               }
+
+               ned.block[blk]->page[pg]->empty = 0;
+       }
+       
+       
+       if(tags)
+       {
+               x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];
+               
+               yaffs_PackTags2((yaffs_PackedTags2 *)x,tags);
+                       
+       }
+       
+       if(tags || data)
+       {
+               nandemul_yield(1);
+       }
+
+       return YAFFS_OK;
+}
+
+
+int nandemul2k_ReadChunkWithTagsFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_ExtendedTags *tags)
+{
+       int blk;
+       int pg;
+       
+       __u8 *x;
+
+       
+       
+       blk = chunkInNAND/PAGES_PER_BLOCK;
+       pg = chunkInNAND%PAGES_PER_BLOCK;
+       
+       
+       if(data)
+       {
+               memcpy(data,ned.block[blk]->page[pg]->data,PAGE_DATA_SIZE);
+       }
+       
+       
+       if(tags)
+       {
+               x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];
+               
+               yaffs_UnpackTags2(tags,(yaffs_PackedTags2 *)x);
+       }
+
+       return YAFFS_OK;
+}
+
+
+static int nandemul2k_CheckChunkErased(yaffs_Device *dev,int chunkInNAND)
+{
+       int blk;
+       int pg;
+       int i;
+
+       
+       
+       blk = chunkInNAND/PAGES_PER_BLOCK;
+       pg = chunkInNAND%PAGES_PER_BLOCK;
+       
+       
+       for(i = 0; i < PAGE_TOTAL_SIZE; i++)
+       {
+               if(ned.block[blk]->page[pg]->data[i] != 0xFF)
+               {
+                       return YAFFS_FAIL;
+               }
+       }
+
+       return YAFFS_OK;
+
+}
+
+int nandemul2k_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
+{
+       
+       
+       if(blockNumber < 0 || blockNumber >= ned.nBlocks)
+       {
+               T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));
+       }
+       else if(ned.block[blockNumber]->damaged)
+       {
+               T(YAFFS_TRACE_ALWAYS,("Attempt to erase damaged block %d\n",blockNumber));
+       }
+       else
+       {
+               nandemul_ReallyEraseBlock(blockNumber);
+       }
+       
+       return YAFFS_OK;
+}
+
+int nandemul2k_InitialiseNAND(yaffs_Device *dev)
+{
+       CheckInit();
+       return YAFFS_OK;
+}
+int nandemul2k_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo)
+{
+       
+       __u8 *x;
+       
+       x = &ned.block[blockNo]->page[0]->data[PAGE_DATA_SIZE];
+       
+       memset(x,0,sizeof(yaffs_PackedTags2));
+       
+       
+       return YAFFS_OK;
+       
+}
+
+int nandemul2k_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo, yaffs_BlockState *state, int *sequenceNumber)
+{
+       yaffs_ExtendedTags tags;
+       int chunkNo;
+
+       *sequenceNumber = 0;
+       
+       chunkNo = blockNo * dev->nChunksPerBlock;
+       
+       nandemul2k_ReadChunkWithTagsFromNAND(dev,chunkNo,NULL,&tags);
+       if(tags.blockBad)
+       {
+               *state = YAFFS_BLOCK_STATE_DEAD;
+       }
+       else if(!tags.chunkUsed)
+       {
+               *state = YAFFS_BLOCK_STATE_EMPTY;
+       }
+       else if(tags.chunkUsed)
+       {
+               *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
+               *sequenceNumber = tags.sequenceNumber;
+       }
+       return YAFFS_OK;
+}
+
+int nandemul2k_GetBytesPerChunk(void) { return PAGE_DATA_SIZE;}
+
+int nandemul2k_GetChunksPerBlock(void) { return PAGES_PER_BLOCK; }
+int nandemul2k_GetNumberOfBlocks(void) {return nandemul2k_CalcNBlocks();}
+
+
+#endif //YAFFS_RAM_ENABLED
+