2 * YAFFS: Yet another FFS. A NAND-flash specific file system.
3 * yaffs_ramem.c NAND emulation on top of a chunk of RAM
5 * Copyright (C) 2002 Aleph One Ltd.
6 * for Toby Churchill Ltd and Brightstar Engineering
8 * Created by Charles Manning <charles@aleph1.co.uk>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
15 //yaffs_ramem2k.c: RAM emulation in-kernel for 2K pages (YAFFS2)
18 const char *yaffs_ramem2k_c_version = "$Id: yaffs_ramem2k.c,v 1.2 2005-04-24 09:26:08 charles Exp $";
21 #define CONFIG_YAFFS_RAM_ENABLED
24 #ifdef CONFIG_YAFFS_RAM_ENABLED
28 #include "yaffs_nandemul2k.h"
29 #include "yaffs_guts.h"
30 #include "yaffsinterface.h"
31 #include "devextras.h"
32 #include "yaffs_packedtags2.h"
36 #define EM_SIZE_IN_MEG (32)
37 #define PAGE_DATA_SIZE (2048)
38 #define PAGE_SPARE_SIZE (64)
39 #define PAGES_PER_BLOCK (64)
43 #define EM_SIZE_IN_BYTES (EM_SIZE_IN_MEG * (1<<20))
45 #define PAGE_TOTAL_SIZE (PAGE_DATA_SIZE+PAGE_SPARE_SIZE)
47 #define BLOCK_TOTAL_SIZE (PAGES_PER_BLOCK * PAGE_TOTAL_SIZE)
49 #define BLOCKS_PER_MEG ((1<<20)/(PAGES_PER_BLOCK * PAGE_DATA_SIZE))
54 __u8 data[PAGE_TOTAL_SIZE]; // Data + spare
55 int empty; // is this empty?
61 nandemul_Page *page[PAGES_PER_BLOCK];
69 nandemul_Block**block;
73 static nandemul_Device ned;
75 static int sizeInMB = EM_SIZE_IN_MEG;
78 static void nandemul_yield(int n)
81 if(n > 0) schedule_timeout(n);
87 static void nandemul_ReallyEraseBlock(int blockNumber)
93 if(blockNumber < 0 || blockNumber >= ned.nBlocks)
98 blk = ned.block[blockNumber];
100 for(i = 0; i < PAGES_PER_BLOCK; i++)
102 memset(blk->page[i],0xff,sizeof(nandemul_Page));
103 blk->page[i]->empty = 1;
109 static int nandemul2k_CalcNBlocks(void)
111 return EM_SIZE_IN_MEG * BLOCKS_PER_MEG;
116 static int CheckInit(void)
118 static int initialised = 0;
133 ned.nBlocks = nBlocks = nandemul2k_CalcNBlocks();
136 ned.block = YMALLOC(sizeof(nandemul_Block*) * nBlocks );
138 if(!ned.block) return YAFFS_FAIL;
144 for(i=fail=0; i <nBlocks; i++)
149 if(!(blk = ned.block[i] = YMALLOC(sizeof(nandemul_Block))))
155 for(j = 0; j < PAGES_PER_BLOCK; j++)
157 if((blk->page[j] = YMALLOC(sizeof(nandemul_Page))) == 0)
162 nandemul_ReallyEraseBlock(i);
163 ned.block[i]->damaged = 0;
172 for(i = 0; i < nAllocated; i++)
178 T(YAFFS_TRACE_ALWAYS,("Allocation failed, could only allocate %dMB of %dMB requested.\n",
179 nAllocated/64,sizeInMB));
183 ned.nBlocks = nBlocks;
190 int nandemul2k_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_ExtendedTags *tags)
199 blk = chunkInNAND/PAGES_PER_BLOCK;
200 pg = chunkInNAND%PAGES_PER_BLOCK;
205 x = ned.block[blk]->page[pg]->data;
207 for(i = 0; i < PAGE_DATA_SIZE; i++)
212 ned.block[blk]->page[pg]->empty = 0;
218 x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];
220 yaffs_PackTags2((yaffs_PackedTags2 *)x,tags);
233 int nandemul2k_ReadChunkWithTagsFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_ExtendedTags *tags)
242 blk = chunkInNAND/PAGES_PER_BLOCK;
243 pg = chunkInNAND%PAGES_PER_BLOCK;
248 memcpy(data,ned.block[blk]->page[pg]->data,PAGE_DATA_SIZE);
254 x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];
256 yaffs_UnpackTags2(tags,(yaffs_PackedTags2 *)x);
263 int nandemul2k_CheckChunkErased(yaffs_Device *dev,int chunkInNAND)
271 blk = chunkInNAND/PAGES_PER_BLOCK;
272 pg = chunkInNAND%PAGES_PER_BLOCK;
275 for(i = 0; i < PAGE_TOTAL_SIZE; i++)
277 if(ned.block[blk]->page[pg]->data[i] != 0xFF)
287 int nandemul2k_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
291 if(blockNumber < 0 || blockNumber >= ned.nBlocks)
293 T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));
295 else if(ned.block[blockNumber]->damaged)
297 T(YAFFS_TRACE_ALWAYS,("Attempt to erase damaged block %d\n",blockNumber));
301 nandemul_ReallyEraseBlock(blockNumber);
307 int nandemul2k_InitialiseNAND(yaffs_Device *dev)
313 int nandemul2k_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo)
318 x = &ned.block[blockNo]->page[0]->data[PAGE_DATA_SIZE];
320 memset(x,0,sizeof(yaffs_PackedTags2));
327 int nandemul2k_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo, yaffs_BlockState *state, int *sequenceNumber)
329 yaffs_ExtendedTags tags;
334 chunkNo = blockNo * dev->nChunksPerBlock;
336 nandemul2k_ReadChunkWithTagsFromNAND(dev,chunkNo,NULL,&tags);
339 *state = YAFFS_BLOCK_STATE_DEAD;
341 else if(!tags.chunkUsed)
343 *state = YAFFS_BLOCK_STATE_EMPTY;
345 else if(tags.chunkUsed)
347 *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
348 *sequenceNumber = tags.sequenceNumber;
353 int nandemul2k_GetBytesPerChunk(void) { return PAGE_DATA_SIZE;}
355 int nandemul2k_GetChunksPerBlock(void) { return PAGES_PER_BLOCK; }
356 int nandemul2k_GetNumberOfBlocks(void) {return nandemul2k_CalcNBlocks();}
359 #endif //YAFFS_RAM_ENABLED