direct/yaffs_fileem2k.c

   1 /*
   2  * YAFFS: Yet another FFS. A NAND-flash specific file system.
   3  * yaffs_ramdisk.c: yaffs ram disk component
   4  *
   5  * Copyright (C) 2002 Aleph One Ltd.
   6  *
   7  * Created by Charles Manning <charles@aleph1.co.uk>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  */
  14
  15 // This provides a YAFFS nand emulation on a file for emulating 2kB pages.
  16 // THis is only intended as test code to test persistence etc.
  17
  18 const char *yaffs_flashif_c_version = "$Id: yaffs_fileem2k.c,v 1.4 2005-07-18 23:12:00 charles Exp $";
  19
  20
  21 #include "yportenv.h"
  22
  23 #include "yaffs_flashif.h"
  24 #include "yaffs_guts.h"
  25 #include "devextras.h"
  26
  27 #include <sys/types.h>
  28 #include <sys/stat.h>
  29 #include <fcntl.h>
  30 #include <unistd.h>
  31
  32 #include "yaffs_fileem2k.h"
  33 #include "yaffs_packedtags2.h"
  34
  35
  36
  37 typedef struct
  38 {
  39         __u8 data[PAGE_SIZE]; // Data + spare
  40 } yflash_Page;
  41
  42 typedef struct
  43 {
  44         yflash_Page page[PAGES_PER_BLOCK]; // The pages in the block
  45
  46 } yflash_Block;
  47
  48
  49
  50 typedef struct
  51 {
  52         int handle;
  53         int nBlocks;
  54 } yflash_Device;
  55
  56 static yflash_Device filedisk;
  57
  58 static int  CheckInit(void)
  59 {
  60         static int initialised = 0;
  61
  62         int i;
  63
  64
  65         int fSize;
  66         int written;
  67
  68         yflash_Page p;
  69
  70         if(initialised)
  71         {
  72                 return YAFFS_OK;
  73         }
  74
  75         initialised = 1;
  76
  77
  78         filedisk.nBlocks = SIZE_IN_MB * BLOCKS_PER_MB;
  79
  80         filedisk.handle = open("yaffsemfile2k", O_RDWR | O_CREAT, S_IREAD | S_IWRITE);
  81
  82         if(filedisk.handle < 0)
  83         {
  84                 perror("Failed to open yaffs emulation file");
  85                 return YAFFS_FAIL;
  86         }
  87
  88
  89         fSize = lseek(filedisk.handle,0,SEEK_END);
  90
  91         if(fSize < filedisk.nBlocks * BLOCK_SIZE)
  92         {
  93                 printf("Creating yaffs emulation file\n");
  94
  95                 lseek(filedisk.handle,0,SEEK_SET);
  96
  97                 memset(&p,0xff,sizeof(yflash_Page));
  98
  99                 for(i = 0; i <  filedisk.nBlocks * BLOCK_SIZE; i+= PAGE_SIZE)
 100                 {
 101                         written = write(filedisk.handle,&p,sizeof(yflash_Page));
 102
 103                         if(written != sizeof(yflash_Page))
 104                         {
 105                                 printf("Write failed\n");
 106                                 return YAFFS_FAIL;
 107                         }
 108                 }
 109         }
 110         else
 111         {
 112                 filedisk.nBlocks = fSize/(BLOCK_SIZE);
 113         }
 114
 115         return 1;
 116 }
 117
 118
 119 int yflash_GetNumberOfBlocks(void)
 120 {
 121         CheckInit();
 122
 123         return filedisk.nBlocks;
 124 }
 125
 126 int yflash_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_ExtendedTags *tags)
 127 {
 128         int written;
 129         int pos;
 130
 131         CheckInit();
 132
 133
 134
 135         if(data)
 136         {
 137                 pos = chunkInNAND * PAGE_SIZE;
 138                 lseek(filedisk.handle,pos,SEEK_SET);
 139                 written = write(filedisk.handle,data,dev->nBytesPerChunk);
 140
 141                 if(written != dev->nBytesPerChunk) return YAFFS_FAIL;
 142         }
 143
 144         if(tags)
 145         {
 146                 pos = chunkInNAND * PAGE_SIZE + PAGE_DATA_SIZE;
 147                 lseek(filedisk.handle,pos,SEEK_SET);
 148                 if( 0 && dev->isYaffs2)
 149                 {
 150
 151                         written = write(filedisk.handle,tags,sizeof(yaffs_ExtendedTags));
 152                         if(written != sizeof(yaffs_ExtendedTags)) return YAFFS_FAIL;
 153                 }
 154                 else
 155                 {
 156                         yaffs_PackedTags2 pt;
 157                         yaffs_PackTags2(&pt,tags);
 158
 159                         written = write(filedisk.handle,&pt,sizeof(pt));
 160                         if(written != sizeof(pt)) return YAFFS_FAIL;
 161                 }
 162         }
 163
 164
 165         return YAFFS_OK;
 166
 167 }
 168
 169 int yflash_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo)
 170 {
 171         int written;
 172
 173         yaffs_PackedTags2 pt;
 174
 175         CheckInit();
 176
 177         memset(&pt,0,sizeof(pt));
 178         lseek(filedisk.handle,(blockNo * dev->nChunksPerBlock) * PAGE_SIZE + PAGE_DATA_SIZE,SEEK_SET);
 179         written = write(filedisk.handle,&pt,sizeof(pt));
 180
 181         if(written != sizeof(pt)) return YAFFS_FAIL;
 182
 183
 184         return YAFFS_OK;
 185
 186 }
 187
 188 int yaffs_CheckAllFF(const __u8 *ptr, int n)
 189 {
 190         while(n)
 191         {
 192                 n--;
 193                 if(*ptr!=0xFF) return 0;
 194                 ptr++;
 195         }
 196         return 1;
 197 }
 198
 199
 200 int yflash_ReadChunkWithTagsFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_ExtendedTags *tags)
 201 {
 202         int nread;
 203         int pos;
 204
 205         CheckInit();
 206
 207
 208
 209         if(data)
 210         {
 211                 pos = chunkInNAND * PAGE_SIZE;
 212                 lseek(filedisk.handle,pos,SEEK_SET);
 213                 nread = read(filedisk.handle,data,dev->nBytesPerChunk);
 214
 215                 if(nread != dev->nBytesPerChunk) return YAFFS_FAIL;
 216         }
 217
 218         if(tags)
 219         {
 220                 pos = chunkInNAND * PAGE_SIZE + PAGE_DATA_SIZE;
 221                 lseek(filedisk.handle,pos,SEEK_SET);
 222                 if(0 && dev->isYaffs2)
 223                 {
 224                         nread= read(filedisk.handle,tags,sizeof(yaffs_ExtendedTags));
 225                         if(nread != sizeof(yaffs_ExtendedTags)) return YAFFS_FAIL;
 226                         if(yaffs_CheckAllFF((__u8 *)tags,sizeof(yaffs_ExtendedTags)))
 227                         {
 228                                 yaffs_InitialiseTags(tags);
 229                         }
 230                         else
 231                         {
 232                                 tags->chunkUsed = 1;
 233                         }
 234                 }
 235                 else
 236                 {
 237                         yaffs_PackedTags2 pt;
 238                         nread= read(filedisk.handle,&pt,sizeof(pt));
 239                         yaffs_UnpackTags2(tags,&pt);
 240                         if(nread != sizeof(pt)) return YAFFS_FAIL;
 241                 }
 242         }
 243
 244
 245         return YAFFS_OK;
 246
 247 }
 248
 249
 250 int yflash_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
 251 {
 252
 253         int i;
 254
 255         CheckInit();
 256
 257         if(blockNumber < 0 || blockNumber >= filedisk.nBlocks)
 258         {
 259                 T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));
 260                 return YAFFS_FAIL;
 261         }
 262         else
 263         {
 264
 265                 __u8 pg[PAGE_SIZE];
 266                 int syz = PAGE_SIZE;
 267                 int pos;
 268
 269                 memset(pg,0xff,syz);
 270
 271                 pos = lseek(filedisk.handle, blockNumber * dev->nChunksPerBlock * PAGE_SIZE, SEEK_SET);
 272
 273                 for(i = 0; i < dev->nChunksPerBlock; i++)
 274                 {
 275                         write(filedisk.handle,pg,PAGE_SIZE);
 276                 }
 277                 pos = lseek(filedisk.handle, 0,SEEK_CUR);
 278
 279                 return YAFFS_OK;
 280         }
 281
 282 }
 283
 284 int yflash_InitialiseNAND(yaffs_Device *dev)
 285 {
 286         CheckInit();
 287
 288         return YAFFS_OK;
 289 }
 290
 291
 292
 293
 294 int yflash_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo, yaffs_BlockState *state, int *sequenceNumber)
 295 {
 296         yaffs_ExtendedTags tags;
 297         int chunkNo;
 298
 299         *sequenceNumber = 0;
 300
 301         chunkNo = blockNo * dev->nChunksPerBlock;
 302
 303         yflash_ReadChunkWithTagsFromNAND(dev,chunkNo,NULL,&tags);
 304         if(tags.blockBad)
 305         {
 306                 *state = YAFFS_BLOCK_STATE_DEAD;
 307         }
 308         else if(!tags.chunkUsed)
 309         {
 310                 *state = YAFFS_BLOCK_STATE_EMPTY;
 311         }
 312         else if(tags.chunkUsed)
 313         {
 314                 *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
 315                 *sequenceNumber = tags.sequenceNumber;
 316         }
 317         return YAFFS_OK;
 318 }
 319