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 1.1 2004-11-03 08:29:28 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_packedtags.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(yaffs_Device *dev)
  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
 111         return 1;
 112 }
 113
 114 int yflash_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_ExtendedTags *tags)
 115 {
 116         int written;
 117         int pos;
 118
 119         CheckInit(dev);
 120
 121
 122
 123         if(data)
 124         {
 125                 pos = chunkInNAND * PAGE_SIZE;
 126                 lseek(filedisk.handle,pos,SEEK_SET);
 127                 written = write(filedisk.handle,data,dev->nBytesPerChunk);
 128
 129                 if(written != dev->nBytesPerChunk) return YAFFS_FAIL;
 130         }
 131
 132         if(tags)
 133         {
 134                 pos = chunkInNAND * PAGE_SIZE + PAGE_DATA_SIZE;
 135                 lseek(filedisk.handle,pos,SEEK_SET);
 136                 if(dev->isYaffs2)
 137                 {
 138
 139                         written = write(filedisk.handle,tags,sizeof(yaffs_ExtendedTags));
 140                         if(written != sizeof(yaffs_ExtendedTags)) return YAFFS_FAIL;
 141                 }
 142                 else
 143                 {
 144                         yaffs_PackedTags pt;
 145                         yaffs_PackTags(&pt,tags);
 146
 147                         written = write(filedisk.handle,&pt,sizeof(pt));
 148                         if(written != sizeof(pt)) return YAFFS_FAIL;
 149                 }
 150         }
 151
 152
 153         return YAFFS_OK;
 154
 155 }
 156
 157 int yflash_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo)
 158 {
 159         int written;
 160
 161         yaffs_PackedTags pt;
 162
 163         CheckInit(dev);
 164
 165         memset(&pt,0,sizeof(pt));
 166         lseek(filedisk.handle,(blockNo * dev->nChunksPerBlock) * PAGE_SIZE + PAGE_DATA_SIZE,SEEK_SET);
 167         written = write(filedisk.handle,&pt,sizeof(pt));
 168
 169         if(written != sizeof(pt)) return YAFFS_FAIL;
 170
 171
 172         return YAFFS_OK;
 173
 174 }
 175
 176 int yaffs_CheckAllFF(const __u8 *ptr, int n)
 177 {
 178         while(n)
 179         {
 180                 n--;
 181                 if(*ptr!=0xFF) return 0;
 182                 ptr++;
 183         }
 184         return 1;
 185 }
 186
 187
 188 int yflash_ReadChunkWithTagsFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_ExtendedTags *tags)
 189 {
 190         int nread;
 191         int pos;
 192
 193         CheckInit(dev);
 194
 195
 196
 197         if(data)
 198         {
 199                 pos = chunkInNAND * PAGE_SIZE;
 200                 lseek(filedisk.handle,pos,SEEK_SET);
 201                 nread = read(filedisk.handle,data,dev->nBytesPerChunk);
 202
 203                 if(nread != dev->nBytesPerChunk) return YAFFS_FAIL;
 204         }
 205
 206         if(tags)
 207         {
 208                 pos = chunkInNAND * PAGE_SIZE + PAGE_DATA_SIZE;
 209                 lseek(filedisk.handle,pos,SEEK_SET);
 210                 if(dev->isYaffs2)
 211                 {
 212                         nread= read(filedisk.handle,tags,sizeof(yaffs_ExtendedTags));
 213                         if(nread != sizeof(yaffs_ExtendedTags)) return YAFFS_FAIL;
 214                         if(yaffs_CheckAllFF((__u8 *)tags,sizeof(yaffs_ExtendedTags)))
 215                         {
 216                                 yaffs_InitialiseTags(tags);
 217                         }
 218                         else
 219                         {
 220                                 tags->chunkUsed = 1;
 221                         }
 222                 }
 223                 else
 224                 {
 225                         yaffs_PackedTags pt;
 226                         nread= read(filedisk.handle,&pt,sizeof(pt));
 227                         yaffs_UnpackTags(tags,&pt);
 228                         if(nread != sizeof(pt)) return YAFFS_FAIL;
 229                 }
 230         }
 231
 232
 233         return YAFFS_OK;
 234
 235 }
 236
 237
 238 int yflash_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
 239 {
 240
 241         int i;
 242
 243         CheckInit(dev);
 244
 245         if(blockNumber < 0 || blockNumber >= filedisk.nBlocks)
 246         {
 247                 T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));
 248                 return YAFFS_FAIL;
 249         }
 250         else
 251         {
 252
 253                 __u8 pg[PAGE_SIZE];
 254                 int syz = PAGE_SIZE;
 255                 int pos;
 256
 257                 memset(pg,0xff,syz);
 258
 259                 pos = lseek(filedisk.handle, blockNumber * dev->nChunksPerBlock * PAGE_SIZE, SEEK_SET);
 260
 261                 for(i = 0; i < dev->nChunksPerBlock; i++)
 262                 {
 263                         write(filedisk.handle,pg,PAGE_SIZE);
 264                 }
 265                 pos = lseek(filedisk.handle, 0,SEEK_CUR);
 266
 267                 return YAFFS_OK;
 268         }
 269
 270 }
 271
 272 int yflash_InitialiseNAND(yaffs_Device *dev)
 273 {
 274         CheckInit(dev);
 275
 276         return YAFFS_OK;
 277 }
 278
 279
 280
 281
 282 int yflash_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo, yaffs_BlockState *state, int *sequenceNumber)
 283 {
 284         yaffs_ExtendedTags tags;
 285         int chunkNo;
 286
 287         *sequenceNumber = 0;
 288
 289         chunkNo = blockNo * dev->nChunksPerBlock;
 290
 291         yflash_ReadChunkWithTagsFromNAND(dev,chunkNo,NULL,&tags);
 292         if(tags.blockBad)
 293         {
 294                 *state = YAFFS_BLOCK_STATE_DEAD;
 295         }
 296         else if(!tags.chunkUsed)
 297         {
 298                 *state = YAFFS_BLOCK_STATE_EMPTY;
 299         }
 300         else if(tags.chunkUsed)
 301         {
 302                 *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
 303                 *sequenceNumber = tags.sequenceNumber;
 304         }
 305         return YAFFS_OK;
 306 }
 307