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 1.5 2006-09-21 08:13:59 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 int yaffs_testPartialWrite = 0;
  59
  60 static int  CheckInit(void)
  61 {
  62         static int initialised = 0;
  63
  64         int i;
  65
  66
  67         int fSize;
  68         int written;
  69
  70         yflash_Page p;
  71
  72         if(initialised)
  73         {
  74                 return YAFFS_OK;
  75         }
  76
  77         initialised = 1;
  78
  79
  80         filedisk.nBlocks = SIZE_IN_MB * BLOCKS_PER_MB;
  81
  82         filedisk.handle = open("yaffsemfile2k", O_RDWR | O_CREAT, S_IREAD | S_IWRITE);
  83
  84         if(filedisk.handle < 0)
  85         {
  86                 perror("Failed to open yaffs emulation file");
  87                 return YAFFS_FAIL;
  88         }
  89
  90
  91         fSize = lseek(filedisk.handle,0,SEEK_END);
  92
  93         if(fSize < filedisk.nBlocks * BLOCK_SIZE)
  94         {
  95                 printf("Creating yaffs emulation file\n");
  96
  97                 lseek(filedisk.handle,0,SEEK_SET);
  98
  99                 memset(&p,0xff,sizeof(yflash_Page));
 100
 101                 for(i = 0; i <  filedisk.nBlocks * BLOCK_SIZE; i+= PAGE_SIZE)
 102                 {
 103                         written = write(filedisk.handle,&p,sizeof(yflash_Page));
 104
 105                         if(written != sizeof(yflash_Page))
 106                         {
 107                                 printf("Write failed\n");
 108                                 return YAFFS_FAIL;
 109                         }
 110                 }
 111         }
 112         else
 113         {
 114                 filedisk.nBlocks = fSize/(BLOCK_SIZE);
 115         }
 116
 117         return 1;
 118 }
 119
 120
 121 int yflash_GetNumberOfBlocks(void)
 122 {
 123         CheckInit();
 124
 125         return filedisk.nBlocks;
 126 }
 127
 128 int yflash_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_ExtendedTags *tags)
 129 {
 130         int written;
 131         int pos;
 132
 133         CheckInit();
 134
 135
 136
 137         if(data)
 138         {
 139                 pos = chunkInNAND * PAGE_SIZE;
 140                 lseek(filedisk.handle,pos,SEEK_SET);
 141                 written = write(filedisk.handle,data,dev->nBytesPerChunk);
 142
 143                 if(yaffs_testPartialWrite){
 144                         close(filedisk.handle);
 145                         exit(1);
 146                 }
 147
 148                 if(written != dev->nBytesPerChunk) return YAFFS_FAIL;
 149         }
 150
 151         if(tags)
 152         {
 153                 pos = chunkInNAND * PAGE_SIZE + PAGE_DATA_SIZE;
 154                 lseek(filedisk.handle,pos,SEEK_SET);
 155                 if( 0 && dev->isYaffs2)
 156                 {
 157
 158                         written = write(filedisk.handle,tags,sizeof(yaffs_ExtendedTags));
 159                         if(written != sizeof(yaffs_ExtendedTags)) return YAFFS_FAIL;
 160                 }
 161                 else
 162                 {
 163                         yaffs_PackedTags2 pt;
 164                         yaffs_PackTags2(&pt,tags);
 165
 166                         written = write(filedisk.handle,&pt,sizeof(pt));
 167                         if(written != sizeof(pt)) return YAFFS_FAIL;
 168                 }
 169         }
 170
 171
 172         return YAFFS_OK;
 173
 174 }
 175
 176 int yflash_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo)
 177 {
 178         int written;
 179
 180         yaffs_PackedTags2 pt;
 181
 182         CheckInit();
 183
 184         memset(&pt,0,sizeof(pt));
 185         lseek(filedisk.handle,(blockNo * dev->nChunksPerBlock) * PAGE_SIZE + PAGE_DATA_SIZE,SEEK_SET);
 186         written = write(filedisk.handle,&pt,sizeof(pt));
 187
 188         if(written != sizeof(pt)) return YAFFS_FAIL;
 189
 190
 191         return YAFFS_OK;
 192
 193 }
 194
 195 int yaffs_CheckAllFF(const __u8 *ptr, int n)
 196 {
 197         while(n)
 198         {
 199                 n--;
 200                 if(*ptr!=0xFF) return 0;
 201                 ptr++;
 202         }
 203         return 1;
 204 }
 205
 206
 207 int yflash_ReadChunkWithTagsFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_ExtendedTags *tags)
 208 {
 209         int nread;
 210         int pos;
 211
 212         CheckInit();
 213
 214
 215
 216         if(data)
 217         {
 218                 pos = chunkInNAND * PAGE_SIZE;
 219                 lseek(filedisk.handle,pos,SEEK_SET);
 220                 nread = read(filedisk.handle,data,dev->nBytesPerChunk);
 221
 222                 if(nread != dev->nBytesPerChunk) return YAFFS_FAIL;
 223         }
 224
 225         if(tags)
 226         {
 227                 pos = chunkInNAND * PAGE_SIZE + PAGE_DATA_SIZE;
 228                 lseek(filedisk.handle,pos,SEEK_SET);
 229                 if(0 && dev->isYaffs2)
 230                 {
 231                         nread= read(filedisk.handle,tags,sizeof(yaffs_ExtendedTags));
 232                         if(nread != sizeof(yaffs_ExtendedTags)) return YAFFS_FAIL;
 233                         if(yaffs_CheckAllFF((__u8 *)tags,sizeof(yaffs_ExtendedTags)))
 234                         {
 235                                 yaffs_InitialiseTags(tags);
 236                         }
 237                         else
 238                         {
 239                                 tags->chunkUsed = 1;
 240                         }
 241                 }
 242                 else
 243                 {
 244                         yaffs_PackedTags2 pt;
 245                         nread= read(filedisk.handle,&pt,sizeof(pt));
 246                         yaffs_UnpackTags2(tags,&pt);
 247                         if(nread != sizeof(pt)) return YAFFS_FAIL;
 248                 }
 249         }
 250
 251
 252         return YAFFS_OK;
 253
 254 }
 255
 256
 257 int yflash_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
 258 {
 259
 260         int i;
 261
 262         CheckInit();
 263
 264         if(blockNumber < 0 || blockNumber >= filedisk.nBlocks)
 265         {
 266                 T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));
 267                 return YAFFS_FAIL;
 268         }
 269         else
 270         {
 271
 272                 __u8 pg[PAGE_SIZE];
 273                 int syz = PAGE_SIZE;
 274                 int pos;
 275
 276                 memset(pg,0xff,syz);
 277
 278                 pos = lseek(filedisk.handle, blockNumber * dev->nChunksPerBlock * PAGE_SIZE, SEEK_SET);
 279
 280                 for(i = 0; i < dev->nChunksPerBlock; i++)
 281                 {
 282                         write(filedisk.handle,pg,PAGE_SIZE);
 283                 }
 284                 pos = lseek(filedisk.handle, 0,SEEK_CUR);
 285
 286                 return YAFFS_OK;
 287         }
 288
 289 }
 290
 291 int yflash_InitialiseNAND(yaffs_Device *dev)
 292 {
 293         CheckInit();
 294
 295         return YAFFS_OK;
 296 }
 297
 298
 299
 300
 301 int yflash_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo, yaffs_BlockState *state, int *sequenceNumber)
 302 {
 303         yaffs_ExtendedTags tags;
 304         int chunkNo;
 305
 306         *sequenceNumber = 0;
 307
 308         chunkNo = blockNo * dev->nChunksPerBlock;
 309
 310         yflash_ReadChunkWithTagsFromNAND(dev,chunkNo,NULL,&tags);
 311         if(tags.blockBad)
 312         {
 313                 *state = YAFFS_BLOCK_STATE_DEAD;
 314         }
 315         else if(!tags.chunkUsed)
 316         {
 317                 *state = YAFFS_BLOCK_STATE_EMPTY;
 318         }
 319         else if(tags.chunkUsed)
 320         {
 321                 *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
 322                 *sequenceNumber = tags.sequenceNumber;
 323         }
 324         return YAFFS_OK;
 325 }
 326