direct/yaffs_fileem.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.
  16 // THis is only intended as test code to test persistence etc.
  17
  18 const char *yaffs_flashif_c_version = "$Id: yaffs_fileem.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
  26 #include "devextras.h"
  27
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #include <fcntl.h>
  31 #include <unistd.h>
  32
  33
  34
  35 #define SIZE_IN_MB 16
  36
  37 #define BLOCK_SIZE (32 * 528)
  38 #define BLOCKS_PER_MEG ((1024*1024)/(32 * 512))
  39
  40
  41
  42 typedef struct
  43 {
  44         __u8 data[528]; // Data + spare
  45 } yflash_Page;
  46
  47 typedef struct
  48 {
  49         yflash_Page page[32]; // The pages in the block
  50
  51 } yflash_Block;
  52
  53
  54
  55 typedef struct
  56 {
  57         int handle;
  58         int nBlocks;
  59 } yflash_Device;
  60
  61 static yflash_Device filedisk;
  62
  63 static int  CheckInit(yaffs_Device *dev)
  64 {
  65         static int initialised = 0;
  66
  67         int i;
  68
  69
  70         int fSize;
  71         int written;
  72
  73         yflash_Page p;
  74
  75         if(initialised)
  76         {
  77                 return YAFFS_OK;
  78         }
  79
  80         initialised = 1;
  81
  82
  83         filedisk.nBlocks = (SIZE_IN_MB * 1024 * 1024)/(16 * 1024);
  84
  85         filedisk.handle = open("yaffsemfile", O_RDWR | O_CREAT, S_IREAD | S_IWRITE);
  86
  87         if(filedisk.handle < 0)
  88         {
  89                 perror("Failed to open yaffs emulation file");
  90                 return YAFFS_FAIL;
  91         }
  92
  93
  94         fSize = lseek(filedisk.handle,0,SEEK_END);
  95
  96         if(fSize < SIZE_IN_MB * 1024 * 1024)
  97         {
  98                 printf("Creating yaffs emulation file\n");
  99
 100                 lseek(filedisk.handle,0,SEEK_SET);
 101
 102                 memset(&p,0xff,sizeof(yflash_Page));
 103
 104                 for(i = 0; i < SIZE_IN_MB * 1024 * 1024; i+= 512)
 105                 {
 106                         written = write(filedisk.handle,&p,sizeof(yflash_Page));
 107
 108                         if(written != sizeof(yflash_Page))
 109                         {
 110                                 printf("Write failed\n");
 111                                 return YAFFS_FAIL;
 112                         }
 113                 }
 114         }
 115
 116         return 1;
 117 }
 118
 119 int yflash_WriteChunkToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, const yaffs_Spare *spare)
 120 {
 121         int written;
 122
 123         CheckInit(dev);
 124
 125
 126
 127         if(data)
 128         {
 129                 lseek(filedisk.handle,chunkInNAND * 528,SEEK_SET);
 130                 written = write(filedisk.handle,data,512);
 131
 132                 if(written != 512) return YAFFS_FAIL;
 133         }
 134
 135         if(spare)
 136         {
 137                 lseek(filedisk.handle,chunkInNAND * 528 + 512,SEEK_SET);
 138                 written = write(filedisk.handle,spare,16);
 139
 140                 if(written != 16) return YAFFS_FAIL;
 141         }
 142
 143
 144         return YAFFS_OK;
 145
 146 }
 147
 148
 149 int yflash_ReadChunkFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare)
 150 {
 151         int nread;
 152
 153         CheckInit(dev);
 154
 155
 156
 157         if(data)
 158         {
 159                 lseek(filedisk.handle,chunkInNAND * 528,SEEK_SET);
 160                 nread = read(filedisk.handle,data,512);
 161
 162                 if(nread != 512) return YAFFS_FAIL;
 163         }
 164
 165         if(spare)
 166         {
 167                 lseek(filedisk.handle,chunkInNAND * 528 + 512,SEEK_SET);
 168                 nread= read(filedisk.handle,spare,16);
 169
 170                 if(nread != 16) return YAFFS_FAIL;
 171         }
 172
 173
 174         return YAFFS_OK;
 175
 176 }
 177
 178
 179 int yflash_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
 180 {
 181
 182         int i;
 183
 184         CheckInit(dev);
 185
 186         if(blockNumber < 0 || blockNumber >= filedisk.nBlocks)
 187         {
 188                 T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));
 189                 return YAFFS_FAIL;
 190         }
 191         else
 192         {
 193
 194                 yflash_Page pg;
 195
 196                 memset(&pg,0xff,sizeof(yflash_Page));
 197
 198                 lseek(filedisk.handle, blockNumber * 32 * 528, SEEK_SET);
 199
 200                 for(i = 0; i < 32; i++)
 201                 {
 202                         write(filedisk.handle,&pg,528);
 203                 }
 204                 return YAFFS_OK;
 205         }
 206
 207 }
 208
 209 int yflash_InitialiseNAND(yaffs_Device *dev)
 210 {
 211         dev->useNANDECC = 1; // force on useNANDECC which gets faked.
 212                                                  // This saves us doing ECC checks.
 213
 214         return YAFFS_OK;
 215 }
 216
 217