direct/yaffs_fileem.c

   1 /*
   2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3  *
   4  * Copyright (C) 2002-2007 Aleph One Ltd.
   5  *   for Toby Churchill Ltd and Brightstar Engineering
   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
  19 const char *yaffs_flashif_c_version = "$Id: yaffs_fileem.c,v 1.3 2007-02-14 01:09:06 wookey Exp $";
  20
  21
  22 #include "yportenv.h"
  23
  24 #include "yaffs_flashif.h"
  25 #include "yaffs_guts.h"
  26
  27 #include "devextras.h"
  28
  29 #include <sys/types.h>
  30 #include <sys/stat.h>
  31 #include <fcntl.h>
  32 #include <unistd.h>
  33
  34
  35
  36 #define SIZE_IN_MB 16
  37
  38 #define BLOCK_SIZE (32 * 528)
  39 #define BLOCKS_PER_MEG ((1024*1024)/(32 * 512))
  40
  41
  42
  43 typedef struct
  44 {
  45         __u8 data[528]; // Data + spare
  46 } yflash_Page;
  47
  48 typedef struct
  49 {
  50         yflash_Page page[32]; // The pages in the block
  51
  52 } yflash_Block;
  53
  54
  55
  56 typedef struct
  57 {
  58         int handle;
  59         int nBlocks;
  60 } yflash_Device;
  61
  62 static yflash_Device filedisk;
  63
  64 static int  CheckInit(yaffs_Device *dev)
  65 {
  66         static int initialised = 0;
  67
  68         int i;
  69
  70
  71         int fSize;
  72         int written;
  73
  74         yflash_Page p;
  75
  76         if(initialised)
  77         {
  78                 return YAFFS_OK;
  79         }
  80
  81         initialised = 1;
  82
  83
  84         filedisk.nBlocks = (SIZE_IN_MB * 1024 * 1024)/(16 * 1024);
  85
  86         filedisk.handle = open("yaffsemfile", O_RDWR | O_CREAT, S_IREAD | S_IWRITE);
  87
  88         if(filedisk.handle < 0)
  89         {
  90                 perror("Failed to open yaffs emulation file");
  91                 return YAFFS_FAIL;
  92         }
  93
  94
  95         fSize = lseek(filedisk.handle,0,SEEK_END);
  96
  97         if(fSize < SIZE_IN_MB * 1024 * 1024)
  98         {
  99                 printf("Creating yaffs emulation file\n");
 100
 101                 lseek(filedisk.handle,0,SEEK_SET);
 102
 103                 memset(&p,0xff,sizeof(yflash_Page));
 104
 105                 for(i = 0; i < SIZE_IN_MB * 1024 * 1024; i+= 512)
 106                 {
 107                         written = write(filedisk.handle,&p,sizeof(yflash_Page));
 108
 109                         if(written != sizeof(yflash_Page))
 110                         {
 111                                 printf("Write failed\n");
 112                                 return YAFFS_FAIL;
 113                         }
 114                 }
 115         }
 116
 117         return 1;
 118 }
 119
 120 int yflash_WriteChunkToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, const yaffs_Spare *spare)
 121 {
 122         int written;
 123
 124         CheckInit(dev);
 125
 126
 127
 128         if(data)
 129         {
 130                 lseek(filedisk.handle,chunkInNAND * 528,SEEK_SET);
 131                 written = write(filedisk.handle,data,512);
 132
 133                 if(written != 512) return YAFFS_FAIL;
 134         }
 135
 136         if(spare)
 137         {
 138                 lseek(filedisk.handle,chunkInNAND * 528 + 512,SEEK_SET);
 139                 written = write(filedisk.handle,spare,16);
 140
 141                 if(written != 16) return YAFFS_FAIL;
 142         }
 143
 144
 145         return YAFFS_OK;
 146
 147 }
 148
 149
 150 int yflash_ReadChunkFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare)
 151 {
 152         int nread;
 153
 154         CheckInit(dev);
 155
 156
 157
 158         if(data)
 159         {
 160                 lseek(filedisk.handle,chunkInNAND * 528,SEEK_SET);
 161                 nread = read(filedisk.handle,data,512);
 162
 163                 if(nread != 512) return YAFFS_FAIL;
 164         }
 165
 166         if(spare)
 167         {
 168                 lseek(filedisk.handle,chunkInNAND * 528 + 512,SEEK_SET);
 169                 nread= read(filedisk.handle,spare,16);
 170
 171                 if(nread != 16) return YAFFS_FAIL;
 172         }
 173
 174
 175         return YAFFS_OK;
 176
 177 }
 178
 179
 180 int yflash_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
 181 {
 182
 183         int i;
 184
 185         CheckInit(dev);
 186
 187         if(blockNumber < 0 || blockNumber >= filedisk.nBlocks)
 188         {
 189                 T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));
 190                 return YAFFS_FAIL;
 191         }
 192         else
 193         {
 194
 195                 yflash_Page pg;
 196
 197                 memset(&pg,0xff,sizeof(yflash_Page));
 198
 199                 lseek(filedisk.handle, blockNumber * 32 * 528, SEEK_SET);
 200
 201                 for(i = 0; i < 32; i++)
 202                 {
 203                         write(filedisk.handle,&pg,528);
 204                 }
 205                 return YAFFS_OK;
 206         }
 207
 208 }
 209
 210 int yflash_InitialiseNAND(yaffs_Device *dev)
 211 {
 212         dev->useNANDECC = 1; // force on useNANDECC which gets faked.
 213                                                  // This saves us doing ECC checks.
 214
 215         return YAFFS_OK;
 216 }
 217
 218