2 * YAFFS: Yet another FFS. A NAND-flash specific file system.
3 * yaffs_ramdisk.c: yaffs ram disk component
5 * Copyright (C) 2002 Aleph One Ltd.
7 * Created by Charles Manning <charles@aleph1.co.uk>
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.
15 // This provides a rma disk under yaffs.
16 // NB this is not intended for NAND emulation.
17 // Use this with dev->useNANDECC enabled, then ECC overheads are not required.
19 const char *yaffs_ramdisk_c_version = "$Id: yaffs_ramdisk.c,v 1.1 2003-01-21 03:32:17 charles Exp $";
24 #include "yaffs_ramdisk.h"
25 #include "yaffs_guts.h"
26 #include "devextras.h"
31 #define BLOCK_SIZE (32 * 528)
32 #define BLOCKS_PER_MEG ((1024*1024)/(32 * 512))
38 __u8 data[528]; // Data + spare
43 yramdisk_Page page[32]; // The pages in the block
51 yramdisk_Block **block;
55 static yramdisk_Device ramdisk;
57 static int CheckInit(yaffs_Device *dev)
59 static int initialised = 0;
74 ramdisk.nBlocks = (SIZE_IN_MB * 1024 * 1024)/(16 * 1024);
76 ramdisk.block = YMALLOC(sizeof(yramdisk_Block *) * ramdisk.nBlocks);
78 if(!ramdisk.block) return 0;
80 for(i=0; i <ramdisk.nBlocks; i++)
82 ramdisk.block[i] = NULL;
85 for(i=0; i <ramdisk.nBlocks && !fail; i++)
87 if((ramdisk.block[i] = YMALLOC(sizeof(yramdisk_Block))) == 0)
93 yramdisk_EraseBlockInNAND(dev,i);
100 for(i = 0; i < nAllocated; i++)
102 YFREE(ramdisk.block[i]);
104 YFREE(ramdisk.block);
106 T(YAFFS_TRACE_ALWAYS,("Allocation failed, could only allocate %dMB of %dMB requested.\n",
107 nAllocated/64,ramdisk.nBlocks * YAFFS_BYTES_PER_BLOCK));
115 int yramdisk_WriteChunkToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_Spare *spare)
123 blk = chunkInNAND/32;
129 memcpy(ramdisk.block[blk]->page[pg].data,data,512);
135 memcpy(&ramdisk.block[blk]->page[pg].data[512],spare,16);
143 int yramdisk_ReadChunkFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare)
151 blk = chunkInNAND/32;
157 memcpy(data,ramdisk.block[blk]->page[pg].data,512);
163 memcpy(spare,&ramdisk.block[blk]->page[pg].data[512],16);
166 struct yaffs_NANDSpare *nsp = (struct yaffs_NANDSpare *)spare;
176 int yramdisk_CheckChunkErased(yaffs_Device *dev,int chunkInNAND)
185 blk = chunkInNAND/32;
189 for(i = 0; i < 528; i++)
191 if(ramdisk.block[blk]->page[pg].data[i] != 0xFF)
201 int yramdisk_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
206 if(blockNumber < 0 || blockNumber >= ramdisk.nBlocks)
208 T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));
213 memset(ramdisk.block[blockNumber],0xFF,sizeof(yramdisk_Block));
219 int yramdisk_InitialiseNAND(yaffs_Device *dev)
221 dev->useNANDECC = 1; // force on useNANDECC which gets faked.
222 // This saves us doing ECC checks.