diff options
Diffstat (limited to 'fs/yaffs2/direct/yaffs_ramdisk.c')
| -rw-r--r-- | fs/yaffs2/direct/yaffs_ramdisk.c | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/fs/yaffs2/direct/yaffs_ramdisk.c b/fs/yaffs2/direct/yaffs_ramdisk.c new file mode 100644 index 0000000..6afee81 --- /dev/null +++ b/fs/yaffs2/direct/yaffs_ramdisk.c @@ -0,0 +1,234 @@ +/* + * YAFFS: Yet Another Flash File System. A NAND-flash specific file system. + * + * Copyright (C) 2002-2007 Aleph One Ltd. + * for Toby Churchill Ltd and Brightstar Engineering + * + * Created by Charles Manning <charles@aleph1.co.uk> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +/* + * yaffs_ramdisk.c: yaffs ram disk component + * This provides a ram disk under yaffs. + * NB this is not intended for NAND emulation. + * Use this with dev->useNANDECC enabled, then ECC overheads are not required. + */ + +const char *yaffs_ramdisk_c_version = "$Id: yaffs_ramdisk.c,v 1.4 2007/02/14 01:09:06 wookey Exp $"; + + +#include "yportenv.h" + +#include "yaffs_ramdisk.h" +#include "yaffs_guts.h" +#include "devextras.h" +#include "yaffs_packedtags1.h" + + + +#define SIZE_IN_MB 2 + +#define BLOCK_SIZE (32 * 528) +#define BLOCKS_PER_MEG ((1024*1024)/(32 * 512)) + + + + + +typedef struct +{ + __u8 data[528]; // Data + spare +} yramdisk_Page; + +typedef struct +{ + yramdisk_Page page[32]; // The pages in the block + +} yramdisk_Block; + + + +typedef struct +{ + yramdisk_Block **block; + int nBlocks; +} yramdisk_Device; + +static yramdisk_Device ramdisk; + +static int CheckInit(yaffs_Device *dev) +{ + static int initialised = 0; + + int i; + int fail = 0; + //int nBlocks; + int nAllocated = 0; + + if(initialised) + { + return YAFFS_OK; + } + + initialised = 1; + + + ramdisk.nBlocks = (SIZE_IN_MB * 1024 * 1024)/(16 * 1024); + + ramdisk.block = YMALLOC(sizeof(yramdisk_Block *) * ramdisk.nBlocks); + + if(!ramdisk.block) return 0; + + for(i=0; i <ramdisk.nBlocks; i++) + { + ramdisk.block[i] = NULL; + } + + for(i=0; i <ramdisk.nBlocks && !fail; i++) + { + if((ramdisk.block[i] = YMALLOC(sizeof(yramdisk_Block))) == 0) + { + fail = 1; + } + else + { + yramdisk_EraseBlockInNAND(dev,i); + nAllocated++; + } + } + + if(fail) + { + for(i = 0; i < nAllocated; i++) + { + YFREE(ramdisk.block[i]); + } + YFREE(ramdisk.block); + + T(YAFFS_TRACE_ALWAYS,("Allocation failed, could only allocate %dMB of %dMB requested.\n", + nAllocated/64,ramdisk.nBlocks * 528)); + return 0; + } + + + return 1; +} + +int yramdisk_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_ExtendedTags *tags) +{ + int blk; + int pg; + + + CheckInit(dev); + + blk = chunkInNAND/32; + pg = chunkInNAND%32; + + + if(data) + { + memcpy(ramdisk.block[blk]->page[pg].data,data,512); + } + + + if(tags) + { + yaffs_PackedTags1 pt; + + yaffs_PackTags1(&pt,tags); + memcpy(&ramdisk.block[blk]->page[pg].data[512],&pt,sizeof(pt)); + } + + return YAFFS_OK; + +} + + +int yramdisk_ReadChunkWithTagsFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_ExtendedTags *tags) +{ + int blk; + int pg; + + + CheckInit(dev); + + blk = chunkInNAND/32; + pg = chunkInNAND%32; + + + if(data) + { + memcpy(data,ramdisk.block[blk]->page[pg].data,512); + } + + + if(tags) + { + yaffs_PackedTags1 pt; + + memcpy(&pt,&ramdisk.block[blk]->page[pg].data[512],sizeof(pt)); + yaffs_UnpackTags1(tags,&pt); + + } + + return YAFFS_OK; +} + + +int yramdisk_CheckChunkErased(yaffs_Device *dev,int chunkInNAND) +{ + int blk; + int pg; + int i; + + + CheckInit(dev); + + blk = chunkInNAND/32; + pg = chunkInNAND%32; + + + for(i = 0; i < 528; i++) + { + if(ramdisk.block[blk]->page[pg].data[i] != 0xFF) + { + return YAFFS_FAIL; + } + } + + return YAFFS_OK; + +} + +int yramdisk_EraseBlockInNAND(yaffs_Device *dev, int blockNumber) +{ + + CheckInit(dev); + + if(blockNumber < 0 || blockNumber >= ramdisk.nBlocks) + { + T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber)); + return YAFFS_FAIL; + } + else + { + memset(ramdisk.block[blockNumber],0xFF,sizeof(yramdisk_Block)); + return YAFFS_OK; + } + +} + +int yramdisk_InitialiseNAND(yaffs_Device *dev) +{ + //dev->useNANDECC = 1; // force on useNANDECC which gets faked. + // This saves us doing ECC checks. + + return YAFFS_OK; +} + + |