/* * YAFFS: Yet another FFS. A NAND-flash specific file system.  * yaffs_ramdisk.c: yaffs ram disk component * * Copyright (C) 2002 Aleph One Ltd. * * 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. * */// This provides a rma 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 1.1 2003/01/21 03:32:17 charles Exp $";#include "yportenv.h"#include "yaffs_ramdisk.h"#include "yaffs_guts.h"#include "devextras.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 * YAFFS_BYTES_PER_BLOCK));		return 0;	}			return 1;}int yramdisk_WriteChunkToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_Spare *spare){	int blk;	int pg;		CheckInit(dev);		blk = chunkInNAND/32;	pg = chunkInNAND%32;			if(data)	{		memcpy(ramdisk.block[blk]->page[pg].data,data,512);	}			if(spare)	{		memcpy(&ramdisk.block[blk]->page[pg].data[512],spare,16);	}	return YAFFS_OK;	}int yramdisk_ReadChunkFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare){	int blk;	int pg;		CheckInit(dev);		blk = chunkInNAND/32;	pg = chunkInNAND%32;			if(data)	{		memcpy(data,ramdisk.block[blk]->page[pg].data,512);	}			if(spare)	{		memcpy(spare,&ramdisk.block[blk]->page[pg].data[512],16);		if(dev->useNANDECC)		{			struct yaffs_NANDSpare *nsp = (struct yaffs_NANDSpare *)spare;			nsp->eccres1 = 0;			nsp->eccres2 = 0;		}	}	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;}