/* * YAFFS: Yet another FFS. A NAND-flash specific file system.  * yaffs_fileem.c  NAND emulation on top of files * * Copyright (C) 2002 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_fileem.c#include "yaffs_fileem.h"#include "yaffs_guts.h"#include "yaffsinterface.h"#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <string.h>#define FILE_SIZE_IN_MEG 2// #define YAFFS_ERROR_TESTING #define BLOCK_SIZE (32 * 528)#define BLOCKS_PER_MEG ((1024*1024)/(32 * 512))#define FILE_SIZE_IN_BLOCKS (FILE_SIZE_IN_MEG * BLOCKS_PER_MEG)#define FILE_SIZE_IN_BYTES (FILE_SIZE_IN_BLOCKS * BLOCK_SIZE)static int h;static __u8 ffChunk[528];static int eraseDisplayEnabled;static int markedBadBlocks[] = { 1, 4, -1};static int IsAMarkedBadBlock(int blk){#if YAFFS_ERROR_TESTING	int *m = markedBadBlocks;		while(*m >= 0)	{		if(*m == blk) return 1;		m++;	}#endif	return 0;}static __u8 yaffs_WriteFailCorruption(int chunkInNAND){#if YAFFS_ERROR_TESTING	// Whole blocks that fail	switch(chunkInNAND/YAFFS_CHUNKS_PER_BLOCK)	{		case 50:		case 52:					return 7;	}		// Single blocks that fail	switch(chunkInNAND)	{		case 2000:		case 2003:		case 3000:		case 3001:					return 3;// ding two bits		case 2001:		case 3003:		case 3004:		case 3005:		case 3006:		case 3007:  return 1;// ding one bit					}#endif	return 0;}static void yaffs_ModifyWriteData(int chunkInNAND,__u8 *data){#if YAFFS_ERROR_TESTING	if(data)	{		*data ^= yaffs_WriteFailCorruption(chunkInNAND);		}#endif}static __u8 yaffs_ReadFailCorruption(int chunkInNAND){	switch(chunkInNAND)	{#if YAFFS_ERROR_TESTING		case 500:					return 3;// ding two bits		case 700:		case 750:					return 1;// ding one bit		#endif		default: return 0;			}}static void yaffs_ModifyReadData(int chunkInNAND,__u8 *data){#if YAFFS_ERROR_TESTING	if(data)	{		*data ^= yaffs_ReadFailCorruption(chunkInNAND);		}#endif}static void  CheckInit(yaffs_Device *dev){	static int initialised = 0;	int length;	int nWritten;		if(!initialised)	{		memset(ffChunk,0xFF,528);		//#ifdef YAFFS_DUMP//		h = open("yaffs-em-file" , O_RDONLY);//#else		h = open("yaffs-em-file" , O_RDWR | O_CREAT, S_IREAD | S_IWRITE);//#endif		if(h < 0)		{			perror("Fatal error opening yaffs emulation file");			exit(1);		}		initialised = 1;				length = lseek(h,0,SEEK_END);		nWritten = 528;		while(length <  FILE_SIZE_IN_BYTES && nWritten == 528)		{			write(h,ffChunk,528);			length = lseek(h,0,SEEK_END);				}		if(nWritten != 528)		{			perror("Fatal error expanding yaffs emulation file");			exit(1);		}				close(h);		#ifdef YAFFS_DUMP		h = open("yaffs-em-file" , O_RDONLY);#else		h = open("yaffs-em-file" , O_RDWR | O_CREAT, S_IREAD | S_IWRITE);#endif	}}int yaffs_FEWriteChunkToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_Spare *spare){	__u8 localData[512];		int pos;		pos = chunkInNAND * 528;		CheckInit(dev);			if(data)	{		memcpy(localData,data,512);		yaffs_ModifyWriteData(chunkInNAND,localData);		lseek(h,pos,SEEK_SET);		write(h,localData,512);	}		pos += 512;		if(spare)	{		lseek(h,pos,SEEK_SET);		write(h,spare,16);		}	return YAFFS_OK;}int yaffs_FEReadChunkFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare){	int pos;	pos = chunkInNAND * 528;			CheckInit(dev);		if(data)	{		lseek(h,pos,SEEK_SET);		read(h,data,512);		yaffs_ModifyReadData(chunkInNAND,data);	}		pos += 512;		if(spare)	{		lseek(h,pos,SEEK_SET);		read(h,spare,16);		}	return YAFFS_OK;}int yaffs_FEEraseBlockInNAND(yaffs_Device *dev,int blockInNAND){	int i;		CheckInit(dev);		if(eraseDisplayEnabled)	{		printf("Erasing block %d\n",blockInNAND);	}		lseek(h,blockInNAND * BLOCK_SIZE,SEEK_SET);	for(i = 0; i < 32; i++)	{		write(h,ffChunk,528);	}		switch(blockInNAND)	{		case 10: 		case 15: return YAFFS_FAIL;			}	return YAFFS_OK;}int yaffs_FEInitialiseNAND(yaffs_Device *dev){	return YAFFS_OK;}