/* * 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 YAFFS nand emulation on a file.// THis is only intended as test code to test persistence etc.const char *yaffs_flashif_c_version = "$Id: yaffs_fileem.c,v 1.1 2003/01/21 03:32:17 charles Exp $";#include "yportenv.h"#include "yaffs_flashif.h"#include "yaffs_guts.h"#include "devextras.h"#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <unistd.h> #define SIZE_IN_MB 16#define BLOCK_SIZE (32 * 528)#define BLOCKS_PER_MEG ((1024*1024)/(32 * 512))typedef struct {	__u8 data[528]; // Data + spare} yflash_Page;typedef struct{	yflash_Page page[32]; // The pages in the block	} yflash_Block;typedef struct{	int handle;	int nBlocks;} yflash_Device;static yflash_Device filedisk;static int  CheckInit(yaffs_Device *dev){	static int initialised = 0;		int i;		int fSize;	int written;		yflash_Page p;		if(initialised) 	{		return YAFFS_OK;	}	initialised = 1;			filedisk.nBlocks = (SIZE_IN_MB * 1024 * 1024)/(16 * 1024);		filedisk.handle = open("yaffsemfile", O_RDWR | O_CREAT, S_IREAD | S_IWRITE);		if(filedisk.handle < 0)	{		perror("Failed to open yaffs emulation file");		return YAFFS_FAIL;	}			fSize = lseek(filedisk.handle,0,SEEK_END);		if(fSize < SIZE_IN_MB * 1024 * 1024)	{		printf("Creating yaffs emulation file\n");				lseek(filedisk.handle,0,SEEK_SET);				memset(&p,0xff,sizeof(yflash_Page));				for(i = 0; i < SIZE_IN_MB * 1024 * 1024; i+= 512)		{			written = write(filedisk.handle,&p,sizeof(yflash_Page));						if(written != sizeof(yflash_Page))			{				printf("Write failed\n");				return YAFFS_FAIL;			}		}			}		return 1;}int yflash_WriteChunkToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_Spare *spare){	int written;	CheckInit(dev);				if(data)	{		lseek(filedisk.handle,chunkInNAND * 528,SEEK_SET);		written = write(filedisk.handle,data,512);				if(written != 512) return YAFFS_FAIL;	}		if(spare)	{		lseek(filedisk.handle,chunkInNAND * 528 + 512,SEEK_SET);		written = write(filedisk.handle,spare,16);				if(written != 16) return YAFFS_FAIL;	}		return YAFFS_OK;	}int yflash_ReadChunkFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare){	int nread;	CheckInit(dev);				if(data)	{		lseek(filedisk.handle,chunkInNAND * 528,SEEK_SET);		nread = read(filedisk.handle,data,512);				if(nread != 512) return YAFFS_FAIL;	}		if(spare)	{		lseek(filedisk.handle,chunkInNAND * 528 + 512,SEEK_SET);		nread= read(filedisk.handle,spare,16);				if(nread != 16) return YAFFS_FAIL;	}		return YAFFS_OK;	}int yflash_EraseBlockInNAND(yaffs_Device *dev, int blockNumber){	int i;			CheckInit(dev);		if(blockNumber < 0 || blockNumber >= filedisk.nBlocks)	{		T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));		return YAFFS_FAIL;	}	else	{			yflash_Page pg;				memset(&pg,0xff,sizeof(yflash_Page));				lseek(filedisk.handle, blockNumber * 32 * 528, SEEK_SET);				for(i = 0; i < 32; i++)		{			write(filedisk.handle,&pg,528);		}		return YAFFS_OK;	}	}int yflash_InitialiseNAND(yaffs_Device *dev){	dev->useNANDECC = 1; // force on useNANDECC which gets faked. 						 // This saves us doing ECC checks.		return YAFFS_OK;}