/* * YAFFS: Yet another FFS. A NAND-flash specific file system.  * yaffs_ramem.c  NAND emulation on top of a chunk of RAM * * 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_ramem.c // Since this creates the RAM block at start up it is pretty useless for testing the scanner.const char *yaffs_ramem_c_version = "$Id: yaffs_ramem.c,v 1.6 2002/11/26 01:15:37 charles Exp $";#ifndef __KERNEL__#define CONFIG_YAFFS_RAM_ENABLED#endif#ifdef CONFIG_YAFFS_RAM_ENABLED#include "yportenv.h"#include "yaffs_nandemul.h"#include "yaffs_guts.h"#include "yaffsinterface.h"#include "devextras.h"#define EM_SIZE_IN_MEG 2#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)#define DEFAULT_SIZE_IN_MB 2typedef struct {	__u8 data[528]; // Data + spare	int count[3];   // The programming count for each area of			// the page (0..255,256..511,512..527	int empty;      // is this empty?} nandemul_Page;typedef struct{	nandemul_Page page[32]; // The pages in the block	__u8 damaged; 		// Is the block damaged?	} nandemul_Block;typedef struct{	nandemul_Block **block;	int nBlocks;} nandemul_Device;static nandemul_Device ned;int sizeInMB = DEFAULT_SIZE_IN_MB;static void nandemul_yield(int n){#ifdef __KERNEL__	if(n > 0) schedule_timeout(n);#endif}static void nandemul_ReallyEraseBlock(int blockNumber){	int i;		nandemul_Block *theBlock = ned.block[blockNumber];		for(i = 0; i < 32; i++)	{		memset(theBlock->page[i].data,0xff,528);		theBlock->page[i].count[0] = 0;		theBlock->page[i].count[1] = 0;		theBlock->page[i].count[2] = 0;		theBlock->page[i].empty = 1;		nandemul_yield(2);	}}int nandemul_CalcNBlocks(void){        switch(sizeInMB)        {        	case 8:        	case 16:        	case 32:        	case 64:        	case 128:        	case 256:        	case 512:        		break;        	default:        		sizeInMB = DEFAULT_SIZE_IN_MB;        }	return sizeInMB * 64;}static int  CheckInit(void){	static int initialised = 0;		int i;	int fail = 0;	int nBlocks; 	int nAllocated = 0;		if(initialised) 	{		return YAFFS_OK;	}			nBlocks = nandemul_CalcNBlocks();		ned.block = YMALLOC(sizeof(nandemul_Block *) * nBlocks);		if(!ned.block) return 0;		for(i=0; i <nBlocks; i++)	{		ned.block[i] = NULL;	}		for(i=0; i <nBlocks && !fail; i++)	{		if((ned.block[i] = YMALLOC(sizeof(nandemul_Block))) == 0)		{			fail = 1;		}		else		{			nandemul_ReallyEraseBlock(i);			ned.block[i]->damaged = 0;			nAllocated++;		}	}		if(fail)	{		for(i = 0; i < nAllocated; i++)		{			YFREE(ned.block[i]);		}		YFREE(ned.block);				T(YAFFS_TRACE_ALWAYS,("Allocation failed, could only allocate %dMB of %dMB requested.\n",		   nAllocated/64,sizeInMB));		return 0;	}		ned.nBlocks = nBlocks;		initialised = 1;		return 1;}int nandemul_WriteChunkToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_Spare *spare){	int blk;	int pg;	int i;		__u8 *x;		__u8 *spareAsBytes = (__u8 *)spare;		CheckInit();		blk = chunkInNAND/32;	pg = chunkInNAND%32;			if(data)	{		x = ned.block[blk]->page[pg].data;				for(i = 0; i < 512; i++)		{			x[i] &=data[i];		}				ned.block[blk]->page[pg].count[0]++;		ned.block[blk]->page[pg].count[1]++;		ned.block[blk]->page[pg].empty = 0;	}			if(spare)	{		x = &ned.block[blk]->page[pg].data[512];					for(i = 0; i < 16; i++)		{			x[i] &=spareAsBytes[i];		}		ned.block[blk]->page[pg].count[2]++;	}		if(spare || data)	{		nandemul_yield(1);	}	return YAFFS_OK;}int nandemul_ReadChunkFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare){	int blk;	int pg;		CheckInit();		blk = chunkInNAND/32;	pg = chunkInNAND%32;			if(data)	{		memcpy(data,ned.block[blk]->page[pg].data,512);	}			if(spare)	{		memcpy(spare,&ned.block[blk]->page[pg].data[512],16);	}	return YAFFS_OK;}int nandemul_CheckChunkErased(yaffs_Device *dev,int chunkInNAND){	int blk;	int pg;	int i;		CheckInit();		blk = chunkInNAND/32;	pg = chunkInNAND%32;			for(i = 0; i < 528; i++)	{		if(ned.block[blk]->page[pg].data[i] != 0xFF)		{			return YAFFS_FAIL;		}	}	return YAFFS_OK;}int nandemul_EraseBlockInNAND(yaffs_Device *dev, int blockNumber){		CheckInit();		if(blockNumber < 0 || blockNumber >= ned.nBlocks)	{		T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));	}	else if(ned.block[blockNumber]->damaged)	{		T(YAFFS_TRACE_ALWAYS,("Attempt to erase damaged block %d\n",blockNumber));	}	else	{		nandemul_ReallyEraseBlock(blockNumber);	}		return YAFFS_OK;}int nandemul_InitialiseNAND(yaffs_Device *dev){	return YAFFS_OK;}#endif //YAFFS_RAM_ENABLED