/* * YAFFS: Yet another FFS. A NAND-flash specific file system. * yboot: A yaffs bootloader. * * 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 Lesser General Public License version 2.1 as * published by the Free Software Foundation. * * * Note: This code (yboot.c) and YAFFS headers are LGPL, the rest of YAFFS C code is covered by GPL. *       The rationale behind this is to allow easy incorporation of yaffs booting with  *       prorietary code. * */#include <string.h>#include <stdio.h>#include "yaffs_guts.h"const char *yboot_c_version="$Id: yboot.c,v 1.2 2005/07/19 19:51:57 charles Exp $";#define MAX_FILE_SIZE	4000000#define MAX_CHUNKS	(MAX_FILE_SIZE/YAFFS_BYTES_PER_CHUNK + 1)static int chunkLocations[MAX_CHUNKS];// External functions for ECC on datavoid nand_calculate_ecc (const unsigned char*dat, unsigned char*ecc_code);int nand_correct_data (unsigned char*dat, unsigned char*read_ecc, unsigned char*calc_ecc);static const char yaffs_countBits[256] ={0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,4,5,5,6,5,6,6,7,5,6,6,7,6,7,7,8};static void spareToTags(yaffs_Spare *spare, yaffs_Tags *tag){	unsigned char *bytes = (char *)tag;	bytes[0] = spare->tagByte0;	bytes[1] = spare->tagByte1;	bytes[2] = spare->tagByte2;	bytes[3] = spare->tagByte3;	bytes[4] = spare->tagByte4;	bytes[5] = spare->tagByte5;	bytes[6] = spare->tagByte6;	bytes[7] = spare->tagByte7;}// yboot_ScanForFile findsstatic int yaffsboot_ScanForFile(yaffs_Device *dev, const char *fileName){	int pg;	int blk;	yaffs_ObjectHeader data;	yaffs_Spare spare;	yaffs_Tags tags;	if (!fileName)	{		//printf("NULL filename\n");		return -1;	}	//printf("Searching block range %d to %d for %s\n", dev->startBlock, dev->endBlock, fileName);	for (blk = dev->startBlock; blk < dev->endBlock; blk++)	{			for (pg = 0; pg < YAFFS_CHUNKS_PER_BLOCK; pg++)		{			dev->readChunkFromNAND(dev, (blk*YAFFS_CHUNKS_PER_BLOCK) + pg, (__u8 *)&data, (yaffs_Spare *)&spare);			if (yaffs_countBits[spare.blockStatus] >=7 && // block OK				yaffs_countBits[spare.pageStatus] >= 7)   // page ok			{				spareToTags(&spare, &tags);								if ( tags.chunkId == 0 &&  // it's a header				     data.parentObjectId == YAFFS_OBJECTID_ROOT && // it's in the root				     strcmp(data.name, fileName) == 0 // name matches				)				{					//printf("%s found at chunk %x objectId is %x\n", fileName, blk* YAFFS_PAGES_PER_BLOCK + pg, tag.objectId);										return tags.objectId;				}			}		}	}	// Sad day... not found.	// printf("%s not found\n",filename);	return -1;}static unsigned char bufferData[YAFFS_BYTES_PER_CHUNK];static int bufferPos = 0;static int bufferChunk = 0;static int bufferInitialised = 0;static int bufferLength = 0;static yaffs_Device *bufferDevice;static int chunkEnd = -1;static int topChunk = -1;static int fileSize = -1;int yaffsboot_InitFile(yaffs_Device *dev, const char *fileName,int *loadedFileSize){	yaffs_Spare spare;	yaffs_Tags  tags;	int fileObjId;	int i;		int blk;	int pg;	int missing;	int chunksMissing = 0;	bufferDevice = dev;			fileObjId = yaffsboot_ScanForFile(dev,fileName);	if(fileObjId < 0)	{		return -1;	}		//printf("Gathering chunks...\n");		for (i = 0; i < MAX_CHUNKS; i++)	{		chunkLocations[i] = -1;	}	for (blk = dev->startBlock; blk <= dev->endBlock; blk++)	{		for (pg = 0; pg < YAFFS_CHUNKS_PER_BLOCK; pg++)		{			dev->readChunkFromNAND(dev, blk * YAFFS_CHUNKS_PER_BLOCK + pg, NULL, &spare);			if (yaffs_countBits[spare.blockStatus] >= 7 &&			    yaffs_countBits[spare.pageStatus] >= 7)			{				spareToTags(&spare, &tags);				if (tags.objectId == fileObjId && tags.chunkId > 0)				{					if(tags.chunkId >= MAX_CHUNKS)					{						printf("Chunk %d out of bounds (max is %d)\n",tags.chunkId, MAX_CHUNKS - 1);						return -1;					}					chunkLocations[tags.chunkId] = (blk*32) + pg;										chunkEnd = (tags.chunkId -1) * YAFFS_BYTES_PER_CHUNK + tags.byteCount;										if(chunkEnd > fileSize) fileSize = chunkEnd;    										if(tags.chunkId > topChunk) topChunk = tags.chunkId;				}			}		}	}	for (missing= 0, i= 1; i<= topChunk; i++)	{		if (chunkLocations[i] < 0)		{			//printf("chunk %x missing\n",i);			chunksMissing++;		}	}	*loadedFileSize = fileSize;		return fileObjId;}int yaffsboot_Reinitialise(void){	bufferInitialised = 0;	return 0;}int yaffsboot_ReadByte(unsigned char *bPtr){	if(!bufferInitialised)	{		//printf("Read buffer initialisation\n");		bufferInitialised = 1;		bufferChunk = 0;		bufferLength = 0;		bufferPos = -1;	}	if(bufferPos < 0)	{		bufferChunk++;		if(bufferChunk> topChunk)		{			printf("Chunk %d past end of file\r\n",bufferChunk);			return -1;		}		if (chunkLocations[bufferChunk] < 0)		{				printf("No chunk %d, zero page\n",bufferChunk);				memset(bufferData,0,YAFFS_BYTES_PER_CHUNK);				bufferLength = YAFFS_BYTES_PER_CHUNK;		}		else		{			yaffs_Spare localSpare;			yaffs_Tags tags;			__u8 calcEcc[3];			bufferDevice->readChunkFromNAND(bufferDevice, chunkLocations[bufferChunk], bufferData, &localSpare);			spareToTags(&localSpare, &tags);			if(0 && bufferChunk <topChunk)			{				bufferLength = YAFFS_BYTES_PER_CHUNK;			}			else			{				bufferLength = tags.byteCount;			}			//printf("Read chunk %d, size %d bytes\n",bufferChunk,bufferLength);			nand_calculate_ecc(bufferData,calcEcc);			nand_correct_data (bufferData,localSpare.ecc1, calcEcc);			nand_calculate_ecc(&bufferData[256],calcEcc);			nand_correct_data (&bufferData[256],localSpare.ecc2, calcEcc);		}		bufferPos = 0;		if(bufferLength <= bufferPos)		{			return -1;		}	}	*bPtr = bufferData[bufferPos];	bufferPos++;	if(bufferPos >= bufferLength)	{		//printf("End of page %d at byte %d\r\n",bufferChunk,bufferLength);		bufferPos = -1;	}	return 0;}