--- /dev/null
+/*
+ * 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 General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <string.h>
+#include <stdio.h>
+#include "yaffs_guts.h"
+
+const char *yboot_c_version="$Id: yboot.c,v 1.1 2003-01-21 03:32:17 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 data
+void 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 finds
+static 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;
+}
+
+
+
+
projects / yaffs / .git / blobdiff