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分类： 嵌入式
2014-08-15 00:02:22
终于可以成功制作页大小为2K + 64 Bytes 的nand flash的image 文件了。令人兴奋啊 ：)
这两天一直苦于自己制作的yaffs2 image文件系统无法被linux-2.6.29.1内核识别，而使用FriendlyARM的mkyaffs2imag-128M工具就没有这个问题。一开始便判断是mkyaffs2image工具有问题，没有生成正确格式的yaffs2 image文件，从而导致内核无法识别，并抛出以下错误信息：
----------------------------------------------------------------------------------------------------------------
……
block 155 is bad
yaffs_read_super: isCheckpointed 0
VFS: Mounted root (yaffs filesystem) readonly on device 31:2.
Freeing init memory: 164K
Warning: unable to open an initial console.
Failed to execute /linuxrc. Attempting defaults...
Kernel panic - not syncing: No init found. Try passing init= option to kernel.
----------------------------------------------------------------------------------------------------------------
网上查了很多相关的资料，对2K data + 64bytes spare 的nand flash上yaffs2文件的存储格式并没有较为清晰的说明。不知道数据的存储模式，就无法正确生成image文件。苦恼了好几天，甚至有些想放弃了。。。
然而今天得到了一个意外的收获，上大概阐述了2K yaffs2 nand flash中数据的组织形式(虽然后来发现该文章中关于结构yaffs2_PackedTags的大小表述有错，应该是28字节，而非25字节)，经过修改后，并且纠正相关bug，成功生成正确的yaffs2 image 文件，download进s3c2440开发板后，顺利启动系统。
有一点很重要，就是mkyaffs2image生成的image 文件的OOB区数据格式要与linux kernel对nand flash进行读取时的数据格式保持一致，所以mkyaffs2image.c中来自linux kernel的数据结构，即包含了mtd-abi.h头文件。
PS：下面本人会附上mkyaffs2image.c的全部内容，供朋友们参考，希望给meet with同样error的兄弟们一些帮助：)
PART2 About 64bytes OOB
下图为64bytes OOB区中的数据组织结构：
图1 64bytes OOB area
PS：
1) OOB最前端的2bytes为0xFF 0xFF，用于标识为非坏块。
2) 每256bytes的数据需要3bytes有ECC校验，因此2K的数据需要24bytes的ECC。
以下为经过修改过后的mkyaffs2image.c的源码：
/*
* YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
*
* Copyright (C) 2002-2007 Aleph One Ltd.
* for Toby Churchill Ltd and Brightstar Engineering
*
* Created by Charles Manning <>
* Nick Bane modifications flagged NCB
* Endian handling patches by James Ng.
* mkyaffs2image hacks by NCB
*
* 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.
*/
/*
* makeyaffs2image.c
*
* Makes a YAFFS2 file system image that can be used to load up a file system.
* Uses default Linux MTD layout - change if you need something different.
*/
#include
#include
#include
#include
#include
#include
#include
#include
#define __user
#include
#include "yaffs_ecc.h"
#include "yaffs_guts.h"
#include "yaffs_packedtags2.h"
#include "mtd-abi.h" //ADDED BY LIUHAO 2009-11-11
unsigned yaffs_traceMask=0;
#define MAX_OBJECTS 10000
#define chunkSize 2048
#define spareSize 64
//MODIFIED BY LIUHAO 2009-11-11 START
//#define PT2_BYTES 25 //Original
#define PT2_BYTES 28
//MODIFIED BY LIUHAO 2009-11-11 END
const char * mkyaffsimage_c_version = "$Id: mkyaffs2image.c,v 1.4 2007-02-14 01:09:06 wookey Exp $";
static int layout_no;
static struct nand_oobinfo oob_layout[] = {
/* KSI:
* Dummy "raw" layout - no ECC, all the bytes are free. Does NOT
* really work, only used for compatibility with CVS YAFFS2 that
* never ever worked with any stock MTD.
*/
{
.useecc = MTD_NANDECC_AUTOPLACE,
.eccbytes = 0,
.eccpos = {},
.oobfree = { {0, 64} }
},
/* KSI:
* Regular MTD AUTOPLACED ECC for large page NAND devices, the
* only one existing in stock MTD so far. It corresponds to layout# 1
* in command line arguments. Any other layouts could be added to
* the list when they made their way in kernel's MTD. The structure
* is simply copied from kernel's drivers/mtd/nand/nand_base.c as-is.
*/
{
.useecc = MTD_NANDECC_AUTOPLACE,
.eccbytes = 24,
.eccpos = {
40, 41, 42, 43, 44, 45, 46, 47,
48, 49, 50, 51, 52, 53, 54, 55,
56, 57, 58, 59, 60, 61, 62, 63},
.oobfree = { {2, 38} }
},
/* End-of-list marker */
{
.useecc = -1,
}
};
typedef struct {
dev_t dev;
ino_t ino;
int obj;
} objItem;
static objItem obj_list[MAX_OBJECTS];
static int n_obj = 0;
static int obj_id = YAFFS_NOBJECT_BUCKETS + 1;
static int nObjects = 0, nDirectories = 0, nPages = 0;
static int outFile;
static int error;
static int convert_endian = 0;
static int obj_compare(const void *a, const void * b)
{
objItem *oa, *ob;
oa = (objItem *)a;
ob = (objItem *)b;
if(oa->dev < ob->dev) return -1;
if(oa->dev > ob->dev) return 1;
if(oa->ino < ob->ino) return -1;
if(oa->ino > ob->ino) return 1;
return 0;
}
static void add_obj_to_list(dev_t dev, ino_t ino, int obj)
{
if(n_obj < MAX_OBJECTS)
{
obj_list[n_obj].dev = dev;
obj_list[n_obj].ino = ino;
obj_list[n_obj].obj = obj;
n_obj++;
qsort(obj_list,n_obj,sizeof(objItem),obj_compare);
}
else
{
// oops! not enough space in the object array
fprintf(stderr,"Not enough space in object array/n");
exit(2);
}
}
static int find_obj_in_list(dev_t dev, ino_t ino)
{
objItem *i = NULL;
objItem test;
test.dev = dev;
test.ino = ino;
if(n_obj > 0)
{
i = bsearch(&test,obj_list,n_obj,sizeof(objItem),obj_compare);
}
if(i)
{
return i->obj;
}
return -1;
}
static void yaffs_PutDataECC(const __u8 * data, unsigned char *oob_buf)
{
unsigned char ecc_code[3];
int eccsteps = chunkSize / 256;
int eccidx = 0, datidx = 0, i;
struct nand_oobinfo *oobsel;
__u32 *oob_config;
oobsel = &oob_layout[layout_no];
oob_config = oobsel->eccpos; //LIUHAO: 24bytes的ECC在spare area中的位置
for (; eccsteps; eccsteps--) {
yaffs_ECCCalculate (&data[datidx], ecc_code);
for (i = 0; i < 3; i++, eccidx++)
oob_buf[oob_config[eccidx]] = ecc_code[i];
datidx += 256;
}
}
/* KSI:
* No big endian for now. This is left for a later time. The existing code
* is FUBAR.
*/
#if 0
/* This little function converts a little endian tag to a big endian tag.
* NOTE: The tag is not usable after this other than calculating the CRC
* with.
*/
static void little_to_big_endian(yaffs_Tags *tagsPtr)
{
#if 0 // FIXME NCB
yaffs_TagsUnion * tags = (yaffs_TagsUnion* )tagsPtr; // Work in bytes.
yaffs_TagsUnion temp;
memset(&temp, 0, sizeof(temp));
// Ick, I hate magic numbers.
temp.asBytes[0] = ((tags->asBytes[2] & 0x0F) << 4) | ((tags->asBytes[1] & 0xF0) >> 4);
temp.asBytes[1] = ((tags->asBytes[1] & 0x0F) << 4) | ((tags->asBytes[0] & 0xF0) >> 4);
temp.asBytes[2] = ((tags->asBytes[0] & 0x0F) << 4) | ((tags->asBytes[2] & 0x30) >> 2) | ((tags->asBytes[3] & 0xC0) >> 6);
temp.asBytes[3] = ((tags->asBytes[3] & 0x3F) << 2) | ((tags->asBytes[2] & 0xC0) >> 6);
temp.asBytes[4] = ((tags->asBytes[6] & 0x03) << 6) | ((tags->asBytes[5] & 0xFC) >> 2);
temp.asBytes[5] = ((tags->asBytes[5] & 0x03) << 6) | ((tags->asBytes[4] & 0xFC) >> 2);
temp.asBytes[6] = ((tags->asBytes[4] & 0x03) << 6) | (tags->asBytes[7] & 0x3F);
temp.asBytes[7] = (tags->asBytes[6] & 0xFC) | ((tags->asBytes[7] & 0xC0) >> 6);
// Now copy it back.
tags->asBytes[0] = temp.asBytes[0];
tags->asBytes[1] = temp.asBytes[1];
tags->asBytes[2] = temp.asBytes[2];
tags->asBytes[3] = temp.asBytes[3];
tags->asBytes[4] = temp.asBytes[4];
tags->asBytes[5] = temp.asBytes[5];
tags->asBytes[6] = temp.asBytes[6];
tags->asBytes[7] = temp.asBytes[7];
#endif
}
#endif
static void nandmtd2_pt2buf(unsigned char *buf, yaffs_PackedTags2 *pt)
{
int i, j = 0, k, n;
//MODIFIED BY LIUHAO 2009-11-11
//unsigned char pt2_byte_buf[PT2_BYTES]; //Original
unsigned char pt2_byte_buf[PT2_BYTES] = {0};
*((unsigned int *) &pt2_byte_buf[0]) = pt->t.sequenceNumber;
*((unsigned int *) &pt2_byte_buf[4]) = pt->t.objectId;
*((unsigned int *) &pt2_byte_buf[8]) = pt->t.chunkId;
*((unsigned int *) &pt2_byte_buf[12]) = pt->t.byteCount;
pt2_byte_buf[16] = pt->ecc.colParity;
//MODIFIED BY LIUHAO 2009-11-11 START
#if 0
//Original
pt2_byte_buf[17] = pt->ecc.lineParity & 0xff;
pt2_byte_buf[18] = (pt->ecc.lineParity >> 8) & 0xff;
pt2_byte_buf[19] = (pt->ecc.lineParity >> 16) & 0xff;
pt2_byte_buf[20] = (pt->ecc.lineParity >> 24) & 0xff;
pt2_byte_buf[21] = pt->ecc.lineParityPrime & 0xff;
pt2_byte_buf[22] = (pt->ecc.lineParityPrime >> 8) & 0xff;
pt2_byte_buf[23] = (pt->ecc.lineParityPrime >> 16) & 0xff;
pt2_byte_buf[24] = (pt->ecc.lineParityPrime >> 24) & 0xff;
#else
pt2_byte_buf[20] = pt->ecc.lineParity & 0xff;
pt2_byte_buf[21] = (pt->ecc.lineParity >> 8) & 0xff;
pt2_byte_buf[22] = (pt->ecc.lineParity >> 16) & 0xff;
pt2_byte_buf[23] = (pt->ecc.lineParity >> 24) & 0xff;
pt2_byte_buf[24] = pt->ecc.lineParityPrime & 0xff;
pt2_byte_buf[25] = (pt->ecc.lineParityPrime >> 8) & 0xff;
pt2_byte_buf[26] = (pt->ecc.lineParityPrime >> 16) & 0xff;
pt2_byte_buf[27] = (pt->ecc.lineParityPrime >> 24) & 0xff;
#endif
k = oob_layout[layout_no].oobfree[j][0];
n = oob_layout[layout_no].oobfree[j][1];
if (n == 0) {
fprintf(stderr, "No OOB space for tags");
exit(-1);
}
for (i = 0; i < PT2_BYTES; i++) {
if (n == 0) {
j++;
k = oob_layout[layout_no].oobfree[j][0];
n = oob_layout[layout_no].oobfree[j][1];
if (n == 0) {
fprintf(stderr, "No OOB space for tags");
exit(-1);
}
}
buf[k++] = pt2_byte_buf[i];
n--;
}
}
static int write_chunk(__u8 *data, __u32 objId, __u32 chunkId, __u32 nBytes)
{
yaffs_ExtendedTags t;
yaffs_PackedTags2 pt;
yaffs_PackedTags2TagsPart ptt; //ADDED BY LIUHAO 2009-11-11
//ADDED BY LIUHAO 2009-11-11
//unsigned char spare_buf[spareSize]; //Original
unsigned char spare_buf[spareSize] = {0};
error = write(outFile,data,chunkSize);
if(error < 0) return error;
yaffs_InitialiseTags(&t);
t.chunkId = chunkId;
// t.serialNumber = 0;
t.serialNumber = 1; // **CHECK**
t.byteCount = nBytes;
t.objectId = objId;
t.sequenceNumber = YAFFS_LOWEST_SEQUENCE_NUMBER;
// added NCB **CHECK**
t.chunkUsed = 1;
//ADDED BY LIUHAO 2009-11-11
//t.extraHeaderInfoAvailable = 1;
/* KSI: Broken anyway -- e.g. &t is pointer to a wrong type... */
#if 0
if (convert_endian)
{
little_to_big_endian(&t);
}
#endif
//MODIFIED BY LIUHAO 2009-11-11 START
#if 0
yaffs_PackTags2(&pt,&t); //Original
#else
memset(&pt, 0, sizeof(yaffs_PackedTags2));
yaffs_PackTags2TagsPart(&pt.t,&t);
yaffs_ECCCalculateOther(
(unsigned char *)&pt.t,
sizeof(yaffs_PackedTags2TagsPart),
&pt.ecc);
#endif
//MODIFIED BY LIUHAO 2009-11-11 END
memset(spare_buf, 0xff, sizeof(spare_buf));
if (layout_no == 0) {
memcpy(spare_buf, &pt, sizeof(yaffs_PackedTags2));
} else {
nandmtd2_pt2buf(spare_buf, &pt);
}
yaffs_PutDataECC(data, &spare_buf[0]);
nPages++;
return write(outFile,spare_buf,spareSize);
}
#define SWAP32(x) ((((x) & 0x000000FF) << 24) | /
(((x) & 0x0000FF00) << 8 ) | /
(((x) & 0x00FF0000) >> 8 ) | /
(((x) & 0xFF000000) >> 24))
#define SWAP16(x) ((((x) & 0x00FF) << 8) | /
(((x) & 0xFF00) >> 8))
/* KSI: Removed for now. TBD later when the proper util (from scratch) is written */
#if 0
// This one is easier, since the types are more standard. No funky shifts here.
static void object_header_little_to_big_endian(yaffs_ObjectHeader* oh)
{
oh->type = SWAP32(oh->type); // GCC makes enums 32 bits.
oh->parentObjectId = SWAP32(oh->parentObjectId); // int
oh->sum__NoLongerUsed = SWAP16(oh->sum__NoLongerUsed); // __u16 - Not used, but done for completeness.
// name = skip. Char array. Not swapped.
oh->yst_mode = SWAP32(oh->yst_mode);
#ifdef CONFIG_YAFFS_WINCE // WinCE doesn't implement this, but we need to just in case.
// In fact, WinCE would be *THE* place where this would be an issue!
oh->notForWinCE[0] = SWAP32(oh->notForWinCE[0]);
oh->notForWinCE[1] = SWAP32(oh->notForWinCE[1]);
oh->notForWinCE[2] = SWAP32(oh->notForWinCE[2]);
oh->notForWinCE[3] = SWAP32(oh->notForWinCE[3]);
oh->notForWinCE[4] = SWAP32(oh->notForWinCE[4]);
#else
// Regular POSIX.
oh->yst_uid = SWAP32(oh->yst_uid);
oh->yst_gid = SWAP32(oh->yst_gid);
oh->yst_atime = SWAP32(oh->yst_atime);
oh->yst_mtime = SWAP32(oh->yst_mtime);
oh->yst_ctime = SWAP32(oh->yst_ctime);
#endif
oh->fileSize = SWAP32(oh->fileSize); // Aiee. An int... signed, at that!
oh->equivalentObjectId = SWAP32(oh->equivalentObjectId);
// alias - char array.
oh->yst_rdev = SWAP32(oh->yst_rdev);
#ifdef CONFIG_YAFFS_WINCE
oh->win_ctime[0] = SWAP32(oh->win_ctime[0]);
oh->win_ctime[1] = SWAP32(oh->win_ctime[1]);
oh->win_atime[0] = SWAP32(oh->win_atime[0]);
oh->win_atime[1] = SWAP32(oh->win_atime[1]);
oh->win_mtime[0] = SWAP32(oh->win_mtime[0]);
oh->win_mtime[1] = SWAP32(oh->win_mtime[1]);
oh->roomToGrow[0] = SWAP32(oh->roomToGrow[0]);
oh->roomToGrow[1] = SWAP32(oh->roomToGrow[1]);
oh->roomToGrow[2] = SWAP32(oh->roomToGrow[2]);
oh->roomToGrow[3] = SWAP32(oh->roomToGrow[3]);
oh->roomToGrow[4] = SWAP32(oh->roomToGrow[4]);
oh->roomToGrow[5] = SWAP32(oh->roomToGrow[5]);
#else
oh->roomToGrow[0] = SWAP32(oh->roomToGrow[0]);
oh->roomToGrow[1] = SWAP32(oh->roomToGrow[1]);
oh->roomToGrow[2] = SWAP32(oh->roomToGrow[2]);
oh->roomToGrow[3] = SWAP32(oh->roomToGrow[3]);
oh->roomToGrow[4] = SWAP32(oh->roomToGrow[4]);
oh->roomToGrow[5] = SWAP32(oh->roomToGrow[5]);
oh->roomToGrow[6] = SWAP32(oh->roomToGrow[6]);
oh->roomToGrow[7] = SWAP32(oh->roomToGrow[7]);
oh->roomToGrow[8] = SWAP32(oh->roomToGrow[8]);
oh->roomToGrow[9] = SWAP32(oh->roomToGrow[9]);
oh->roomToGrow[10] = SWAP32(oh->roomToGrow[10]);
oh->roomToGrow[11] = SWAP32(oh->roomToGrow[11]);
#endif
}
#endif
static int write_object_header(int objId, yaffs_ObjectType t, struct stat *s, int parent, const char *name, int equivalentObj, const char * alias)
{
__u8 bytes[chunkSize];
yaffs_ObjectHeader *oh = (yaffs_ObjectHeader *)bytes;
memset(bytes,0xff,sizeof(bytes));
oh->type = t;
oh->parentObjectId = parent;
strncpy(oh->name,name,YAFFS_MAX_NAME_LENGTH);
if(t != YAFFS_OBJECT_TYPE_HARDLINK)
{
oh->yst_mode = s->st_mode;
oh->yst_uid = s->st_uid;
// NCB 12/9/02 oh->yst_gid = s->yst_uid;
oh->yst_gid = s->st_gid;
oh->yst_atime = s->st_atime;
oh->yst_mtime = s->st_mtime;
oh->yst_ctime = s->st_ctime;
oh->yst_rdev = s->st_rdev;
}
if(t == YAFFS_OBJECT_TYPE_FILE)
{
oh->fileSize = s->st_size;
}
if(t == YAFFS_OBJECT_TYPE_HARDLINK)
{
oh->equivalentObjectId = equivalentObj;
}
if(t == YAFFS_OBJECT_TYPE_SYMLINK)
{
strncpy(oh->alias,alias,YAFFS_MAX_ALIAS_LENGTH);
}
/* KSI: FUBAR. Left for a leter time. */
#if 0
if (convert_endian)
{
object_header_little_to_big_endian(oh);
}
#endif
return write_chunk(bytes,objId,0,0xffff);
}
static int process_directory(int parent, const char *path)
{
DIR *dir;
struct dirent *entry;
nDirectories++;
dir = opendir(path);
if(dir)
{
while((entry = readdir(dir)) != NULL)
{
/* Ignore . and .. */
if(strcmp(entry->d_name,".") &&
strcmp(entry->d_name,".."))
{
char full_name[500];
struct stat stats;
int equivalentObj;
int newObj;
sprintf(full_name,"%s/%s",path,entry->d_name);
lstat(full_name,&stats);
if(S_ISLNK(stats.st_mode) ||
S_ISREG(stats.st_mode) ||
S_ISDIR(stats.st_mode) ||
S_ISFIFO(stats.st_mode) ||
S_ISBLK(stats.st_mode) ||
S_ISCHR(stats.st_mode) ||
S_ISSOCK(stats.st_mode))
{
newObj = obj_id++;
nObjects++;
printf("Object %d, %s is a ",newObj,full_name);
/* We're going to create an object for it */
if((equivalentObj = find_obj_in_list(stats.st_dev, stats.st_ino)) > 0)
{
/* we need to make a hard link */
printf("hard link to object %d/n",equivalentObj);
error = write_object_header(newObj, YAFFS_OBJECT_TYPE_HARDLINK, &stats, parent, entry->d_name, equivalentObj, NULL);
}
else
{
add_obj_to_list(stats.st_dev,stats.st_ino,newObj);
if(S_ISLNK(stats.st_mode))
{
char symname[500];
memset(symname,0, sizeof(symname));
readlink(full_name,symname,sizeof(symname) -1);
printf("symlink to /"%s/"/n",symname);
error = write_object_header(newObj, YAFFS_OBJECT_TYPE_SYMLINK, &stats, parent, entry->d_name, -1, symname);
}
else if(S_ISREG(stats.st_mode))
{
printf("file, ");
error = write_object_header(newObj, YAFFS_OBJECT_TYPE_FILE, &stats, parent, entry->d_name, -1, NULL);
if(error >= 0)
{
int h;
__u8 bytes[chunkSize];
int nBytes;
int chunk = 0;
h = open(full_name,O_RDONLY);
if(h >= 0)
{
memset(bytes,0xff,sizeof(bytes));
while((nBytes = read(h,bytes,sizeof(bytes))) > 0)
{
chunk++;
write_chunk(bytes,newObj,chunk,nBytes);
memset(bytes,0xff,sizeof(bytes));
}
if(nBytes < 0)
error = nBytes;
printf("%d data chunks written/n",chunk);
close(h);
}
else
{
perror("Error opening file");
}
}
}
else if(S_ISSOCK(stats.st_mode))
{
printf("socket/n");
error = write_object_header(newObj, YAFFS_OBJECT_TYPE_SPECIAL, &stats, parent, entry->d_name, -1, NULL);
}
else if(S_ISFIFO(stats.st_mode))
{
printf("fifo/n");
error = write_object_header(newObj, YAFFS_OBJECT_TYPE_SPECIAL, &stats, parent, entry->d_name, -1, NULL);
}
else if(S_ISCHR(stats.st_mode))
{
printf("character device/n");
error = write_object_header(newObj, YAFFS_OBJECT_TYPE_SPECIAL, &stats, parent, entry->d_name, -1, NULL);
}
else if(S_ISBLK(stats.st_mode))
{
printf("block device/n");
error = write_object_header(newObj, YAFFS_OBJECT_TYPE_SPECIAL, &stats, parent, entry->d_name, -1, NULL);
}
else if(S_ISDIR(stats.st_mode))
{
printf("directory/n");
error = write_object_header(newObj, YAFFS_OBJECT_TYPE_DIRECTORY, &stats, parent, entry->d_name, -1, NULL);
process_directory(newObj,full_name);
}
}
}
else
{
printf(" we don't handle this type/n");
}
}
}
closedir(dir);
}
return 0;
}
void usage(void)
{
printf("usage: mkyaffs2image layout# dir image_file [convert]/n");
printf(" layout# NAND OOB layout # (0 - raw, 1 - nand_oob_64)/n");
printf(" dir the directory tree to be converted/n");
printf(" image_file the output file to hold the image/n");
printf(" 'convert' make a big-endian img on a little-endian machine. BROKEN !/n");
exit(1);
}
int main(int argc, char *argv[])
{
struct stat stats;
int i;
printf("mkyaffs2image: image building tool for YAFFS2 built "__DATE__"/n");
if ((argc < 4) || (sscanf(argv[1], "%u", &layout_no) != 1))
{
usage();
}
i = 0;
while (oob_layout[i].useecc != -1)
i++;
if (layout_no >= i)
usage();
if ((argc == 5) && (!strncmp(argv[4], "convert", strlen("convert"))))
{
fprintf (stderr, "WARNING: ENDIAN CONVERSION IS BROKEN/n");
/* KSI: Broken as of now. TBD. Fail. */
usage();
convert_endian = 1;
}
if(stat(argv[2],&stats) < 0)
{
printf("Could not stat %s/n",argv[2]);
exit(1);
}
if(!S_ISDIR(stats.st_mode))
{
printf(" %s is not a directory/n",argv[2]);
exit(1);
}
outFile = open(argv[3],O_CREAT | O_TRUNC | O_WRONLY, S_IREAD | S_IWRITE);
if(outFile < 0)
{
printf("Could not open output file %s/n",argv[3]);
exit(1);
}
printf("Processing directory %s into image file %s/n",argv[2],argv[3]);
error = write_object_header(1, YAFFS_OBJECT_TYPE_DIRECTORY, &stats, 1,"", -1, NULL);
if(error)
error = process_directory(YAFFS_OBJECTID_ROOT,argv[2]);
close(outFile);
if(error < 0)
{
perror("operation incomplete");
exit(1);
}
else
{
printf("Operation complete./n"
"%d objects in %d directories/n"
"%d NAND pages/n",nObjects, nDirectories, nPages);
}
close(outFile);
exit(0);
}
PART2 About 16bytes OOB
另外，下面用关键性的数据结构简单展示一下16bytes OOB区内的组织格式：
typedef struct {
unsigned chunkId:20;
unsigned serialNumber:2;
unsigned byteCountLSB:10;
unsigned objectId:18;
unsigned ecc:12;
unsigned byteCountMSB:2;
} yaffs_Tags;
//LIUHAO: yaffs_TagsUnion共用体，方便实现对yaffs_Tags中数据的处理。
typedef union {
yaffs_Tags asTags;
__u8 asBytes[8];
} yaffs_TagsUnion;
//LIUHAO: 512bytes data + 16bytes spare时spare区中的数据格式
//其中ecc1[3]为512bytes前半区的ecc校验码
// ecc2[3]为512bytes后半区的ecc校验码
/* Spare structure for YAFFS1 */
typedef struct {
__u8 tagByte0;
__u8 tagByte1;
__u8 tagByte2;
__u8 tagByte3;
__u8 pageStatus; /* set to 0 to delete the chunk */
__u8 blockStatus;
__u8 tagByte4;
__u8 tagByte5;
__u8 ecc1[3];
__u8 tagByte6;
__u8 tagByte7;
__u8 ecc2[3];
} yaffs_Spare;
总结：
对于未知的领域和问题，唯独我们坚持，才会最终得到正确的答案。一句话说得好：人类最伟大的品质在于坚持，所有的梦想和目标都会因些而实现。
