/* 
* unyaffs: extract files from yaffs2 file system image to the current directory 
* 
* Created by Kai Wei & lt; [email protected] & gt; 
* This program is free software; You can redistribute it and/or modify the 
* it under the terms of the GNU General Public License version 2 as 
* published by the Free Software Foundation. 
*/

#include  
#include  
#include  
#include  
#include  
#include  
#include  

# include "unyaffs. H" 

# define CHUNK_SIZE 2048 
# define SPARE_SIZE 64 
# define MAX_OBJECTS 10000 
# define YAFFS_OBJECTID_ROOT 1 


Unsigned char data [CHUNK_SIZE + SPARE_SIZE]; 
Unsigned char * chunk_data=https://bbs.csdn.net/topics/data; 
Unsigned char * spare_data=https://bbs.csdn.net/topics/data + CHUNK_SIZE; 
Int img_file; 

Char * obj_list [MAX_OBJECTS]; 
Int process_chunk () 
{
Int out_file, remain, s; 
Char * full_path_name; 

Spare_data yaffs_PackedTags2 * pt=(yaffs_PackedTags2 *); 
If (pt - & gt; T.b yteCount==0 XFFFF) {//a new object 

Yaffs_ObjectHeader * oh=(yaffs_ObjectHeader *) malloc (sizeof (yaffs_ObjectHeader)); 
Memcpy (oh, chunk_data, sizeof (yaffs_ObjectHeader)); 

Full_path_name=(char *) malloc (strlen (oh - & gt; Name) + strlen (obj_list [oh - & gt; parentObjectId]) + 2); 
If (full_path_name==NULL) {
Perror (" malloc full path name \ n "); 
} 
Strcpy (full_path_name obj_list [oh - & gt; parentObjectId]); 
Strcat (full_path_name, "/"); 
Strcat (full_path_name, oh - & gt; Name); 
Obj_list [pt - & gt; t.o bjectId]=full_path_name; 

The switch (oh - & gt; Type) {
Case YAFFS_OBJECT_TYPE_FILE: 
Remain=oh - & gt; The fileSize; 
Out_file=creat (full_path_name, oh - & gt; Yst_mode); 
While (remain & gt; 0 {
If (read_chunk ()) 
return -1; 
S=(remain & lt; Pt - & gt; T.b yteCount)? Remain: pt - & gt; T.b yteCount; 
If (write (out_file chunk_data, s)==1) 
return -1; 
Remain -=s; 
} 
Close (out_file); 
break; 
Case YAFFS_OBJECT_TYPE_SYMLINK: 
Symlink (oh - & gt; Alias, full_path_name); 
break; 
Case YAFFS_OBJECT_TYPE_DIRECTORY: 
The mkdir (full_path_name, 0777); 
break; 
Case YAFFS_OBJECT_TYPE_HARDLINK: 
Link (obj_list [oh - & gt; equivalentObjectId], full_path_name); 
break; 
} 
} 
} 


Int read_chunk () 
{
Ssize_t s; 
Int ret=1; 
Memset (0 XFF chunk_data, sizeof (chunk_data)); 
S=read (img_file, data, CHUNK_SIZE + SPARE_SIZE); 
If (s==1) {
Perror (" read image file \ n "); 
{} else if (s==0) 
Printf (" the end of the image \ n "); 
} else if (s==(CHUNK_SIZE + SPARE_SIZE))) {
Ret=0; 
} else {
Fprintf (stderr, "broken image file \ n"); 
} 
return ret; 
} 

Int main (int arg c, char * * argv) 
{
If (arg c!=2) {
Printf (" the Usage: unyaffs image_file_name \ n "); 
The exit (1); 
} 
Img_file=open (argv [1], O_RDONLY); 
If (img_file==1) {
Printf (" open image file failed \ n "); 
The exit (1); 
} 

Obj_list [YAFFS_OBJECTID_ROOT]=". "; 
While (1) {
If (read_chunk ()==1) 
break; 
Process_chunk (); 
} 
Close (img_file); 
return 0; 
} 

/* 
* definition copied from yaffs project 
*/

# # ifndef __UNYAFFS_H__ 
# define __UNYAFFS_H__ 


# define YAFFS_MAX_NAME_LENGTH 255 
# define YAFFS_MAX_ALIAS_LENGTH 159 
Definition of types *//* 
Typedef unsigned char __u8; 
Typedef unsigned short __u16; 
Typedef unsigned __u32; 

Typedef struct {
Unsigned sequenceNumber; 
Unsigned objectId; 
Unsigned chunkId; 
Unsigned byteCount; 
} yaffs_PackedTags2TagsPart; 

Typedef struct {
Unsigned char colParity; 
Unsigned lineParity; 
Unsigned lineParityPrime; 
} yaffs_ECCOther; 

Typedef struct {
Yaffs_PackedTags2TagsPart t; 
Yaffs_ECCOther ecc; 
} yaffs_PackedTags2; 

Typedef enum {
YAFFS_ECC_RESULT_UNKNOWN, 
YAFFS_ECC_RESULT_NO_ERROR, 
YAFFS_ECC_RESULT_FIXED, 
YAFFS_ECC_RESULT_UNFIXED 
} yaffs_ECCResult; 

Typedef enum {
YAFFS_OBJECT_TYPE_UNKNOWN, 
YAFFS_OBJECT_TYPE_FILE, 
YAFFS_OBJECT_TYPE_SYMLINK, 
YAFFS_OBJECT_TYPE_DIRECTORY, 
YAFFS_OBJECT_TYPE_HARDLINK, 
YAFFS_OBJECT_TYPE_SPECIAL 
} yaffs_ObjectType; 


Typedef struct {

Unsigned validMarker0; 
Unsigned chunkUsed;/* the Status of the chunk, informs the or unused */
Unsigned objectId;/* If 0 then this is not part of an object (unused) */
Unsigned chunkId;/* If 0 then this is a header, else a data chunk */
Unsigned byteCount;/* Only valid for the data chunks */

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