This page hosts a formal specification of cramfs using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
All parsing code for Java generated by Kaitai Struct depends on the Java runtime library. You have to install it before you can parse data.
The Java runtime library is published in the Maven Central Repository. Refer to the artifact page for instructions how to add it into your project with the build tool that you use.
Parse a local file and get structure in memory:
Cramfs data = Cramfs.fromFile("path/to/local/file.bin");
Or parse structure from a byte array:
byte[] someArray = new byte[] { ... };
Cramfs data = new Cramfs(new ByteBufferKaitaiStream(someArray));
After that, one can get various attributes from the structure by invoking getter methods like:
data.superBlock() // => get super block
// This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
import io.kaitai.struct.ByteBufferKaitaiStream;
import io.kaitai.struct.KaitaiStruct;
import io.kaitai.struct.KaitaiStream;
import java.io.IOException;
import java.util.Arrays;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Map;
import java.util.HashMap;
public class Cramfs extends KaitaiStruct {
public static Cramfs fromFile(String fileName) throws IOException {
return new Cramfs(new ByteBufferKaitaiStream(fileName));
}
public Cramfs(KaitaiStream _io) {
this(_io, null, null);
}
public Cramfs(KaitaiStream _io, KaitaiStruct _parent) {
this(_io, _parent, null);
}
public Cramfs(KaitaiStream _io, KaitaiStruct _parent, Cramfs _root) {
super(_io);
this._parent = _parent;
this._root = _root == null ? this : _root;
_read();
}
private void _read() {
this.superBlock = new SuperBlockStruct(this._io, this, _root);
}
public static class SuperBlockStruct extends KaitaiStruct {
public static SuperBlockStruct fromFile(String fileName) throws IOException {
return new SuperBlockStruct(new ByteBufferKaitaiStream(fileName));
}
public SuperBlockStruct(KaitaiStream _io) {
this(_io, null, null);
}
public SuperBlockStruct(KaitaiStream _io, Cramfs _parent) {
this(_io, _parent, null);
}
public SuperBlockStruct(KaitaiStream _io, Cramfs _parent, Cramfs _root) {
super(_io);
this._parent = _parent;
this._root = _root;
_read();
}
private void _read() {
this.magic = this._io.readBytes(4);
if (!(Arrays.equals(magic(), new byte[] { 69, 61, -51, 40 }))) {
throw new KaitaiStream.ValidationNotEqualError(new byte[] { 69, 61, -51, 40 }, magic(), _io(), "/types/super_block_struct/seq/0");
}
this.size = this._io.readU4le();
this.flags = this._io.readU4le();
this.future = this._io.readU4le();
this.signature = this._io.readBytes(16);
if (!(Arrays.equals(signature(), new byte[] { 67, 111, 109, 112, 114, 101, 115, 115, 101, 100, 32, 82, 79, 77, 70, 83 }))) {
throw new KaitaiStream.ValidationNotEqualError(new byte[] { 67, 111, 109, 112, 114, 101, 115, 115, 101, 100, 32, 82, 79, 77, 70, 83 }, signature(), _io(), "/types/super_block_struct/seq/4");
}
this.fsid = new Info(this._io, this, _root);
this.name = new String(this._io.readBytes(16), Charset.forName("ASCII"));
this.root = new Inode(this._io, this, _root);
}
private Integer flagFsidV2;
public Integer flagFsidV2() {
if (this.flagFsidV2 != null)
return this.flagFsidV2;
int _tmp = (int) (((flags() >> 0) & 1));
this.flagFsidV2 = _tmp;
return this.flagFsidV2;
}
private Integer flagHoles;
public Integer flagHoles() {
if (this.flagHoles != null)
return this.flagHoles;
int _tmp = (int) (((flags() >> 8) & 1));
this.flagHoles = _tmp;
return this.flagHoles;
}
private Integer flagWrongSignature;
public Integer flagWrongSignature() {
if (this.flagWrongSignature != null)
return this.flagWrongSignature;
int _tmp = (int) (((flags() >> 9) & 1));
this.flagWrongSignature = _tmp;
return this.flagWrongSignature;
}
private Integer flagSortedDirs;
public Integer flagSortedDirs() {
if (this.flagSortedDirs != null)
return this.flagSortedDirs;
int _tmp = (int) (((flags() >> 1) & 1));
this.flagSortedDirs = _tmp;
return this.flagSortedDirs;
}
private Integer flagShiftedRootOffset;
public Integer flagShiftedRootOffset() {
if (this.flagShiftedRootOffset != null)
return this.flagShiftedRootOffset;
int _tmp = (int) (((flags() >> 10) & 1));
this.flagShiftedRootOffset = _tmp;
return this.flagShiftedRootOffset;
}
private byte[] magic;
private long size;
private long flags;
private long future;
private byte[] signature;
private Info fsid;
private String name;
private Inode root;
private Cramfs _root;
private Cramfs _parent;
public byte[] magic() { return magic; }
public long size() { return size; }
public long flags() { return flags; }
public long future() { return future; }
public byte[] signature() { return signature; }
public Info fsid() { return fsid; }
public String name() { return name; }
public Inode root() { return root; }
public Cramfs _root() { return _root; }
public Cramfs _parent() { return _parent; }
}
public static class ChunkedDataInode extends KaitaiStruct {
public static ChunkedDataInode fromFile(String fileName) throws IOException {
return new ChunkedDataInode(new ByteBufferKaitaiStream(fileName));
}
public ChunkedDataInode(KaitaiStream _io) {
this(_io, null, null);
}
public ChunkedDataInode(KaitaiStream _io, Cramfs.Inode _parent) {
this(_io, _parent, null);
}
public ChunkedDataInode(KaitaiStream _io, Cramfs.Inode _parent, Cramfs _root) {
super(_io);
this._parent = _parent;
this._root = _root;
_read();
}
private void _read() {
this.blockEndIndex = new ArrayList<Long>();
for (int i = 0; i < (((_parent().size() + _root().pageSize()) - 1) / _root().pageSize()); i++) {
this.blockEndIndex.add(this._io.readU4le());
}
this.rawBlocks = this._io.readBytesFull();
}
private ArrayList<Long> blockEndIndex;
private byte[] rawBlocks;
private Cramfs _root;
private Cramfs.Inode _parent;
public ArrayList<Long> blockEndIndex() { return blockEndIndex; }
public byte[] rawBlocks() { return rawBlocks; }
public Cramfs _root() { return _root; }
public Cramfs.Inode _parent() { return _parent; }
}
public static class Inode extends KaitaiStruct {
public static Inode fromFile(String fileName) throws IOException {
return new Inode(new ByteBufferKaitaiStream(fileName));
}
public enum FileType {
FIFO(1),
CHRDEV(2),
DIR(4),
BLKDEV(6),
REG_FILE(8),
SYMLINK(10),
SOCKET(12);
private final long id;
FileType(long id) { this.id = id; }
public long id() { return id; }
private static final Map<Long, FileType> byId = new HashMap<Long, FileType>(7);
static {
for (FileType e : FileType.values())
byId.put(e.id(), e);
}
public static FileType byId(long id) { return byId.get(id); }
}
public Inode(KaitaiStream _io) {
this(_io, null, null);
}
public Inode(KaitaiStream _io, KaitaiStruct _parent) {
this(_io, _parent, null);
}
public Inode(KaitaiStream _io, KaitaiStruct _parent, Cramfs _root) {
super(_io);
this._parent = _parent;
this._root = _root;
_read();
}
private void _read() {
this.mode = this._io.readU2le();
this.uid = this._io.readU2le();
this.sizeGid = this._io.readU4le();
this.namelenOffset = this._io.readU4le();
this.name = new String(this._io.readBytes(namelen()), Charset.forName("utf-8"));
}
private Integer attr;
public Integer attr() {
if (this.attr != null)
return this.attr;
int _tmp = (int) (((mode() >> 9) & 7));
this.attr = _tmp;
return this.attr;
}
private ChunkedDataInode asRegFile;
public ChunkedDataInode asRegFile() {
if (this.asRegFile != null)
return this.asRegFile;
KaitaiStream io = _root()._io();
long _pos = io.pos();
io.seek(offset());
this.asRegFile = new ChunkedDataInode(io, this, _root);
io.seek(_pos);
return this.asRegFile;
}
private Integer permU;
public Integer permU() {
if (this.permU != null)
return this.permU;
int _tmp = (int) (((mode() >> 6) & 7));
this.permU = _tmp;
return this.permU;
}
private ChunkedDataInode asSymlink;
public ChunkedDataInode asSymlink() {
if (this.asSymlink != null)
return this.asSymlink;
KaitaiStream io = _root()._io();
long _pos = io.pos();
io.seek(offset());
this.asSymlink = new ChunkedDataInode(io, this, _root);
io.seek(_pos);
return this.asSymlink;
}
private Integer permO;
public Integer permO() {
if (this.permO != null)
return this.permO;
int _tmp = (int) ((mode() & 7));
this.permO = _tmp;
return this.permO;
}
private Integer size;
public Integer size() {
if (this.size != null)
return this.size;
int _tmp = (int) ((sizeGid() & 16777215));
this.size = _tmp;
return this.size;
}
private Integer gid;
public Integer gid() {
if (this.gid != null)
return this.gid;
int _tmp = (int) ((sizeGid() >> 24));
this.gid = _tmp;
return this.gid;
}
private Integer permG;
public Integer permG() {
if (this.permG != null)
return this.permG;
int _tmp = (int) (((mode() >> 3) & 7));
this.permG = _tmp;
return this.permG;
}
private Integer namelen;
public Integer namelen() {
if (this.namelen != null)
return this.namelen;
int _tmp = (int) (((namelenOffset() & 63) << 2));
this.namelen = _tmp;
return this.namelen;
}
private DirInode asDir;
public DirInode asDir() {
if (this.asDir != null)
return this.asDir;
KaitaiStream io = _root()._io();
long _pos = io.pos();
io.seek(offset());
this._raw_asDir = io.readBytes(size());
KaitaiStream _io__raw_asDir = new ByteBufferKaitaiStream(_raw_asDir);
this.asDir = new DirInode(_io__raw_asDir, this, _root);
io.seek(_pos);
return this.asDir;
}
private FileType type;
public FileType type() {
if (this.type != null)
return this.type;
this.type = FileType.byId(((mode() >> 12) & 15));
return this.type;
}
private Integer offset;
public Integer offset() {
if (this.offset != null)
return this.offset;
int _tmp = (int) ((((namelenOffset() >> 6) & 67108863) << 2));
this.offset = _tmp;
return this.offset;
}
private int mode;
private int uid;
private long sizeGid;
private long namelenOffset;
private String name;
private Cramfs _root;
private KaitaiStruct _parent;
private byte[] _raw_asDir;
public int mode() { return mode; }
public int uid() { return uid; }
public long sizeGid() { return sizeGid; }
public long namelenOffset() { return namelenOffset; }
public String name() { return name; }
public Cramfs _root() { return _root; }
public KaitaiStruct _parent() { return _parent; }
public byte[] _raw_asDir() { return _raw_asDir; }
}
public static class DirInode extends KaitaiStruct {
public static DirInode fromFile(String fileName) throws IOException {
return new DirInode(new ByteBufferKaitaiStream(fileName));
}
public DirInode(KaitaiStream _io) {
this(_io, null, null);
}
public DirInode(KaitaiStream _io, Cramfs.Inode _parent) {
this(_io, _parent, null);
}
public DirInode(KaitaiStream _io, Cramfs.Inode _parent, Cramfs _root) {
super(_io);
this._parent = _parent;
this._root = _root;
_read();
}
private void _read() {
if (_io().size() > 0) {
this.children = new ArrayList<Inode>();
{
int i = 0;
while (!this._io.isEof()) {
this.children.add(new Inode(this._io, this, _root));
i++;
}
}
}
}
private ArrayList<Inode> children;
private Cramfs _root;
private Cramfs.Inode _parent;
public ArrayList<Inode> children() { return children; }
public Cramfs _root() { return _root; }
public Cramfs.Inode _parent() { return _parent; }
}
public static class Info extends KaitaiStruct {
public static Info fromFile(String fileName) throws IOException {
return new Info(new ByteBufferKaitaiStream(fileName));
}
public Info(KaitaiStream _io) {
this(_io, null, null);
}
public Info(KaitaiStream _io, Cramfs.SuperBlockStruct _parent) {
this(_io, _parent, null);
}
public Info(KaitaiStream _io, Cramfs.SuperBlockStruct _parent, Cramfs _root) {
super(_io);
this._parent = _parent;
this._root = _root;
_read();
}
private void _read() {
this.crc = this._io.readU4le();
this.edition = this._io.readU4le();
this.blocks = this._io.readU4le();
this.files = this._io.readU4le();
}
private long crc;
private long edition;
private long blocks;
private long files;
private Cramfs _root;
private Cramfs.SuperBlockStruct _parent;
public long crc() { return crc; }
public long edition() { return edition; }
public long blocks() { return blocks; }
public long files() { return files; }
public Cramfs _root() { return _root; }
public Cramfs.SuperBlockStruct _parent() { return _parent; }
}
private Integer pageSize;
public Integer pageSize() {
if (this.pageSize != null)
return this.pageSize;
int _tmp = (int) (4096);
this.pageSize = _tmp;
return this.pageSize;
}
private SuperBlockStruct superBlock;
private Cramfs _root;
private KaitaiStruct _parent;
public SuperBlockStruct superBlock() { return superBlock; }
public Cramfs _root() { return _root; }
public KaitaiStruct _parent() { return _parent; }
}