mirror of
https://github.com/danbulant/Cosmos
synced 2026-05-19 20:39:01 +00:00
352 lines
No EOL
16 KiB
C#
352 lines
No EOL
16 KiB
C#
//#define EXT2Debug
|
|
using System;
|
|
using System.Collections.Generic;
|
|
using System.Linq;
|
|
using System.Text;
|
|
using Cosmos.Hardware;
|
|
using HW=Cosmos.Hardware;
|
|
using Cosmos.Sys.FileSystem;
|
|
|
|
namespace Cosmos.Sys.FileSystem.Ext2 {
|
|
public unsafe partial class Ext2 : Filesystem {
|
|
private readonly BlockDevice mBackend;
|
|
private SuperBlock mSuperblock;
|
|
private GroupDescriptor[] mGroupDescriptors;
|
|
private byte[] mBuffer;
|
|
private byte* mBufferAddress;
|
|
|
|
public Ext2(BlockDevice aBackend) {
|
|
mBackend = aBackend;
|
|
Initialize();
|
|
}
|
|
|
|
private void Initialize() {
|
|
Console.WriteLine("Start Ext2.Initialize");
|
|
mBuffer = new byte[mBackend.BlockSize];
|
|
fixed (byte* xBufferAddress = &mBuffer[0]) {
|
|
mBufferAddress = xBufferAddress;
|
|
}
|
|
// first get the superblock;
|
|
var mBufferAsSuperblock = (SuperBlock*)mBufferAddress;
|
|
int xAddr = (int)mBufferAddress;
|
|
Console.WriteLine("Buffer address: " + xAddr);
|
|
Console.WriteLine("Start reading superblock");
|
|
mBackend.ReadBlock(2,
|
|
mBuffer);
|
|
Console.WriteLine("End reading");
|
|
mSuperblock = *mBufferAsSuperblock;
|
|
DebugUtil.Send_Ext2SuperBlock(mSuperblock);
|
|
// read the group descriptors
|
|
Console.WriteLine("INodeCount: " + mSuperblock.INodesCount);
|
|
Console.WriteLine("INode#1: " + mBufferAddress[0]);
|
|
Console.WriteLine("INode#2: " + mBufferAddress[1]);
|
|
Console.WriteLine("INode#3: " + mBufferAddress[2]);
|
|
Console.WriteLine("INode#4: " + mBufferAddress[3]);
|
|
|
|
Console.WriteLine("BlockCount: " + mSuperblock.BlockCount);
|
|
Console.WriteLine("INodesPerGroup: " + (int)mSuperblock.INodesPerGroup);
|
|
if (mSuperblock.INodesPerGroup == 0x4000)
|
|
{
|
|
Console.WriteLine("INodesPerGroup has correct value!");
|
|
}
|
|
uint xGroupDescriptorCount = mSuperblock.INodesCount / mSuperblock.INodesPerGroup;
|
|
mGroupDescriptors = new GroupDescriptor[xGroupDescriptorCount];
|
|
var xDescriptorPtr = (GroupDescriptor*)mBufferAddress;
|
|
Console.WriteLine("Process GroupDescriptors: " + xGroupDescriptorCount);
|
|
Console.ReadLine();
|
|
for (int i = 0; i < xGroupDescriptorCount; i++) {
|
|
Console.WriteLine("Processing GroupDescriptor " + i);
|
|
uint xATABlock ;
|
|
|
|
if ( BlockSize == 1024 )
|
|
{
|
|
xATABlock = ( BlockSize * 2 ) / mBackend.BlockSize ;
|
|
}
|
|
else
|
|
{
|
|
xATABlock = ( BlockSize ) / mBackend.BlockSize ;
|
|
}
|
|
|
|
xATABlock += (uint)(i / 16);
|
|
if ((i % 16) == 0) {
|
|
Console.WriteLine("Read new GroupDescriptorBlock");
|
|
mBackend.ReadBlock(xATABlock,
|
|
mBuffer);
|
|
Console.WriteLine("End Read");
|
|
}
|
|
mGroupDescriptors[i] = xDescriptorPtr[i % 16];
|
|
Console.WriteLine("End of GroupDescriptor check");
|
|
}
|
|
Console.WriteLine("Send GroupDescriptors to log");
|
|
DebugUtil.Send_Ext2GroupDescriptors(mGroupDescriptors);
|
|
}
|
|
|
|
public override uint BlockSize {
|
|
get {
|
|
return ((uint)1024) << mSuperblock.LogBlockSize;
|
|
}
|
|
}
|
|
|
|
public override ulong RootId {
|
|
get {
|
|
return 3;
|
|
}
|
|
}
|
|
|
|
private bool GetBitState(uint aBitmapStart,
|
|
int aIndex) {
|
|
var xPhyBlock = aBitmapStart * 8;
|
|
xPhyBlock += (uint)aIndex % 4096;
|
|
mBackend.ReadBlock(xPhyBlock,
|
|
mBuffer);
|
|
aIndex /= 4096;
|
|
int xBufferIndex = aIndex / 8;
|
|
aIndex /= 8;
|
|
return (mBufferAddress[xBufferIndex] & (1 << aIndex)) != 0;
|
|
}
|
|
|
|
public override FilesystemEntry[] GetDirectoryListing(ulong aId) {
|
|
var xBaseINodeNumber = (uint)aId;
|
|
HW.DebugUtil.SendNumber("Ext2",
|
|
"Getting DirectoryListing of INode",
|
|
xBaseINodeNumber,
|
|
32);
|
|
INode xINode;
|
|
GetINode(xBaseINodeNumber,
|
|
out xINode);
|
|
Console.Write("INode read");
|
|
return new FilesystemEntry[0];
|
|
byte[] xFSBuffer = new byte[BlockSize];
|
|
var xResult = new List<FilesystemEntry>(10);
|
|
var xDirEntriesPerFSBlock = BlockSize / sizeof(DirectoryEntry);
|
|
uint xBlockId = 0;
|
|
while (ReadINodeBlock(xINode,
|
|
xBlockId,
|
|
xFSBuffer)) {
|
|
Console.WriteLine("Read INode block");
|
|
HW.DebugUtil.WriteBinary("Ext2",
|
|
"Directory Entry binary",
|
|
xFSBuffer,
|
|
0,
|
|
(int)BlockSize);
|
|
HW.DebugUtil.SendNumber("Ext2",
|
|
"First byte of datablock",
|
|
xFSBuffer[0],
|
|
8);
|
|
int xIndex = 0;
|
|
while (xIndex < BlockSize) {
|
|
var xINodeNumber = BitConverter.ToUInt32(xFSBuffer,
|
|
xIndex);
|
|
var xRecLength = BitConverter.ToUInt16(xFSBuffer,
|
|
xIndex + 4);
|
|
if (xINodeNumber > 0) {
|
|
if (xINodeNumber != xBaseINodeNumber) {
|
|
var xNameLength = xFSBuffer[xIndex + 6];
|
|
var xFileType = xFSBuffer[xIndex + 7];
|
|
if (!(xNameLength == 2 && xFSBuffer[xIndex + 8] == (byte)'.' && xFSBuffer[xIndex + 9] == (byte)'.')) {
|
|
var xFSEntry = new FilesystemEntry {
|
|
Id = xINodeNumber,
|
|
IsDirectory = (xFileType == 2),
|
|
IsReadonly = true,
|
|
Filesystem = this
|
|
};
|
|
//xFSEntry.Size = GetINode(xINodeNumber).Size;
|
|
char[] xName = new char[xNameLength];
|
|
for (int c = 0; c < xName.Length; c++) {
|
|
xName[c] = (char)xFSBuffer[xIndex + 8 + c];
|
|
}
|
|
xFSEntry.Name = new string(xName);
|
|
if (!xFSEntry.Name.Equals("lost+found")) {
|
|
xResult.Add(xFSEntry);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
xIndex += xRecLength;
|
|
}
|
|
xBlockId++;
|
|
}
|
|
for (int i = 0; i < xResult.Count; i++) {
|
|
INode xTheINode;
|
|
GetINode((uint)xResult[i].Id,
|
|
out xTheINode);
|
|
xResult[i].Size = xTheINode.Size;
|
|
}
|
|
Console.WriteLine("Returning list of items: " + xResult.Count);
|
|
return xResult.ToArray();
|
|
}
|
|
|
|
private void GetINode(uint aINodeNumber,
|
|
out INode oINode) {
|
|
var xId = aINodeNumber - 1;
|
|
var xGroup = (uint)(xId / mSuperblock.INodesPerGroup);
|
|
var xGroupIndex = (uint)(xId % mSuperblock.INodesPerGroup);
|
|
HW.DebugUtil.SendMessage("Ext2",
|
|
"Reading INode");
|
|
HW.DebugUtil.SendNumber("Ext2",
|
|
"INode Id",
|
|
(uint)xId,
|
|
32);
|
|
HW.DebugUtil.SendNumber("Ext2",
|
|
"Group",
|
|
xGroup,
|
|
32);
|
|
HW.DebugUtil.SendNumber("Ext2",
|
|
"GroupIndex",
|
|
xGroupIndex,
|
|
32);
|
|
// read the inode:
|
|
var xTableBlockOffset = (uint)(xGroupIndex % (ulong)(BlockSize / sizeof(INode)));
|
|
var xTableBlock = mGroupDescriptors[xGroup].INodeTable;
|
|
xTableBlock += xGroupIndex / (uint)(BlockSize / sizeof(INode));
|
|
HW.DebugUtil.SendNumber("Ext2",
|
|
"TableBlockOffset(1)",
|
|
xTableBlockOffset,
|
|
32);
|
|
xTableBlock *= (BlockSize / mBackend.BlockSize);
|
|
xTableBlock += xTableBlockOffset / (uint)(mBackend.BlockSize / sizeof(INode));
|
|
xTableBlockOffset = xTableBlockOffset % (uint)(mBackend.BlockSize / sizeof(INode));
|
|
// below these two lines, the blocks are physical blocks!
|
|
HW.DebugUtil.SendNumber("Ext2",
|
|
"Physical TableBlock",
|
|
xTableBlock,
|
|
32);
|
|
HW.DebugUtil.SendNumber("Ext2",
|
|
"TableBlockOffset(Final)",
|
|
xTableBlockOffset,
|
|
32);
|
|
mBackend.ReadBlock(xTableBlock,
|
|
mBuffer);
|
|
INode xINode=new INode();
|
|
fixed (byte* xTempAddress = &mBuffer[0]) {
|
|
var xINodeAddress = (INode*)xTempAddress;
|
|
xINode = xINodeAddress[(int)xTableBlockOffset];
|
|
HW.DebugUtil.SendNumber("Ext2",
|
|
"INode mode first byte",
|
|
mBufferAddress[sizeof(INode)],
|
|
32);
|
|
HW.DebugUtil.SendNumber("Ext2",
|
|
"INode mode",
|
|
(ushort)xINode.Mode,
|
|
32);
|
|
}
|
|
oINode = xINode;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Reads the contents of an inode, resolving all indirect/bi-indirect/tri-indirect block arrays
|
|
/// </summary>
|
|
/// <param name="aINode"></param>
|
|
/// <param name="aBlockId">This is zero-based!</param>
|
|
/// <param name="aBuffer"></param>
|
|
/// <returns></returns>
|
|
private bool ReadINodeBlock(INode aINode,
|
|
uint aBlockId,
|
|
byte[] aBuffer) {
|
|
if (aBuffer.Length != BlockSize) {
|
|
throw new Exception("Incorrect buffer size!");
|
|
}
|
|
HW.DebugUtil.SendNumber("Ext2",
|
|
"BlockId",
|
|
aBlockId,
|
|
32);
|
|
uint* xBlocks = &aINode.Block;
|
|
if (aBlockId >= 0 && aBlockId <= 11) {
|
|
var xBlockId = xBlocks[aBlockId];
|
|
if (xBlockId == 0) {
|
|
return false;
|
|
}
|
|
ReadDataBlock(xBlockId,
|
|
aBuffer);
|
|
return true;
|
|
} else {
|
|
uint xIndirectBlockRefsPerDataBlock = BlockSize / 4;
|
|
HW.DebugUtil.SendNumber("Ext2",
|
|
"Indirect block reference count per data block",
|
|
xIndirectBlockRefsPerDataBlock,
|
|
32);
|
|
if ((aBlockId - 12) < xIndirectBlockRefsPerDataBlock) {
|
|
var xBlockId = xBlocks[12];
|
|
if (xBlockId == 0) {
|
|
return false;
|
|
}
|
|
ReadDataBlock(xBlockId,
|
|
aBuffer);
|
|
var xTheBlock = BitConverter.ToUInt32(aBuffer,
|
|
(int)((aBlockId - 11) * 4));
|
|
ReadDataBlock(xTheBlock,
|
|
aBuffer);
|
|
return true;
|
|
}
|
|
Console.WriteLine("Reading indirect blocks not yet supported!");
|
|
}
|
|
return false;
|
|
}
|
|
|
|
private void ReadDataBlock(uint aBlockId,
|
|
byte[] aBuffer) {
|
|
var xPhyBlocksPerFSBlock = (BlockSize / mBackend.BlockSize);
|
|
HW.DebugUtil.SendNumber("Ext2",
|
|
"PhyBlocksPerFSBlock",
|
|
xPhyBlocksPerFSBlock,
|
|
32);
|
|
aBlockId *= xPhyBlocksPerFSBlock;
|
|
for (var i = 0; i < xPhyBlocksPerFSBlock; i++) {
|
|
mBackend.ReadBlock((uint)(aBlockId + i),
|
|
mBuffer);
|
|
Array.Copy(mBuffer,
|
|
0,
|
|
aBuffer,
|
|
(mBackend.BlockSize * i),
|
|
mBackend.BlockSize);
|
|
}
|
|
}
|
|
|
|
public override bool ReadBlock(ulong aId,
|
|
ulong aBlock,
|
|
byte[] aBuffer) {
|
|
INode xTheINode;
|
|
uint xId = (uint)aId;
|
|
HW.DebugUtil.SendNumber("Ext2",
|
|
"ReadingBlock of INode",
|
|
xId,
|
|
32);
|
|
HW.DebugUtil.SendNumber("Ext2",
|
|
"Reading Blocknr",
|
|
(uint)aBlock,
|
|
32);
|
|
GetINode(xId,
|
|
out xTheINode);
|
|
return ReadINodeBlock(xTheINode,
|
|
(uint)aBlock,
|
|
aBuffer);
|
|
}
|
|
|
|
public static bool BlockDeviceContainsExt2(BlockDevice aDevice) {
|
|
if (aDevice.BlockCount > 3)
|
|
{
|
|
byte[] xBuffer = new byte[aDevice.BlockSize];
|
|
// todo: implement better detection
|
|
aDevice.ReadBlock(2,
|
|
xBuffer);
|
|
Console.WriteLine("Block read");
|
|
Hardware.DebugUtil.WriteBinary("Ext2",
|
|
"Detecting Ext2 (1)",
|
|
xBuffer,
|
|
55,
|
|
4);
|
|
bool xResult = (xBuffer[56] == 0x53 && xBuffer[57] == 0xEF);
|
|
if (xResult)
|
|
{
|
|
Console.WriteLine("Ext2 valid!");
|
|
}
|
|
else
|
|
{
|
|
Console.WriteLine("Ext2 not valid!");
|
|
}
|
|
return xResult;
|
|
}
|
|
return false;
|
|
}
|
|
}
|
|
} |