2 files changed, 298 insertions, 12 deletions

diff --git a/dev/kernel/FSKit/Ext2+IFS.h b/dev/kernel/FSKit/Ext2+IFS.h
new file mode 100644
index 00000000..661c8d5f
--- /dev/null
+++ b/dev/kernel/FSKit/Ext2+IFS.h
@@ -0,0 +1,271 @@
+/* -------------------------------------------
+
+  Copyright (C) 2024-2025, Amlal El Mahrouss, all rights reserved.
+
+------------------------------------------- */
+
+#pragma once
+
+#include <FSKit/Ext2.h>
+#include <KernelKit/DriveMgr.h>
+#include <KernelKit/HeapMgr.h>
+#include <KernelKit/KPC.h>
+#include <NeKit/ErrorOr.h>
+#include <NeKit/KernelPanic.h>
+#include <NeKit/Utils.h>
+
+namespace Kernel {
+/// @brief Context for an EXT2 filesystem on a given drive
+class Ext2Context final {
+ public:
+  DriveTrait*       drive{nullptr};
+  EXT2_SUPER_BLOCK* superblock{nullptr};
+
+  /// @brief context with a drive
+  Ext2Context(Kernel::DriveTrait* drv) : drive(drv) {}
+
+  /// @brief Clean up
+  ~Ext2Context() {
+    if (superblock) {
+      Kernel::mm_free_ptr(superblock);
+      superblock = nullptr;
+    }
+  }
+
+  Ext2Context(const Ext2Context&) = delete;
+  Ext2Context& operator=(const Ext2Context&) = delete;
+
+  Ext2Context(Ext2Context&& other) noexcept : drive(other.drive), superblock(other.superblock) {
+    other.drive      = nullptr;
+    other.superblock = nullptr;
+  }
+
+  Ext2Context& operator=(Ext2Context&& other) noexcept {
+    if (this != &other) {
+      if (superblock) {
+        Kernel::mm_free_ptr(superblock);
+      }
+      drive            = other.drive;
+      superblock       = other.superblock;
+      other.drive      = nullptr;
+      other.superblock = nullptr;
+    }
+    return *this;
+  }
+
+  SizeT BlockSize() const {
+    if (!superblock) return kExt2FSBlockSizeBase;
+    return kExt2FSBlockSizeBase << superblock->fLogBlockSize;
+  }
+
+  operator BOOL() { return superblock != nullptr; }
+};
+
+/// ======================================================================= ///
+/// IFS FUNCTIONS
+/// ======================================================================= ///
+
+inline BOOL ext2_read_block(Kernel::DriveTrait* drv, Kernel::UInt32 lba, VoidPtr buffer,
+                            Kernel::UInt32 size) {
+  if (!drv || !buffer) return false;
+
+  Kernel::DriveTrait::DrivePacket pkt{};
+  pkt.fPacketContent = buffer;
+  pkt.fPacketSize    = size;
+  pkt.fPacketLba     = lba;
+  drv->fInput(pkt);
+
+  return pkt.fPacketGood;
+}
+
+inline BOOL ext2_write_block(Kernel::DriveTrait* drv, Kernel::UInt32 lba, const VoidPtr buffer,
+                             Kernel::UInt32 size) {
+  if (!drv || !buffer) return false;
+
+  Kernel::DriveTrait::DrivePacket pkt{};
+  pkt.fPacketContent = const_cast<VoidPtr>(buffer);
+  pkt.fPacketSize    = size;
+  pkt.fPacketLba     = lba;
+  drv->fOutput(pkt);
+  return pkt.fPacketGood;
+}
+
+inline Kernel::ErrorOr<EXT2_SUPER_BLOCK*> ext2_load_superblock(Ext2Context* ctx) {
+  if (!ctx || !ctx->drive) return Kernel::ErrorOr<EXT2_SUPER_BLOCK*>(Kernel::kErrorInvalidData);
+
+  auto buf = Kernel::mm_alloc_ptr(sizeof(EXT2_SUPER_BLOCK), true, false);
+  if (!buf) return Kernel::ErrorOr<EXT2_SUPER_BLOCK*>(Kernel::kErrorHeapOutOfMemory);
+
+  Kernel::UInt32 blockLba = kExt2FSSuperblockOffset / ctx->drive->fSectorSz;
+
+  if (!ext2_read_block(ctx->drive, blockLba, buf, sizeof(EXT2_SUPER_BLOCK))) {
+    Kernel::mm_free_ptr(buf);
+    return Kernel::ErrorOr<EXT2_SUPER_BLOCK*>(Kernel::kErrorDisk);
+  }
+
+  auto sb = reinterpret_cast<EXT2_SUPER_BLOCK*>(buf);
+  if (sb->fMagic != kExt2FSMagic) {
+    Kernel::mm_free_ptr(buf);
+    return Kernel::ErrorOr<EXT2_SUPER_BLOCK*>(Kernel::kErrorInvalidData);
+  }
+
+  ctx->superblock = sb;
+  return Kernel::ErrorOr<EXT2_SUPER_BLOCK*>(sb);
+}
+
+// Load inode
+inline Kernel::ErrorOr<Ext2Node*> ext2_load_inode(Ext2Context* ctx, Kernel::UInt32 inodeNumber) {
+  if (!ctx || !ctx->superblock) return Kernel::ErrorOr<Ext2Node*>(Kernel::kErrorInvalidData);
+
+  auto nodePtr = Kernel::mm_alloc_ptr(sizeof(Ext2Node), true, false);
+  if (!nodePtr) return Kernel::ErrorOr<Ext2Node*>(Kernel::kErrorHeapOutOfMemory);
+
+  auto ext2Node         = reinterpret_cast<Ext2Node*>(nodePtr);
+  ext2Node->inodeNumber = inodeNumber;
+
+  // Compute block group and index within group
+  Kernel::UInt32 inodesPerGroup = ctx->superblock->fInodesPerGroup;
+  Kernel::UInt32 group          = (inodeNumber - 1) / inodesPerGroup;
+
+  // dummy: just offset first inode
+  Kernel::UInt32 inodeTableBlock = ctx->superblock->fFirstInode + group;
+
+  if (!ext2_read_block(ctx->drive, inodeTableBlock, &ext2Node->inode, sizeof(EXT2_INODE))) {
+    Kernel::mm_free_ptr(nodePtr);
+    return Kernel::ErrorOr<Ext2Node*>(Kernel::kErrorDisk);
+  }
+
+  ext2Node->cursor = 0;
+  return Kernel::ErrorOr<Ext2Node*>(ext2Node);
+}
+
+/*
+ * Ext2FileSystemParser Class
+ *
+ * Provides high-level interface for EXT2 filesystem operations
+ */
+class Ext2FileSystemParser {
+ private:
+  Ext2Context ctx;  // Internal EXT2 context
+
+ public:
+  /*
+   * Constructor
+   * Initializes the parser with a drive interface
+   *
+   * @param drive: Pointer to drive trait for disk I/O operations
+   */
+  explicit Ext2FileSystemParser(DriveTrait* drive);
+
+  /*
+   * Open a file or directory by path
+   *
+   * @param path: Full path to the file/directory (e.g., "/home/user/file.txt")
+   * @param restrict_type: Access mode restriction (e.g., "r", "w", "rw")
+   * @return: VoidPtr handle to the opened file/directory, or nullptr on failure
+   */
+  VoidPtr Open(const char* path, const char* restrict_type);
+
+  /*
+   * Read data from an open file node
+   *
+   * @param node: File node handle returned by Open()
+   * @param flags: Read operation flags
+   * @param size: Number of bytes to read
+   * @return: Pointer to allocated buffer containing read data, or nullptr on failure
+   *          Caller is responsible for freeing the returned buffer
+   */
+  VoidPtr Read(VoidPtr node, Int32 flags, SizeT size);
+
+  /*
+   * Write data to an open file node
+   *
+   * @param node: File node handle returned by Open()
+   * @param data: Buffer containing data to write
+   * @param flags: Write operation flags
+   * @param size: Number of bytes to write
+   */
+  Void Write(VoidPtr node, VoidPtr data, Int32 flags, SizeT size);
+
+  /*
+   * Seek to a specific position in the file
+   *
+   * @param node: File node handle
+   * @param offset: Byte offset from beginning of file
+   * @return: true on success, false on failure
+   */
+  BOOL Seek(VoidPtr node, SizeT offset);
+
+  /*
+   * Get current position in the file
+   *
+   * @param node: File node handle
+   * @return: Current byte offset from beginning of file
+   */
+  SizeT Tell(VoidPtr node);
+
+  /*
+   * Reset file position to beginning
+   *
+   * @param node: File node handle
+   * @return: true on success, false on failure
+   */
+  BOOL Rewind(VoidPtr node);
+
+  /*
+   * Read data from a named file within a directory node
+   *
+   * @param name: Name of file within the directory
+   * @param node: Directory node handle
+   * @param flags: Read operation flags
+   * @param size: Number of bytes to read
+   * @return: Pointer to allocated buffer containing read data, or nullptr on failure
+   */
+  VoidPtr Read(const char* name, VoidPtr node, Int32 flags, SizeT size);
+
+  /*
+   * Write data to a named file within a directory node
+   *
+   * @param name: Name of file within the directory
+   * @param node: Directory node handle
+   * @param data: Buffer containing data to write
+   * @param flags: Write operation flags
+   * @param size: Number of bytes to write
+   */
+  Void Write(const char* name, VoidPtr node, VoidPtr data, Int32 flags, SizeT size);
+
+  /*
+   * Create a new regular file
+   *
+   * @param path: Full path for the new file
+   * @return: VoidPtr handle to the created file, or nullptr on failure
+   */
+  VoidPtr Create(const char* path);
+
+  /*
+   * Create a new directory
+   *
+   * @param path: Full path for the new directory
+   * @return: VoidPtr handle to the created directory, or nullptr on failure
+   */
+  VoidPtr CreateDirectory(const char* path);
+
+  /*
+   * Close and free a file/directory node
+   * Note: This method is not shown in the implementation but would typically be needed
+   *
+   * @param node: Node handle to close and free
+   */
+  Void Close(VoidPtr node);
+
+  /*
+   * Get file/directory information
+   * Note: This method is not shown in the implementation but would typically be needed
+   *
+   * @param node: Node handle
+   * @param info: Structure to fill with file information (size, type, permissions, etc.)
+   * @return: true on success, false on failure
+   */
+  BOOL GetInfo(VoidPtr node, VoidPtr info);
+};
+}  // namespace Kernel
diff --git a/dev/kernel/FSKit/Ext2.h b/dev/kernel/FSKit/Ext2.h
index 35129dcd..be2e34a6 100644
--- a/dev/kernel/FSKit/Ext2.h
+++ b/dev/kernel/FSKit/Ext2.h
@@ -13,20 +13,20 @@
 #include <hint/CompilerHint.h>
 
 /// @file Ext2.h
-/// @brief EXT2 filesystem structures and constants.
+/// @brief EXT2 filesystem structures, constants, and base wrappers.
 
+/// EXT2 Constants
 #define kExt2FSMagic (0xEF53)
 #define kExt2FSMaxFileNameLen (255U)
 #define kExt2FSSuperblockOffset (1024)
 #define kExt2FSRootInodeNumber (2)
-
 #define kExt2FSInodeSize (128U)
 #define kExt2FSBlockSizeBase (1024U)
 
 #define kExt2FSRev0 (0)
 #define kExt2FSRev1 (1)
 
-/// @brief EXT2's file types.
+/// EXT2 file types
 enum {
   kExt2FileTypeUnknown      = 0,
   kExt2FileTypeRegular      = 1,
@@ -38,7 +38,17 @@ enum {
   kExt2FileTypeSymbolicLink = 7
 };
 
-/// @brief The super block structure, located at LBA 1024.
+typedef struct EXT2_GROUP_DESCRIPTOR final {
+  UInt32 fBlockBitmap;
+  UInt32 fInodeBitmap;
+  UInt32 fInodeTable;
+  UInt16 fFreeBlocksCount;
+  UInt16 fFreeInodesCount;
+  UInt16 fBgUsedDirsCount;
+  UInt16 fBgPad;
+  UInt32 fBgReserved[3];
+} EXT2_GROUP_DESCRIPTOR;
+
 struct PACKED EXT2_SUPER_BLOCK final {
   Kernel::UInt32 fInodeCount;
   Kernel::UInt32 fBlockCount;
@@ -55,7 +65,7 @@ struct PACKED EXT2_SUPER_BLOCK final {
   Kernel::UInt32 fWriteTime;
   Kernel::UInt16 fMountCount;
   Kernel::UInt16 fMaxMountCount;
-  Kernel::UInt16 fMagic;  // should be 0xEF53
+  Kernel::UInt16 fMagic;
   Kernel::UInt16 fState;
   Kernel::UInt16 fErrors;
   Kernel::UInt16 fMinorRevision;
@@ -78,7 +88,6 @@ struct PACKED EXT2_SUPER_BLOCK final {
   Kernel::Char   fLastMounted[64];
   Kernel::UInt32 fAlgoBitmap;
 
-  // Optional journal fields and padding
   Kernel::UInt8  fPreallocBlocks;
   Kernel::UInt8  fPreallocDirBlocks;
   Kernel::UInt16 fReservedGDTBlocks;
@@ -112,22 +121,28 @@ struct PACKED EXT2_INODE final {
   Kernel::UInt32 fFlags;
   Kernel::UInt32 fOSD1;
 
-  Kernel::UInt32
-      fBlock[15];  // 0-11: direct, 12: indirect, 13: double indirect, 14: triple indirect
+  Kernel::UInt32 fBlock[15];  // direct 0-11, indirect 12, double 13, triple 14
 
   Kernel::UInt32 fGeneration;
   Kernel::UInt32 fFileACL;
-  Kernel::UInt32 fDirACL;  // Only for revision 1+
+  Kernel::UInt32 fDirACL;
   Kernel::UInt32 fFragmentAddr;
 
   Kernel::UInt8 fOSD2[12];
 };
 
+/// Directory entry
 struct PACKED EXT2_DIR_ENTRY final {
   Kernel::UInt32 fInode;
   Kernel::UInt16 fRecordLength;
   Kernel::UInt8  fNameLength;
   Kernel::UInt8  fFileType;
-  Kernel::Char
-      fName[kExt2FSMaxFileNameLen];  // null-terminated, not fixed-length in actual on-disk layout
-};
\ No newline at end of file
+  Kernel::Char   fName[kExt2FSMaxFileNameLen];
+};
+
+/// VFS usage
+struct Ext2Node {
+  Kernel::UInt32 inodeNumber;
+  EXT2_INODE     inode;
+  Kernel::UInt32 cursor{0};
+};