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diff --git a/docs/tex/hefs.tex b/docs/tex/hefs.tex index e74cf5e3..3370af48 100644 --- a/docs/tex/hefs.tex +++ b/docs/tex/hefs.tex @@ -1,32 +1,123 @@ \documentclass{article} -\usepackage[a4paper,margin=1in]{geometry} +\usepackage[a4paper, margin=1in]{geometry} +\usepackage{amsmath, amssymb} \usepackage{listings} \usepackage{xcolor} -\usepackage{amsmath} -\usepackage{hyperref} -\usepackage{longtable} -\usepackage{titlesec} -\usepackage{fancyhdr} -\usepackage{caption} \usepackage{graphicx} +\usepackage{enumitem} +\usepackage{caption} +\usepackage{longtable} -\definecolor{codegray}{gray}{0.95} -\lstset{ - backgroundcolor=\color{codegray}, +\definecolor{lightgray}{gray}{0.95} + +\lstdefinestyle{cstyle}{ + language=C++, + backgroundcolor=\color{lightgray}, basicstyle=\ttfamily\small, + keywordstyle=\color{blue}, + commentstyle=\color{green!60!black}, + stringstyle=\color{orange}, + numbers=left, + numberstyle=\tiny, breaklines=true, frame=single, - tabsize=4, - language=C++, showstringspaces=false } -\title{HeFS: High-Throughput Extended File System Specification} +\title{HeFS (Hierarchical Embedded File System) Specification} \author{Amlal El Mahrouss} -\date{2025} +\date{2024–2025} \begin{document} \maketitle -\end{document} +\section{Overview} +HeFS is a custom filesystem developed as part of the NeKernel project. It offers a journaling-like inode tree structure using red-black tree-inspired navigation for directories. Designed for robust use in desktop and server workloads, it supports various encoding modes and drive types. + +\section{Boot Node Structure} +\begin{longtable}{|l|l|p{8cm}|} +\hline +\textbf{Field} & \textbf{Type} & \textbf{Description} \\ +\hline +\verb|fMagic| & \verb|char[8]| & Filesystem magic (" HeFS") \\ +\verb|fVolName| & \verb|Utf16Char[128]| & Volume name \\ +\verb|fVersion| & \verb|UInt32| & Filesystem version (e.g., 0x0100) \\ +\verb|fSectorCount| & \verb|UInt64| & Total sector count \\ +\verb|fSectorSize| & \verb|UInt64| & Size of each sector \\ +\verb|fDriveKind| & \verb|UInt8| & Type of drive (e.g., HDD, SSD, USB) \\ +\verb|fEncoding| & \verb|UInt8| & Encoding mode (UTF-8, UTF-16, etc.) \\ +\verb|fStartIND| & \verb|UInt64| & Starting LBA of inode tree \\ +\verb|fEndIND| & \verb|UInt64| & Ending LBA of inode tree \\ +\verb|fChecksum| & \verb|UInt32| & CRC32 of boot node \\ +\verb|fDiskSize| & \verb|UInt64| & Logical size of the disk \\ +\hline +\end{longtable} + +\section{File Types and Flags} +\subsection*{File Kinds} +\begin{itemize}[label=--] + \item \verb|0x00| — Regular File + \item \verb|0x01| — Directory + \item \verb|0x02| — Block Device + \item \verb|0x03| — Character Device + \item \verb|0x04| — FIFO + \item \verb|0x05| — Socket + \item \verb|0x06| — Symbolic Link +\end{itemize} + +\subsection*{Drive Types} +\begin{itemize}[label=--] + \item \verb|0xC0| — Hard Drive + \item \verb|0xC1| — SSD + \item \verb|0xCC| — Mass Storage Device (USB) +\end{itemize} + +\section{Index Node Structure} +The inode tree allows for fast access and recovery via dual start/end block mappings and timestamped metadata. + +\begin{lstlisting}[style=cstyle, caption={HEFS\_INDEX\_NODE structure}] +struct HEFS_INDEX_NODE { + Utf16Char fName[256]; + UInt32 fFlags; + UInt16 fKind; + UInt32 fSize; + UInt32 fChecksum, fRecoverChecksum, fBlockChecksum, fLinkChecksum; + ATime fCreated, fAccessed, fModified, fDeleted; + UInt32 fUID, fGID; + UInt32 fMode; + UInt64 fBlockLinkStart[16], fBlockLinkEnd[16]; + UInt64 fBlockStart[16], fBlockEnd[16]; + UInt64 fBlockRecoveryStart[16], fBlockRecoveryEnd[16]; +}; +\end{lstlisting} + +\section{Directory Node Structure} +Each directory is a red-black tree node with child and sibling pointers. + +\begin{lstlisting}[style=cstyle, caption={HEFS\_INDEX\_NODE\_DIRECTORY structure}] +struct HEFS_INDEX_NODE_DIRECTORY { + Utf16Char fName[256]; + UInt32 fFlags; + UInt16 fKind; + UInt32 fSize; + UInt32 fChecksum, fIndexNodeChecksum; + ATime fCreated, fAccessed, fModified, fDeleted; + UInt32 fUID, fGID; + UInt32 fMode; + UInt64 fIndexNodeStart[16], fIndexNodeEnd[16]; + UInt8 fColor; + Lba fNext, fPrev, fChild, fParent; +}; +\end{lstlisting} + +\section{Future Work} +Planned extensions include: +\begin{itemize} + \item Journaling recovery logic + \item Advanced permission flags + \item Logical volume management support + \item Cross-filesystem linking (EPM integration) +\end{itemize} + +\end{document}
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