From 044b1eceac05368adaac03cbd094f2c970960f07 Mon Sep 17 00:00:00 2001 From: Tom-on64 Date: Wed, 31 Jul 2024 13:05:16 +0200 Subject: [PATCH] Added Filesystem Specification --- docs/fs-spec.txt | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) create mode 100644 docs/fs-spec.txt diff --git a/docs/fs-spec.txt b/docs/fs-spec.txt new file mode 100644 index 0000000..dc6f88b --- /dev/null +++ b/docs/fs-spec.txt @@ -0,0 +1,39 @@ += fsys = + +Sector = 512 Bytes +Block = 4096 Bytes + +Reserved sectors: + Sector 0 - Bootsector, will be loaded by the Bios into memory and executed (512B) + Sector 1..4 - Superblock, contains metadata about the filesystem itself (4KiB) + +Superblock structure: (4096B) + FS Name + FS Size (Sector) + FS Size (Block) + INode Count + INodes per sector + INode Bitmap Block + Data Bitmap Block + INodes Start + Data Start + Root INode Number + Extents per indirect + +INode structure: (64B) + Type + Size (bytes) + Block Count (size in blocks) + Mode + Extents[] + Single Indirect + Double Indirect? + +Extent: (8B) + Block + Length + +Directory Entry: (64B) + INode Number + Name (max length 60 Bytes) +