ISO9660

ISO9660

The ISO-9660 standard for CD-ROM filesystems, implemented in JNode's org.jnode.fs.iso9660 plugin.

Overview

ISO-9660 is an international standard filesystem for CD-ROM media. JNode provides read/write support through its ISO-9660 filesystem plugin.

Key Components

File	Purpose
fs/src/fs/org/jnode/fs/iso9660/ISO9660FileSystem.java	Main filesystem implementation
fs/src/fs/org/jnode/fs/iso9660/ISO9660FileSystemType.java	Filesystem type factory
fs/src/fs/org/jnode/fs/iso9660/ISO9660Volume.java	Volume descriptor parsing
fs/src/fs/org/jnode/fs/iso9660/ISO9660Directory.java	Directory entry handling
fs/src/fs/org/jnode/fs/iso9660/ISO9660File.java	File entry handling
fs/src/fs/org/jnode/fs/iso9660/ISO9660Entry.java	Base entry class
fs/src/fs/org/jnode/fs/iso9660/EntryRecord.java	Directory record parsing
fs/src/fs/org/jnode/fs/iso9660/Descriptor.java	Volume descriptor base class
fs/src/fs/org/jnode/fs/iso9660/PrimaryVolumeDescriptor.java	Primary volume descriptor
fs/src/fs/org/jnode/fs/iso9660/SupplementaryVolumeDescriptor.java	Supplementary volume descriptor
fs/src/fs/org/jnode/fs/iso9660/VolumeDescriptor.java	Volume descriptor wrapper
fs/src/fs/org/jnode/fs/iso9660/ISO9660DTime.java	Date/time structure
fs/src/fs/org/jnode/fs/iso9660/ISO9660Constants.java	Constants (volume types, separators)

ISO-9660 Structure

Volume Descriptors

The ISO-9660 filesystem begins with a sequence of volume descriptors:

• Boot Record (type 0) — Bootable system information
• Primary Volume Descriptor (type 1) — Main volume metadata
• Supplementary Volume Descriptor (type 2) — Joliet extension support
• Partition Descriptor (type 3) — Volume partition information
• Volume Descriptor Set Terminator (type 255) — End of descriptor sequence

Directory Structure

ISO-9660 uses a root directory entry at sector 16 (for standard media). Directory entries contain:

• Length of Directory Record (LENGTH)
• Extended Attribute Record Length (EATR)
• Location of Extent (LBA)
• Data Length of Extent (size)
• Recording date/time
• File flags (directory, hidden, etc.)
• Filename (8.3 format: NAME.EXT;VERSION)

JNode Implementation

JNode's ISO-9660 implementation:

• Supports ISO-9660 Level 1 (8.3 filenames, ASCII only)
• Supports ISO-9660 Level 2 (up to 31 character filenames)
• Parses both primary and supplementary volume descriptors
• Implements directory iteration via ISO9660Directory
• Provides file access via ISO9660File

Related Pages

• Boot-CD-ROM-Builder — How ISO images are created during build
• FileSystemType — Filesystem plugin interface
• VFS-Layer — Virtual filesystem layer