Overview
ISO/IEC 13346-2:1999 defines the volume and boot block recognition requirements for write-once and rewritable media that use non-sequential recording (e.g., many optical and removable media). Part 2 is one element of the ISO/IEC 13346 family and specifies the format and system-level rules used to detect volumes and boot descriptors on media, so systems can reliably identify, interpret and optionally boot from recorded media. The standard covers sector numbering, the layout of a volume recognition space and volume recognition area, and the recorded descriptor sequences used to advertise volume and boot information.
Key topics and technical requirements
- Sector addressing and numbering: sectors are numbered with consecutive integers starting at sector 0 for the initial sector; sector numbers reflect ascending physical addresses per the relevant recording standard.
- Volume recognition space and area: a contiguous sequence of sectors is defined as the volume recognition space; the volume recognition area contains the descriptor-based volume recognition sequence beginning after byte 32 767 of that space.
- Descriptor-based recognition: a volume recognition sequence is composed of a set of descriptors (Volume Structure Descriptor, Beginning/Terminating Extended Area Descriptors, Boot Descriptor, etc.) recorded on sector boundaries. Each descriptor identifies the standard or clause that specifies how to interpret its contents.
- Boot descriptors: Boot Descriptor structures provide information intended to bring a system to a known state (architecture type, boot extent location/length, load/start addresses, flags, creation date/time, boot use).
- Levels of medium interchange: the standard defines interchange levels (Level 1, Level 2) that establish expectations for compatibility between originating and receiving systems.
- System requirements and conformance: specifies required functions for originating systems (to produce conforming media) and for receiving systems (to locate, interpret and optionally use boot/volume data).
Applications and practical value
- Ensures interoperability of removable media between authoring systems, operating systems, firmware and boot loaders.
- Used by developers of optical disc formats, file-system implementers, device firmware engineers, and system integrators to support bootable media and standardized volume recognition.
- Supports archiving, software distribution, embedded system deployment and cross-platform media exchange where predictable boot behavior and volume discovery are required.
Who should use this standard
- Firmware and boot-loader engineers
- Optical media authors and mastering tool developers
- File system and OS developers implementing media recognition
- Hardware vendors and integrators building drives and readers
Related standards
- ISO/IEC 13346 (Parts 1, 3, 4, 5) - the multi-part volume and file structure framework
- ECMA-167 (equivalent origin) and prior volume/file standards such as ISO 9660 (for historic comparison)
Keywords: ISO/IEC 13346-2, volume recognition, boot descriptor, write-once media, rewritable media, non-sequential recording, volume recognition space, boot block recognition, medium interchange, volume structure descriptor.
