Boot File System

The Boot File System (named BFS on Linux, but BFS also refers to the Be File System) was used on UnixWare to store files necessary to its boot process.^[1]

BFS

Developer(s)	Bell Labs[citation needed]
Full name	Boot File System
Introduced	with UNIX System V
Partition IDs	0x63 (MBR)
Structures
Directory contents	single inode table
File allocation	16-bit inodes
Limits
Max filename length	14 characters
Other
Supported operating systems	SVR4, UnixWare[citation needed]

It does not support directories, and only allows contiguous allocation for files, to make it simpler to be used by the boot loader.

Implementations

Besides the UnixWare support, Martin Hinner wrote a bfs kernel module for Linux that supports it.^[2]

He documented the file system layout as part of the process.^[3]

The Linux kernel implementation of BFS was written by Tigran Aivazian and it became part of the standard kernel sources on 28 October 1999 (Linux version 2.3.25).^[4]

The original BFS was written at AT&T Bell Laboratories for the UNIX System V, Version 4.0 porting base in 1986.^{[citation needed]} It was written by Ron Schnell, who is also the author of Dunnet (game).^{[citation needed]}

BFS was the first non-S5^{[clarification needed]} (System V) Filesystem written using VFS (Virtual Filesystem) for AT&T UNIX.