In computing

Computing

Computing is usually defined as the activity of using and improving computer hardware and software. It is the computer-specific part of information technology...

, romfs (ROM filesystem) is an extremely simple file system

File system

A file system is a means to organize data expected to be retained after a program terminates by providing procedures to store, retrieve and update data, as well as manage the available space on the device which contain it. A file system organizes data in an efficient manner and is tuned to the...

 lacking many features, intended for burning important files onto an EEPROM

EEPROM

EEPROM stands for Electrically Erasable Programmable Read-Only Memory and is a type of non-volatile memory used in computers and other electronic devices to store small amounts of data that must be saved when power is removed, e.g., calibration...

. It is available on Linux

Linux

Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

, and possibly other Unix-like

Unix-like

A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....

 systems.

It is very useful as an initial ROM holding kernel modules that can be loaded later as needed. It is very small, code wise.

The description of the filesystem layout is available on LXR -- romfs.txt.

Bo Brantén has created a RomFS file system driver for Windows NT/2k/XP.

Nikolay Aleksandrov has written RomFS image extraction and manipulation tool called romfser. Primarily targeted at the BSD family of operating systems because they lack support for RomFS.