It is a simple to use RAM-based file system specially designed for debugging purposes. debugfs exists as a simple way for kernel developers to make information available to user space.
Unlike /proc, which is only meant for information about a process, or sysfs, which has strict one-value-per-file rules, debugfs has no rules at all. Developers can put any information they want there.
To compile a Linux kernel with the debugfs facility, the CONFIG_DEBUG_FS option must be set to yes.
It is typically mounted in /sys/kernel/debug with a command like:
mount -t debugfs none /sys/kernel/debug
It can be manipulated using several calls from the C header file linux/debugfs.h
- debugfs_create_file — for creating a file in the debug filesystem
- debugfs_create_dir — for creating a directory inside the debug filesystem
- debugfs_remove — for removing a debugfs entry from the debug filesytem.
- Linux: DebugFS, by Jeremy, December 11, 2004, KernelTrap. (Announcement of debugfs by Greg KH.)
- Debugfs, Posted:December 13, 2004, by corbet, LWN
- Linux Kernel Documentation :: filesystems : debugfs.txt documentation from the source code (Based on kernel version 22.214.171.124. Page generated on 2010-09-02 21:39 EST.)
- An updated guide to debugfs, By Jonathan Corbet, May 25, 2009, LWN
- 2.5 Debugfs A guide to using debugfs, Ariane Keller, Version 0.8, July 2008, Kernel Space - User Space Interfaces