In computing, busdma is a set of APIs designed to help make device drivers less dependent on platform specific code, allowing the host operating system to be more easily ported to new computer hardware.

Originally implemented as the bus_dma APIs by the developers of the NetBSD operating system, busdma has been adopted by OpenBSD, FreeBSD and their derivitives. Both NetBSD and OpenBSD have additional "bus_space" APIs that have been amalgamated into the version of busdma incorporated into FreeBSD. DragonFly BSD developers are also slowly converting their drivers to use busdma.

External Links:

• NetBSD bus_dma manual page (http://netbsd.gw.com/cgi-bin/man-cgi?bus_dma++NetBSD-current)
• FreeBSD busdma and SMPng driver conversion project page (http://www.freebsd.org/projects/busdma/)
• FreeBSD busdma manual page (http://www.freebsd.org/cgi/man.cgi?query=busdma&apropos=0&sektion=0&manpath=FreeBSD+5.2-RELEASE+and+Ports&format=html)