Setting up Linux compatibility on FreeBSD 6

Are you using FreeBSD for your OS? Then today is your day to shine. Yup, since we spend so much time talking about Linux and the like, I figured that it might be high time to toss some FreeBSD goodies into the mix for a change…

As a FreeBSD desktop user I occasionally feel left out when it comes to the availability of applications, particularly desktop applications or binary-only browser plugins produced by commercial closed source vendors. Sometimes a good alternative lurks in the vast FreeBSD ports collection, but not always. The version available may lag a couple of revisions behind what I need, or the port might exclude my particular architecture. Fortunately, FreeBSD can run binaries and shared libraries that have been compiled for Linux and other Unix ABIs (such as SVR4 and SCO).

In this article I will cover the steps necessary to enable and configure Linux binary compatibility on FreeBSD 6. I’ll also share a couple of my own experiences with getting some well-known desktop Linux applications to run on FreeBSD 6.

How does it work?

Although it is by no means essential to understand how Linux compatibility actually works, it sometimes helps to have an idea when it comes to problem solving.

Linux compatibility isn’t instruction-level emulation or some kind of virtual machine. The Linux ABI is implemented in the FreeBSD kernel, so in most senses the Linux binaries could be considered to be running natively. Through what appears to be some sleight-of-hand the system selects at run time the Right Thing to do to run an executable. This is partly figured out based on branding information encoded in an ELF binary header. A command-line tool called brandelf can be used to report the brand: Source: NewsForge

[tags]sco,freebsd,closed source vendors,desktop users,linux binary compatibility[/tags]