As I usually have a few classes at school which requires special software, I wanted to be able to run some of this software on my own computer, as there are student versions of some of the software. One of these is ModelSim from MentorGraphics. ModelSim is basically a simulator for hardware designs, and I use it to simulate VHDL. Unfortunately, ModelSim only comes for Windows, Linux and Solaris. As I only run FreeBSD on my laptop, no software for me :( But wait, FreeBSD have the linuxulator!, which allows Linux binaries to be run unmodified on a FreeBSD host (It is basically an implementation of Linux syscalls within the FreeBSD kernel). The steps I needed to go through to install the Linux version of ModelSim was pretty easy.

First of all, one of the emulators/linux_base* ports needs to be installed. I chose linux_base-fc6, as I’d like the Linux 2.6 support (although I’m not sure if that is actually needed). After installing the port, a linux userland appears in /compat/linux. To make sure I don’t get any problems with programs needing procfs, I mount linprocfs(5) as well.

There, easy! Ready to run linux programs. Now, ModelSim comes with its own installer, which needs a few additional files that you can get at their web-site. However, programs may depend on additional libraries, and this is IMO the most tricky part about the linuxulator. In my case, I got some errors complaining about not finding libXsomething. Luckily, there are a few ports that you can install for the most common libraries. In this case, I had to install x11/linux-xorg-libs. Although a very old version, I was able to run the ModelSim installer and the installed binaries afterwards. Awesome!