I recently went through Open Security Training's Intro to x86 assembly programming. Here is a quick review.

Reference: Open Security Training Website and Youtube Playlist

In general, I thought this was a worthwhile course to go through, despite having a pretty firm grasp on the material. I watched it at 2x speed and did do most of the suggested exercises.

Its free and posted under Creative Commons, which is extremely generous.

However, because it was a live class, there was definitely a fair amount of 'dead air' in between examples and when students were getting set up. The audio and video quality are not particularly good, either.

I did start to take the intermediate x86 class, and I have to say its much worse quality based on my individual learning style. They spend a ton of time on topics which seem to be important (GDT/LDT for one), but it lacked a lot of context as to why this is important to understand, where it fits into the overall topic and how what is being described is relevant. For instance, talking about how to parse a GDT on a particular system, what particular offsets are for particular types of data and so on. For me, this is the type of thing that should land in a reference text until its time to get down to concrete examples of why something is relevant.

I have since switched over to Hardware Software Interface which is an unmaintained University of Washington course. I am finding it to be more to my style of learning without getting too bogged down in minutia. This is definitely not going as deep as some of the OST.info materials, but I feel like I'm getting a refresher and a roadmap for future deep dives.