Let's Learn x86-64 Assembly! Part 0 - Setup and First Steps
published on Apr 18 2020
The way I was taught x86 assembly at the university had been completely outdated for many years by the time I had my first class. It was around 2008 or 2009, and 64-bit processors had already started becoming a thing even in my neck of the woods. Meanwhile, we were doing DOS, real-mode, memory segmentation and all the other stuff from the bad old days.
Nevertheless, I picked up enough of it during the classes (and over the subsequent years) to be able to understand the stuff coming out of the other end of a compiler, and that has helped me a few times. However, I've never manually written any substantial amount of x86 assembly for something non-trivial. Due to being locked up inside (on account of a global pandemic), I decided to change that situation, to pass the time.
I wanted to focus on x86-64 specifically, and completely forget/skip any and all legacy crap that is no longer relevant for this architecture. After getting a bit deeper into it, I also decided to publish my notes in the form of tutorials on this blog since there seems to be a desire for this type of content.
Everything I write in these posts will be a normal, 64-bit, Windows program. We'll be using Windows because that is the OS I'm running on all of my non-work machines, and when you drop down to the level of writing assembly it starts becoming incresingly impossible to ignore the operating system you're running on. I will also try to go as "from scratch" as possible - no libraries, we're only allowed to call out to the operating system and that's it.
In this first, introductory part (yeah, I'm planning a series and I know I will regret this later), I will talk about the tools we will need, show how to use them, explain how I generally think about programming in assembly and show how to write what is perhaps the smallest viable Windows program.
Getting the Tools
There are two main tools that we will use throughout this series.
Assembler
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