Best Resources for Learning x86 Assembly Language

Learning x86 Assembly Language can be a rewarding but challenging task. A strong foundation in computer architecture is beneficial, and starting with a simpler assembler like MIPS can ease the transition. Once you are familiar with the basics, diving into x86 assembly will be less daunting.

Books to Start With

There are several excellent books that can help you get started with x86 Assembly. A CSAPP (Computer Systems: A Programmer's Perspective) is highly recommended. Although it is not specifically tailored for Intel x86 assembly, it provides a comprehensive understanding of the underlying concepts, which can be beneficial for learning assembly.

Another invaluable resource is the Art of Assembly Language. This book is widely regarded as the 'bible' of x86 assembly and offers a thorough introduction, starting from chapter 3. It covers everything you need from the basics to more complex concepts.

For those using GNU/Linux, Assembly Language Step by Step by Jeff Duntemann is also an excellent choice.

Online Resources and Emulators

In addition to books, online resources and emulators can be very helpful.
Agner Fog's instruction tables provide detailed information on the performance of different x86 instructions. This can be immensely useful for performance optimization tasks.

For a hands-on approach, you might consider using an x86 emulator such as wabt (WebAssembly Table Format). Reading through the source code can provide insights into the inner workings of x86 assembly.

Another useful tool is the classic debug.exe, a command-line debugger originally included in MS-DOS. If you can find an older machine with debug.exe, you can run small assembly programs and even reverse engineer parts of the BIOS or OS. The process of reverse engineering can be educational, as you can document your findings by redirecting the output to a file, labeling it, and adding comments.

Here is a sample command you can use to redirect the debugger's output:

This command will capture all the debugger's output to a file named myfile.txt.

Lastly, the gx86 x86 emulator in JavaScript provides a graphical interface for running x86 programs in a browser. The source code of this emulator is rich with explanations that parallel the documentation provided by Intel, offering a deep dive into how x86 assembly works.

Conclusion

Learning x86 Assembly Language can be a challenging but immensely rewarding task. By combining books, online resources, and practical tools, you can gain a solid understanding of this powerful programming language. Remember, the key to mastering assembly is practice, so start experimenting with simple programs and gradually move to more complex ones.