We need a text section to store the program instructions, and a bss section to store our variable. (It’s pretty bad practice.) But in Assembly, that’s all you have. You’d be forgiven for not knowing this is valid C code. For now, here are some examples: mov, 5 var = 5 We’ll go into more detail about these instructions later. You should already be familiar with what these do – they help explain your code to other people who are reading it. Jumps to a part of the program if the two values are equalĬomments in Assembly are anything that comes after a semicolon ( ). There are many instructions in Assembly, but we’ll focus on the following ones. StatementsĪ statement in Assembly follows the following format: mnemonic To access the value of var, we surround its name in square brackets. If we wanted to reserve two bytes, we would’ve put a 2 at the end. This creates a variable called var and reserves four bytes for it. Instead, we can tell the assembler exactly how many bytes to reserve. We can’t just declare their value, like in a normal language. Variables, as we’ve already talked about, are stored in the bss section. For example, the data section would be declared using: section. Sections are declared simply by typing section. data - This section is used for constant globals.bss - All of the global variables are stored here.text - This section contains the actual instructions that your code will run.Experience in low-level programming (C, C++, Rust, and Go are good languages to know)Įxecutable programs can be divided into three sections ( you can use more, but this tutorial will stick to three).An Assembler (NASM on Linux or MASM on Windows).

A 32-bit or 64-bit operating system (preferably Linux).An x86 computer (This won’t work on a Raspberry Pi, for example).Different computers need different code to work. Programs that have to work directly with hardware, such as driversĪssembly isn’t the same on all systems, unfortunately.Assembly makes it easier to calculate exactly how long a program will take to run.Aggressive optimization (C and Rust are already very fast, but they’re not perfect).This is certainly easier than using Assembly, but to this day, there are still tasks which systems programming languages cannot accomplish. The next step above that would be to use a programming language, such as C, Java, or Typescript. The difference is that Assembly makes these instructions human-readable. Enter AssemblyĪssembly is still really down to the metal, where every detail of how the computer does its task must be specified. The problem is that it’s very difficult to look at hexadecimal and decipher what it does.

Just type in the hexadecimal code and let it run.

Eventually, someone got the bright idea to have the computer be programmable. In the beginning, there were punch cards.

Mac assembly language