The Assembler
The processor understand the instructions as numbers.
Every opcode was given a mnemonic to make it easier to remember.
For example:
| Encoding | Instruction |
|---|---|
B8 03 00 00 00 | mov eax, 3 |
F7 F1 | div ecx |
The assembler translates the text based instructions into numeric encoding.
Common x86 Assemblers
- MASM (Microsoft Macro Assembler)
- NASM (Netwide Assembler): cross platform.
- GAS (GNU Assembler): cross platform.
- FASM (Flat Assembler): cross platform written in assembly.