pyasm2 - x86 assembler library (C) 2012 Jurriaan Bremer

Although its called pyasm2, this is not per se a successor of Pyasm or pyASM. pyasm2 aims to be as flexible as possible, it will support x86, SSE and SSE2.

A key feature of pyasm2 is the ability to have blocks of instructions and being able to give the base address at a later time, that is, you don't need to know the address of instructions before-hand. For example, you can construct a series of instructions, request the size that will be needed in order to store all instructions as sequence, allocate this memory and write the instructions from there, this approach is very useful when making JIT compilers etc.

The syntax of pyasm2 is supposed to be as simple as possible.

For example, an instruction such as "mov eax, dword [ebx+edx*2+32]" can be encoded using pyasm2 as the following.

mov(eax, dword [ebx+edx*2+32])

These memory addresses also support segment registers, e.g.

mov(eax, dword[fs:0xc0])

although this is currently only supported in 64bit python versions.

Furthermore, pyasm2 makes it possible to chain multiple instructions. Take for example the following statement.

block(mov(eax, ebx), push(32))

However, for more implementation-specific details, please refer to the IMPLEMENTATION file.