Assembly

A few cheatsheet-like things about the Assembly language

Registers

Generally, r-prefixed registers are 64-bit, e-prefixed registers are 32-bit, non-prefixed registers are 16-bit, and l-suffixed registers are 8-bit. For r8-15 see the special cases below (source):

64-bit register	Lower 32 bits	Lower 16 bits	Lower 8 bits
rax	eax	ax	al
rbx	ebx	bx	bl
rcx	ecx	cx	cl
rdx	edx	dx	dl
rsi	esi	si	sil
rdi	edi	di	dil
rbp	ebp	bp	bpl
rsp	esp	sp	spl
r8	r8d	r8w	r8b (r8l)
r9	r9d	r9w	r9b (r9l)
r10	r10d	r10w	r10b (r10l)
r11	r11d	r11w	r11b (r11l)
r12	r12d	r12w	r12b (r12l)
r13	r13d	r13w	r13b (r13l)
r14	r14d	r14w	r14b (r14l)
r15	r15d	r15w	r15b (r15l)

See Shellcode for writing malicious Assembly code and some examples of compiling