NASM (Netwide Assembler) notes

rax (64-bit), eax (lower 32-bit), ah (higher 16-bit), al (lower 16-bit)
 
Same pattern: rax, rbx, rcx, rdx
 
rsp - stack pointer, points to the top of the stack.
rbp - stack base pointer, points to the base of the current stack frame.
rip - instruction pointer, points to the next instruction to be executed.

mov rax, rbx        ; rax = rbx
mov rax, [rbx]      ; rax = *rbx (rbx is a pointer)
mov rax, 1          ; rax = 1
 
int 0x80            ; Call OS interrupt

or  rax, rbx        ; rax = rax | rbx
and rax, rbx        ; rax = rax & rbx
xor rax, rbx        ; rax = rax ^ rbx
not rax             ; rax = ~rax
 
shl rax, 31         ; rax = rax << 31
shr rax, 2          ; rax = rax >> 2

xor rax, rax        ; rax = 0
 
; Clear 57 bit (counting from 0) in rbx register
and rbx, ~(1 << 57)
 
; Set 57 bit (counting from 0) in rbx register
or  rbx, ~(1 << 57)
 
; Toggle 57 bit (counting from 0) in rbx register
xor rbx, (1 << 57)