You get this error because your assembly is malformatted. Register accesses are done like %eax
, $
is used for immediate operands. Furthermore, GCC, by default (see DanielKO's comment), uses the AT&T syntax, which has the destination on the right and the source on the left. Is this what you are looking for?
mov $0xcf, %eax
Also, your pusha
is unbalanced, ie you don't clean up the stack correctly before you return from your function. It would be nice to know what your overall goal is, because right now it seems like you copied and pasted only an incomplete fraction of the source.