#include void __movsb(unsigned char *Destination, unsigned char const *Source, size_t Count) { __asm__ __volatile__ ( "rep; movsb" : [Destination] "=D" (Destination), [Source] "=S" (Source), [Count] "=c" (Count) : "[Destination]" (Destination), "[Source]" (Source), "[Count]" (Count) ); }