cp_within_target
cp_within_target(EFIBOOT, "/boot/EFI/boot", 0);
ret = cp_within_target("/usr/mdec/boot", "/", 0);
cp_within_target(s, path, 0) :
ret = cp_within_target("/usr/mdec/prekern", "/prekern", 0);
int cp_within_target(const char *, const char *, int);