Other existing machines have individual syscalls. See e.g. sysdeps/unix/sysv/linux/ia64/syscalls.list sysdeps/unix/sysv/linux/x86_64/syscalls.list sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list Calls defined there override sysdeps/unix/sysv/linux/foo.c implementations. Thanks, Roland