read(fd Int, address Pointer, length Int) -> Int { return syscall(0x2000003, fd, address, length) } write(fd Int, address Pointer, length Int) -> Int { return syscall(0x2000004, fd, address, length) } open(file Pointer, flags Int, mode Int) -> Int { return syscall(0x2000005, file, flags, mode) } close(fd Int) -> Int { return syscall(0x2000006, fd) }