040000 tree 1d7a38175da54a4c64408deb064b4a907950c2ad	atomic
040000 tree 0601688e8126e1c914eaa4eb83d6c54ffe7b3416	math
040000 tree 7ea9e9e03b3c2c0654b5f7ab43781f5753bc9769	sys
040000 tree 4631fcf9b33e3f8bdfc9fd901540fd858f9416ca	syscall