040000 tree b028d3ed0afd38127bdc351ccc8692adadd11aff	boot_serial
040000 tree be5e0d7c96817ff30375eecb0bfc194a3cc9b4fe	bootutil
040000 tree f0ea30b9e7c6400e65da113e559ede976449d40e	mynewt
040000 tree f41c05ebfc6f59e9e7dd1db2ede931f15dbe1c21	zephyr