1 // Copyright 2017 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 // Functions to access/create device major and minor numbers matching the 6 // encoding used in Dragonfly's sys/types.h header. 7 // 8 // The information below is extracted and adapted from sys/types.h: 9 // 10 // Minor gives a cookie instead of an index since in order to avoid changing the 11 // meanings of bits 0-15 or wasting time and space shifting bits 16-31 for 12 // devices that don't use them. 13 14 package unix 15 16 // Major returns the major component of a DragonFlyBSD device number. 17 func Major(dev uint64) uint32 { 18 return uint32((dev >> 8) & 0xff) 19 } 20 21 // Minor returns the minor component of a DragonFlyBSD device number. 22 func Minor(dev uint64) uint32 { 23 return uint32(dev & 0xffff00ff) 24 } 25 26 // Mkdev returns a DragonFlyBSD device number generated from the given major and 27 // minor components. 28 func Mkdev(major, minor uint32) uint64 { 29 return (uint64(major) << 8) | uint64(minor) 30 } 31