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 14package unix 15 16// Major returns the major component of a DragonFlyBSD device number. 17func Major(dev uint64) uint32 { 18 return uint32((dev >> 8) & 0xff) 19} 20 21// Minor returns the minor component of a DragonFlyBSD device number. 22func 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. 28func Mkdev(major, minor uint32) uint64 { 29 return (uint64(major) << 8) | uint64(minor) 30} 31