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.
5 // Functions to access/create device major and minor numbers matching the
6 // encoding used in Dragonfly's sys/types.h header.
8 // The information below is extracted and adapted from sys/types.h:
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.
16 // Major returns the major component of a DragonFlyBSD device number.
17 func Major(dev uint64) uint32 {
18 return uint32((dev >> 8) & 0xff)
21 // Minor returns the minor component of a DragonFlyBSD device number.
22 func Minor(dev uint64) uint32 {
23 return uint32(dev & 0xffff00ff)
26 // Mkdev returns a DragonFlyBSD device number generated from the given major and
28 func Mkdev(major, minor uint32) uint64 {
29 return (uint64(major) << 8) | uint64(minor)