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 OpenBSD's sys/types.h header.
7
8package unix
9
10// Major returns the major component of an OpenBSD device number.
11func Major(dev uint64) uint32 {
12	return uint32((dev & 0x0000ff00) >> 8)
13}
14
15// Minor returns the minor component of an OpenBSD device number.
16func Minor(dev uint64) uint32 {
17	minor := uint32((dev & 0x000000ff) >> 0)
18	minor |= uint32((dev & 0xffff0000) >> 8)
19	return minor
20}
21
22// Mkdev returns an OpenBSD device number generated from the given major and minor
23// components.
24func Mkdev(major, minor uint32) uint64 {
25	dev := (uint64(major) << 8) & 0x0000ff00
26	dev |= (uint64(minor) << 8) & 0xffff0000
27	dev |= (uint64(minor) << 0) & 0x000000ff
28	return dev
29}
30