| Holger Hildebrandt | fa07499 | 2020-03-27 15:42:06 +0000 | [diff] [blame] | 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 | } |