1 // Copyright 2018 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.
8 // Functions to access/create device major and minor numbers matching the
13 // Major returns the major component of a Linux device number.
14 func Major(dev uint64) uint32 {
15 return uint32((dev & 0x3fffffff00000000) >> 32)
18 // Minor returns the minor component of a Linux device number.
19 func Minor(dev uint64) uint32 {
20 return uint32((dev & 0x00000000ffffffff) >> 0)
23 // Mkdev returns a Linux device number generated from the given major and minor
25 func Mkdev(major, minor uint32) uint64 {
27 DEVNO64 = 0x8000000000000000
28 return ((uint64(major) << 32) | (uint64(minor) & 0x00000000FFFFFFFF) | DEVNO64)