dev_openbsd.go raw

   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  
   8  package unix
   9  
  10  // Major returns the major component of an OpenBSD device number.
  11  func Major(dev uint64) uint32 {
  12  	return uint32((dev & 0x0000ff00) >> 8)
  13  }
  14  
  15  // Minor returns the minor component of an OpenBSD device number.
  16  func 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.
  24  func 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