golang.org/x/sys@v0.20.1-0.20240517151509-673e0f94c16d/unix/dev_dragonfly.go (about)

     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  }