| // Copyright 2018 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // +build aix |
| // +build ppc |
| |
| // Functions to access/create device major and minor numbers matching the |
| // encoding used by the Linux kernel and glibc. |
| // |
| // The information below is extracted and adapted from bits/sysmacros.h in the |
| // glibc sources: |
| // |
| // dev_t in glibc is 64-bit, with 32-bit major and minor numbers. glibc's |
| // default encoding is MMMM Mmmm mmmM MMmm, where M is a hex digit of the major |
| // number and m is a hex digit of the minor number. This is backward compatible |
| // with legacy systems where dev_t is 16 bits wide, encoded as MMmm. It is also |
| // backward compatible with the Linux kernel, which for some architectures uses |
| // 32-bit dev_t, encoded as mmmM MMmm. |
| |
| package unix |
| |
| // Major returns the major component of a Linux device number. |
| func Major(dev uint64) uint32 { |
| return uint32((dev >> 16) & 0xffff) |
| } |
| |
| // Minor returns the minor component of a Linux device number. |
| func Minor(dev uint64) uint32 { |
| return uint32(dev & 0xffff) |
| } |
| |
| // Mkdev returns a Linux device number generated from the given major and minor |
| // components. |
| func Mkdev(major, minor uint32) uint64 { |
| return uint64(((major) << 16) | (minor)) |
| } |