linuxptp/README.org

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* Introduction
This software is an implementation of the Precision Time Protocol
(PTP) according to IEEE standard 1588 for Linux. The dual design
goals are to provide a robust implementation of the standard and to
use the most relevant and modern Application Programming Interfaces
(API) offered by the Linux kernel. Supporting legacy APIs and other
platforms is not a goal.
* License
The software is copyrighted by the authors and is licensed under the
GNU General Public License. See the file, COPYING, for details of
the license terms.
* Features
- Supports hardware and software time stamping via the Linux
SO_TIMESTAMPING socket option.
- Supports the Linux PTP Hardware Clock (PHC) subsystem by using the
clock_gettime family of calls, including the clock_adjtimex system
call.
- Implements Boundary Clock (BC), Ordinary Clock (OC) and
Transparent Clock (TC).
- Transport over UDP/IPv4, UDP/IPv6, and raw Ethernet (Layer 2).
- Supports IEEE 802.1AS-2011 in the role of end station.
- Modular design allowing painless addition of new transports and
clock servos.
- Implements unicast operation.
- Supports a number of profiles, including:
- The automotive profile
- The default 1588 profile.
- The enterprise profile.
- The telecom profiles G.8265.1, G.8275.1, and G.8275.2.
- Supports the NetSync Monitor protocol.
- Implements Peer to peer one-step.
- Supports bonded, IPoIB, and vlan interfaces.
* Getting the Code
You can download the latest released version at Source Forge.
http://sourceforge.net/projects/linuxptp/files/latest/download
The source code is managed using the git version control system. To
get your own copy of the project sources, use the following command.
#+BEGIN_EXAMPLE
git clone git://git.code.sf.net/p/linuxptp/code linuxptp
#+END_EXAMPLE
If the git protocol is blocked by your local area network, then you
can use the alternative HTTP protocol instead.
#+BEGIN_EXAMPLE
git clone http://git.code.sf.net/p/linuxptp/code linuxptp
#+END_EXAMPLE
* System Requirements
In order to run this software, you need Linux kernel version 3.0 or
newer. Check whether your network interface supports PTP with the
following command.
#+BEGIN_EXAMPLE
ethtool -T eth0
#+END_EXAMPLE
This command shows whether a MAC supports hardware or software time
stamping. The following example output indicates support for
hardware time stamping.
#+BEGIN_EXAMPLE
Time stamping parameters for eth6:
Capabilities:
hardware-transmit (SOF_TIMESTAMPING_TX_HARDWARE)
software-transmit (SOF_TIMESTAMPING_TX_SOFTWARE)
hardware-receive (SOF_TIMESTAMPING_RX_HARDWARE)
software-receive (SOF_TIMESTAMPING_RX_SOFTWARE)
software-system-clock (SOF_TIMESTAMPING_SOFTWARE)
hardware-raw-clock (SOF_TIMESTAMPING_RAW_HARDWARE)
PTP Hardware Clock: 1
Hardware Transmit Timestamp Modes:
off (HWTSTAMP_TX_OFF)
on (HWTSTAMP_TX_ON)
Hardware Receive Filter Modes:
none (HWTSTAMP_FILTER_NONE)
all (HWTSTAMP_FILTER_ALL)
#+END_EXAMPLE
The next example shows the case where the MAC only supports software
time stamping. The ~ptp4l~ program requires either the ~-S~ command
line argument or the ~time_stamping software~ configuration option
when using such interfaces.
#+BEGIN_EXAMPLE
Time stamping parameters for enp6s0:
Capabilities:
software-transmit (SOF_TIMESTAMPING_TX_SOFTWARE)
software-receive (SOF_TIMESTAMPING_RX_SOFTWARE)
software-system-clock (SOF_TIMESTAMPING_SOFTWARE)
PTP Hardware Clock: none
Hardware Transmit Timestamp Modes: none
Hardware Receive Filter Modes: none
#+END_EXAMPLE
Note the ~software-transmit (SOF_TIMESTAMPING_TX_SOFTWARE)~
capability. If this is lacking, then the MAC cannot be used at
all. However, adding this capability entails adding a single line
of code to the device driver.
* Installation
1. Just type 'make'
2. If you compiled your own kernel (and the headers are not
installed into the system path), then you should set the
KBUILD_OUTPUT environment variable as in the example, above.
3. In order to install the programs and man pages into /usr/local,
run the 'make install' target. You can change the installation
directories by setttings the variables prefix, sbindir, mandir,
and man8dir on the make command line.
* Getting Involved
The software development is hosted at Source Forge.
https://sourceforge.net/projects/linuxptp/
** Reporting Bugs
Please report any bugs or other issues with the software to the
linuxptp-users mailing list.
https://lists.sourceforge.net/lists/listinfo/linuxptp-users
** Development
If you would like to get involved in improving the software, please
join the linuxptp-devel mailing list.
https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
*** Submitting Patches
1. Before submitting patches, please make sure that you are starting
your work on the *current HEAD* of the git repository.
2. Please checkout the ~CODING_STYLE.org~ file for guidelines on how to
properly format your code.
3. Describe your changes. Each patch will be reviewed, and the reviewers
need to understand why you did what you did.
4. *Sign-Off* each commit, so the changes can be properly attributed to
you and you explicitely give your agreement for distribution under
linuxptp's license. Signing-off is as simple as:
#+BEGIN_EXAMPLE
git commit -s
#+END_EXAMPLE
or by adding the following line (replace your real name and email)
to your patch:
#+BEGIN_EXAMPLE
Signed-off-by: Random J Developer <random@developer.example.org>
#+END_EXAMPLE
5. Finally, send your patches via email to the linuxptp-devel mailing
list, where they will be reviewed, and eventually be included in the
official code base.
#+BEGIN_EXAMPLE
git send-email --to linuxptp-devel@lists.sourceforge.net origin/master
#+END_EXAMPLE
* Thanks
Thanks to AudioScience Inc for sponsoring the 8021.AS support.
- http://www.audioscience.com
Thanks to Exablaze for donating an ExaNIC X10
- http://exablaze.com/exanic-x10
Thanks to Intel Corporation for donating four NICs, the 82574,
82580, 82599, and the i210.
- http://www.intel.com
- http://e1000.sourceforge.net
Thanks to Meinberg Funkuhren for donating a LANTIME M1000.
- https://www.meinbergglobal.com
Thanks to Moser Baer for sponsoring the Telecom Profiles and unicast
support.
- http://www.mobatime.com
For testing I use an OTMC 100 grandmaster clock donated by OMICRON Lab.
- http://www.omicron-lab.com/ptp