Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) .. SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) ==================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) Linux X.25 Project
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) ==================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) As my third year dissertation at University I have taken it upon myself to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) write an X.25 implementation for Linux. My aim is to provide a complete X.25
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) Packet Layer and a LAPB module to allow for "normal" X.25 to be run using
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) Linux. There are two sorts of X.25 cards available, intelligent ones that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) implement LAPB on the card itself, and unintelligent ones that simply do
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) framing, bit-stuffing and checksumming. These both need to be handled by the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) I therefore decided to write the implementation such that as far as the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) Packet Layer is concerned, the link layer was being performed by a lower
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) layer of the Linux kernel and therefore it did not concern itself with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) implementation of LAPB. Therefore the LAPB modules would be called by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) unintelligent X.25 card drivers and not by intelligent ones, this would
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) provide a uniform device driver interface, and simplify configuration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) To confuse matters a little, an 802.2 LLC implementation for Linux is being
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) written which will allow X.25 to be run over an Ethernet (or Token Ring) and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) conform with the JNT "Pink Book", this will have a different interface to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) the Packet Layer but there will be no confusion since the class of device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) being served by the LLC will be completely separate from LAPB. The LLC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) implementation is being done as part of another protocol project (SNA) and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) by a different author.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) Just when you thought that it could not become more confusing, another
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) option appeared, XOT. This allows X.25 Packet Layer frames to operate over
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) the Internet using TCP/IP as a reliable link layer. RFC1613 specifies the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) format and behaviour of the protocol. If time permits this option will also
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) be actively considered.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) A linux-x25 mailing list has been created at vger.kernel.org to support the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) development and use of Linux X.25. It is early days yet, but interested
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) parties are welcome to subscribe to it. Just send a message to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) majordomo@vger.kernel.org with the following in the message body:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) subscribe linux-x25
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) end
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) The contents of the Subject line are ignored.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) Jonathan
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) g4klx@g4klx.demon.co.uk