^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) 6pack Protocol
^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) This is the 6pack-mini-HOWTO, written by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) Andreas Könsgen DG3KQ
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) :Internet: ajk@comnets.uni-bremen.de
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) :AMPR-net: dg3kq@db0pra.ampr.org
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) :AX.25: dg3kq@db0ach.#nrw.deu.eu
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) Last update: April 7, 1998
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 1. What is 6pack, and what are the advantages to KISS?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) ======================================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 6pack is a transmission protocol for data exchange between the PC and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) the TNC over a serial line. It can be used as an alternative to KISS.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 6pack has two major advantages:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) - The PC is given full control over the radio
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) channel. Special control data is exchanged between the PC and the TNC so
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) that the PC knows at any time if the TNC is receiving data, if a TNC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) buffer underrun or overrun has occurred, if the PTT is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) set and so on. This control data is processed at a higher priority than
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) normal data, so a data stream can be interrupted at any time to issue an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) important event. This helps to improve the channel access and timing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) algorithms as everything is computed in the PC. It would even be possible
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) to experiment with something completely different from the known CSMA and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) DAMA channel access methods.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) This kind of real-time control is especially important to supply several
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) TNCs that are connected between each other and the PC by a daisy chain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) (however, this feature is not supported yet by the Linux 6pack driver).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) - Each packet transferred over the serial line is supplied with a checksum,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) so it is easy to detect errors due to problems on the serial line.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) Received packets that are corrupt are not passed on to the AX.25 layer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) Damaged packets that the TNC has received from the PC are not transmitted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) More details about 6pack are described in the file 6pack.ps that is located
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) in the doc directory of the AX.25 utilities package.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 2. Who has developed the 6pack protocol?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) ========================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) The 6pack protocol has been developed by Ekki Plicht DF4OR, Henning Rech
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) DF9IC and Gunter Jost DK7WJ. A driver for 6pack, written by Gunter Jost and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) Matthias Welwarsky DG2FEF, comes along with the PC version of FlexNet.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) They have also written a firmware for TNCs to perform the 6pack
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) protocol (see section 4 below).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 3. Where can I get the latest version of 6pack for LinuX?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) =========================================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) At the moment, the 6pack stuff can obtained via anonymous ftp from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) db0bm.automation.fh-aachen.de. In the directory /incoming/dg3kq,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) there is a file named 6pack.tgz.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 4. Preparing the TNC for 6pack operation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) ========================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) To be able to use 6pack, a special firmware for the TNC is needed. The EPROM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) of a newly bought TNC does not contain 6pack, so you will have to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) program an EPROM yourself. The image file for 6pack EPROMs should be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) available on any packet radio box where PC/FlexNet can be found. The name of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) the file is 6pack.bin. This file is copyrighted and maintained by the FlexNet
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) team. It can be used under the terms of the license that comes along
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) with PC/FlexNet. Please do not ask me about the internals of this file as I
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) don't know anything about it. I used a textual description of the 6pack
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) protocol to program the Linux driver.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) TNCs contain a 64kByte EPROM, the lower half of which is used for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) the firmware/KISS. The upper half is either empty or is sometimes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) programmed with software called TAPR. In the latter case, the TNC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) is supplied with a DIP switch so you can easily change between the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) two systems. When programming a new EPROM, one of the systems is replaced
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) by 6pack. It is useful to replace TAPR, as this software is rarely used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) nowadays. If your TNC is not equipped with the switch mentioned above, you
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) can build in one yourself that switches over the highest address pin
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) of the EPROM between HIGH and LOW level. After having inserted the new EPROM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) and switched to 6pack, apply power to the TNC for a first test. The connect
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) and the status LED are lit for about a second if the firmware initialises
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) the TNC correctly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) 5. Building and installing the 6pack driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) ===========================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) The driver has been tested with kernel version 2.1.90. Use with older
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) kernels may lead to a compilation error because the interface to a kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) function has been changed in the 2.1.8x kernels.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) How to turn on 6pack support:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) =============================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) - In the linux kernel configuration program, select the code maturity level
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) options menu and turn on the prompting for development drivers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) - Select the amateur radio support menu and turn on the serial port 6pack
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) driver.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) - Compile and install the kernel and the modules.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) To use the driver, the kissattach program delivered with the AX.25 utilities
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) has to be modified.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) - Do a cd to the directory that holds the kissattach sources. Edit the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) kissattach.c file. At the top, insert the following lines::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) #ifndef N_6PACK
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) #define N_6PACK (N_AX25+1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) Then find the line:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) int disc = N_AX25;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) and replace N_AX25 by N_6PACK.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) - Recompile kissattach. Rename it to spattach to avoid confusions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) Installing the driver:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) ----------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) - Do an insmod 6pack. Look at your /var/log/messages file to check if the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) module has printed its initialization message.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) - Do a spattach as you would launch kissattach when starting a KISS port.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) Check if the kernel prints the message '6pack: TNC found'.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) - From here, everything should work as if you were setting up a KISS port.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) The only difference is that the network device that represents
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) the 6pack port is called sp instead of sl or ax. So, sp0 would be the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) first 6pack port.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) Although the driver has been tested on various platforms, I still declare it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) ALPHA. BE CAREFUL! Sync your disks before insmoding the 6pack module
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) and spattaching. Watch out if your computer behaves strangely. Read section
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 6 of this file about known problems.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) Note that the connect and status LEDs of the TNC are controlled in a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) different way than they are when the TNC is used with PC/FlexNet. When using
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) FlexNet, the connect LED is on if there is a connection; the status LED is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) on if there is data in the buffer of the PC's AX.25 engine that has to be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) transmitted. Under Linux, the 6pack layer is beyond the AX.25 layer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) so the 6pack driver doesn't know anything about connects or data that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) has not yet been transmitted. Therefore the LEDs are controlled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) as they are in KISS mode: The connect LED is turned on if data is transferred
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) from the PC to the TNC over the serial line, the status LED if data is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) sent to the PC.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 6. Known problems
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) =================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) When testing the driver with 2.0.3x kernels and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) operating with data rates on the radio channel of 9600 Baud or higher,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) the driver may, on certain systems, sometimes print the message '6pack:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) bad checksum', which is due to data loss if the other station sends two
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) or more subsequent packets. I have been told that this is due to a problem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) with the serial driver of 2.0.3x kernels. I don't know yet if the problem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) still exists with 2.1.x kernels, as I have heard that the serial driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) code has been changed with 2.1.x.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) When shutting down the sp interface with ifconfig, the kernel crashes if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) there is still an AX.25 connection left over which an IP connection was
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) running, even if that IP connection is already closed. The problem does not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) occur when there is a bare AX.25 connection still running. I don't know if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) this is a problem of the 6pack driver or something else in the kernel.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) The driver has been tested as a module, not yet as a kernel-builtin driver.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) The 6pack protocol supports daisy-chaining of TNCs in a token ring, which is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) connected to one serial port of the PC. This feature is not implemented
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) and at least at the moment I won't be able to do it because I do not have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) the opportunity to build a TNC daisy-chain and test it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) Some of the comments in the source code are inaccurate. They are left from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) the SLIP/KISS driver, from which the 6pack driver has been derived.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) I haven't modified or removed them yet -- sorry! The code itself needs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) some cleaning and optimizing. This will be done in a later release.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) If you encounter a bug or if you have a question or suggestion concerning the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) driver, feel free to mail me, using the addresses given at the beginning of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) this file.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) Have fun!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) Andreas
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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