Documentation for “Zerocat PS/2-Keyboard”
Generated on: Sat, 18 Jun 2022 13:33:21 +0200
Repository: git://zerocat.org/zerocat/projects/ps2-keyboard
Version: v0.0.0-1-97c1fb5
Branch: master
Copyright (C) 2017, 2018, 2020, 2021, 2022 Kai Mertens kmx@posteo.net
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".
Within this project’s git repository, versions are tagged according to the following pattern:
v<major>.<minor>.<revision>
<major> – The resulting product is a major change or upgrade.<minor> – Additional functionality or new features are introduced.<revision> – Bug fixes, minor changes, graphical stuff.git log output.The goal of Zerocat PS/2-Keyboard is to provide you with a save keyboard, driven by a free-design microcontroller board.
All paths within this document are relative in respect to the original
location of this source file, which is located in the project’s doc/
folder.
It is assumed that you are running a GNU/Linux-libre operating system.
Use git to clone the project’s sources:
git clone git://zerocat.org/zerocat/projects/ps2-keyboard
Change into the project’s documentation folder:
cd ps2-keyboard/doc/
Study this README.md to get started:
cat ../doc/README.md
If you are on GNU Guix System, use make to create a dedicated profile, once. This allows you to match your environment to the one used by Zerocat, thus producing bit-identical results:
make -C ../guix pull
Create an empty environment with dedicated guix channel:
make -C ../guix environment
Create a shell with all prerequisites set up:
make -C ../guix shell
To leave the shell and the environment, later on, when you are done with this project, type:
exit
exit
To remove this project’s handy guix profile, type:
make -C ../guix clean
This will remove symlinks only. If you want to remove the profile from your system, run the GNU Guix Garbage Collector.
To list all available targets, type:
make -C ../guix help
If you are on another distro, check file ../guix/manifest.scm and install the listed packages with your package manager, manually. Adapt package names as required.
To build the documentation, type:
make -C ../doc
To get a full list of available targets, type:
make -C ../doc help
To clean-up, type:
make -C ../doc clean
To build the firmware, type:
make -C ../firmware/src
To get a full list of available targets, type:
make -C ../firmware/src help
To clean-up, type:
make -C ../firmware/src clean
Zerocat PS/2-Keyboard ships copyrighted work.
Zerocat PS/2-Keyboard is free software. It makes use of free software approved licenses only and should be freely distributable:
Authorship, copyright and license information may be provided in more detail on a per-folder and/or per-file basis. Check the sources.
Please report a bug if you find the distribution hindered.
See Zerocat Website for contact information.
Documentation source files are written in markdown syntax. They should carry their individual copyright and license notices right below the title giving headline, e.g.:
<Title-of-Document>
===================
Copyright (C) <Year> <Name-of-Author> <Email-Address>
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3
or any later version published by the Free Software Foundation;
with no Invariant Sections, no Front-Cover Texts, and no Back-Cover
Texts. A copy of the license is included in the section entitled
"GNU Free Documentation License".
<Other-Headline>
----------------
...content...
The generated documentation carries a license notice right at top on
its title page, with copyright statements generated from git log
output.
Sections of the generated documentation are build from selected markdown source files, with their individual copyright and license notice stripped.
In order to enrich the generated documentation ...
*.md markdown source files to ../doc/.... and adapt ../doc/Makefile to produce nice output.
In case more tools are needed, don't forget to update ../guix/manifest.scm.
To make your image look nice within the documentation, select a landscape layout of 16:9 aspect ratio.
Use ImageMagick to prepare your image, e.g.:
If your image is big, reduce it to a maximal width of 2000 pixel:
mogrify -resize 2000x <image>
Please clean image files from metadata, before committing, i.e.:
mogrify -strip <image>
If you embed your image into a markdown documentation file, use this syntax:
![<path/to/image>][]
[<path/to/image>]: <path/to/image> "title message"
or alternatly:
![<path/to/image>][my-image-shortcut]
[my-image-shortcut]: <path/to/image> "title message"
These patterns will guarantee that <img> tags will have their src,
alt and title attributes properly set within the html output.
Please use this license header for code source files:
Zerocat PS/2-Keyboard --- Get rid of keyloggers.
Copyright (C) <Year> <Name-of-Author> <Email-Address>
This file is part of Zerocat PS/2-Keyboard.
Zerocat PS/2-Keyboard is free software: you can redistribute it
and/or modify it under the terms of the GNU General Public
License as published by the Free Software Foundation, either
version 3 of the License, or (at your option) any later
version.
Zerocat PS/2-Keyboard is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied
warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Zerocat PS/2-Keyboard.
If not, see <http://www.gnu.org/licenses/>.
If you intend to write shell scripts, use this skeleton to make them work for GNU Guix:
#!/bin/sh
# Re-exec if we are not using Bash or are using Bash in POSIX mode.
if [ -z "$BASH" ] || [ "$BASH" = "/bin/sh" ]; then
bash=`command -v bash`
if [ -z "$bash" ]; then
echo "Couldn't find Bash, sorry!"
exit 1
else
exec "$bash" "$0" "$@"
fi
fi
# We're using Bash now.
set -o errexit
set -o nounset
set -o pipefail
# Your code goes here ...
Update ../doc/NEWS.md and list your contributions.
You can use git shortlog to get a starting point for your edit.
Looking for articles by author Adam Chapweske
PS/2 is now considered a legacy port, which continues to be included on many computer motherboards.
PS/2 ports may be favored for security reasons [...] as they allow USB ports to be totally disabled, preventing the connection of [...] malicious USB devices
The PS/2 interface provides no restriction on key rollover.
The PS/2 interface has near-universal compatibility with BIOS.
They cause fewer problems when KVM switching with non-Wintel systems.
The PC 97 standard introduced a color code: the keyboard port, and the plugs on compliant keyboards, were purple; mouse ports and plugs were green.
The pinouts of the connectors (keyboard vs. mouse) are the same, but most computers will not recognize devices connected to the wrong port.
PS/2 ports are designed to connect the digital I/O lines of the microcontroller in the external device directly to the digital lines of the microcontroller on the motherboard. They are not designed to be hot swappable.
Standard PS/2 mice send interrupts at a default rate of 100 hertz when they have data to send to the computer.
PS/2 allows the sample rate to be overridden, with PS/2 supporting a sampling rate of up to 200 Hertz.
Function | 6-pin DIN (PS/2) | 5-pin DIN (AT/XT) | 6-pin SDL
-------- | ---------------- | ----------------- | ---------
+5V | 4 | 5 | E
DATA | 1 | 2 | B
not connected | 2, 6 | 3 | A, F
GND | 3 | 4 | C
CLK | 5 | 1 | D
>
> Socket: Plug:
> 6 _ 5 5 _ 6
> o | | o · | | ·
> |_| |_|
> o o · ·
> 4 3 3 4
> o o · ·
> 2 1 1 2
>
>
> Socket: Plug:
> _ _ _ _
> \_/ \_/
>
> 3 1 1 3
> o o · ·
> 5 4 4 5
> o 2 o · 2 ·
> o ·
>
>
> Socket: Plug:
>
>
> xxxxxxxxxxxxxxx xxxxxxxxxxxxxxx
> | | | | | | | | | | | |
> F E D B C A A B C D E F
>
>
Mainboards and ThinkPad docking stations often carry a so called PS/2 Combi Port, with keyboard and mouse icons at the outlet. The exact wiring is unknown to the author, three options should be taken into account. Each option would require different usage of a dedicated Y-Splitter-Cable.
Combi Port is a PS/2-Keyboard Port with extra clock and data lines for mouse at pins 6 and 2.
Combi Port is a PS/2-Mouse Port with extra clock and data lines for keyboard at pins 6 and 2.
Combi Port is a standard PS/2 port (pins 6 and 2 not connected) which is able to detect the type of device at boot time. Using both devices (keyboard and mouse) simultaneously is not supported.
Port types 1.) and 2.) would require to use a Y-Splitter-Cable (see Figure A) for simultaneous operation of keyboard and mouse. Port type 2.) would additionally require to twist the plugs, thus using the mouse with the keyboard plug and vice-versa.
>
> Figure A: PS/2 Y-Splitter-Cable
> ===============================
>
> 6-pin Mini-DIN 6-pin Mini-DIN 6-pin Mini-DIN
> (PS/2 Combi Port) (PS/2-Keyboard) (PS/2-Mouse)
>
> 1 -------------------------- 1
> 2 --------------------------------------------------------1
> 3 -------------------------- 3 -------------------------- 3
> 4 -------------------------- 4 -------------------------- 4
> 5 -------------------------- 5
> 6 --------------------------------------------------------5
>
>
Note the different layout of a Y-Splitter-Cable which allows for simultaneous usage of keyboard-like devices:
>
> Figure B: PS/2 Y-Splitter-Cable
> ===============================
>
> 6-pin Mini-DIN 6-pin Mini-DIN 6-pin Mini-DIN
> (PS/2 Keyboard Port) (PS/2 Keyboard) (PS/2 Barcode Scanner)
>
> 1 -------------------------- 1 -------------------------- 1
> 3 -------------------------- 3 -------------------------- 3
> 4 -------------------------- 4 -------------------------- 4
> 5 -------------------------- 5 -------------------------- 5
>
>
Coreboot seems to not support PS/2 hardware in first place. Documentation about PS/2 is often lacking details on coreboot’s board status pages. i.e.:
Exact lists about which hardware works how has to be gathered individually and would be a required source of information.
Source Files
Generated Images
What about ground connection? Ground Loop?
+-----------------------+ +----------------------+
| | | |
| ASRock E350M1 |<-- USB Power -->| Zerocat |
| Coreboot Machine |<---- PS/2 ----->| PS/2 Controller |
| with PS/2 Port, | | Board |
| no Keyboard attached | | |
| | +----------------------+
+-----------------------+ ^
^ |
| |
| RS232
| |
| |
| v
+-----------+ +----------------------+
| | | |
| 230VAC |------------------->| Laptop ZC-X60 |
| Power | | + Docking |
| | | + RS232 Port |
+-----------+ | |
| uploads firmware, |
| issues key-strokes |
| |
+----------------------+
+-----------------------+
| | +----------------------+
| Laptop ZC-T60 | | |
| + Docking |<-- USB Power -->| Zerocat |
| + RS232 Port? |<---- RS232 ---->| PS/2 Controller |
| + PS/2 Port |<---- PS/2 ----->| Board |
| | | |
| | +----------------------+
+-----------------------+
^
|
|
+-----------+
| |
| 230VAC |
| Power |
| |
+-----------+
Nothing evolved, so far. Let’s start with this basic board:
Board Schematic PNG Preview
Article about USB Security Flaw
https://en.wikipedia.org/w/index.php?title=PS/2_port
General info about PS/2
http://www.computer-engineering.org/ps2keyboard/
The PS/2 Keyboard Interface
http://www.computer-engineering.org/ps2protocol/
The PS/2 Mouse/Keyboard Protocol
http://www.computer-engineering.org/ps2keyboard/scancodes1.html
Keyboard Scan Codes -- Set 1
http://www.computer-engineering.org/ps2keyboard/scancodes2.html
Keyboard Scan Codes -- Set 2
http://www.computer-engineering.org/ps2keyboard/scancodes3.html
Keyboard Scan Codes -- Set 3
http://wiki.osdev.org/PS/2_Keyboard
good short description
http://www.win.tue.nl/~aeb/linux/kbd/scancodes.html
Keyboard scancodes in detail
https://hackaday.com/2016/01/13/stallmans-one-mistake/
See photo in section “Keyboards And Webcams And Hard Drives”.
https://deskthority.net/wiki/TrackPoint
Informative resource on keyboards and pointing devices
ThinkPad X200 Keyboard Disassembled (Mechanics of one Key Missing)
Original Layout: DE
Seems to have 8 rows and 15 columns of keys:
However, the corresponding X200 sysboard schematics depicts a matrix of 8 rows and 16 columns.
No internal keyboard controller in use.
Foil connector pads in total: 40 (see photo)
Double layer connector cable, schematic needed!
simple flat connector pads to keyboard: 40
splits towards... (see photo)
Sysboard Plug “JAE CONN40A-1-U1GP”
Similar, but wrong JAE Connectors:
and trackpoint board (6x signal, 2x power)
note cable is covered with self-adhesive thick aluminium foil when mounted
integrated trackpoint hardware
soldered towards flat-cable with eight pads
Trackpoint controller is PTPM754DR 32-pin SSOP, no datasheet available. To get some ideas, please refer to:
visible markings:
additional chip (Quad OpAmp):
Keyboard Cable, splits towards Systemboard and Trackpoint
Systemboard Connector, unknown Type
Schematic of an X200 Keyboard Cable with 32-pin PTPM754DR TrackPoint Controller
As visible from the x200 keyboard cable schematics, the keyboard foil pads are organized in...
...resulting in 36 active pads.
Double Layer with integrated Vias
Keyboard Connector Pads, Top and Bottom
Please read PS/2 to get prepared for PS/2 basics.
The trackpoint board is connected to the keyboard cable by eight soldered pads, referenced by names Pad-1..Pad-8 within this documentation. Pad-1 is located close to the board’s edge.
Pad Number | Function | Remarks | 9-pin Sub-D Test Plug
---------- | -------- | ------- | ---------------------
1 | CLK | close to board’s edge | 9
2 | RST | can be connected to positive POR, alternatively | 4
3 | MIDDLE BUTTON | - | 8
4 | RIGHT BUTTON | - | 3
5 | LEFT BUTTON | - | 7
6 | DATA | - | 2
7 | VSS (GND) | connected to thicker route in keyboard cable | 6
8 | VCC (+5V) | connected to thicker, edgemost route of keyboard cable | 1
- | - | - | 5
>
> Alternative POR at RST (Pad 2)
> ==============================
>
> C
> VCC --------||------+
> 2.2µF |
> | R
> RST ----------------+------/\/\/------- GND
> 100K
>
The Keyboard Cable has been modified to ease experimenting with the disassembled Trackpoint Board. Test Connector is a SUB-D9 male plug.
Modified Keyboard Cable to Ease Experimenting
Controller in use is the TPM754 from Philips Semiconductors. This is a 8051-based machine which runs proprietary code from IBM:
“IBM has licensed Philips Semiconductors to sell microcontrollers with TrackPoint code. By purchasing a TPM from Philips, the purchaser becomes a sub-licensee of Philips. The selling price of Philips’ TPM includes the royalties for IBM’s intellectual property, which Philips in turn pays to IBM. Customers for TPMs do not need to sign any licensing agreement with either IBM or Philips. This code is the intellectual property of IBM, which is covered by numerous patents, and must be treated accordingly.” --- Philips Semiconductors TPM754 Datasheet
The TPM754 comes in different packages with different ordering codes. Unfortunately there is no datasheet nor pinout available for the 32-pin SSOP package (ordering code PTPM754DR), but in regard to measurements and the 28-pin SSOP datasheet, the pinout can be guessed in a straight foreward approach.
Pin | Function | Connected Board Pad | External PS/2 Mouse (6-pin Mini-DIN)
--- | -------- | ------------------- | ------------------------------------
1 | RxD/T0/P3.4 | - | Pin 1 (DATA)
2 | TxD/T1/P3.5 | Pad 1 (CLK), close to edge | -
3 | ECI/P3.6 | - | -
4 | INT1/P3.7 | - | Pin 5 (CLK)
5 | RST | Pad 2 (RST) | -
6 | X2 | - | -
7 | X1 | - | -
8 | VSS | Pad 7 (GND) | Pin 3 (GND)
9 | ZIN | - | -
10 | YIN | - | -
11 | XIN | - | -
12 | XYZRAMP | - | -
13 | AVSS | - | -
14 | AVCC | - | -
15 | not connected | - | -
16 | not connected | - | -
17 | VCC? AVCC? | - | -
18 | not connected | - | -
19 | DECOUPLE | - | -
20 | VREG | - | -
21 | XYDACBIAS | - | -
22 | XYSOURCE | - | -
23 | ZDAC/ASEL | - | -
24 | XYDAC | - | -
25 | P1.2 | - | -
26 | VCC | Pad 8 (VCC) | Pin 4 (VCC)
27 | CEX/P1.1 | - | -
28 | INT0/P1.0 | Pad 6 (DATA) | -
29 | P3.0 | Pad 5 (LEFT BUTTON) | -
30 | P3.1 | Pad 4 (RIGHT BUTTON) | -
31 | P3.2 | Pad 3 (MIDDLE BUTTON) | -
32 | P3.3 | - | -
Warning: If the TrackPoint is replaced by a PS/2-Mouse, interfacing with the sysboard’s H8 controller doesn't work. Probably, H8 and TrackPoint Controller do not talk according to PS/2 standards??
Although no interface is provided to attach an additional external PS/2 Mouse, pins 1 and 4 of the TPM754 can be used as a workaround in conjunction with the VCC and GND power lines. The IBM code separates data streams from Trackpoint and Mouse clearly, so that one device moves the screen pointer without being irritated by the other.
Experimental Setup with External PS/2 Mouse
Connecting the Trackpoint Board
>
> Connect Trackpoint via Test Plug to a Standard PS/2 Mouse Port
> ==============================================================
>
>
> +---------VCC---------------------+--------> to Pin 4
> | +----------------DATA-----------|--------> to Pin 1
> | | |
> | | +------RST-------+---||-----+
> | | | | 2.2uF
> 1|2|3 4|5 |
> \ · · · · · / +--/\/\/---+
> \ · · · · / 100K |
> 6|7 8 9| |
> | | |
> | +-----------CLOCK----------|--------> to Pin 5
> +---------GND--------------------+--------> to Pin 3
>
> Sub-D9 Test Plug ----> PS/2 6-pin Mini-DIN
>
>
This setup has been proved to work with a D945GCLF Intel Desktop Board, running blobless coreboot firmware and the Trisquel7 Operating System. The Trackpoint and its attached external PS/2-Mouse is recognized at the PS/2 Mouse Port along with a PS/2-Keyboard (IBM Model M) attached to the PS/2 Keyboard Port. The reset line of the Trackpoint is simulated by the alternative Power-On-Reset circuit.
Trackpoint with External PS/2-Mouse at Standard PS/2 Mouse Port of a Blobless Coreboot Machine
>
> PS/2-Keyboard Setup using an X200 Keyboard Matrix with Trackpoint and external Mouse
> ====================================================================================
>
>
> ····························································································
> : :
> : +-----------------------------------+ :
> : +-----------------------+ | Board with Free-Design Controller | :
> : | X200 Keyboard |-----GND---/4----------| ================================= | :
> : | ============= | | | :
> : | |=====PB and Hotkey=========discard or translate====+ | :
> : | No controller in use. | |___ | | :
> : | |-----KBDID0----------->| | | | :
> : | * Power Button (PB) |-----KBDID1----------->| ? | | | :
> : | * Fn Hotkey |-----KBDID2----------->|___| | | :
> : | * Matrix 16x8 | | | | :
> : | * 3 Mouse Buttons |-----Matrix 16x8-----------------/24----------+ | | :
> : | * KBDID0..2 Lines | | | | | :
> : | * 4x Ground |---Mouse Button M----->| | /2 | :
> : | = 36 Pads |---Mouse Button R----->| | | | :
> : | |---Mouse Button L----->| | | | :
> : +-----------------------+ | v v | :
> : | +················+ | :
> : | : translate into : | :
> : +-----------------------+ | : PS/2 : | :
> : | TrackPoint Board |<<====+5V, GND===============\\ +················+ | :
> : | ================ | | || ^ | :
> : | |<---Mouse Button M-----| __||___________ | | :
> : | 8051-based controller |<---Mouse Button R-----| | +5V, GND | | | :
> : | (PTPM754DR) runs |<---Mouse Button L-----| |_______________| | | :
> : | proprietary code | | | ^ ^ | | :
> : | from IBM. |<-------Reset----------| | | | | | :
> : | | | /2 /2 /2 /2 | :
> : | * 3x Mouse Buttons | PS/2-Trackpoint | | | | | | :
> : | * PS/2 (clock, data) |<=======clock/data================+ | | | :
> : | * Reset Line | PS/2-Mouse | | | | | | :
> : | * Ground | | | | +-----| | :
> : | * +5V Power | Ext. PS/2 Mouse | v | | | :
> : | * Ext. PS/2 |<======clock/data===========+ | | | :
> : | = 10 Lines | | | | | | :
> : | | | | | | | :
> : +-----------------------+ +----|-----|-----------|------------+ :
> : | | | :
> : PS/2-Keyboard with Trackpoint /4 /4 /4 :
> ························································|·····|···········|·················
> | | |
> +--------Ext. PS/2-Mouse-----------------+ | |
> | | |
> | v v
> | +-----------------------------------------------------+
> v | :| PS/2 | | PS/2 |: |
> +------------------------+ | :| Mouse | | Keyboard |: |
> | External PS/2 Mouse | | :|_______| |__________|: |
> | =================== | | ·····PS/2-Combi-Port?····· |
> | | | |
> | proprietary controller | | Blobfree Coreboot Computer or Laptop |
> | | | ==================================== |
> | * PS/2 | | |
> | = 4 Lines | | * with two PS/2 Ports |
> | | | * or with one PS/2 Combi Port and Y-Splitter-Cable |
> +------------------------+ | |
> | Working Example(s): |
> | |
> | * D945GCLF Desktop Board with Blobless Coreboot |
> | |
In case a desktop board with blobless coreboot is used as host, this PS/2 free-design keyboard would significantly improve the computer user’s situation in respect to freedom and security. Let’s go for prototyping!
Version 1.3, 3 November 2008
Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. http://fsf.org/
Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.
The purpose of this License is to make a manual, textbook, or other functional and useful document "free" in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others.
This License is a kind of "copyleft", which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software.
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You may add a section Entitled "Endorsements", provided it contains nothing but endorsements of your Modified Version by various parties—for example, statements of peer review or that the text has been approved by an organization as the authoritative definition of a standard.
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In the combination, you must combine any sections Entitled "History" in the various original documents, forming one section Entitled "History"; likewise combine any sections Entitled "Acknowledgements", and any sections Entitled "Dedications". You must delete all sections Entitled "Endorsements".
You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects.
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If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one half of the entire aggregate, the Document's Cover Texts may be placed on covers that bracket the Document within the aggregate, or the electronic equivalent of covers if the Document is in electronic form. Otherwise they must appear on printed covers that bracket the whole aggregate.
Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License, and all the license notices in the Document, and any Warranty Disclaimers, provided that you also include the original English version of this License and the original versions of those notices and disclaimers. In case of a disagreement between the translation and the original version of this License or a notice or disclaimer, the original version will prevail.
If a section in the Document is Entitled "Acknowledgements", "Dedications", or "History", the requirement (section 4) to Preserve its Title (section 1) will typically require changing the actual title.
You may not copy, modify, sublicense, or distribute the Document except as expressly provided under this License. Any attempt otherwise to copy, modify, sublicense, or distribute it is void, and will automatically terminate your rights under this License.
However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation.
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"Incorporate" means to publish or republish a Document, in whole or in part, as part of another Document.
An MMC is "eligible for relicensing" if it is licensed under this License, and if all works that were first published under this License somewhere other than this MMC, and subsequently incorporated in whole or in part into the MMC, (1) had no cover texts or invariant sections, and (2) were thus incorporated prior to November 1, 2008.
The operator of an MMC Site may republish an MMC contained in the site under CC-BY-SA on the same site at any time before August 1, 2009, provided the MMC is eligible for relicensing.
To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page:
Copyright (C) YEAR YOUR NAME.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3
or any later version published by the Free Software Foundation;
with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
A copy of the license is included in the section entitled "GNU
Free Documentation License".
If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace the "with … Texts." line with this:
with the Invariant Sections being LIST THEIR TITLES, with the
Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.
If you have Invariant Sections without Cover Texts, or some other combination of the three, merge those two alternatives to suit the situation.
If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.