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SUSE Linux Enterprise Server for Arm 15 SP2

Raspberry Pi Quick Start

Publication Date: March 28, 2024

This guide contains an overview of SUSE Linux Enterprise Server for Arm on the Raspberry Pi* platform and will guide you through the setup procedure.

Author: Fabian Vogt, Release Engineer, SUSE
Author: Jay Kruemcke, Product Manager, SUSE
Author: Andreas Faerber, Project Manager, SUSE

1 Platform Overview

To use SUSE Linux Enterprise Server for Arm on the Raspberry Pi, a 64-bit Arm* compatible Raspberry Pi* is required. SUSE Linux Enterprise Server for Arm 15 SP2 is tested to work on Raspberry Pi 3 Model A+, Model B, Model B+, and Raspberry Pi 4 Model B boards as well as on Raspberry Pi Compute Module 3 and 3+ on MyPi Industrial IoT Integrator Board.

1.1 Technical Details of the Raspberry Pi 3 Model B

The Raspberry Pi is a series of small single-board computers based on a System-on-a-Chip (SoC) by Broadcom*, featuring various peripherals on the board.

Overview of the Raspberry Pi 3 Model B connectors © Efa / English Wikipedia / CC BY-SA 3.0
Figure 1: Overview of the Raspberry Pi 3 Model B Connectors, © Efa / English Wikipedia / CC BY-SA 3.0
Photo of the Raspberry Pi 3 Model B connectors © Evan-Amos / Own work / Public Domain
Figure 2: Photo of the Raspberry Pi 3 Model B Connectors, © Evan-Amos / Own work / Public Domain
Selected Features of the Raspberry Pi 3 Model B/B+
CPU

The Broadcom BCM2837 SoC includes a quad-core Arm* Cortex*-A53 Application Processor supporting the Armv8 32-bit and 64-bit instruction sets. With the default configuration, it is clocked up to 1.2 GHz.

RAM

1024 MiB DDR2 memory mounted on the back of the board.

Graphics

Broadcom* VideoCore* IV providing OpenGL* ES 2.0 support. Displays can be connected over HDMI*, composite (TRRS jack), or MIPI* DSI* (ribbon cable).

Ethernet

A USB Ethernet controller on the board provides 10/100 Mbit/s Ethernet (Model B) or 10/100/1000 Mbit/s Ethernet with a maximum throughput of 300 Mbit/s (Model B+).

WLAN

The BCM43438 chip on Model B supports IEEE-802.11b, IEEE-802.11g, and IEEE-802.11n in the 2.4 GHz band. It also provides Bluetooth 2.0 to 4.1 (Low Energy). The BCM43455 chip on Model B+ supports IEEE-802.11b, IEEE-802.11g, IEEE-802.11n, and IEEE-802.11ac in the 2.4 GHz and 5 GHz bands. It provides Bluetooth 4.2 (Low Energy).

Storage

The microSDHC card slot allows for a memory card to be inserted as the primary boot medium.

Power

The Raspberry Pi 3's main power source is the Micro USB connector. If your Raspberry Pi comes with a power supply, it is recommended to use the bundled power supply only.

USB

A total of four USB 2.0 ports are available.

Connectors

A 0.1 inch multi-function pin header is also available. Note that not all functionality of this header is exposed in SUSE Linux Enterprise Server for Arm 15 SP2.

1.2 SUSE Linux Enterprise Server for Arm 15 SP2

SUSE Linux Enterprise Server for Arm is the first fully supported commercial Linux operating system product available for the Raspberry Pi. You can purchase subscriptions which entitle you to receive all released bug and security fixes, feature updates, and technical assistance from SUSE's worldwide support. Learn more about subscription and support options at https://www.suse.com/support/programs/subscriptions/?id=SUSE_Linux_Enterprise_Server.

Note
Note: Trial Version

If you want to try out SUSE Linux Enterprise Server for Arm 15 SP2 on the Raspberry Pi, SUSE will provide you with a trial version. This gives you access to free patches and updates for a period of 60 days. You must sign in to the SUSE Customer Center at https://scc.suse.com/ using your Customer Center account credentials to receive this free offer. If you do not have a Customer Center account, you must create one to take advantage of the trial version.

Minimum System Requirements for Installation

  • Raspberry Pi 3 Model A+, B, or B+, or Raspberry Pi 4 Model B.

  • microSD card with at least 8 GB capacity.

  • USB keyboard, mouse.

  • HDMI cable and monitor.

  • Power supply with at least 2.5 A capacity.

1.2.1 Differences Compared to Raspbian

Raspbian is the de-facto default distribution for the Raspberry Pi. The following paragraphs provide a short overview of differences between SUSE Linux Enterprise Server for Arm on the Raspberry Pi and Raspbian.

Based on Upstream Kernel

Raspbian uses a kernel with modifications especially for the Raspberry Pi. SUSE Linux Enterprise Server for Arm uses the default SUSE Linux Enterprise kernel for AArch64, which is derived from the official mainline kernel.

AArch64 Instruction Set

SUSE Linux Enterprise Server for Arm on the Raspberry Pi is the first distribution for the Raspberry Pi using the AArch64 instruction set.

Boot Process

In Raspbian, the kernel is loaded directly. This is not supported by SUSE Linux Enterprise Server for Arm, where the U-Boot boot loader is used to provide an EFI boot environment. A GRUB2 EFI binary is chain-loaded to provide a graphical boot screen.

Root File System

SUSE Linux Enterprise Server for Arm for the Raspberry Pi uses Btrfs as the file system for the root partition. Compression is enabled by default for better SD card performance.

1.2.2 YaST

YaST is the installation and configuration framework for SUSE Linux Enterprise. It is popular for its ease of use, flexible graphical interfaces and the capability to customize your system quickly during and after installation. YaST can be used to configure your entire system: You can configure hardware, set up networking, manage system services, and tune your security settings. All these tasks can be accessed from the YaST control center. To start it, choose YaST in the menu or run the command xdg-su -c yast2. You will be prompted to enter the password of the root user.

The YaST control center
Figure 3: The YaST Control Center

When started, YaST shows an overview of available modules (Figure 3, “The YaST Control Center”). Simply click an icon to open a module.

1.2.3 Zypper

Zypper is the package manager for SUSE Linux Enterprise. It is the tool for installing, updating, and removing packages and for managing repositories.

The general syntax for Zypper invocations is:

zypper [global-options] command [command-options][arguments] ...
Note
Note: Short Command Form

For most commands, there is both a short and a long form. An overview is available with zypper --help.

Installing a package
# zypper install mplayer
Removing a package
# zypper remove mplayer
List available patches
> zypper list-patches
Install available patches
# zypper patch
Note
Note: Installing Software Updates

The recommended way to install available software updates is by using the YaST Online Updater. To start it, choose Online Update in Settings under Desktop Apps in the IceWM menu.

1.2.4 Limitations

Graphics not hardware-accelerated

X.Org hardware acceleration is disabled to improve system stability and reliability.

For other limitations refer to the online version of the Release Notes at https://www.suse.com/releasenotes/aarch64/SUSE-SLES/15-SP2/.

2 Installation

SUSE Linux Enterprise Server for Arm for the Raspberry Pi is distributed as an XZ-compressed image file for microSD cards. This section will guide you through the process of preparing the card for the first boot. If you already have a microSD card containing the image, you can skip this section and go straight to Section 3, “Booting for the First Time”.

Note
Note: SD Card Space Requirements

It is recommended to use a card with a capacity of at least 8 GB.

Warning
Warning: All Data on the Card Will Be Lost!

By following the procedure below, all data on the SD card will be overwritten and therefore irrevocably lost. Be very careful when choosing the destination device of the image writing process.

2.1 Preparing the Card on Linux

Before and after you plug in the SD card, run the lsblk command. Between the two runs of lsblk, there should be a difference of one or more lines. The first column and first row is the name of the node representing the SD card in your system. To write the image to the card, use the dd command:

xz -cd IMAGE | dd of=/dev/SDCARDDEV bs=4096
Example 1: Writing the Image to the Card using dd

This command decompresses the image SLES15-SP2-JeOS.aarch64-15.2-RaspberryPi-GM.raw.xz to the SD card mmcblk0:

> xz -cd SLES15-SP2-JeOS.aarch64-15.2-RaspberryPi-GM.raw.xz | sudo dd of=/dev/mmcblk0 bs=4096 iflag=fullblock status=progress

2.2 Preparing the Card on Microsoft Windows Operating Systems

The following steps will guide you through the installation of the image onto the SD card on Microsoft® Windows® operating systems. You need to meet these prerequisites:

  1. Open the downloaded image using Easy 7-Zip. Extract the file content into a directory with sufficient free space.

    7zip extraction dialog
  2. Run Win32 Disk Imager and select the extracted file as Image File. Then, choose the correct drive letter as Device. Click Write to start the procedure.

    Win32 Disk Imager Writing Process
    Note
    Note: Finding the correct device

    If you are unsure which drive letter to choose from in the list, remove the SD card and run Win32 Disk Imager again. The option that disappeared is the right target device.

2.3 Preparing the Card on macOS

The following steps will guide you through the installation of the image onto the SD card on macOS®. You need to meet these prerequisites:

  1. Open Finder at the location where the downloaded image is stored. Use the Open With selection to choose The Unarchiver instead of the default Archive utility and extract the content into a directory with sufficient free space.

    Open the Image with The Unarchiver
  2. Open a Terminal window and change into the destination directory of the uncompressed image. Enter diskutil list before and after the SD card is inserted to find out which device to use.

  3. Run diskutil unmountDisk /dev/diskX, where X is the disk number from the previous step.

  4. Run sudo dd bs=4096 if=imageFile.raw of=/dev/diskX, where X is the disk number and imageFile.raw is the name of the uncompressed image.

    > sudo dd bs=4096 if=SLES15-SP2-JeOS.aarch64-15.2-RaspberryPi-GM.raw.xz of=/dev/disk4
    Password:
    5550+0 records in
    5550+0 records out
    5819596800 bytes transferred in 1131.796649 secs (5141910 bytes/sec)
  5. Now unmount the disk (which is now labelled EFI) as usual.

3 Booting for the First Time

After insertion of the prepared microSD card, connect a display, Ethernet cable, and USB keyboard and mouse first, then provide power over Micro USB. After a few seconds you should be able to see a few lines of text on the screen. If that is not the case, recheck the connection to the display.

Note
Note: Operation without Mouse

The JeOS First Boot Assistant can be used without a mouse by only using the keyboard. Every user interface element has an accelerator configured, visible as a highlighted letter. To activate such an accelerator, press the letter together with Alt.

On the first boot, the system will expand to fill the entire SD card, so be patient.

3.1 Initial System Setup with JeOS First Boot Assistant

After a few minutes, the JeOS First Boot Assistant will lead you through the initial system setup.

Note
Note: JeOS First Boot Assistant via a serial connection

To run the JeOS First Boot Assistant wizard via a serial connection, you need to remove the console=tty from the kernel command line console=ttyS0,115200 console=tty in GRUB 2 even if there is no HDMI cable connected.

  1. Note that this minimized JeOS image comes without language selection. After the assistant finishes, you will be able to install and select your system locale.

  2. First, the keyboard layout needs to be configured. Use the arrow keys or first letter and select OK.

    JeOS First Boot Assistant showing keyboard configuration on first boot
  3. Read the License Agreement. You need to accept it.

    JeOS First Boot Assistant displaying the license text
  4. Select the time zone by using the arrow keys or first letter.

    YaST asking for the time zone
  5. Select OK to proceed.

  6. You will be asked to provide a root password now. Do not forget what you enter here, as you will need it for administration.

    JeOS First Boot Assistant asking you to set a password for the root user
  7. Confirm the root password you just provided by typing it in again.

    JeOS First Boot Assistant asking you to confirm the password for the root user
  8. Note that you should register your system after installation, as detailed in Section 3.2, “Registration Process”.

    JeOS First Boot Assistant showing registration instructions
    Note
    Note: Deferring Registration

    You will not receive updates or patches until you register using SUSEConnect.

  9. Select OK to continue.

  10. Finally, you are offered the option to configure a wireless network. If you have a wired Ethernet connection, you can skip this step by selecting No.

    JeOS First Boot Assistant asking you whether to configure a wireless network

    If you select Yes, you will see the following screens:

    1. Select a wireless network to connect to and proceed with OK.

      JeOS First Boot Assistant asking you to select a wireless network
    2. Select the authentication method for the wireless network and proceed with OK.

      JeOS First Boot Assistant asking you to select an authentication method for the wireless network
    3. Enter the passphrase for the wireless network and proceed with OK.

      JeOS First Boot Assistant asking you to enter the passphrase for the wireless network
Note
Note: WPA EAP authentication

WPA authentication supports just the 'mschapv2' EPA authentication, which is used as default.

If you chose to skip configuration of wireless networks or if you fully completed their configuration, the JeOS First Boot Assistant will exit. The system continues to boot to a login prompt.

You can now log in with root user and the password you chose earlier.

Note
Note: Canceling the JeOS First Boot Assistant

If at any point you select to Cancel the assistant, the system will shut down. You can then disconnect the power supply, make any necessary changes, and start over.

3.2 Registration Process

It is very important to register your SUSE Linux Enterprise Server for Arm subscription to ensure full functionality of your Raspberry Pi system. The SD card image provided by SUSE contains a minimal set of packages that are intended for the initial boot process and to get your Raspberry Pi onto the network.

When you have registered your SUSE Linux Enterprise Server for Arm subscription, you can download other packages you may need, such as compilers. The SUSE Linux Enterprise Server version that runs on your Raspberry Pi is the same version that runs on AMD64/Intel 64, POWER, IBM Z, or on other Arm-based systems.

Important
Important: Setting the Clock

Because the Raspberry Pi does not have a persistent Real Time Clock, make sure that the clock is set to the current date and time before attempting to use Zypper or YaST to install additional packages.

You can initially register your system with the SUSEConnect tool. Afterwards you can also make use of the YaST Product Registration module.

Note
Note: Evaluation Code

Sixty day evaluation subscriptions may be requested at the following page: https://www.suse.com/products/arm/

After you have obtained a registration code from a subscription card, you need to activate your subscription on the SUSE Customer Center at:

https://scc.suse.com/

To register your subscription, perform the following steps:

  1. Log in to the SUSE Customer Center using a browser on another machine. Create an account if required:

    Log in to the SUSE Customer Center
  2. Click Manually Activate Subscriptions:

    Manual activation of subscription.
  3. Click the dialog field Activate a single subscription:

    Activate a single subscription.
  4. Enter the registration code and accept the terms and conditions:

    Enter the registration code.
  5. Confirm the subscription activation and the organization assignment. Click Activate:

    Confirm the activation.
  6. Your subscription is now active and ready to be used:

    You now have an active subscription.

To register the system, use the SUSEConnect tool as instructed earlier:

# SUSEConnect -e company@example.com -r YOUR_CODE
Registering system to SUSE Customer Center
Using E-Mail: company@example.com

Announcing system to https://scc.suse.com ...

Activating SLES 15.2 aarch64 ...
-> Adding service to system ...

Activating sle-module-basesystem 15.2 aarch64 ...
-> Adding service to system ...
-> Installing release package ...

Activating sle-module-server-applications 15.2 aarch64 ...
-> Adding service to system ...
-> Installing release package ...

Successfully registered system

This may take a few moments. Afterwards you will have access to online repositories for installing more packages, as described in Section 1.2.3, “Zypper”.

Example 2: Installing YaST

Later sections may assume you have installed YaST for system configuration:

# zypper in -t pattern yast2_basis
Note
Note: Module Availability

Your subscription gives you access to more than the above Basesystem Module and Server Applications Module. To activate additional modules, you can use the YaST Add System Extensions or Modules module.

4 Initial System Configuration

In this section it is explained how to perform the initial system configuration for SUSE Linux Enterprise Server for Arm for the Raspberry Pi 15 SP2.

4.1 Changing the Language

Follow these steps to change the default language:

  1. Install the glibc-locale package:

    # zypper in glibc-locale
  2. Set the language as desired:

    # localectl set-locale LANG=de_DE.UTF-8
Note
Note: Translation Packages

Certain applications may require you to install an additional -lang package before you can see texts translated to the chosen language.

4.2 Changing the Host Name

Follow these steps to change the default host name:

  1. Open the YaST network module either by running yast2 lan or clicking the network icon in the YaST control center.

  2. Select Hostname/DNS in the top tab bar.

  3. Type the new host name into the Hostname field.

  4. Click OK to save the change. After YaST exits, you need to log out and in again.

4.3 Setting Up Networking

The default configuration has DHCP enabled on the Ethernet port. If that suits your network environment, you can skip this section. If you require the use of a static IP address, use YaST:

  1. Open the YaST network module either by running yast2 lan or clicking the network icon in the YaST control center.

  2. In YaST, you will see the network interface being selected. Select the built-in Ethernet and choose Edit to open the address configuration.

  3. Select Statically Assigned IP Address and type in the desired values for IP Address and Subnet Mask. Click Next.

  4. With a static network configuration, you will also need to specify a DNS server (if applicable) and a gateway. For the gateway, select Routing in the tab bar and enter the IPs of the gateways into the specific fields.

  5. The DNS server is set in the Hostname/DNS tab. After choosing that tab, enter the IPs of the name servers into the respective Name Server fields.

Similarly to the procedure described above, YaST also lets you configure the built-in Wi-Fi network adapter.

For detailed information about the network configuration in SUSE Linux Enterprise Server for Arm, consult the respective sections of the SUSE Linux Enterprise Server Deployment and Administration guides at https://documentation.suse.com/sles/15-SP2/.

5 General System Usage

After the initial configuration procedure and the first boot of the system, you can now use various components of the system.

5.1 Desktop

SUSE Linux Enterprise Server for Arm for the Raspberry Pi 15 GA had packages for a minimal X11 desktop (IceWM) preinstalled.

SUSE Linux Enterprise Server for Arm for the Raspberry Pi 15 SP2 comes as a tiny text-based appliance, allowing you to install any available desktop of your choice or none for headless usage. Should you want to recreate the package selection of the previous images, a pattern x11_raspberrypi is provided for convenience.

If not done already, you will need to enable the Desktop Applications Module. Assuming you have registered the base product already, as described in Section 3.2, “Registration Process”, the fastest way to enable the module is:

# SUSEConnect -p sle-module-desktop-applications/15.2/aarch64
Registering system to SUSE Customer Center

Updating system details on https://scc.suse.com ...

Activating sle-module-desktop-applications 15.2 aarch64 ...
-> Adding service to system ...
-> Installing release package ...

Successfully registered system

You can then install the desktop packages pattern:

# zypper install -t pattern x11_raspberrypi

5.2 Bluetooth

Raspberry Pi 3 and later have a Bluetooth* controller on-board that can be used for various purposes, such as wireless keyboards, mice, or audio devices.

To install the BlueZ software stack:

# zypper install bluez

To enable the Bluetooth* controller for use with bluetoothctl and related applications, for example, on Raspberry Pi 3 Model B with the default UART configuration, run:

# hciattach /dev/ttyAMA1 bcm43xx 921600
bcm43xx_init
Flash firmware /lib/firmware/BCM43430A1.hcd
Set Controller UART speed to 921600 bit/s
Device setup complete

Note: The command is the same for Raspberry Pi 4 Model B, just the chipset name and thus firmware filename in the output will be different.

You can then use hciconfig hci0 up to bring the device up and use hcitool scan to scan the environment for discoverable devices.

6 Product Documentation

This introduction only covered the most basic tasks.

6.1 Product Documentation

You can find the complete documentation for SUSE Linux Enterprise Server for Arm 15 SP2 at https://documentation.suse.com/.

Note
Note: Applicability of Product Documentation

Not all content in the product documentation applies to SUSE Linux Enterprise Server for Arm on the Raspberry Pi, because the Raspberry Pi differs significantly from other hardware platforms.

6.2 SUSE Forums

A valid and activated subscription entitles you to receive bug and security fixes, feature updates, and technical assistance from SUSE's support organization. Learn more at https://www.suse.com/support/. Via the SUSE Customer Center at https://scc.suse.com/ you can open an incident.

In addition, SUSE has provided conversation forums where you can get answers to questions. Go to https://forums.suse.com/. Under the main forum category SUSE Linux Enterprise Server select the sub-forum SLES for Raspberry Pi.

Important
Important: Forums Are Not an Official Support Channel

The SUSE forum is not an official support channel from SUSE. The individual articles or statements were contributed voluntarily by community members and users of the respective products. SUSE cannot verify either that the actions described in the articles do what they claim to do, or that they do not have unintended consequences. Therefore, neither SUSE LLC, its affiliates, nor the authors may be held liable for possible errors or the consequences thereof.

Visit https://www.suse.com/support/ for more information about official support options.

7 Trademarks

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  6. Include, immediately after the copyright notices, a license notice giving the public permission to use the Modified Version under the terms of this License, in the form shown in the Addendum below.

  7. Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document's license notice.

  8. Include an unaltered copy of this License.

  9. Preserve the section Entitled "History", Preserve its Title, and add to it an item stating at least the title, year, new authors, and publisher of the Modified Version as given on the Title Page. If there is no section Entitled "History" in the Document, create one stating the title, year, authors, and publisher of the Document as given on its Title Page, then add an item describing the Modified Version as stated in the previous sentence.

  10. Preserve the network location, if any, given in the Document for public access to a Transparent copy of the Document, and likewise the network locations given in the Document for previous versions it was based on. These may be placed in the "History" section. You may omit a network location for a work that was published at least four years before the Document itself, or if the original publisher of the version it refers to gives permission.

  11. For any section Entitled "Acknowledgements" or "Dedications", Preserve the Title of the section, and preserve in the section all the substance and tone of each of the contributor acknowledgements and/or dedications given therein.

  12. Preserve all the Invariant Sections of the Document, unaltered in their text and in their titles. Section numbers or the equivalent are not considered part of the section titles.

  13. Delete any section Entitled "Endorsements". Such a section may not be included in the Modified Version.

  14. Do not retitle any existing section to be Entitled "Endorsements" or to conflict in title with any Invariant Section.

  15. Preserve any Warranty Disclaimers.

If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version's license notice. These titles must be distinct from any other section titles.

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.

You may add a passage of up to five words as a Front-Cover Text, and a passage of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be added by (or through arrangements made by) any one entity. If the Document already includes a cover text for the same cover, previously added by you or by arrangement made by the same entity you are acting on behalf of, you may not add another; but you may replace the old one, on explicit permission from the previous publisher that added the old one.

The author(s) and publisher(s) of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version.

You may combine the Document with other documents released under this License, under the terms defined in section 4 above for modified versions, provided that you include in the combination all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice, and that you preserve all their Warranty Disclaimers.

The combined work need only contain one copy of this License, and multiple identical Invariant Sections may be replaced with a single copy. If there are multiple Invariant Sections with the same name but different contents, make the title of each such section unique by adding at the end of it, in parentheses, the name of the original author or publisher of that section if known, or else a unique number. Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work.

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.

You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document.

A compilation of the Document or its derivatives with other separate and independent documents or works, in or on a volume of a storage or distribution medium, is called an "aggregate" if the copyright resulting from the compilation is not used to limit the legal rights of the compilation's users beyond what the individual works permit. When the Document is included in an aggregate, this License does not apply to the other works in the aggregate which are not themselves derivative works of the Document.

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 for under this License. Any other attempt to copy, modify, sublicense or distribute the Document is void, and will automatically terminate your rights under this License. However, parties who have received copies, or rights, from you under this License will not have their licenses terminated so long as such parties remain in full compliance.

The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See https://www.gnu.org/copyleft/.

Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License "or any later version" applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation.

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 1.2
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.