Use backports for compiling WireGuard from source. This makes it compatible also with older kernels.

Signed-off-by: DL6ER <dl6er@dl6er.de>

docs/guides/wireguard/server.md

@@ -26,27 +26,60 @@ sudo apt install wireguard wireguard-tools wireguard-dkms
 If there is no `wireguard` package available for your system, you can follow the instructions below to compile WireGuard from source.
 
 <!-- markdownlint-disable code-block-style -->
-???+ info "Compile WireGuard from source"
+??? info "Compile WireGuard from source"
 
-    With the following commands, you can install WireGuard from source
+    With the following commands, you can install WireGuard from source as a backport of the WireGuard kernel module for Linux to 3.10 ≤ kernel ≤ 5.5 as an out-of-tree module. More recent kernels already include WireGuard themselves and you only need to install the `wireguard` tools.
+
+    ### Update your local system
 
     ``` bash
     sudo apt update && sudo apt upgrade -y
-    sudo apt install raspberrypi-kernel-headers libmnl-dev libelf-dev build-essential git -y
-    git clone https://git.zx2c4.com/WireGuard
-    cd WireGuard/src
-    sudo make
-    sudo make install
     ```
 
-    With these commands, you can update your locally compiled WireGuard at any time:
+    ### Install the toolchain
+
+    === "Raspberry Pi"
+
+        ``` bash
+        sudo apt install -y raspberrypi-kernel-headers libelf-dev build-essential pkg-config git
+        ```
+
+    === "Linux"
+
+        ``` bash
+        sudo apt install -y linux-headers-$(uname -r) libelf-dev build-essential libmnl-dev git
+        ```
+
+    ## Download and compile the `wireguard` module
 
     ``` bash
-    cd WireGuard/
-    git pull
-    cd src
-    sudo make
-    sudo make install
+    git clone https://git.zx2c4.com/wireguard-linux-compat
+    make -C wireguard-linux-compat/src -j$(nproc)
+    sudo make -C wireguard-linux-compat/src install
+    ```
+
+    You can ignore messages like
+
+    ``` plain
+    Warning: modules_install: missing 'System.map' file. Skipping depmod.
+    ```
+
+    !!! info "Check the module installation was successful"
+
+        Run
+
+        ``` bash
+        sudo modprobe wireguard
+        ```
+
+        If there is no output, `wireguard` was loaded correctly. Note that it may be necessary to re-install the `wireguard` module when you update your system's kernel.
+
+    ## Download and compile the `wireguard` tools (`wg`, etc.)
+
+    ``` bash
+    git clone https://git.zx2c4.com/wireguard-tools
+    make -C wireguard-tools/src -j$(nproc)
+    sudo make -C wireguard-tools/src install
     ```
 
     The ZX2C4 git repository is the official source for `wireguard-linux`, see [WireGuard#Repositories](https://www.wireguard.com/repositories/) (external link)

mkdocs.yml

@@ -39,6 +39,9 @@ markdown_extensions:
   - pymdownx.extra
   # (https://facelessuser.github.io/pymdown-extensions/extensions/details/)
   - pymdownx.details
+  # Tabbed provides a syntax to easily add tabbed Markdown content.
+  # https://facelessuser.github.io/pymdown-extensions/extensions/tabbed/
+  - pymdownx.tabbed
   # Adds syntax for defining footnotes in Markdown documents (https://python-markdown.github.io/extensions/footnotes/)
   - footnotes
   # Adds the ability to define abbreviations