From 31abeb7085ceb0a470ba679b35588c13d82f161b Mon Sep 17 00:00:00 2001
From: Michele Cereda <cereda.michele@gmail.com>
Date: Sat, 18 Feb 2023 15:58:49 +0100
Subject: [PATCH] Disable radio on RaspberryPi

---
 knowledge base/apt.md             |  3 ++
 knowledge base/raspberry pi os.md | 64 +++++++++++++++++++++++++------
 knowledge base/rfkill.md          | 28 ++++++++++++++
 3 files changed, 84 insertions(+), 11 deletions(-)
 create mode 100644 knowledge base/rfkill.md

diff --git a/knowledge base/apt.md b/knowledge base/apt.md
index c286317..6f52c19 100644
--- a/knowledge base/apt.md	
+++ b/knowledge base/apt.md	
@@ -3,6 +3,9 @@
 ## TL;DR
 
 ```sh
+# Check for broken dependencies.
+sudo apt-get check
+
 # Update the packages lists.
 sudo apt update
 
diff --git a/knowledge base/raspberry pi os.md b/knowledge base/raspberry pi os.md
index 68dc3e9..e7a9c25 100644
--- a/knowledge base/raspberry pi os.md	
+++ b/knowledge base/raspberry pi os.md	
@@ -1,25 +1,43 @@
 # Raspberry Pi OS
 
-1. [Store files on the SD even when the overlay file system is active](#store-files-on-the-sd-even-when-the-overlay-file-system-is-active)
+1. [Disable WiFi and Bluetooth](#disable-wifi-and-bluetooth)
+   1. [Through boot configuration](#through-boot-configuration)
+   2. [Through rfkill](#through-rfkill)
 2. [Swap](#swap)
 3. [Run containers](#run-containers)
    1. [Kernel containerization features](#kernel-containerization-features)
    2. [Firewall settings](#firewall-settings)
-4. [Sources](#sources)
+4. [Store files on the SD even when the overlay file system is active](#store-files-on-the-sd-even-when-the-overlay-file-system-is-active)
+5. [Further readings](#further-readings)
+6. [Sources](#sources)
 
-## Store files on the SD even when the overlay file system is active
+## Disable WiFi and Bluetooth
 
-The files just need to be stored on a different file system from `/`. You can partition the SD and use that, or create a file and mount it as a virtual file system:
+### Through boot configuration
 
-```sh
-truncate -s '6G' 'file'
-mkfs.ext4 'file'
-mkdir 'mount/point'
-sudo mount -t 'ext4' -o 'loop' 'file' 'mount/point'
-sudo chown 'user':'group' 'mount/point'
-touch 'mount/point/new-file'
+Disable one or both in the `all` section of `/boot/config.txt`:
+
+```ini
+[all]
+dtoverlay=disable-wifi
+dtoverlay=disable-bt
 ```
 
+### Through rfkill
+
+1. block one or both:
+
+   ```sh
+   rfkill block wifi
+   rfkill block bluetooth
+   ```
+
+1. check they are correctly soft-blocked:
+
+   ```sh
+   rfkill list
+   ```
+
 ## Swap
 
 Disable the swap file.
@@ -57,6 +75,23 @@ update-alternatives --set iptables  /usr/sbin/iptables-legacy
 update-alternatives --set ip6tables /usr/sbin/ip6tables-legacy
 ```
 
+## Store files on the SD even when the overlay file system is active
+
+The files just need to be stored on a different file system from `/`. You can partition the SD and use that, or create a file and mount it as a virtual file system:
+
+```sh
+truncate -s '6G' 'file'
+mkfs.ext4 'file'
+mkdir 'mount/point'
+sudo mount -t 'ext4' -o 'loop' 'file' 'mount/point'
+sudo chown 'user':'group' 'mount/point'
+touch 'mount/point/new-file'
+```
+
+## Further readings
+
+- [rfkill]
+
 ## Sources
 
 - The [k3s] project page
@@ -64,7 +99,14 @@ update-alternatives --set ip6tables /usr/sbin/ip6tables-legacy
 - [Run Kubernetes on a Raspberry Pi with k3s]
 - Project's [issue 2067]
 
+<!-- project's references -->
+
+<!-- internal references -->
+[rfkill]: rfkill.md
+
+<!-- external references -->
 [build your very own self-hosting platform with raspberry pi and kubernetes]: https://kauri.io/build-your-very-own-self-hosting-platform-with-raspberry-pi-and-kubernetes/5e1c3fdc1add0d0001dff534/c
+[how to disable your raspberry pi's wi-fi]: https://pimylifeup.com/raspberry-pi-disable-wifi/
 [issue 2067]: https://github.com/k3s-io/k3s/issues/2067#issuecomment-664052806
 [k3s]: https://k3s.io/
 [run kubernetes on a raspberry pi with k3s]: https://opensource.com/article/20/3/kubernetes-raspberry-pi-k3s
diff --git a/knowledge base/rfkill.md b/knowledge base/rfkill.md
new file mode 100644
index 0000000..837e606
--- /dev/null
+++ b/knowledge base/rfkill.md	
@@ -0,0 +1,28 @@
+# rfkill
+
+1. [TL;DR](#tldr)
+2. [Sources](#sources)
+
+## TL;DR
+
+```sh
+# List devices.
+rfkill list
+
+# Block a device.
+rfkill block 'wifi'
+rfkill block 'id'
+
+# Unblock a device.
+rfkill unblock 'bluetooth'
+rfkill unblock 'id'
+```
+
+## Sources
+
+- [How to disable your Raspberry Pi's Wi-Fi]
+
+<!-- project's references -->
+<!-- internal references -->
+<!-- external references -->
+[how to disable your raspberry pi's wi-fi]: https://pimylifeup.com/raspberry-pi-disable-wifi/