Minimal Debian (u-boot, kernel, and Debian from scratch)
- Alex
- Jun 1, 2020
- 2 min read
This article is at https://forum.clockworkpi.com/t/os-minimal-debian-u-boot-kernel-and-debian-from-scratch/5707
By Joao_Manoel
I created a clean Debian, and u-boot from scratch to be used in our device.
The menu is Retroarch. It boots directly to it in KMS mode (without X11). I have been working on an optimized version of retroarch with brightness control, more OSD options, power off, reboot on the menu, and other small features, but I decided to use the retroarch from the official repository. Maybe someone wants to use my build for other stuff, and it is very easy to uninstall retroarch now (apt uninstall retroarch). I’ll launch my retroarch in a dpkg file in the future to keep compatibility.
The OS only uses ~500MB of disk space, but I couldn’t shrink the partition I used, so you need at least a 2 GB SD card ( You will have 1.5GB of free space).
I documented as much as possible so someone else can recreate what I did. The skeleton (u-boot, kernel, partition procedure) can be the base for a Buildroot or another distribution.
Functionalities
Based on Debian Bullseye for the latest MESA driver with full lima support.
Clean OS with only Debian packages (no handmade compiled binaries) and small tweaks for hardware compatibility with gameshell.
No strange symbolic links nor duplicate files.
Max CPU frequency of 1.4GHz.
I don’t consider it an overclock. It is inside CPU specs, you can always use the governor settings to limit the frequency and increase battery life. The default governor is performance.
Standby mode (freeze) by pressing quickly the power key.
Power off by long-press (~2 seconds) the power key.
500 MB of space occupied in the disk.
The system uses the minimum necessary to have a full Debian distribution with all the functionalities such as:
Package management (apt-get).
Wifi management with wpa-supplicant.
Bluetooth with bluez server.
DHCP server for USB ethernet functionality. I’m using network 192.168.11.x because some routers use the 192.168.10.x and using it will cause network problems.
SSH server.
Retroarch as a menu, and starting at boot. Takes around ~20 seconds from power on to get RetroArch running.
RAM usage of only 29MB, and 51MB with RetroArch running.
Cedrus support enabled in the kernel.
This is for video encoding/decoding in hardware. The libva driver still not complete, but we should have it soon. This will be good if you want to record your game with retroarch and ffmpeg driver.
Charging LED is now in userspace (next release 0.2).
I Patched the kernel. Now you have the charging LED (Orange LED) in the userspace at (/sys/class/leds/axp20x\:chgled/). You can control it manually (to use it for what you want like a normal led), or automatic (controlled by the charger).
Enabled status LED (green LED) to monitor (next release 0.2):
Activity (CPU usage) [default mode], you can change it in the userspace.
Heartbeat. (I will use it later to signalize standby mode)
Known Issues
HDMI doesn’t work.
LED’s doesn’t work. FIXED (next release 0.2).
The British Airways Heathrow Airport Terminal offers an excellent travel experience with its modern design, efficient check-in process, and well-organized layout. Passengers can enjoy premium lounges, a wide variety of dining and shopping options, and smooth connections throughout the airport. The helpful staff and clear signage make navigating the British Airways Heathrow Airport Terminal easy and stress-free, ensuring a comfortable journey for both business and leisure travelers.
I arranged my Umrah journey with Ready 2 Travels, and the service exceeded all expectations. From the very beginning, everything was handled with professionalism and care, making the entire process seamless and worry-free. Their ATOL protection provided complete reassurance, and the team guided us clearly through every visa step. Our stay in Makkah was outstanding—a clean, luxurious 5-star hotel just minutes from the Haram, which made performing Umrah incredibly convenient. The trip was peaceful, well-managed, and spiritually uplifting. If you’re looking for a reliable and experienced UK-based agency for Hajj or Umrah, Ready 2 Travels is an excellent choice. JazakAllah Khair.
Thanks for sharing such well-organized information.
Relay Socket
A yoga wheel for stretching is a powerful and supportive prop that helps deepen stretches while maintaining proper alignment. It is especially useful for releasing tension in the spine, shoulders, chest, and hips, areas that often feel tight due to stress or long hours of sitting. Using a yoga wheel for stretching allows the body to open gradually, making poses like backbends and heart openers more accessible and comfortable. Beginners can rely on the wheel for support, while advanced practitioners can use it to intensify stretches and improve flexibility. Regular practice with a yoga wheel for stretching can also enhance posture, increase spinal mobility, and promote better breathing by opening the chest. When used mindfully, it becomes an effective tool for…
I recently arranged my Umrah pilgrimage through the Islamic Travel Agency, and I can’t recommend them highly enough. The entire experience was smooth, well-organised, and truly professional. Their ATOL protection gave me real peace of mind, and their team provided exceptional support, including clear, step-by-step visa guidance. Our accommodation in Makkah was excellent—a spotless, comfortable 5-star hotel located just a short walk from the Haram, which made completing our Umrah so much easier. It was a completely stress-free and spiritually enriching journey from start to finish. If you’re searching for a trustworthy and knowledgeable UK-based Islamic travel agency for Hajj or Umrah, this is the one to choose. JazakAllah Khair!