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).



Hi, I am a travel guide, and I’m happy to share useful information about the Qatar Airways Chicago Office. The Qatar Airways Office in Chicago serves as a helpful contact point for passengers traveling with Qatar Airways from Illinois. Travelers can get assistance with flight bookings, ticket modifications, baggage inquiries, and special service requests.
Really interesting approach to building Debian from scratch! It reminds me of the precision needed when working on a Land Rover Engine—every detail matters. If anyone is looking for performance upgrades, a Range Rover Engine or even reconditioned engines can make a huge difference, especially when considering something like a Land Rover Discovery 3 for sale.
New York Amtrak Stations and Routes connect travelers to many destinations across the Northeast, Midwest, and beyond, with Penn Station in Manhattan serving as the main hub. Whether you’re planning a trip or searching for a Train Station Near Me, Amtrak makes it simple to find the closest option. If plans change, the Amtrak Cancellation Policy explains how to adjust or cancel your ticket, and for misplaced items, the Amtrak Lost and Found service helps reunite passengers with their belongings.
I planned my Makkah Trip for Umrah with a UK-based travel agency, and the experience exceeded all expectations. From the very beginning, everything was handled with professionalism and care, making the entire journey seamless and stress-free. The ATOL-protected services provided complete peace of mind, and the team guided us clearly through every step of the visa process. Our stay in Makkah was exceptional. We were accommodated in a clean and luxurious 5-star hotel just minutes away from the Haram, which made performing Umrah extremely convenient and spiritually uplifting. The entire Makkah Trip was peaceful, well-organized, and truly rewarding. For anyone looking for a reliable and experienced UK-based agency for Hajj or Umrah, this is an excellent choice.
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.