DEV Community

rim dinov
rim dinov

Posted on

Stripping Down the Linux Kernel: A 8.9MB Build for Radxa Zero 3 (RK3566)

  1. Introduction: Why go minimal? The Goal: Why 8.9MB? Explain the benefit of a small kernel for headless SBCs (faster boot, lower RAM usage, reduced attack surface).

The Hardware: Brief mention of the Radxa Zero 3 and its RK3566 SoC.

The Result: Mention that this configuration was officially acknowledged by Radxa engineers.

  1. Prerequisites & Environment Setup Toolchain: How to install the cross-compiler on Ubuntu/Debian.

Bash
sudo apt install gcc-aarch64-linux-gnu make libncurses-dev flex bison
Source Code: Link to the official Radxa/Rockchip kernel source.

  1. The Core Optimization Logic (The "How-To") This is the most important part. Break down your rk3566-minimal.config into logical steps:

Step 1: CPU & Architecture. Setting up CONFIG_ARM64_64K_PAGES and why it helps performance.

Step 2: Security First. Explaining why we keep PAC (Pointer Authentication) and BTI (Branch Target Identification) even in a minimal build.

Step 3: The "Cuts". What did we remove?

Disabling DRM (Graphics) for headless use.

Removing Sound/Multimedia subsystems.

Stripping unused HID and USB drivers.

Step 4: Compiler Optimization. Using CONFIG_CC_OPTIMIZE_FOR_SIZE=y.

  1. Step-by-Step Build Process Provide the exact commands you used:

make ARCH=arm64 rk3566-minimal_defconfig (or applying your custom config).

make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -j$(nproc)

Verifying the output size.

  1. Deployment: Flashing and Testing How to replace the kernel image on the SD card.

Using dmesg to verify that everything initialized correctly.

Pro Tip: Mention how to check memory usage immediately after boot.

  1. Conclusion & Future Work Summary of what was achieved.

Call to action: "Check out the full config on my GitHub" (Link to radxa-zero3-minimal-kernel).

Mention your next steps (maybe integrating this into a custom buildroot/yocto image).

You can find the config and build instructions here:
https://github.com/rdin777/radxa-zero3-minimal-kernel

Top comments (0)