Radxa Dragon 6A

The Radxa Dragon Q6A is a credit card-sized single-board computer built around Qualcomm’s QCS6490 — the same silicon family found in the Fairphone 5 and Qualcomm’s own RB3gen2 reference platform. It packs an octa-core Kryo 670 CPU, an Adreno 643 GPU, and a 12 TOPS Hexagon NPU into a board with Gigabit Ethernet, WiFi 6, HDMI, triple camera connectors, and an M.2 NVMe slot. Starting at around $60, it sits in an interesting spot — significantly more compute per dollar than a Raspberry Pi 5, with a genuine ML inference pipeline that doesn’t require an external accelerator. Qualcomm provides Yocto builds for RB3Gen2 boards and Radxa mentions this in their documentation but doesn’t provide any how-to. In this article, we shall explore the steps taken to get Yocto running with Mainline Linux Kernel.

Here are steps to reproduce it by yourself, if you are the happy owner of this board, currently priced at 48 EUR on the Arduino shop for the 2 GB version. This is done without removing the original kernel. Your board will still boot such kernel by default.

Setup and prerequisites

To do this by yourself, you will need:

• An Arduino Q board

• A USB-C hub with external power, to power the board and to connect external devices such as USB mass storage or USB-Ethernet.

Root Commit’s contributions to Linux 6.19

Linux 6.19 is out with 7 contributions from Root Commit:

• riscv: dts: spacemit: add Ethernet and PDMA to OrangePi RV2

• dt-bindings: riscv: spacemit: Add OrangePi R2S board

• riscv: dts: spacemit: Add OrangePi R2S board device tree

• dt-bindings: arm: rockchip: merge Asus Tinker and Tinker S

• dt-bindings: arm: rockchip: Add Asus Tinker Board 3/3S

• arm64: dts: rockchip: Add Asus Tinker Board 3 and 3S device tree

Introduction

Orange PI 3B is a cheap and attractive Raspberry Pi sized single board computer based on the Rockchip RK3566:

• Rockchip RK3566 (4x ARM Cortex-A55 @ 1.6GHz)

• ARM Mali-G52-2EE GPU (OpenGL ES 1.1/2.0/3.0/3.1/3.2, Vulkan 1.1, OpenCL 2.0)

• LPDDR4 RAM (2/4/8 GB)

• Micro-SD card slot

• SPI flash (16/32 MB)

• Optional eMMC pluggable module (16/32/64/128/256 GB)

• Wi-Fi5 + Bluetooth 5.0, BLE

• 1x USB 2.0 Type A OTG, 2x USB 2.0 Type A HOST, 1x USB 3.0 Type A Host

Introduction

Five days ago, I received the Orange Pi RV2 board I ordered. For about 54 EUR / 64 USD (+ shipping), this board has very attractive features, in particular:

Top view - Source Orange Pi

• 8 GB of LPDDR4X RAM (2 and 4 GB options exist)

This is another blog post about securing your Yocto built systems:

• Securing Yocto Built Systems overview presentation slides

• Yocto Security: Production and Development Images

• Yocto security: Kernel Hardening ⬅️

Introduction

The Linux kernel is the cornerstone and stronghold of a Linux based system. Unlike user-space applications which run with limited privileges, if it’s compromised, there is almost no limit to what an attacker can do.

While nothing is unbreakable, there are two types of settings you can change to make your kernel harder to compromise:

Linux 6.17 has just been released, and it’s already running here at Root Commit.

The first system it’s been running on is this Toradex Verdin iMX8M Mini SOM (below the heat sink!) on the Dahlia Carrier board. I’m using this board for a medical device project at the moment.

Here are my notes for building Linux 6.17 for this device:

• Get the Linux 6.17 sources (through git or tarball)

This blog post is part of a series about securing your Yocto built systems:

• Securing Yocto Built Systems overview presentation slides

• Yocto Security: Production and Development Images ⬅️

• Yocto security: Kernel Hardening

What to avoid

So, you use Yocto to build an image for your embedded device. You tweak the image and distribution settings to get the features you need, and other developers use the SDK built by Yocto to create and build the User Interface and other applications.

Last week, I gave a “Making Yocto Built Images More Secure” presentation at the Embedded Linux Conference in Amsterdam.

The main goal was to share the research I’ve done so far for a customer project, and gather feedback from the audience.

If you compare the device tree as loaded by Linux, available in /sys/firmware/fdt, you will see that it differs from the one that you loaded in U-Boot. Taking the time to make the comparison is quite instructive.

Let’s do this on my Toradex Verdin iMX8M Mini SoM on the Dahlia carrier board.

Decompiling the DTB

It’s easy to decompile any Device Tree Binary (DTB) file using dtc, the Device Tree Compiler.

1. Copy /sys/firmware/fdt from your live Linux system to external storage (assuming your external storage is mounted on /mnt/usb)
   cp /sys/firmware/fdt /mnt/usb/linux.dtb