Embedded Linux Yocto

Embedded Linux and Yocto learning materials

• Embedded_Linux&Yocto_topics

Overview

This repository provides a scalable enterprise-grade Embedded Linux platform built using the Yocto Project.

The goal of this platform is to support multiple SoC vendors and hardware boards under a unified architecture with:

• Common BSP workflows
• CI/CD automation
• Reproducible builds
• OTA update support
• Secure boot integration
• Manufacturing flashing workflows
• Automated validation
• Long-term maintainability

The platform is designed for:

• Industrial systems
• Robotics
• AI edge devices
• Automotive gateways
• Medical devices
• IoT gateways
• Multimedia systems
• FPGA platforms

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Supported Platforms

ARM / ARM64 Boards

Raspberry Pi Family

Supported:

• Raspberry Pi 4
• Raspberry Pi 5
• CM4
• CM5

Main Layer:

• meta-raspberrypi

Features:

• SD/eMMC boot
• USB boot
• Wayland/Weston
• Camera support
• GPU acceleration
• OTA support

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NXP i.MX Boards

Supported:

• i.MX6
• i.MX7
• i.MX8M
• i.MX8MP
• i.MX93

Main Layer:

• meta-freescale

Features:

• Secure boot
• GPU/VPU acceleration
• AI acceleration
• Industrial BSP support
• eMMC/NAND/NVMe support

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Texas Instruments Boards

Supported:

• AM62x
• AM64x
• AM65x
• J721E
• BeagleBone AI

Main Layer:

• meta-ti

Features:

• MCU+Linux architecture
• IPC support
• Industrial Ethernet
• Edge AI acceleration
• Vision processing

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NVIDIA Jetson Boards

Supported:

• Jetson Nano
• Xavier NX
• AGX Xavier
• Orin NX
• AGX Orin

Main Layer:

• meta-tegra

Features:

• CUDA
• TensorRT
• AI acceleration
• Multimedia pipelines
• GPU compute

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Rockchip Boards

Supported:

• RK3566
• RK3568
• RK3588

Main Layers:

• meta-rockchip

Features:

• Multimedia acceleration
• NPU support
• HDMI/MIPI pipelines
• NVMe support

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Xilinx / AMD FPGA Boards

Supported:

• ZCU102
• KV260
• VCK190
• ZedBoard

Main Layers:

• meta-xilinx

Features:

• FPGA bitstream integration
• Vitis AI
• Hardware accelerators
• Secure boot
• JTAG workflows

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STM32 MPU Boards

Supported:

• STM32MP157
• STM32MP13

Main Layer:

• meta-st-stm32mp

Features:

• OP-TEE
• Cortex-M co-processor
• Industrial control
• Low power systems

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Qualcomm Boards

Supported:

• RB5
• RB3 Gen2
• DragonBoard

Main Layer:

• meta-qcom

Features:

• DSP acceleration
• AI acceleration
• Camera pipelines
• Android-style boot flows

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RISC-V Boards

Supported:

• VisionFive 2
• HiFive Unmatched
• Milk-V
• Banana Pi RISC-V

Main Layers:

• meta-riscv
• vendor BSP layers

Features:

• Open hardware ecosystem
• OpenSBI support
• Upstream Linux focus

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Toradex Platforms

Supported:

• Verdin iMX8MP
• Verdin AM62
• Apalis iMX8
• Colibri iMX6

Main Layers:

• meta-toradex-bsp-common
• meta-toradex-nxp
• meta-toradex-ti

Features:

• Torizon OS
• OTA support
• Industrial BSPs
• Container workflows

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Repository Structure

repo/
├── docs/
├── scripts/
├── ci/
├── kas/
├── build-configs/
├── meta-company-common/
├── meta-company-security/
├── meta-company-connectivity/
├── meta-company-gui/
├── meta-company-ai/
├── meta-company-industrial/
├── meta-company-ota/
├── meta-company-virtualization/
├── meta-company-robotics/
├── vendor/
│   ├── meta-raspberrypi/
│   ├── meta-freescale/
│   ├── meta-ti/
│   ├── meta-tegra/
│   ├── meta-xilinx/
│   ├── meta-qcom/
│   ├── meta-st-stm32mp/
│   ├── meta-rockchip/
│   └── meta-riscv/
└── tools/

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Build System Architecture

Core Technologies

Component	Purpose
Yocto Project	Build framework
OpenEmbedded	Metadata ecosystem
BitBake	Task execution
kas	Build orchestration
Docker/Podman	Build containers
GitLab/GitHub Actions	CI/CD
RAUC/Mender	OTA updates
labgrid/LAVA	Hardware testing

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Build Environment Setup

Host Requirements

Recommended:

• Ubuntu 22.04 LTS
• 16+ CPU cores
• 64GB RAM
• 500GB SSD

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Install Dependencies

sudo apt install gawk wget git diffstat unzip texinfo \
gcc build-essential chrpath socat cpio python3 python3-pip \
python3-pexpect xz-utils debianutils iputils-ping \
python3-git python3-jinja2 libsdl1.2-dev xterm \
zstd liblz4-tool

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Repository Initialization

Clone Repository

git clone <repo-url>
cd repo

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Sync Vendor Layers

./scripts/sync-layers.sh

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Initialize Environment

source scripts/setup-env.sh

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Using kas

Build Raspberry Pi Image

kas build kas/raspberrypi/rpi5.yml

Build NXP Image

kas build kas/nxp/imx8mp.yml

Build TI Image

kas build kas/ti/am62.yml

Build Jetson Image

kas build kas/nvidia/orin.yml

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Image Types

Image	Purpose
core-image-minimal	Minimal Linux
core-image-full-cmdline	CLI systems
core-image-weston	Wayland GUI
multimedia-image	Multimedia systems
ai-image	AI edge systems
industrial-image	Industrial deployments
factory-image	Manufacturing flashing

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Flashing Workflows

Supported Flash Methods

Method	Platforms
SD card	Raspberry Pi, RISC-V
eMMC flashing	NXP, TI, Toradex
USB recovery	STM32, Toradex
Fastboot	Qualcomm
SDK Manager	NVIDIA
JTAG	Xilinx
Network boot	All major platforms

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Verification Framework

Validation Levels

Boot Validation

Checks:

• UART logs
• Bootloader
• Kernel boot
• Device tree
• RootFS mount

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Peripheral Validation

Checks:

• Ethernet
• Wi-Fi
• Bluetooth
• USB
• CAN
• SPI
• I2C
• GPIO
• UART

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Graphics Validation

Checks:

• Weston
• DRM/KMS
• OpenGL ES
• Vulkan
• HDMI/MIPI display

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AI Validation

Checks:

• TensorRT
• Vitis AI
• DSP/NPU acceleration
• ONNX Runtime

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Security Validation

Checks:

• Secure boot
• OP-TEE
• Signed images
• TPM integration
• Encrypted storage

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OTA Validation

Checks:

• A/B updates
• Rollback
• Image integrity
• Partition switching

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CI/CD Architecture

Pipeline Flow

Git Push
   ↓
Static Analysis
   ↓
kas Build
   ↓
SPDX/SBOM Generation
   ↓
Artifact Packaging
   ↓
Flash Hardware
   ↓
UART Capture
   ↓
Hardware Validation
   ↓
OTA Validation
   ↓
Release Publish

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CI Features

Supported:

• Incremental builds
• Shared sstate cache
• Shared downloads cache
• Artifact retention
• Parallel hardware testing
• Multi-board matrix builds
• SBOM generation
• CVE scanning

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Release Management

Release Types

Release	Purpose
Development	Daily builds
QA	Validation builds
Release Candidate	Pre-production
Production	Stable release
LTS	Long-term support

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OTA Architecture

Supported Frameworks:

• RAUC
• Mender
• OSTree
• Aktualizr

Features:

• A/B partitions
• Rollback
• Signed bundles
• Delta updates
• Fleet management

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Security Features

Supported Security Components

Feature	Support
Secure Boot	Yes
TPM	Yes
OP-TEE	Yes
dm-verity	Yes
SELinux	Optional
Disk Encryption	Yes
Signed OTA	Yes

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Manufacturing Support

Factory Workflow

Factory PC
   ↓
Recovery Mode
   ↓
Flash Device
   ↓
Run Validation
   ↓
Generate Device Certificate
   ↓
Store Manufacturing Logs

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Hardware Lab Infrastructure

Recommended Lab Setup

Component	Recommendation
Power control	USB relay/PDU
UART capture	Serial servers
Flash automation	labgrid
Test orchestration	LAVA
Thermal testing	Controlled chamber
Network isolation	VLAN setup

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Development Best Practices

DO

• Use kas for reproducible builds
• Keep vendor layers unmodified
• Create custom company layers
• Enable UART on all boards
• Automate validation
• Version lock all layers
• Use shared sstate cache
• Maintain release manifests

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DON'T

• Modify vendor BSP directly
• Hardcode machine-specific hacks
• Skip secure boot validation
• Ignore OTA rollback testing
• Use SD cards for production systems

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Common Development Workflow

Feature Development
        ↓
Local Build
        ↓
Static Validation
        ↓
Hardware Flash
        ↓
Peripheral Tests
        ↓
CI Validation
        ↓
OTA Validation
        ↓
Release Tagging

---

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Future Roadmap

Planned additions:

• Yocto Scarthgap LTS support
• Full SBOM automation
• CVE dashboards
• Fleet OTA management
• Secure enclave integration
• Kubernetes at edge
• AI benchmarking framework
• Rust embedded support
• Zephyr co-processor integration

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Recommended Tools

Build Tools

• kas
• BitBake
• repo
• Docker
• Podman

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Validation Tools

• labgrid
• LAVA
• pytest
• Robot Framework

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Debug Tools

• UART adapters
• JTAG probes
• OpenOCD
• Wireshark
• perf
• trace-cmd

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Contribution Guidelines

Requirements

Before submitting:

• Run lint checks
• Validate on hardware
• Provide test logs
• Update documentation
• Include release notes

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