📘 README.md — Orange Pi 4 Pro Armbian Mainline Build

🧩 Overview

This repository contains a custom Armbian board definition for the Orange Pi 4 Pro (Allwinner A733 / sun60iw2), enabling reproducible builds of mainline Linux (6.19+) using the Armbian build framework.

The goal is to provide:

• A clean, minimal, reproducible build environment
• A fully open DTS/DTSI + patch workflow
• A safe way to rebuild images without overwriting a working SD card
• A version‑controlled place for board configs, family configs, kernel configs, and patches

This repo intentionally excludes all build artifacts, caches, and binary blobs.

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🏗️ Repository Structure

orangepi-4pro-armbian/ │ ├── config/ │ ├── boards/ │ │ └── orangepi-4pro.conf │ ├── sources/ │ │ └── families/ │ │ └── sun60iw2.conf │ └── kernel/ │ └── linux-sun60iw2-mainline.config │ ├── patches/ │ ├── kernel/ │ │ └── sun60iw2-mainline/ │ └── u-boot/ │ └── sun60iw2/ │ ├── scripts/ │ └── build.sh │ ├── .gitignore └── README.md

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🧠 Key Components

1. Board Definition (orangepi-4pro.conf)

Defines the board‑level metadata used by Armbian:

• BOARDFAMILY="sun60iw2"
• Kernel source + branch (mainline stable)
• Kernel config file
• U‑Boot target family

This file contains only variable assignments, no functions.

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2. Family Definition (sun60iw2.conf)

Implements platform‑specific logic for the Allwinner A733 / sun60iw2 family:

• Declares LINUXFAMILY="sun60iw2"
• Enables BRANCHES="mainline"
• Disables ATF compilation (ATF_COMPILE='no')
• Disables Armbian’s out‑of‑tree wireless drivers (SKIP_EXTRA_DRIVERS="yes")
• Provides a write_uboot_platform() function

U‑Boot Handling

Mainline U‑Boot currently does not produce a monolithic u-boot-sunxi-with-spl.bin for this SoC.

To avoid build failures, the repo uses: write_uboot_platform() { echo "Skipping U-Boot write (using existing bootloader)" return 0 }

This allows the image to boot using the vendor bootloader already present on SD/eMMC.

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3. Kernel Configuration

A minimal kernel config is provided:

config/kernel/linux-sun60iw2-mainline.config

This is used to build Linux 6.19+ with only the essential drivers for early bring‑up.

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4. Patches

All DTS, DTSI, and kernel patches live under:

patches/kernel/sun60iw2-mainline/

These patches are GPL‑2.0 licensed (matching the kernel) and safe to publish.

Note:
Binary DTB files are not included — only source patches.

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5. Build Script

scripts/build.sh provides a reproducible build command: ./compile.sh build
BOARD=orangepi-4pro
BRANCH=mainline
BUILD_MINIMAL=yes
KERNEL_CONFIGURE=no
RELEASE=bookworm
SKIP_EXTERNAL_DRIVERS=yes

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🔒 Licensing Notes

All DTS/DTSI files and patches in this repo follow the Linux kernel’s license: SPDX-License-Identifier: GPL-2.0

This means:

• You are allowed to modify and redistribute them
• Publishing them on GitHub is fully compliant
• Only binary DTB files are excluded (for safety and clarity)

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🚫 What This Repo Does NOT Contain

To keep the repo clean and safe:

• No cache/
• No output/
• No .img files
• No .deb files
• No vendor blobs
• No compiled DTB files
• No boot0 / boot_package.fex
• No proprietary firmware

Everything here is source only.

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🚀 Building an Image

Clone Armbian: git clone https://github.com/armbian/build cd build git clone git@github.com:YOURNAME/orangepi-4pro-armbian.git userpatches

Then run: ./userpatches/scripts/build.sh

Your image will appear in: output/images/

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🧪 Bootloader Strategy

This build currently uses:

• Vendor U‑Boot (from SD/eMMC)
• Mainline kernel 6.19+
• Mainline DTB
• Armbian rootfs

This is the safest approach during early bring‑up.

Switching to full mainline U‑Boot is possible later.

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📡 Why No DTB Files?

DTB binaries are:

• opaque
• not reviewable
• potentially dangerous
• easy to misuse

Instead, this repo includes:

• DTS
• DTSI
• patches

…which are transparent, safe, and GPL‑compliant.

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🧭 Status

• ✔ Board definition working
• ✔ Family definition working
• ✔ Kernel 6.19 builds
• ✔ Initramfs + uInitrd generated
• ✔ Image builds successfully
• ✔ U‑Boot write skipped safely
• ☐ UART bring‑up
• ☐ DTS refinement
• ☐ Regulator/clock/DVFS tuning
• ☐ HDMI/PCIe/GMAC/WiFi enablement