Buildroot Configuration

This repository contains the configuration and support files for building a custom Linux system using Buildroot for the STM32MP157-DK1 development board.

🧠 What is Buildroot?

Buildroot is a simple, efficient, and powerful tool to generate embedded Linux systems through cross-compilation.

🧩 Board Used

• STM32MP157-DK1, Raspberry Pi,Allwinner Chip (or any development board)
• STMicroelectronics MPU

📁 Repository Contents

• configs/stm32mp157_defconfig - Custom Buildroot configuration file
• board/stm32mp157/ - Post-build scripts and board-specific data
• README.md - Project documentation

🔧 Requirements

• Linux build host (Ubuntu 20.04+ recommended)
• Git, build-essential, cpio, rsync, unzip, wget, gcc, make
• Python3, libncurses-dev, bc, etc.
• Internet access to download packages

🚀 Getting Started

1. Clone this repo and Buildroot

git clone https://github.com/buildroot/buildroot.git
cd buildroot
git checkout 2024.02  # or latest stable release
cp ../stm32mp157-buildroot/configs/stm32mp157_defconfig configs/
make stm32mp157_defconfig

🛠️ Build the Image

make -jx

📤 Output

output/images/
├── zImage                # Linux kernel
├── rootfs.ext4           # Root filesystem
├── boot.scr              # U-Boot boot script
├── sdcard.img            # Full SD card image (optional)

💽 Flash to SD Card

Insert your SD card and identify the correct device path (e.g., /dev/sdX). Then flash:

sudo dd if=output/images/sdcard.img of=/dev/sdX bs=1M status=progress
sync

🚀 Boot the STM32MP157-DK1

1-Insert the SD card.

2-Connect the USB-to-UART or HDMI display.

3-Power on the board.

4-You should see Linux boot messages.

📜 Post-Build Script

You can customize the root filesystem with a post-build.sh script:

#!/bin/sh
echo "Customizing root filesystem..."
cp /path/to/local/script.sh $TARGET_DIR/usr/local/bin/
chmod +x $TARGET_DIR/usr/local/bin/script.sh

Add this script path under System configuration → Custom scripts in make menuconfig.

🖼️ Screenshots (Optional)

U-Boot 2024.01 (Apr 29 2025 - 10:00:00 +0000)

CPU: STM32MP157C Rev.B
DRAM: 512 MiB
NAND: 0 MiB
MMC: STM32 SD/MMC: 0
In: serial
Out: serial
Err: serial
Net: No ethernet found.
Hit any key to stop autoboot: 0
Booting Linux...

Starting kernel ...

[    0.000000] Booting Linux on physical CPU 0x0
[    0.000000] Linux version 6.6.9 (buildroot@localhost) ...
[    2.123456] Freeing unused kernel memory...
[    3.456789] Welcome to Buildroot
stm32mp157 login: root
Welcome to Buildroot

# uname -a
Linux buildroot 6.6.9 #1 SMP Tue Apr 29 10:00:00 UTC 2025 armv7l GNU/Linux
# df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/root        32M   15M   17M  47% /
tmpfs            64M     0   64M   0% /tmp

🙋 Author & Credits

Developed by Sajad Mosayebi

This project is inspired by the open-source STM32 ecosystem and Buildroot community.

Buildroot: https://buildroot.org

STM32MP1 Docs: https://wiki.st.com/stm32mpu