defaultdk2

Minimal bringup repository for the STM32MP157F-DK2 — everything needed to bring the board to life with no excess.

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Overview

This repository contains the bare-minimum source to initialize and run the STM32MP157F-DK2 heterogeneous platform:

• CA7 side — Device Tree sources for the Cortex-A7 Linux core
• CM4 side — Firmware for the Cortex-M4 real-time core
• Drivers — Peripheral and HAL drivers
• OpenAMP middleware — Inter-processor communication between the A7 and M4 cores

The goal is a clean, reproducible starting point — no bloat, no assumptions beyond what the silicon requires.

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Repository Structure

defaultdk2/
├── CA7/
│   └── DeviceTree/
│       └── defaultdk2/       # Device Tree sources for the A7 Linux core
├── CM4/                      # Cortex-M4 firmware project
├── Drivers/                  # HAL and peripheral drivers
└── Middlewares/
    └── Third_Party/
        └── OpenAMP/          # OpenAMP IPC middleware

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Hardware Target

Property	Value
Board	STM32MP157F-DK2
SoC	STM32MP157F
A7 Core	Dual Cortex-A7 @ 800 MHz
M4 Core	Cortex-M4 @ 209 MHz
IPC	OpenAMP (RPMsg)

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CA7 — Device Tree

The CA7/DeviceTree/defaultdk2/ directory contains the .dts / .dtsi sources describing the board's hardware layout for the Linux kernel running on the Cortex-A7.

Build the DTB as part of your Yocto/BitBake flow or manually with:

dtc -I dts -O dtb -o stm32mp157f-dk2.dtb stm32mp157f-dk2.dts

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CM4 — Firmware

The CM4/ directory contains the Cortex-M4 firmware. It is designed to be loaded by the A7 via the remoteproc framework at runtime.

Flash or load via remoteproc:

# Copy firmware to the remoteproc firmware directory on the target
cp CM4/build/defaultdk2_CM4.elf /lib/firmware/

# Start the M4 core
echo defaultdk2_CM4.elf > /sys/class/remoteproc/remoteproc0/firmware
echo start > /sys/class/remoteproc/remoteproc0/state

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OpenAMP / RPMsg

Inter-processor communication between the A7 and M4 uses OpenAMP with RPMsg channels. The middleware sources in Middlewares/Third_Party/OpenAMP/ are built into both the CM4 firmware and consumed by the Linux remoteproc/rpmsg stack on the A7 side.

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Prerequisites

Tool	Purpose
STM32CubeIDE / arm-none-eabi-gcc	CM4 firmware build
Yocto / BitBake (or standalone dtc)	CA7 Device Tree build
OpenSTLinux or custom Linux image	A7 runtime
STM32CubeProgrammer	Initial flashing

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Getting Started

1. Clone this repository.
2. Build the CM4 firmware using STM32CubeIDE or your preferred ARM toolchain.
3. Integrate or replace the Device Tree in your Linux build.
4. Flash the board and boot — the M4 core can be started via remoteproc post-boot.

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License

See individual file headers for applicable STMicroelectronics and open-source licenses.