Raspberry Pi 4B

Introduction

The Raspberry Pi 4B project is an example project within the XWOS main repository. The project directory is located at xwbd/RPi4B.

• Hardware homepage: https://www.raspberrypi.com/products/raspberry-pi-4-model-b/
• SoC: BCM2711

Development Environment Setup Guide

Download Source Code

git clone https://gitee.com/xwos/XWOS.git

or

git clone https://github.com/xwos/XWOS.git

vscode

Debugging requires installing vscode first.

Install plugins:

• Cortex-Debug
• C/C++
• Chinese (Simplified) (简体中文) Language Pack for Visual Studio Code

Install Toolchain

xwtc is a collection of tools for XWOS compilation. It can be downloaded from Baidu Cloud Drive and installed according to the included 说明.md.

• https://pan.baidu.com/s/1WwSaEajt6JqgMOLOa8iPEQ
• Extraction code: xwos
• Note: Make sure to set the environment variable XWTC. The gdb path configured in .vscode/launch.json will use this environment variable.

If the user uses Ubuntu-24.04 as the development environment, some additional tools need to be installed:

sudo dpkg-reconfigure dash # Select "No"
sudo apt install build-essential
sudo apt install emacs # For a pure command-line server environment, use emacs-nox instead

openocd

• https://github.com/xpack-dev-tools/openocd-xpack/releases
• Download the latest version according to your platform.

Ubuntu

• 1. Extract.
• 2. Open Home, press ctrl+h to show hidden files, find .local/. Copy the extracted contents (folders like bin, openocd, libexec, etc.) into .local/ and merge.
• 3. Re-login for the changes to take effect.

Windows

• 1. Extract.
• 2. Right-click This PC –> Properties –> Advanced System Settings –> Environment Variables.
• 3. Find the environment variable Path, add the path to the extracted bin folder.
• 4. Re-login for the changes to take effect.

Build

There are two ways to build:

• Open a terminal and enter:
  • Switch to the board directory: cd xwbd/RPi4B
  • Build: make -j20
  • Clean: make d
• In Vscode, select Terminal –> Run Task
  • Build: build
  • Clean: clean

Debugging

Create Bootable TF Card

• Go to the Raspberry Pi official website https://www.raspberrypi.com/software/ and download Raspberry Pi Imager
• Use Raspberry Pi Imager to create a bootable SD card
  • Device: select RASPBERRY PI 4
  • System can be:
    • RASPBERRY PI OS(64-BIT) or
    • Use custom and select an Ubuntu image
• Open the TF card’s system-boot partition and delete all files in it.
• Copy all files from the xwbd/RPi4B/firmware/ directory to the TF card’s system-boot partition.

Connect Debugger

Connect Terminal UART

• Baud rate: 2000000 BPS

Start Debugging

• Insert TF card
• Insert power
• Wait a moment (wait for the Raspberry Pi 4B GPU to complete system initialization, read config.txt, and load firmware)
• On the Run and Debug page:
  • First power-on:
    • JLink: select Rpi4b-AllCores-Openocd-Jlink-Launch
    • DapLink: select Rpi4b-AllCores-Openocd-Daplink-Launch
  • Attach to a running system:
    • JLink: select Rpi4b-AllCores-Openocd-Jlink-Attach
    • DapLink: select Rpi4b-AllCores-Openocd-Daplink-Attach

Debugging Tips

Boot Timing May Be Incorrect When Using Debugger

• After debug launch, CPU0 will stop at soc_init(), and other CPUs will spin in SPIN_TABLE.
• Continue running CPU0 to the cpu0_mthd_mainfunc() thread’s soc_boot_mp(), where CPU0 will start other CPUs. Only at this point can you click other CPUs’ Continue button.

High Peripheral Address Mode

• The Vscode plugin Cortex-Debug only supports 32-bit addresses. Enabling high peripheral address mode will cause the peripheral register display function to fail.