rt-thread/bsp/raspberry-pi/raspi3-32/README.md

# Raspberry PI 3B 32 BSP (Board Support Package) Execution Instruction 

[中文页](README_zh.md) |

## Introduction

This document records the execution instruction of the BSP (board support package) provided by the RT-Thread development team for the Raspberry PI 3B 32 development board.

[![raspi3_f](https://github.com/RT-Thread/rt-thread/raw/master/bsp/raspberry-pi/raspi3-32/figures/raspi3_f.jpg)](https://github.com/RT-Thread/rt-thread/blob/master/bsp/raspberry-pi/raspi3-32/figures/raspi3_f.jpg)

[![raspi3_b](https://github.com/RT-Thread/rt-thread/raw/master/bsp/raspberry-pi/raspi3-32/figures/raspi3_b.jpg)](https://github.com/RT-Thread/rt-thread/blob/master/bsp/raspberry-pi/raspi3-32/figures/raspi3_b.jpg)

## Hardware Features

| Hardware       | Description                               |
| -------------- | ----------------------------------------- |
| CPU            | quad-core ARM Cortex A53(ARMv8)           |
| Main Frequency | 1.2 GHz                                   |
| GPU            | VideoCore IV                              |
| GPU Frequency  | 400MHz                                    |
| Memory         | 1GB (0x0000000 - 0x40000000)              |
|                | 0x3f000000 - 0x40000000 is for peripheral |

**The description of functional pins is as shown as follow:**

[![GPIO-Pinout-Diagram-2](https://github.com/RT-Thread/rt-thread/raw/master/bsp/raspberry-pi/raspi3-32/figures/GPIO-Pinout-Diagram-2.png)](https://github.com/RT-Thread/rt-thread/blob/master/bsp/raspberry-pi/raspi3-32/figures/GPIO-Pinout-Diagram-2.png)

## **Compilation Instruction**

The [env](https://www.rt-thread.io/download.html?download=Env) tool is recommended for compiling in Windows environments.

The cross-compiler gcc-arm-none-eabi-4_8-2014q1_linux is recommended in Linux environment. If you don’t have compiling tool, please uncompress the downloaded package like this:

```
tar vxf gcc-arm-none-eabi-4_8-2014q1_linux.tar.bz2
```

In Linux environment, you need to modify the settings of the compiler directory, and modify the actual directory of the compiling tool in bsp/raspi3-32/rtconfig. py, remember to add the suffix /bin here.

```
EXEC_PATH = r'/opt/gcc-arm-none-eabi-4_8-2014q1_gri/bin'
```

Enter the rt-thread/bsp/raspi3-32 directory and run the following command to compile this BSP:

```
scons
```

If everything goes well, a new 'rtthread.elf' and 'kernel7.img' file will be generated. ‘kernel7.img' is what we need to put into the root directory of the Raspberry PI 3B SD card.

###  **Eclipse compiling environment**

- Step 1: Install the eclipse plugin 'cdt'.
- Step 2: Open eclipse cdt and set workspace, and set the workspace to 'rt-thread/bsp/raspberry-pi/raspi3-32'.
- Step 3: Import the project by selecting 'General->Existing Projects into Workspace' and then 'Browse ...'. Noted that the compiling only supports scons now.
  

## **Running**

### **Prepare the [Raspbian](https://downloads.raspberrypi.org/raspbian_lite_latest) SD card**

Download the raspbian image, for example, "2018-06-27-raspbian-stretch-lite.zip". Unpack it.

**Burn the SD card on Windows**

On Windows, download the burning tool " [etcher.io](https://www.balena.io/etcher/) ", run it and choose the unpacked image "2018-06-27-raspbian-stretch-lite.img".

When the burning process is completed, put "kernel8.img" into the boot partition to replace the file wit the same name.

**Burn the SD card on Linux**

Prepare an empty SD card, plug it in the computer and then execute the command below:

"sudo dd if=2018-06-27-raspbian-stretch-lite.img of=/dev/xxx bs=32M conv=fsync"

Note that the device file "/dev/xxx" should be replaced with the real SD card.

### **Prepare the serial port wire**

The BSP uses GPIO 14 & GPIO 15 of raspi 3 as the communication ports, as shown in the following image:



[![raspberrypi-console](https://github.com/RT-Thread/rt-thread/raw/master/bsp/raspberry-pi/raspi3-32/figures/raspberrypi-console.png)](https://github.com/RT-Thread/rt-thread/blob/master/bsp/raspberry-pi/raspi3-32/figures/raspberrypi-console.png)

The serial port parameters: 115200 8N1, hardware and software flow control is off.

## **Running Result**

Insert the burned SD card into Raspberry Pi, power up, the output information on the serial port should be like this:

```
heap: 0x0005d784 - 0x0045d784

 \ | /
- RT -     Thread Operating System
 / | \     4.0.2 build Jan  9 2020
 2006 - 2019 Copyright by rt-thread team
[I/I2C] I2C bus [i2c0] registered
[I/I2C] I2C bus [i2c1] registered
[I/SDIO] SD card capacity 15558144 KB.
found part[0], begin: 1048576, size: 63.0MB
found part[1], begin: 67108864, size: 14.793GB
file system initialization done!
boot cpu:3
msh />cpu = 0x00000003
cpu 3 startup.
start OK: CPU 3
boot cpu:2
cpu = 0x00000002
cpu 2 startup.
start OK: CPU 2
boot cpu:1
cpu = 0x00000001
cpu 1 startup.
start OK: CPU 1
Hello RT-Thread!

msh />
```

## **Peripheral Condition**

| Drive          | Support | Remark |
| -------------- | ------- | ------ |
| UART           | Support | UART0  |
| GPIO           | Support |        |
| IIC            | Support |        |
| SPI            | Support |        |
| CPU Timer      | Support |        |
| SD card driver | Support |        |