helper_Buildroot-RaspberryPi3.md

Buildroot Raspberry Pi 3

1. Overview

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

2. Environment

Host: Ubuntu 20.04 x86_64

$ sudo apt install -y sed make binutils gcc g++ bash patch gzip bzip2 perl tar cpio python unzip rsync wget libncurses-dev

3. Build with Buildroot

Host: Ubuntu 20.04 x86_64

Target: Raspberry Pi3

3.1. To build Image

A. Download buildroot-2022.02.tar.gz

$ wget https://buildroot.org/downloads/buildroot-2022.02.tar.gz
$ tar xvzf buildroot-2022.02.tar.gz
$ cd buildroot-2022.02

B. menuconfig

# for the original curses-based configurator
$ make menuconfig
# new curses-based configurator
$ make nconfig
# for the Qt-based configurator
$ make xconfig
# for the GTK-based configurator
$ make gconfig

$ make list-defconfigs

B.1. Select raspberrypi3_64_defconfig

也可以使用預設參數，本篇選擇 raspberrypi3_64_defconfig

# make <defconfig name>
# Build for raspberrypi
$ make raspberrypi_defconfig
# Build for raspberrypi3_64
$ make raspberrypi3_64_defconfig

# 進行微調
$ make menuconfig

• Toolchain/C library/glibc
• System Configuration/System Banner
• System Configuration/Root password
• Target packages/Networking applications/dropbear
• Target packages/Networking applications/iftop
• Target packages/System tools/htop
• Target packages/Filesystem and flash utilities/e2fsprogs
• Target packages/Filesystem and flash utilities/nfs-utils
• Target packages/Compressors and decompressors/bzip2
• Target packages/Compressors and decompressors/zip

C. Build

$ make all

3.2. To Generate Toolchain

$ make sdk

$ ll output/images/aarch64-buildroot-linux-gnu_sdk-buildroot.tar.gz
$ cp output/images/aarch64-buildroot-linux-gnu_sdk-buildroot.tar.gz /opt

$ cd /opt
$ tar -zxvf aarch64-buildroot-linux-gnu_sdk-buildroot.tar.gz
$ cd /opt/aarch64-buildroot-linux-gnu_sdk-buildroot
$ tree -L 1./
.
├── aarch64-buildroot-linux-gnu
├── bin
├── etc
├── include
├── lib
├── lib64 -> lib
├── libexec
├── relocate-sdk.sh
├── sbin
├── share
└── usr -> .

10 directories, 1 file

$ ./relocate-sdk.sh

$ ll /opt/aarch64-buildroot-linux-gnu_sdk-buildroot/bin/*-gcc
lrwxrwxrwx 1 lanka lanka 17  五  19  2023 /opt/aarch64-buildroot-linux-gnu_sdk-buildroot/bin/aarch64-buildroot-linux-gnu-gcc -> toolchain-wrapper*
lrwxrwxrwx 1 lanka lanka 17  五  19  2023 /opt/aarch64-buildroot-linux-gnu_sdk-buildroot/bin/aarch64-linux-gcc -> toolchain-wrapper*

$ /opt/aarch64-buildroot-linux-gnu_sdk-buildroot/bin/aarch64-buildroot-linux-gnu-gcc --print-sysroot
/opt/aarch64-buildroot-linux-gnu_sdk-buildroot/aarch64-buildroot-linux-gnu/sysroot

$ export PJ_SYSROOT=/opt/aarch64-buildroot-linux-gnu_sdk-buildroot/aarch64-buildroot-linux-gnu/sysroot

4. Burn Your Image into SD CARD

flowchart LR
	SD[SD CARD]
	Image --> |dd|SD
	Image --> |balenaEtcher|SD
	

Loading

A. use dd

$ cd output/images

$ ls -ls sdcard.img

#unmount your sdcard first
$ sudo umount /dev/sdb1

#write img file to microsd card
$ sudo dd if=output/images/sdcard.img of=/dev/sdb bs=1M

B. use balenaEtcher-Portable-1.5.49

個人比較喜歡用 Etcher，執行時請使用系統管理者啟動

5. Boot from SD Card

$ uname -a
Linux lanka-pi3 5.10.92-v8 #1 SMP PREEMPT Wed Apr 6 11:04:25 CST 2022 aarch64 GNU/Linux

$ cat /proc/version
Linux version 5.10.92-v8 (lanka@msi-vbx) (aarch64-buildroot-linux-gnu-gcc.br_real (Buildroot -svn8) 10.3.0, GNU ld (GNU Binutils) 2.36.1) #1 SMP PREEMPT Wed Apr 6 11:04:25 CST 2022

$ cat /etc/os-release
NAME=Buildroot
VERSION=-svn8
ID=buildroot
VERSION_ID=2022.02
PRETTY_NAME="Buildroot 2022.02"

$ cat /etc/issue
Welcome to Buildroot

$ ls -al /bin/sh
lrwxrwxrwx    1 root     root             7 Apr  6  2022 /bin/sh -> busybox

6. Build helloworld on Host

$ export PATH=/opt/aarch64-buildroot-linux-gnu_sdk-buildroot/bin:$PATH

$ cd /tmp
$ vi helloworld.c
#include <stdio.h>

int main(int argc, char *argv[])
{

	printf("Hello World !!!\n");
	return 0;
}

$ aarch64-buildroot-linux-gnu-gcc helloworld.c -o helloworld
# 避免動態連結 --static
$ aarch64-buildroot-linux-gnu-gcc --static helloworld.c -o helloworld

$ file helloworld
helloworld: ELF 64-bit LSB shared object, ARM aarch64, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-aarch64.so.1, for GNU/Linux 5.10.0, not stripped

A. Qemu user mode

# run with qemu
$ sudo apt install qemu-user qemu-user-static

$ qemu-aarch64 helloworld
#or
$ LD_LIBRARY_PATH=$PJ_SYSROOT/lib qemu-aarch64 $PJ_SYSROOT/lib/ld-linux-aarch64.so.1 /tmp/helloworld
Hello world !!!

7. Run helloworld on Pi

# Please scp helloworld from Ubuntu -> Pi 
$ helloworld
Hello world !!!

Appendix

I. Study

I.1. Building custom Linux for Raspberry Pi using Buildroot

I.2. Building a custom Linux OS for RaspberryPi using buildroot

I.3. Building Raspberry Pi Systems with Buildroot

II. Debug

III. Glossary

IV. Tool Usage

Author

Created and designed by Lanka Hsu.

License

HelperX is available under the BSD-3-Clause license. See the LICENSE file for more info.