Ubuntu System Porting Guide for Renesas RZ/G2L-based Remi Pi

1. Overview

Linux system platform has a variety of open source system building frameworks, which facilitate the developer in building and customizing embedded systems. Currently, some of the more common ones include Buildroot, Yocto, OpenEmbedded and so on.

Meanwhile, more traditional desktop systems have also joined the embedded environment system, such as Ubuntu and Debian, to provide more convenient and practical systems for embedded development. This article mainly introduces the complete process of customizing a complete embedded Ubuntu 22.04 system based on Ubuntu 22.04 core and MYIR’s Remi Pi, including the preparation of the development environment, the acquisition and transplantation of Ubuntu 22.04 system, LXDE lightweight desktop management, and so on.

This guide does not cover the introduction of the basic knowledge related to the Linux BSP system, and will directly use the BSP provided by myir-image-full released by MYIR. For more information on how to create BSP files, please refer to the “Remi Pi_Linux Software Developer's Guide”.

1.1 Software Resources

The Ubuntu system used by Remi Pi is based on the ubuntu-base-22.04-base-arm64.tar.gz version (download link below), and adds abundant system resources and other software resources on this basis.

Ubuntu Base 22.04.2 LTS (Jammy Jellyfish)

Note: The login name for the ubuntu system provided by MYIR is: root. Password: 123456

2. Preparation of Development Environment

Based on the Ubuntu base system, some hardware and software environments required in the development process include the essential development host environment, the necessary software tools, and access to code and materials. The specific preparations will be described in detail below.

2.1 Development Host Environment

This section describes how to build a development environment suitable for the Renesas Remi Pi platform, which uses the multi-core heterogeneous RZ/G series processors. The RZ/G2L has dual ARM Cortex-A53 cores. By reading this chapter, you will understand the installation and usage of related hardware tools, software development and debugging tools. And you can quickly set up the related development environment to prepare for subsequent development and debugging.

Host Hardware

The construction of the entire SDK package project has high requirements for the development host, which requires a processor with a dual-core or higher CPU, 8GB or more of memory, and a 100GB hard disk or higher configuration. It can be a PC or server with Linux system installed, or a virtual machine running a Linux system, or WSL2 under a Windows system.

Host Operating System

Usually the installation is chosen to be performed on a local host running a Linux distribution such as Fedora, openSUSE, Debian, Ubuntu, RHEL or CentOS. Here we recommend Ubuntu 22.04 64bit desktop version, and subsequent development will be introduced with this system as an example.

Installation of Required Software Package

Please refer to the “Remi Pi_Linux Software Development Guide” for installation, and only one package will be required for installation here.

PC@system1:~$  sudo apt-get update

PC@system1:~$  sudo apt-get install qemu-user-static

3. Porting the Ubuntu 22.04 File System

3.1 Introduction

Ubuntu-base is the minimum file system officially built by Ubuntu, which includes the Debian package manager. The size of the base package is usually only tens of megabytes, behind which there is the entire ubuntu software repository support. Ubuntu software generally has good stability. Based on Ubuntu-base, Linux software can be installed on demand, with deep customization capabilities, and it is commonly used for embedded rootfs construction.

Several common methods for building embedded file systems include busybox, yocto and buildroot. But Ubuntu offers a convenient and powerful package management system with strong community support, allowing for the installation of new software packages directly through apt-get install. This article describes how to build a complete Ubuntu system based on Ubuntu-base. Ubuntu supports many architectures such as arm, X86, powerpc, ppc, and more. This article is mainly focusing on building a complete ubuntu system based on arm as an example.

3.2 Obtaining the Source Code

We provide two ways to obtain the source code, one is to obtain the zip package directly from the 04-sources folder of MYIR's disk image, and the other is to use wget to obtain the official source code for building. Please choose one of the methods according to your actual needs to perform the building process.

3.2.1 Obtaining Source Code via wget

The details of the procedure are as follows:

PC@system1:~$ sudo wget https://cdimage.ubuntu.com/ubuntu-base/releases/22.04/release/ubuntu-base-22.04-base-arm64.tar.gz

Create rootfs folder, then unzip the downloaded ubuntu-base-22.04-base-arm64.tar.gz zip archive to the rootfs folder: (Please operate according to your actual path and folder)

PC@system1:~$ mkdir rootfs

PC@system1:~$ tar -xf ubuntu-base-22.04.1-base-arm64.tar.gz -C rootfs/

The contents of the unzipped folder are as follows:

PC@system1:~$ tree -d -L 1 rootfs

ubuntu_rootfs

├── bin -> usr/bin

├── boot

├── dev

├── etc

├── home

├── lib -> usr/lib

├── media

├── mnt

├── opt

├── proc

├── root

├── run

├── sbin -> usr/sbin

├── snap

├── srv

├── sys

├── tmp

├── usr

└── var

3.3 Preparing the chroot Environment

3.3.1 Installation of the Emulator

PC@system1:~$ cp /usr/bin/qemu-aarch64-static ./rootfs/usr/bin/

(If the host does not install the qemu-user-static toolkit, you can install the toolkit by entering the following command)

PC@system1:~$ sudo apt install qemu-user-static

Copy the host DNS configuration file to the arm framework Ubuntu filesystem (this must be copied, otherwise the following operations could not be performed).

PC@system1:~$ cp /etc/resolv.conf ./rootfs/etc/resolv.conf

3.3.2 Creating a Mount Script

Copy the following script code into the ch-mount.sh file and change the permissions (777) to executable.

PC@system1:~$  vi ch-mount.sh

#!/bin/bash

function mnt() {

echo "MOUNTING"

sudo mount -t proc /proc ${2}proc

sudo mount -t sysfs /sys ${2}sys

sudo mount -o bind /dev ${2}dev

sudo mount -o bind /dev/pts ${2}dev/pts

sudo chroot ${2}

}

function umnt(){

echo "UNMOUNTING"

sudo umount ${2}proc

sudo umount ${2}sys

sudo umount ${2}dev/pts

sudo umount ${2}dev

}

if [ "$1" == "-m" ] && [ -n "$2" ] ;

then

mnt $1 $2

elif [ "$1" == "-u" ] && [ -n "$2" ];

then

umnt $1 $2

else

echo ""

echo "Either 1'st, 2'nd or bothparameters were missing"

echo ""

echo "1'st parameter can be one ofthese: -m(mount) OR -u(umount)"

echo "2'nd parameter is the full pathof rootfs directory(with trailing '/')"

echo ""

echo "For example: ch-mount -m/media/sdcard/"

echo ""

echo 1st parameter : ${1}

echo 2nd parameter : ${2}

fi

3.4 Installation Package Files

3.4.1 Mounting System

First mount the ubuntu filesystem using ch-mount.sh.

PC@system1:~$ ./ch-mount.sh -m ./rootfs/

MOUNTING

root@system1:/#

root@system1:/# ls

bin dev  home  media  opt   root  sbin  sys  usr

boot etc  lib   mnt    proc  run   srv   tmp  var

After successful mounting, you can configure the ubuntu filesystem and install some necessary software.

3.4.2 Basic Package Installation

Please install the following packages according to your requirements, and it is recommended to install all of them. (Please install them in order to avoid errors during installation)

root@system1:/# chmod 777 /tmp         (to avoid failures when updating)

root@system1:/# apt update

root@system1:/# apt-get install language-pack-zh-hant language-pack-zh-hans

root@system1:/# apt install language-pack-en-base

root@system1:/# apt install dialog rsyslog

root@system1:/# apt install systemd avahi-daemon avahi-utils udhcpc ssh (Required installation)

root@system1:/# apt install sudo

root@system1:/# apt install vim

root@system1:/# apt install net-tools

root@system1:/# apt install ethtool

root@system1:/# apt install ifupdown

root@system1:/# apt install iputils-ping

root@system1:/# apt install htop

root@system1:/# apt install lrzsz

root@system1:/# apt install gpiod

root@system1:/# apt install wpasupplicant

root@system1:/# apt install kmod

root@system1:/# apt install iw

root@system1:/# apt install usbutils

root@system1:/# apt install memtester

root@system1:/# apt install alsa-utils

root@system1:/# apt install ufw

root@system1:/# apt install psmisc

Adding log, users debugging ubuntu system

root@system1:/# touch /var/log/rsyslog

root@system1:/# chown syslog:adm /var/log/rsyslog

root@system1:/# chmod 666 /var/log/rsyslog

root@system1:/# systemctl unmask rsyslog

root@system1:/# systemctl enable rsyslog

Installation of Network and Language Package Support

root@system1:/# apt-get install synaptic

root@system1:/# apt-get install rfkill

root@system1:/# apt-get install network-manager

root@system1:/# apt install -y --force-yes --no-install-recommends fonts-wqy-microhei

root@system1:/# apt install -y --force-yes --no-install-recommends ttf-wqy-zenhei

3.4.3 Installation of Desktop System

Installation of LXDE Desktop System

root@system1:/# apt-get install xinit

root@system1:/# apt-get install lxde

Installation of Browser and Audio

root@system1:/# sudo apt install epiphany-browser

root@system1:/# sudo apt install xine-ui

3.4.4 Create User

Set root password: 123456

root@system1:/# passwd root

Enter new UNIX password:

Retype new UNIX password:

passwd: password updated successfully

Removable root user password login

root@system1:/# passwd -d root

Be sure to execute the following command, or you will sudo error

sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set

root@system1:/# chown root:root /usr/bin/sudo

root@system1:/# chmod 4755 /usr/bin/sudo

Create a username: myir

Password: 123456

root@system1:/# adduser myir

perl: warning: Setting locale failed.

perl: warning: Please check that your locale settings:

LANGUAGE = (unset),

LC_ALL = (unset),

LC_TIME = "zh_CN.UTF-8",

LC_IDENTIFICATION = "zh_CN.UTF-8",

LC_TELEPHONE = "zh_CN.UTF-8",

LC_NUMERIC = "zh_CN.UTF-8",

LC_ADDRESS = "zh_CN.UTF-8",

LC_NAME = "zh_CN.UTF-8",

LC_MONETARY = "zh_CN.UTF-8",

LC_PAPER = "zh_CN.UTF-8",

LC_MEASUREMENT = "zh_CN.UTF-8",

LANG = "zh_CN.UTF-8"

are supported and installed on your system.

perl: warning: Falling back to the standard locale ("C").

Adding user `myir' ...

Adding new group `myir' (1000) ...

Adding new user `myir' (1000) with group `myir' ...

Creating home directory `/home/myir' ...

Copying files from `/etc/skel' ...

Enter new UNIX password:

Retype new UNIX password:

passwd: password updated successfully

Changing the user information for myir

Enter the new value, or press ENTER for the default

Full Name [ ]: cy

Room Number [ ]: 604

Work Phone [ ]:

Home Phone [ ]:

Other [ ]:

Is the information correct? [Y/n] y

Setting Up Permissions

sudo vi /etc/sudoers

root ALL=(ALL:ALL) ALL

myir (Add according to your own username) ALL=(ALL:ALL) ALL

When adding the user above, the warning that appears in the middle can be used with the following command:

root@system1:/# export LC_ALL=C

3.4.5 Other Configurations

Set hosts and hostname, add 127.0.0.1 myir

root@system1:/# vi /etc/hosts

Clear the content of the hostname file, add myir (according to the actual user name to add)

root@system1:/# vi /etc/hostname

Modify the passwd file

root@system1:/# vi /etc/passwd

Find this line: _apt:x:100:65534::/nonexistent:/usr/sbin/nologin

Change to: _apt:x:0:65534::/nonexistent:/usr/sbin/nologin

Create the link file (be sure to execute it, or it will report an error when executing the binary executable program)

root@system1:/# ln -s /lib /lib64

Configure the NIC interface, add the following contents

root@system1:/# vi /etc/network/interfaces

auto eth0

iface eth0 inet dhcp

3.4.6 Uninstallation of the System

You can uninstall the system after the above steps are completed. Type exit directly into the system to exit the system and use the command to uninstall.

root@system1:/# exit

Exit

PC@system1:~$

PC@system1:~$ ./ch-mount.sh -u ubuntu-rootfs/

UNMOUNTING

The ubuntu file system is now configured.

3.5 Packaging for Ubuntu System

3.5.1 Creating ext4 Format Files

According to the above procedures, we have already created the ubuntu-rootfs file system, and now we need to create it into a .ext4 file, which can be used to flash to the development board.

PC@system1:~$ dd if=/dev/zero of=ubuntu22.04.ext4 bs=1M count=3300

Please decide the size according to the actual situation, here is an example of 3.3G size.

PC@system1:~$ mkfs.ext4 ubuntu22.04.ext4

Create a temporary folder temp, then mount the ubuntu22.04.ext4 file

PC@system1:~$ mkdir temp

PC@system1:~$ sudo mount ubuntu22.04.ext4 temp

Copy the contents of the ubuntu-rootfs folder to the mounted filesystem and unmount it.

PC@system1:~$ sudo cp -avrf ubuntu-rootfs/* temp

PC@system1:~$ sudo umount temp

3.5.2 Creating SD Boot Images

First, extract RemiPi_SDUpdate.tar.bz2 from the 03_Tools/myir tools folder of the downloaded resources to the virtual machine (users should extract it according to your actual situation)

PC@system1:~$ tar -xf RemiPi_SDUpdate.tar.bz2

PC@system1:~$ cd RemiPi_SDUpdate/renesas-sd

PC@system1:~/RemiPi_SDUpdate/renesas-sd$ ls

image README.md   rzg2_bsp_scripts  fat16     output  rootfs

Replace the packaged ubuntu 22.04 filesystem into the rootfs/home/root/g2l_images folder

PC@system1:~/RemiPi_SDUpdate/renesas-sd/rootfs/home/root/g2l_images$ tree -L 1

├── DDR_1G

├── Image

├── Manifest

├── mys-rzg2l-sdcard.dtb

├── mys-rzg2l-wifi.dtb

└── ubuntu22.04.ext4

1 directory, 5 files

Modify the Manifest file

PC@system1:~/RemiPi_SDUpdate/renesas-sd/rootfs/home/root/g2l_images$ cat Manifest

bl2file="bl2_bp-myir-remi-1g_pmic.bin"

fipfile="fip-myir-remi-1g_pmic.bin"

imagefile="Image"

dtbfile="*.dtb"

rootfsfile="ubuntu22.04.ext4"

ledname="162"

Modify the configuration of your actual path, please refer to chapter 4.3 of Remi Pi_Linux Software Development Guide to modify the myir_config.ini configuration file, and change the path in it to your actual path.

Finally, you can enter the following folder and execute the script to make the image.

PC@system1:~/RemiPi_SDUpdate/renesas-sd$ cd rzg2_bsp_scripts/image_creator/

PC@system1: ~/RemiPi_SDUpdate/renesas-sd/rzg2_bsp_scripts/image_creator$ ./create_image.sh myir_config.ini

Please refer to chapter 4.2 in Remi Pi_Linux Software Development Guide for the burning procedure.

4. Learn about LXDE

4.1 Introduction of LXDE

LXDE is a lightweight and rapid desktop environment. It is designed to be user-friendly and take up few resources while keeping resource usage low.LXDE uses less memory and CPU to present as feature-rich desktop environment as possible. Unlike other desktop environments, LXDE strives to be a modular desktop environment so that each component can be used independently. This allows porting LXDE to different distributions and platforms more easily.

LXDE contains several core components that can be used in desktop environments to manage the entire system resources. The main components are listed below:

- LXPanel: This is LXDE's panel system, similar to GNOME's GNOME Panel or KDE's Kicker. it provides rapid access to

applications, system tools, folders and the clipboard.

- LXSession: This is the LXDE session manager, which is responsible for starting and terminating the LXDE desktop 

environment.

- LXDE-OpenBox: This is a window editor that provides window layout and navigation.LXDE uses OpenBox as its default 

window editor.

- PCManFM: This is a lightweight file editor that provides file and folder browsing, copying, moving, deleting, etc.

In addition to these core components, LXDE has some other auxiliary tools, such as LXAppearance (for changing themes and logos), LXTask (task manager) and so on.

4.2 Startup LXDE

After booting up, you can log in manually by entering the password 123456, or by executing the (startx /usr/bin/lxsession -s LXDE &) command at the serial terminal, as shown in Figure 4-1:

Figure 4-1

After logging in successfully, since the default background is black, you can select the background image by clicking the right mouse button and then selecting.

Desktop Preferences->Appearance->Wallpaper(/usr/share/lxde/wallpapers/lxde_blue.jpg), as in Figure 4-2:

Figure 4-2

The background image is modified successfully, as in Figure 4-3:

Figure 4-3

5. Reference Information

- Linux kernel open source community

https://www.kernel.org/

- Ubuntu

http://cdimage.ubuntu.com/ubuntu-base/releases/18.04.5/release/

- freedesktop

https://www.freedesktop.org/wiki/

- MYIR Remi Pi

https://en.myir.cn/d/RemiPi/88.html