Linux Root File Systems
- Wells Lu
The SP7350 supports 13 root file systems:
BusyBox 1.37.0
Ubuntu Server 20.04.6 / 22.04.4 / 24.04.1
Ubuntu MATE 20.04.6 / 22.04.4 / 24.04.1
Ubuntu XFCE 20.04.6 / 22.04.4 / 24.04.1
Buildroot 2024.02
Yocto 4.2.4
Yocto 3.0.2 (32-bit)
Users can choose a root file system based on their specific use case. The following sections provide detailed explanations of these root file systems.
Table of Contents
1. Choosing a Root File System
When you run 'make config' to configure your build environment, after selecting the board and boot device, you will be prompted to choose a root file system. Refer to the picture below:
Please type the corresponding number to select one of the listed root file systems. For example, enter “7” to select “Ubuntu MATE 24.04.1”.
After completing the build process, the compiled root filesystem is located at:
linux/rootfs/initramfs/disk/The image of the target root filesystem is then made and stored at:
out/rootfs.img2. BusyBox 1.37.0
BusyBox constructs a lightweight root file system for embedded Linux systems by combining tiny versions of many common UNIX utilities into a single small executable, often just a few hundred kilobytes. This reduces the overall memory footprint and system overhead compared to having separate executables for each utility, contributing to faster boot times.
The source of BusyBox 1.37.0 is be downloaded from:
Users can use menuconfig of BusyBox to select additional utilities. Navigate to the BusyBox directory:
linux/rootfs/initramfs/busybox-1.37.0And run ‘make menuconfig’, for example:
A BusyBox Configuration menu will appear:
Users can move the cursor to enable the desired utilities. For example, to enable FTP server support, navigate to 'Networking Utilities' and enable 'ftpd (30 kb)'.
Exit BusyBox Configuration menu and choose ‘Save’ to save the changes to default configuration file ‘.config’. Run 'make' to rebuild the images. The 'ftpd' utility will be included in the new root file system:
To update your settings as the default configuration, copy the file 'linux/rootfs/initramfs/busybox-1.37.0/.config' to 'linux/rootfs/initramfs/configs/bbx_dynamic_defconfig':
The default account is 'root,' and no password is required.
Refer to the snapshot of the UART console when Linux has just started successfully:
The snapshot of the virtual terminal (tty1) on MIPI/DSI or HDMI display:
3. Ubuntu Server 20.04.6 / 22.04.4 / 24.04.1
Ubuntu Server is a popular open-source operating system designed to run on servers. Developed and maintained by Canonical Ltd., it provides a robust, secure, and versatile platform for various server tasks, from web hosting to cloud computing.
The base root file system of Ubuntu 20.04.6 is downloaded from:
ubuntu-base-20.04.6-base-arm64.tar.gz
The base root file system of Ubuntu 22.04.4 is downloaded from:
ubuntu-base-22.04.4-base-arm64.tar.gz
The base root file system of Ubuntu 24.04.1 is downloaded from:
ubuntu-base-24.04.1-base-arm64.tar.gz
The following packages or utilities are added to the base root file system:
ubuntu-standard
ubuntu-minimal
ubuntu-server
curl
iputils-ping
net-tools
network-manager
openssh-server
The pre-built root file-system has limited utilities or packages. Users can extend the functionality by installing extra utilities or packages from Ubuntu APT servers on the internet. For example, to install iperf3, users can issue the following commands:
This process can be repeated for any other required packages, ensuring the root file-system meets specific application needs.
The default account and password are: sunplus, sunplus
The initial size of the root file-system is approximately 1.9 GB.
This root file-system is created using the shell script located at ‘linux/rootfs/initramfs/ubuntu/make-ubuntu-rootfs.sh’. Users can modify it to pre-install some packages, utilities, or adjust system settings.
Refer to the snapshot of the UART console when Linux has just started successfully:
The snapshot of the virtual terminal (tty1) on LCD display:
4. Ubuntu MATE 20.04.6 / 22.04.4 / 24.04.1
Ubuntu MATE is a user-friendly, open-source operating system that combines the robust foundation of Ubuntu with the MATE desktop environment. This combination offers a traditional, highly customizable desktop experience suitable for users of all levels, from beginners to experienced Linux enthusiasts.
The MATE desktop environment allows users to utilize graphical user interface (GUI) applications and utilities. GUIs are generally more intuitive and user-friendly than command-line interfaces (CLIs). Icons, buttons, and visual indicators simplify system navigation, application access, and task execution without needing to memorize commands. Features such as window management, taskbars, and application launchers enable quick task switching and easier organization of open applications.
The base root file system of Ubuntu 20.04.6 is downloaded from:
ubuntu-base-20.04.6-base-arm64.tar.gz
The base root file system of Ubuntu 22.04.4 is downloaded from:
ubuntu-base-22.04.4-base-arm64.tar.gz
The base root file system of Ubuntu 24.04.1 is downloaded from:
ubuntu-base-24.04.1-base-arm64.tar.gz
The following packages are added to the base root file system:
ubuntu-standard
ubuntu-minimal
ubuntu-mate-desktop
curl
iputils-ping
net-tools
openssh-server
oem-config-gtk
The pre-built root file-system has limited utilities or packages. Users can extend the functionality by installing extra utilities or packages from Ubuntu APT servers on the internet.
The default account and password are: sunplus, sunplus
The initial size of the root file-system is approximately 6.2 GB.
This root file-system is created using the shell script located at ‘linux/rootfs/initramfs/ubuntu/make-ubuntu-rootfs.sh’. Users can modify it to pre-install some packages, utilities, or adjust system settings. For example, users can add to run ‘oem-config-prepare' to arrange for 'oem-config-firstboot’ to be run when the system first boots.
This is particularly helpful for OEM installations where end-users need to complete the initial setup.
Refer to the snapshot of the UART console when Linux has just started successfully:
The snapshot of the MATE 20.04 Desktop on LCD display:
5. Ubuntu XFCE 20.04.6 / 22.04.4 / 24.04.1
Ubuntu XFCE, also known as Xubuntu, is an official flavor of Ubuntu that features the lightweight XFCE desktop environment. It is designed to provide a fast, stable, and visually appealing user experience, making it an excellent choice for users seeking efficiency and performance, especially on less powerful hardware. It consumes less system resources than MATE desktop environment.
The base root file system of Ubuntu 20.04.6 is downloaded from:
ubuntu-base-20.04.6-base-arm64.tar.gz
The base root file system of Ubuntu 22.04.4 is downloaded from:
ubuntu-base-22.04.4-base-arm64.tar.gz
The base root file system of Ubuntu 24.04.1 is downloaded from:
ubuntu-base-24.04.1-base-arm64.tar.gz
The following packages are added to the base root file system:
ubuntu-standard
ubuntu-minimal
xubuntu-desktop
curl
iputils-ping
net-tools
openssh-server
oem-config-gtk
The following packages are removed:
light-locker
xfce4-screensaver
The pre-built root file-system has limited utilities or packages. Users can extend the functionality by installing extra utilities or packages from Ubuntu APT servers on the internet.
This root file-system is created using the shell script located at ‘linux/rootfs/initramfs/ubuntu/make-ubuntu-rootfs.sh’. Users can modify it to pre-install some packages, utilities, or adjust system settings.
The default account and password are: sunplus, sunplus
The initial size of the root file-system is approximately 6.1 GB.
Refer to the snapshot of the UART console when Linux has just started successfully:
The snapshot of the XFCE 20.04 Desktop on LCD display:
6. Buildroot 2024.02
Buildroot is a popular open-source tool used for building embedded Linux systems. It automates the process of compiling and configuring various components to create a custom Linux distribution tailored for embedded devices. Buildroot uses a configuration file where you specify the target architecture, desired packages, filesystem layout, kernel configuration, and other parameters. It includes a package management system that allows you to select which components to include in your embedded Linux system.
The source of Buildroot is downloaded from:
SP7350 integrates Buildroot for generating the root file system. Depending on your computer's performance, downloading and compiling Buildroot sources may take several tens minutes.
Users can use menuconfig to select extra utilities, packages, or libraries. From the project top directory, run:
make bconfig
Alternatively, navigate to the Buildroot directory (linux/rootfs/initramfs/buildroot) and run:
make menuconfig
A Buildroot Configuration menu will appear:
Users can move cursor and press ‘space’ or 'y' key to enable the desired packages, libraries, or utilities. For example, to enable DRM library 'libdrm' support, navigate to 'Target packages' → 'Libraries' → 'Graphics' and enable 'libdrm':
Also enable libdrm’s test program:
Save before leave the configuration menu. Run ‘make’ to build images again. The new DRM library will be included in root file-system:
To save the modifications to the defconfig file, go to the Buildroot directory and run 'make savedefconfig':
Run ‘git diff’ to show the changes:
Two new items:
are added to defconfig file: initramfs/buildroot/configs/sp7350_defconfig
The initial size of the root file-system is approximately 815 MB.
The default account is root, and the system will log in automatically upon successful boot. For reference, see the snapshot of the UART console right after Linux has started successfully.
The default username is root, and no password is required to access the virtual terminal (available via MIPI/DSI or HDMI display). For reference, see the snapshot of the virtual terminal on the HDMI LCD panel after Linux has booted successfully.
6. Yocto 4.2.4
Yocto is an open-source project that provides a set of tools and frameworks to create custom Linux-based systems, specifically for embedded devices. It is a collection of tools, metadata, and workflows that allow developers to generate tailored Linux distributions.
Yocto uses a modular and layered structure, where you can add or remove layers of functionality (e.g., additional software packages or hardware support). This allows for great flexibility in tailoring the distribution. The build tool, BitBake, in Yocto that automates the compilation and packaging of software components. It uses recipes (metadata files) to describe how software should be built and integrated. Yocto provides thousands of existing recipes for common software components used in embedded systems.
The source of Yocto is downloaded from:
SP7350 integrates Yocto for generating the root file system. Depending on your computer's performance, downloading and compiling Yocto sources may take several tens minutes.
The initial size of the root file-system is approximately 621 MB.
To customize the root file system, users can modify the BitBake recipe img-sp7350.bb located in the following directory:
For example, if you want to add a package (recipe) named xxx, you can append the package to the build process by adding the following line to img-sp7350.bb:
Where xxx represents the name of the package you wish to install. Notice the space before xxx; it ensures it is added correctly to the list.
The UART console will automatically log in upon boot. For reference, see the snapshot of the UART console when Linux starts successfully.
To log in to the virtual terminal on MIPI/DSI or HDMI display, use the passwd command to set the root password. For example:
Refer to the snapshot of the virtual terminal on the HDMI LCD panel once Linux has successfully booted.
7. Yocto 3.0.2 (32-bit)
This is a pre-built 32-bit root file system created by the Sunplus Yocto server. It is originally designed for Sunplus SP7021 platforms and includes a limited set of packages and utilities. The size of the root file system is approximately 896 MB.
The UART console will automatically log in. For reference, see the snapshot of the UART console when Linux starts successfully.
The default username and password are root and 123, respectively, for the virtual terminal (accessible via MIPI/DSI or HDMI display). Refer to the snapshot of the virtual terminal on the HDMI LCD panel after Linux has started successfully.