TorizonCore Technical Overview
Introduction
Torizon is an embedded computing platform that enables robust, scalable, and easy-to-maintain software. The Torizon's primary component is TorizonCore: a minimal embedded Linux image featuring, among other essential services, a container runtime and components for secure offline and remote over-the-air (OTA) update.
Torizon fully supports the following Computer on Modules:
- Apalis iMX8
- Apalis iMX6
- Colibri iMX8X
- Colibri iMX7 1GB
- Colibri iMX6DL
- Colibri iMX6ULL 1GB
- Verdin iMX8M Mini
- Verdin iMX8M Plus
This article provides a technical TorizonCore's architectural overview and explores its main components and the tools to work with the system. For step-by-step instructions to start working with Torizon, please see the Torizon Quickstart Guide.
TorizonCore Images
There are some image variants of TorizonCore. See a comparison table below with the currently supported images:
| Image | Evaluation Containers |
|---|---|
| TorizonCore | No containers are pre-provisioned into this image |
| TorizonCore with Evaluation Containers | The Portainer container manager and other containers are pre-provisioned into the image |
Learn more about the evaluation containers in the section Container Runtime: Docker.
TorizonCore Architecture
A fundamental advantage of the Torizon platform is the possibility to work on application architectures based on multiple containers. This software development technique provides significant benefits such as modularity, scalability, integration, and distributed development.
In this section, we will explore the main components of TorizonCore and also the recommended Debian containers provided by Toradex to work with TorizonCore.
Linux Kernel
Toradex builds TorizonCore on top of its Linux BSPs. An in-house software development team works with the hardware team to design and maintain high-quality Linux BSPs targeting the usage in production devices.
Some characteristics of the TorizonCore image:
Toradex provides TorizonCore in a pre-built binary image. This image features essential command-line utilities and a reasonable amount of peripherals enabled in the Linux kernel. Hence, for most of the use cases, the usage of these binaries is the most recommended approach to design the application, and it is unnecessary to re-build TorizonCore from the source.
In cases in which image re-building and customization are inevitable, TorizonCore is open-source, and Toradex provides instructions to build TorizonCore with Yocto.
Toradex maintain its BSPs with updated software for bootloader and Linux kernel following mainline. An exception may exist for recently launched platforms, where the BSP may contain downstream SoC vendor components until Toradex recognizes the mainline efforts are mature enough to be deployed to production.
The developers can also follow the Toradex Yocto Project BSP Layers release roadmap and TorizonCore release roadmap page to get updated information about known issues, scheduled bug fixes, and feature improvements.
There is no software package management in the base system. The recommended application development and maintenance processes are through the usage of Docker containers.
Torizon updates: OSTree and Aktualizr
Traditional update solutions in the industry, including Torizon Remote Updates and Secure Offline Updates, widely adopt Aktualizr and OSTree technologies. They comprise the part of Torizon updates features that runs on embedded devices.
Aktualizr comprises a C++ application working on the client-side of Torizon Remote and Offline Updates. It manages the software update process and implements Uptane, supporting device authentication and provisioning. Aktualizr works alongside OSTree.
OSTree is a technology used by TorizonCore to deliver bootable filesystem trees to a device. The basic principle is having a git-like set of work with the filesystem tree.
Container Runtime: Docker
By the definition of Docker website:
A container is a standard unit of software that packages up code and all its dependencies, so the application runs quickly and reliably from one computing environment to another. A Docker container image is a lightweight, standalone, executable package of software that includes everything needed to run an application: code, runtime, system tools, system libraries, and settings.
- Docker engine enables the execution and management of containers in the device.
- Toradex provides Docker container images based on Debian designed for the usage with its Computer on Modules
- Docker daemon starts automatically after boot. It is possible to start containers automatically with the daemon.
- TorizonCore images available for online installation with Toradex Easy Installer come with containers pre-provisioned focused on development:
- Weston
- Chromium
- Portainer
- Container with Development Tools
- To simplify the customer's production process, Toradex provides the possibility for developers to download TorizonCore images with no containers pre-provisioned and combine it with his own containers, generating a monolithic element to deploy on the board.
Root Filesystem
The root file system is the top of the hierarchical file tree. TorizonCore mounts its rootfs as read-only, since it improves device security, reduce the probability system files corruption and, enables rootfs images to be easily updated. Furthermore, to have a read-only root filesystem mounted is a requiremente for OSTree, which is a system adopted by Torizon to perform upgrades of filesystem trees.
However, there are two special cases. OSTree preserves /etc and /var during upgrades, implying that they are writeable directories (rw). On those cases:
/etc: It's upgraded by OSTree by a 3-way merge. It means that, on the upgrade process, OSTree will apply any local changes to the new copy, while leaving the old untouched. For more information, refer to OSTree documentation./var: This directory is not managed by OSTree. In this case,/varis not touched by OSTree at all, and shared between all of its deployments.
TorizonCore Tools
TorizonCore Debian Containers
Application developers will take advantage of the TorizonCore Debian based containers images as a starting point for their Dockerfiles.
As an example, projects targeting TorizonCore running on a Apalis iMX8 can use the command FROM --platform=linux/arm64 torizon/debian:3-bookworm in its Dockerfile.
Below some highlights of these containers:
- Uses the slim release of Debian.
- Contain group permissions necessary to access hardware peripherals and recommended software packages for execution in Toradex modules.
- TorizonCore Debian images are also open-source.
- Graphical container images with Weston/Wayland/XWayland and GPU support are also available for some modules.
See the Toradex Debian based containers images article for in-depth information.
Integrated Development Environments (IDEs) support
Toradex provides a Visual Studio Code extension to work with TorizonCore: Torizon IDE Extension 2.
Other Toradex and 3rd Party Containers
- The Torizon resources article lists the ready-to-run demonstration 3rd party containers that Toradex offers in partnership with different industry segments and technologies.
- The List of Container Images for Torizon has brief information about the containers maintained by Toradex and partners.
- Visit the Dockerhub page to find out other available Docker containers targeting execution in ARM architecture.
Webinars
This section has on-demand webinars to help you through development.