The document discusses dedicated embedded Linux systems, detailing features, advantages, and disadvantages compared to other operating systems. It emphasizes the importance of reproducibility, configurability, and advanced features in embedded Linux development, as well as the flexibility provided by build systems like oe-lite. Additionally, it highlights the need for Linux experience and the complexity involved in system choices while advocating for the efficiency of dedicated embedded Linux in various development scenarios.

1. Dedicated Embedded Linux
Esben Haabendal, Prevas A/S

2. About me
Esben Haabendal, Prevas A/S
Linux user and developer since 1994.
Embedded Linux professional since 2003.
Founder and developer of OE-lite,

3. About OE-lite
framework for building dedicated embedded Linux systems
Based on OpenEmbedded’s “best-in-class” design
KISS
Design and optimized for typical requirements for industrial
embedded systems.
Open Source
http://oe-lite.org

4. What is dedicated embedded Linux?
Dedicated Embedded Linux vs. Linux as most people know it.
Built using an Embedded Linux build system
Buildroot
OpenEmbedded (Yocto)
LTIB
PTXdist
OE-lite
or home-brewed
Not RedHat, Fedora, Debian, Ubuntu, SUSE, ….

5. Standing on the shoulders of giants
Linux is a giant.
We are all dwarfs.
Extensive portfolio of existing Linux SW and tools to use.
Maintenance based on the (free) work of FOSS community.

6. New features are often available on Linux first.
Open Source encourages high quality code. Bad code is visible!

7. Pros and Cons
Compared to….
Embedded Linux vs PLC
Embedded Linux vs dedicated embedded software
Embedded Linux vs (insert your favorite OS)
Dedicated embedded Linux vs. Linux

8. Software Development Tools
Dedicated embedded Linux provides the developers with the tools they need.
Practically all programming languages.
Advanced IDE offerings.
Huge number of supporting development tools.
Libraries, middleware, frameworks.
Memory protection.
Pro: Allows for efficient application development.

9. Reproducability
Ability to reliably reproduce the embedded system.
Essential for delivering updated systems.
There are many ways for building embedded Linux systems, that does
not achieve reproducability.
Some dedicated embedded Linux buildsystems (like Buildroot and
OE-lite) are good at this.
Pro: Can reliably reproduce the embedded Linux system.

10. Configurability / Customization
Ability to design and implement according to needs instead of adapting needs
to design.
Using complex OS (like Linux) can impose restrictions on this.
Flexible customization methods makes the build system more
complex.
OE-lite Linux is aims at providing a flexible customization system
while keeping it simple.
Pro: Can design and implement the system according to requirements and
needs.

11. Advanced Features
Advanced features are coming to get you!
Communication protocols: IPv4, IPv6, USB, Bluetooth, WLAN, CAN,
PowerLink, EtherCAT, ….
Modern GUI/touch applications.
Web browser.
3D graphics.
Pro: Linux has it all.

12. Simplicity
"Everything should be made as simple as possible, but no simpler." — Albert
Einstein.
Linux systems are inherently complex.
Embedded Linux ditto.
Building and maintaining complex systems can be made simple.
Embedded Linux build systems are not equal.
Learning how to use a simple build system is easier than learning to
use a complex build system.
Pro: Dedicated embedded Linux is relatively easy (given the right choice of
embedded Linux build system)
Con: But not that easy….

13. Linux as a platform abstraction layer
Most HW vendors provides Linux support.
Separation of application code from HW platform.
Standardized APIs for easy moving of applications between different
embedded Linux platform.

14. Re-use
Developing the same thing more than once…. might not be the smartest thing
to do.
Re-use for new variants of same type of product
Re-use for completely other products
How:
Embedded Linux system is (should be) a platform abstraction layer.
Write portable application code.
Re-usable system integration.
Pro: Embedded Linux can provide development efficiency through re-use.

15. Configuration Management
Ability to configure the software according to requirements.
Embedded Linux build systems provide system integration level
configuration management.
Flexibility and ease-of-use varies.
Enabler for efficient platform and product variant handling.
Pro: Dedicated embedded Linux can provide efficient variant handling.

16. Pros of Dedicated Embedded Linux
Royalty free
Efficient application development.
Development tools.
Advanced features available.
Re-use of own and others works.
Design and implement according to requirement and needs.
Efficient variant handling.
Reproducable system builds.
Relatively easy….

17. Cons of Dedicated Embedded Linux
A bit complicated.
System complexity.
Lots of options/choices.
Linux/OS experience needed.

18. When to use Dedicated Embedded
Linux
Embedded system development time spent on
1. Hardware support / adaptation
2. Middleware development
3. Application development
Dedicated Embedded Linux provides efficient means for #1, especially if
hardware is complex or if Linux BSP is already available.
Dedicated Embedded Linux should provide all (or at least most) of what you
need for #2. Projects requiring advanced features has most to gain here.
Dedicated Embedded Linux provides efficient means for #3.

19. Prior use
Linux is #1 OS for embedded systems, and most of the software available has a
good history of "prior use" in embedded systems.
Duplication of this work is expensive.

20. Product/Platform Lifetime
Embedded Linux systems tends to become platforms for building new
products.
Embedded Linux systems therefore needs to be maintained and updated.

21. Q&A

23. OE-lite from 10.000 feet
OE-lite Bakery, the make of OE-lite
OE-lite manifest, specifies the stack of OE-lite layers that is used to
build the product(s).
OE-lite metadata layer, contains descriptions of how to build software
components (recipes).
Open Source OE-lite metadata for re-use between all OE-lite projects.
Project specific OE-lite metadata for project specific software and
system integration.

24. OE-lite strong points
KISS
Reliable builds
Variant handling through USE flags
Time to market
Low effort development
Low effort maintenance
Product maintenance and upgrade path
Application level re-use through common platform level API’s
Platform building and cross product/project re-use
Free and Open Source