Which Embedded Linux Distribution?

Abhikhurana writes "I work for a company which designs a variety of video surveillance devices (such as MPEG4 video servers). Traditionally, these products have been based on proprietary OSs such as Nucleus and VxWorks. Now, we are redesigning a few of our products and I am trying to convince my company to go down the Linux route. Understandably, our management is quite skeptical about that and so I was asked by our CTO to recommend a few RTOSs which have mature networking stacks and which work well on ARM platform. I know that there are many embedded Linux based distributions out there. There are commercial ones such as Montavista, LynuxWorks, free ones such as uclinux, muLinux and some Linux like distros such as Ecos. What is the most stable and best community supported embedded Linux distribution out there?"

Coming Soon: Ubuntu

[div_2n]

If their employment page [ubuntu.com] is any indication, I'd say Ubuntu will be very soon.

GPL is not a problem ...

[twitter]

... except with people saying things like this:

Just a friendly reminder, but don't forget to tell your higher-ups that using a *modified* Linux in their product means they have to release the source. Don't forget that, or you may be in for a nasty suprise.

How friendly/nasty of you. First, you assume the company is anal about the working of their systems or sharing kernel fixes and drivers. Second, it does not matter anyway. They can put all of the stuff they can't or don't want to share into code they don't share. The GPL does not force you to break MPEG4 NDAs, it won't publicize code you don't mix in, or steal your wife. All it does is make sure you pass on the same rights for code that's not yours that others passed onto you. The GPL encourages people to share but it never forces an issue. To draw GPL ire, you have to close off someone else's code.

Re:Well

[dhasenan]

On an embedded system, you probably don't need anything running but the kernel, udev, and your application. You don't need most of your libraries; it's going to be more efficient to statically link everything. You don't need bash. You don't need Python. You don't need a package manager. For this task (networked cameras), you need ifconfig, a dhcp client, maybe a stripped Apache, and your custom application. And you can probably incorporate ifconfig / dhcp functionality into a library (take them from BSD or something licensed under LGPL) and put them in your application, which could also handle init if space is tight. (Though you probably don't want this, in case your appliance has to be reset.)

In short, while you can use Gentoo to build your target system, it won't effectively be Gentoo by the time you're finished. And it doesn't matter which distribution you choose at that point.

The one you build...

[wolf31o2]

As I am sure you can guess, I'll answer with a simple answer, which likely means the most up front work but also the best capabilities. You'll want to build one yourself. This doesn't mean that you have to do all the work. As an example, I'll (obviously) use Gentoo. You install Gentoo and build your Gentoo-based distribution with exactly what you want in it. Since Gentoo is source-based to begin with, it should be easy to transition to your actual platform. Of course you won't want a C compiler and such on your actual platform, you do that on your development systems. This is really how most embedded Linux is done, with a development machine building the customized distribution for the actual release platform. I'll be honest and say that my experience with other embedded Linux is pretty much nil, but Gentoo will do what you want, and we have great community support. The nice thing about using Gentoo is it is basically the same thing as the normal distribution, and we support the platforms used for most embedded devices. Of course, you'll want to use what suits your needs best.

Observation about support

[Anonymous Coward]

Something you can point out to your doubtful manaagers...

Having worked with pSoS, vxWorks, and embedded Linux, I have found the support process to be identical for both pay and free OSs:

1. Ask the provider for help.
2. Ask on a user's group / mailing list.
3. Get the code and fix it yourself.

You will be ignored at stage 1 nearly every time, because the Linux development people are busy, and because your proprietary OS provider has enough bigger, better paying customers that they can afford to ignore you. In stage 2, a free OS often has a bigger user group which is much more willing to share, so you stand a better chance of getting an answer there. Of course, you usually end up at step 3 anyway, which is free for eCos/Linux (give or take paying the developer), but which costs tens of thousands of dollars for the vxWorks etc...

Why people use Montevista or Windriver

[Anonymous Coward]

I've done a number of embedded Linux ports, on a wide variety of hardware. My experience has been that the ONLY reason why people go with Montevista or Windriver is CYA (Cover your A**). It's the paperpushers (managers and bean counters) who like these companies, not the techies.

As far as support goes, both companies are well known for not providing any serious support. Sure, they'll take your money (usually) so that you can say you have a support contract. But forget getting any real help.

The bottom line is that you really need kernel talent in-house if you're doing any sort of embedded project, regardless of what O.S. you're using. This is simply the name of the game.

To put things in perspective, I once saw a Cisco Business Unit which had a Purchase Order for a support contract with Montevista try to get Montevista to take it. The sales staff at Montevista wouldn't even return their calls!!!

I know that sounds hard to believe; I couldn't believe it myself, and I was there. Normally people die to try to get Cisco's business, especially for an entire BU. This is as close to free money that you can get. And yet they simply wouldn't return the phone calls until much later.

This is truly amazing. But it gives you an idea of what these companies are like. And still, people do business with them. Go figure.