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Digia acquires Qt

Digia acquires Qt

Posted Aug 16, 2012 15:01 UTC (Thu) by mikov (subscriber, #33179)
In reply to: Digia acquires Qt by krake
Parent article: Digia acquires Qt

An embedded system is a typically fixed function device where the end user is not provided with the ability to service the software. Think a microwave oven or a TV. It is a description of functionality and intent, not hardware form factor.

A PC without a general purpose OS is embedded and the Raspberry PI with Debian and Gnome desktop isn't.

In any case it doesn't matter how you call it, as that is the kind of system I meant in my initial post. We use words to convey shared meaning and that is what embedded means traditionally.

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Digia acquires Qt

Posted Aug 16, 2012 16:01 UTC (Thu) by krake (subscriber, #55996) [Link]

Well, of course if you specifically choose a definition that has as its primary characteristic that the system is not changable, then you remove all the other alternatives which would make your theory falsifyable.

A lot of systems used in modern control panel type applications run general purpose operating systems such as Windows CE, Linux, or QNX and on COTS (commerical off the shelf) boards. Most machine vendors deploying such panels for their machines are investing in DRM measures to prevent system alteration.

I consider those to be embedded systems as well, thus disagreeing with the statement that all embedded systems be unmodifyable.

Digia acquires Qt

Posted Aug 16, 2012 16:50 UTC (Thu) by mikov (subscriber, #33179) [Link]

Your assertion that "modifiable systems are modifiable" is meaningless in the context of this discussion.

The issue at hand is using LGPL on the very common type of system where the software is not end user serviceable. It doesn't matter whether we call that "embedded" or not.

Digia acquires Qt

Posted Aug 16, 2012 18:02 UTC (Thu) by krake (subscriber, #55996) [Link]

How can that assertion be meaningless?

An unmodifiable system will never satisfy the requirement, a modifiable system will.

There is no passus in either the LGPL or the GPL that says it has to be easy.
If you want to modify any Free Software program on a Linux Live CD, you have to copy the software from CD to modifiable media, apply your changes, remaster the CD image and burn that new image.

Modifying an OS image and reflashing a device is no different.

"It doesn't matter whether we call that "embedded" or not"

Indeed. Embedded does not imply unmodifiable or vice versa. Hence my objection to the original statement. Neither embedded nor mobile devices are by definition unmodifiable.

Digia acquires Qt

Posted Aug 16, 2012 19:11 UTC (Thu) by mikov (subscriber, #33179) [Link]

By your definition any system is modifiable because it can be modified after an arbitrary amount of effort. For example, it might require breaking a encryption key which takes years. But no matter, it is still *possible*, the only difference is the amount of time and effort it takes. Where do you draw the line?

Clearly such a definition is meaningless.

What matters is the intent. Does the device deliberately provide the user with the ability to service the software? A desktop PC running a standard desktop does. A desktop PC running kiosk software *does not*.

Granted, Jonno has posted some thoughtful arguments that modifying the actual device might not be strictly required in the legal sense for LGPL2. That is a line of reasoning that deserves serious consideration.

Digia acquires Qt

Posted Aug 16, 2012 19:51 UTC (Thu) by krake (subscriber, #55996) [Link]

"By your definition any system is modifiable because it can be modified after an arbitrary amount of effort."


"What matters is the intent."


"A desktop PC running kiosk software *does not*."

I think you are over generalizing again. I know of quite some Kiosk PCs which are installed, configured and updated by their respective owners or their employees and have not been rendered unmodifiable (neither technically nor legally) by the device's manufacturer.

Just like with embedded devices, the device category does not imply the availability or absence of customizability.
Some systems detect updates on a server (or even boot through from server), some require remote access (e.g. SSH), some can be updated through a physically connected media, some need swapping of their system drive, some need to be powered down, connected to an updater device and reprogrammed through that.

Since you like general statements so much I'd say that the majority of systems is designed that way and only a very small portion has been artifically restricted by technical (e.g. cryptography) or legal (e.g. renting instead of selling) measures.

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