pkg kde talk - Aug 2010 - Qt Linux-Embedded for Debian - are you working on this?

Hello,

I only very recently learned about the Qt embedded series
that there is for Linux. This is, so I understood it,
 basically the whole functionality of Qt but without the
dependency on X. To me this sounds very worthwhile to have
also as (separate) Debian packages since highly attractive
to the embedded world.

On Tuesday 17 August 2010 01:04:55 Steffen M?ller wrote:
> Would it be reasonable to possibly perform this second build as an
> extension of your regular qt4-x11 package (which would then somehow have a
> wrong name, but who cares) with the --embedded flag set. What comes to
Hi

I have thought of this more than once, but it has mostly stalled for various 
reasons (beside the time involved in doing it)

1) qt4-x11 source package is already a buildd killer (both in time and space 
usage, 3-4 days of build time, more than 4G of space)
2) for most real usages of Qt/linuxfb, you would want a specific feature set 
that you actually need, and then need to recompile anyways

and the most important one
3) qt/linuxfb is not binary compatible with qt/x11, so for all relevant 
libraries and applications, we would also need to do two build passes, one for 
the linux stuff and one for x11, making it not really that interesting.

The api is the same, so you can still, in 99.5 or so of the cases do the 
development against qt/x11 and just deploy it against qt/Linuxfb

/Sune
-- 
Man, do you know how to insert a CPU?

From the folder inside Windows you should never close the case in order to 
click on the site of a computer.

On Tue, Aug 17, 2010 at 01:04:55AM +0200, Steffen M?ller
wrote:
> I only very recently learned about the Qt embedded series
> that there is for Linux. This is, so I understood it,
>  basically the whole functionality of Qt but without the
> dependency on X. To me this sounds very worthwhile to have
> also as (separate) Debian packages since highly attractive
> to the embedded world.
This has recently been packaged by Linaro and is currently in Ubuntu''s
New queue.  It''s done as a separate source packages which means it
doesn''t get in the way of those of us who only care about the X11
version but is a large duplication of code.  Being a different ABI
existing Qt apps won''t work with it, they would need recompiled.
Nokia are currently working on a new embedded version called
Lighthouse which is more generic and will work with more outputs so
this QWS version may not have a very long lifetime.

https://edge.launchpad.net/~afrantzis/+archive/qt4-qws
to appear soon at https://edge.launchpad.net/ubuntu/+source/qt4-qws

Jonathan

Hi Sune,

On 08/17/2010 01:38 AM, Sune Vuorela wrote:
> On Tuesday 17 August 2010 01:04:55 Steffen M?ller wrote:
>   
>> Would it be reasonable to possibly perform this second build as an
>> extension of your regular qt4-x11 package (which would then somehow
have a
>> wrong name, but who cares) with the --embedded flag set. What comes to
>>     
> I have thought of this more than once, but it has mostly stalled for
various
> reasons (beside the time involved in doing it)
>   
divide that time by 3/2 (some overhead for parallelism)
> 1) qt4-x11 source package is already a buildd killer (both in time and
space
> usage, 3-4 days of build time, more than 4G of space)
>   
I agree. And one should probably try to find ways to reduce those
(still) rather enormous resources. On the other hand, this is exactly
the benefit that the Debian packaging would bring....plus some
more.
> 2) for most real usages of Qt/linuxfb, you would want a specific feature
set
> that you actually need, and then need to recompile anyways
>   
they have some plugin mechanism that the Debian packages could possibly
mimic in some way.  The first packaging will not be perfect. To me such
optimisations are likely to go eventually into the production system. I
am more after allowing development more easily.
> and the most important one
> 3) qt/linuxfb is not binary compatible with qt/x11, so for all relevant 
> libraries and applications, we would also need to do two build passes, one
for
> the linux stuff and one for x11, making it not really that interesting.
>   
As of today, there is no alternative to using X on your desktop, and there
probably won''t be any such alternative any time soon. This is not what
I am after.

But for embedded devices, you often have just a single application to be
run. For the very very deeply embedded deviced you would not even use
Qt, but for the upcoming microwaves or washing machines or fridges or
heating devices I could well imagine some basic Qt application to run
and while developing that you don''t care too much if the Qt library is
perfectly optimised for your platform ... I hope. And even then, to have
a Debian package to start from for your builds is probably
helpful.
> The api is the same, so you can still, in 99.5 or so of the cases do the 
> development against qt/x11 and just deploy it against qt/Linuxfb
>   
But that deployment is not within the reach of Debian, not even for the
development environments. If the qvfb helps to get from those 99.5% up
to 99.95%, then this should already be rather valuable for the
developers'' peace of mind. And without that deployment we
don''t see the
discussions towards optimisations or general abstractions of the boot
process and other bits.

I am still in favour of it. Maybe we can help the buildds in some way.

Best,

Steffen