[maemo-developers] how to port a software based on QT to N800?

[From: Harald Fernengel]

On Thursday 14 June 2007 11:54:39 Manoël Trapier wrote:
> Le jeudi 14 juin 2007 à 10:51 +0200, Harald Fernengel a écrit :
> > Hi,
> >
> > On Wednesday 13 June 2007 16:39:31 Markus Wagner wrote:
> > > PS: Anybody has patches for Qt4.3 ?! (Seems to have multiple issuses
> > > with ARM/ARMEL)
> >
> > I built the 4.3.0 snapshot a while ago without any trouble.
> >
> > As far as I remember I built Qt first for the host (i386), then changed
> > scratchbox to the ARM target, reconfigured and built only the libraries.
> > That way, the host tools (moc, uic, rcc) don't have to run in the QEMU
> > emulation.
>
> There is at least 1 big bug with ARM on QT 4.2.x (and 4.3.x). QT define
> the type qreal to be float instead of double, and a lot of functions
> want a double and not a qreal. And remove this tend to add a new bug in
> qtestcase.h where a function is redefined when we compile for arm for
> 'supporting' qreal=float.. So the C++ compiler complain about a
> redefinition.
>
>
> I add here a patch for QT 4.2.3 (should be OK for other version) which
> patch 3 things, the two bug I speak about before, and modifiy the qmake
> build file for use host-* tools instead of their ARM conterparts.

For some reason, "host-g++" was just hanging on my machine, so I had to build 
qmake statically with the i386 configuration (configure sb for i386, 
configure Qt, run the qmake link command again with "-static", reconfigure sb 
to use arm as target, configure Qt again).

The qreal issues are fixed in Qt 4.3.0, so all that cool eye candy will run 
with decent FPS on the N800/N770.

Basically, all that's needed to build Qt/X11 in scratchbox is the remaining 
diff below.

Harald

diff -r -d -u qt-x11-opensource-src-4.2.3.orig/qmake/Makefile.unix 
qt-x11-opensource-src-4.2.3/qmake/Makefile.unix
--- qt-x11-opensource-src-4.2.3.orig/qmake/Makefile.unix        2007-02-21 
10:58:41.000000000 +0100
+++ qt-x11-opensource-src-4.2.3/qmake/Makefile.unix     2007-05-21 
13:44:34.000000000 +0200
@@ -1,3 +1,15 @@
+#Maemo/Scratchbox patch
+CXX        =   host-g++
+CC         =   host-gcc
+LINK   =   host-ld
+#End
+
+#Maemo/Scratchbox patch
+CXX        =   host-g++
+CC         =   host-gcc
+LINK   =   host-ld
+#End
+
 SOURCE_PATH = @SOURCE_PATH@
 BUILD_PATH = @BUILD_PATH@
 QTOBJS = @QMAKE_QTOBJS@