[Qt-embedded-interest] Difference between -embedded and -xplatform?

[Tom Cooksey]

> Hi,
>
> Can someone explain the difference between using the -xplatform and
> the -embedded flags when compiling? I am cross compiling Qt Embedded
> for my target device, and had to setup a mkspec file to do so. All is
> working and I'm using the -xplatform flag, but I'm curious if the -
> embedded flag changes the compiled result somehow? Thanks,

If you're cross compiling, you always need to pass -embedded <ARCH> (note: 
-arch should also work instead for packages). Normally that's enough - Qt will 
assume your compiler is called ARCH-linux-g++. However, as you have found, 
sometimes you need to create a mkspec for your cross-compile environment. 
That's what's passed in by -xplatform. So, -embedded sets the architecture (To 
enable the correct inline assembly) and -xplatform sets the mkspec if you need 
something other than the default.

I guess at some point it would be good to be able to specify the architecture 
in the mkspec. Hmmm...



Cheers,

Tom

PS: If you're on a >=armv6 platform, use armv6 as the architecture as Qt uses 
some optimisations which are only possible on armv6 and above (which speed up 
blending of RGB565 among other things)