Cross Compiling Problems

**memoody** · 2nd November 2010, 15:53

I'm hoping someone can help me with this... here is my situation: I would simply like to build and run an Qt Linux Embedded application targeted for an x86 processor on which I've installed Qt/Linux Embedded 4.7.

Starting with a GUI application I had originally created in Qt for Windows, I had no problem building and running the same application in my Ubuntu desktop machine. Here, I had simply downloaded and installed the Qt/X11 4.7 SDK and then simply rebuilt without incident and everything worked great.

I am now trying to follow the documentation to cross compile the same application for my Qt/Linux Embedded system, but am completely confused about how to proceed. The very first instruction says to specify the cross compiler in the PATH, but what is that actually referring to? Simply stated - where do I get the cross compiler? Since my Ubuntu machine and my target machine are both 32-bit Linux systems with similar kernels and gcc/g++ compilers, can I just use the Ubuntu compiler?

I've created a chroot environment where I installed the Qt/Embedded 4.7 library framework - am I supposed to point at that?

Thanks in advance (wasn't sure if I should put this in the Newb forum or here...)

**memoody** · 2nd November 2010, 20:37

Well, I have found some tutorials that explain my previous cross compiling question, but I am still unable to build an application for a Linux Embedded environment. I think/assume it is related to some PATH or ENV setting, but I don't know what it is.

I have created two Qt Embedded Linux builds - one with "-qvfb" and one with "-embedded", doing configure, make, and make install for both of them. But, when I go into Qt Creator project options and select qmake from either of the embedded builds, I get an "This Qt-Version is invalid" error.

If I go into "Manage" from the Qt Creator project options, and I hover the mouse over either of the two embedded qmake selections, a box pops up with the qmake configuration - in there, I see that the "mkspec" entry is blank and there is no "compiler" option in the list. How do I set these?

When building the two embedded builds, I merely followed the instructions from here:
http://doc.qt.nokia.com/4.6/qvfb.html

Thanks for your help

**memoody** · 3rd November 2010, 20:39

Well, I guess I'll just keep responding to myself, hoping it'll help someone else. I've made it further along in the process, where I am now able to build and run my embedded applications for "qvfb". I think my problem was related to some sort of leftover environment variable setting or something like that. I closed all terminals and Qt Creator, reopened, and I was able to select the qvfb version of qmake to build with.

Now my next problem is that even though I have built my applications with -qvfb, they are not showing up in the QVFB instance that I am running. I am able to start QVFB from my main install of QT and configure it as I wish, but when I run my application, it does not show up in the QVFB - instead it shows up on its own with the color scheme of the buttons all screwed up (when I recompile with the normal qmake, it displays properly).

I have tried various command line options to try to force my application to show in the QVFB display, but I haven't had any luck at all. I have also tried to run the example applications (as is, and by rebuilding them), with the exact same behavior.

If anyone can help, I'd appreciate it.