[Development] i.MX8 embedded Linux support

[Zeno Endemann]

Thanks for the confirmation.

Actually I wasn't expecting the eglfs_viv[_wl] stuff to even work with 
current releases of the Vivante blob, but after a short test it does 
indeed work (however performance appears to be much worse than using 
eglfs_kms). Anyway, I don't really see a reason for anyone to stay on 
that deprecated interface though, considering the relative immaturity of 
the platform.

Thanks again,

Laszlo Agocs wrote on 11.09.19 15:31:
> Hi,
> 
> Yes, it is a trend to move away from basing EGL/OpenGL implementations 
> on top of the (deprecated) fbdev, and instead move onto drm. Sometimes, 
> and I suspect this is the case with Vivante as well, vendors offer both 
> variants of the drivers. With eglfs this means the backend has to be 
> selected based on what's there in the system at run time. (in this case 
> this means choosing between eglfs_viv[_wl] or eglfs_kms)
> 
> Qt upstream has no explicit support for i.MX8 (there are no device specs 
> in mkspecs/devices since none got contributed so far), but, as you also 
> found out, eglfs is known to work, so in that sense the i.MX8 is 
> supported. Don't know if Wayland got tested so far.
> 
> I suppose Yocto and other distro build tools have Qt available for i.MX8 
> targets as well. How they configure things there (what drivers, which 
> eglfs backend) is up to them. For example, as I understand, the 
> pre-built, Yocto-based reference images from the commercial Qt for 
> Device Creation offering are still using the fbdev-based stack and so 
> the eglfs_viv path for i.MX8. (but I could be wrong here)
> 
> Best regards,
> Laszlo
> 
> ------------------------------------------------------------------------
> *From:* Development <development-bounces at qt-project.org> on behalf of 
> Zeno Endemann via Development <development at qt-project.org>
> *Sent:* Wednesday, September 11, 2019 2:53 PM
> *To:* development at qt-project.org <development at qt-project.org>
> *Subject:* [Development] i.MX8 embedded Linux support
> Hi,
> 
> So unless I misunderstand something, for the i.MX8 NXP/Vivante changed
> their proprietary graphic stack significantly. The framebuffer and X11
> driver are deprecated, only Wayland will be supported, and they have
> switched from the Linux framebuffer interface to (a fork of) libdrm.
> 
> I was able to run a Qt Quick application on an i.MX8M Mini using this
> new infrastructure, i.e. using the regular eglfs_kms platform plugin. So
> I am wondering if the qtbase configure script should be adapted to
> detect i.MX8, and for that not build eglfs_viv, eglfs_viv_wl and
> eglfs_kms_egldevice anymore.
> 
> Or more generally I'd like to ask if there is already further work or
> information on supporting embedded Linux on i.MX8. For example, I
> suppose the yocto layer needs some updates to reflect all this.
> 
> 
> Thanks,
> 
> Zeno Endemann
> _______________________________________________
> Development mailing list
> Development at qt-project.org
> https://lists.qt-project.org/listinfo/development