i.MX ProcessorsのトピックRe: How to create multiple frame buffer layer under /dev

How to create multiple frame buffer layer under /dev

ekrem_sahin — Mon, 17 Aug 2020 12:41:39 GMT

Hello,

I am trying to create multiple frame buffer device under /dev such as /dev/fb0 , /dev/fb1 ,/dev/fb2 to /dev/fbN and for this reason need to modify kernel source for imx8qm.I found that there is drivers/video/fbdev/imxfb.c may be an option but it is not added to build system for imx8qm.I am using yocto release 4.14.98 and need some idea to manage this.

Could you please give me some start point ?

Best Regards

Re: How to create multiple frame buffer layer under /dev

Bio_TICFSL — Tue, 18 Aug 2020 13:41:15 GMT

Hello Ekrem,

Do not understand the question, but you can create a multiple fbN since Fbi displays the specified file(s) on the linux console using the framebuffer device, now if you like to have multiple /dev/fbX it need to have different displays to do it, this page will show you:

Adding a custom display

Regards

Re: How to create multiple frame buffer layer under /dev

ekrem_sahin — Wed, 19 Aug 2020 05:27:14 GMT

Hello,

Letme ask my question in a more detailed manner.I have only hdmi device on my imx8qm-mek device which creates /dev/fb0 and want to create more frame buffer layer on hdmi since for example I want to put a qt application onto /dev/fb0 and for example, want to create multiple smaller square areas on top of qt application to draw different shapes,text etc which I need to have different frame buffer devices such as /dev/fb1, /dev/fb2 to /dev/fbn.

By modifying some of kernel sources in hacky way, I could manage to create /dev/fb1 but it is not working as I expected and I need to do it correctly.So Could you please help me on this ?

Best Regards