topic Re: Android to use Second Screen in i.MX Processors

Android to use Second Screen

mike_sims — Wed, 01 Jun 2016 18:54:22 GMT

I have a i.mx6 SABRE SD board which has 2 display outputs. I have a fixed function for FB0/FB1 and would like to have Android use the second display at FB2/FB3 instead.

I have been pouring through documentation on the web and source code (Android 6.0.1), but it has not become obvious to me how I define which devices are available to Android. I looked in the device specific files of Devices/FSL and Hardware/IMX/mx6 and believe there may be a way to hard-code this in these files, but to date, I have not seen how to configure this at runtime.

Can someone please point me to how I might accomplish this...

Thank you!!

Re: Android to use Second Screen

jamesbone — Fri, 03 Jun 2016 15:02:03 GMT

Even there is a way to modify the source of FB devices, I strongly suggest that you do not do it, because there are drivers in the i.MX like GPU/ VPU that expect to have FB0 and FB1 as the default sources for the LCD.

Re: Android to use Second Screen

mike_sims — Fri, 03 Jun 2016 21:00:20 GMT

Hi James,

Thanks for your feedback.

Reviewing the code in hardware/imx/mx6/hwcomposer/hwc_display.cpp (hwc_judge_display_state), it seems possible to change the initial for loop to start at a higher number. This would populate the struct ctx->mDispInfo with the higher FB Info. I believe this is similar to the method used in the mx7...

Is the information in mDispInfo not used by the remainder of the FSL HAL??

Regards...