TDA4VM: how to disable GPU for QNX OS in A72

yichi zhang

Prodigy 130 points

Part Number: TDA4VM

i want to know that if we could disable GPU for TDA4 when QNX os running in A72.

over 2 years ago

0 Karan Saxena over 2 years ago

TI__Guru* 77774 points

Can you please refer this FAQ and see how to disable GPU from u-boot?

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1227640/faq-tda4vm-tda4vl-tda4al-tda4vh-dra821-how-can-we-make-the-jacinto-sdk-compatible-for-device-variants

For disabling the same from QNX, I've asked another engineer to help. They should be able to respond to this.

Regards

Karan

+1 KB over 2 years ago in reply to Karan Saxena

TI__Guru** 120721 points

The GPU H/W module is accessed in two general locations in the PSDKQA + BSP.

The BSP startup, has commands to initialize GPU.
The graphics.conf for the QNX 'screen' process controls GPU configuration.

To "remove" the GPU, both of these areas would require modifications.

BSP

Remove the call to init_gpu in bsp/src/hardware/startup/boards/j721e/evm/hw_init.c.

QNX Screen

If the DSS is not being controlled by the A72 (psdkqa/qnx/scripts/usr/lib/graphics/jacinto7/graphics.conf.dss_on_r5), then the easiest way to remove the GPU is to not start the QNX screen.

If DSS is required, but GPU is not, then the psdkqa/qnx/scripts/usr/lib/graphics/jacinto7/graphics.conf.dss_on_a72 needs to be modified.

The graphics.conf is documented by QNX/Blackberry at - Configuring Screen (qnx.com). If the 'egl' entry in the graphics.conf is removed then the GPU will not be configured by screen.

Regards,

Processors

Processors forum

TDA4VM: how to disable GPU for QNX OS in A72