Disable HDMI output during UEFI

Hi,

I am using SDK 5.1.2 L4T 35.4.1 on Evm and on custom hardware,
I am also able to build and replace/update UEFI image succesfully.
I have used the r35.4.1-updates combo for UEFI image build,

Please I have 2 questions

  1. Do i only have to replace uefi_jetson.bin or also replace BOOTAA64.efi
  2. How can i disable the HDMI output of UEFI compleatly, I want a black screen until linux takes over, is this possible ?

Thank You

Hi amir.s,

It depends on you use case, you could replace both and perform full flash to make sure your modification applied correctly.

Do you mean that you want to disable any display output in UEFI?

Hi KevinFFF,
1.
Ok I will replace both BOOT & jetson_uefi

Acctually i Managed to disable UEFI on HDMI by remarking the T194 Display Driver in UEFI code, Like so:
Remarked Display Driver in: Platform/NVIDIA/Jetson/Jetson.dsc.inc|
#Silicon/NVIDIA/Tegra/T194/Drivers/T194GraphicsOutputDxe/T194GraphicsOutputDxe.inf {

#BaseMemoryLib|MdePkg/Library/BaseMemoryLib/BaseMemoryLib.inf
#}

Also Remarked Driver Inf in file :Platform/NVIDIA/Jetson/Jetson.fdf.inc|

#INF Silicon/NVIDIA/Tegra/T194/Drivers/T194GraphicsOutputDxe/T194GraphicsOutputDxe.inf

These changes made the HDMI during UEFI boot to be compleatly disabled, kernel boot succesfully and takes over the HDMI ok.
if you think what I did may cause issues please let me know.

Thanks
Amir

It should be okay with those changed in configuration file if you don’t need display functions in UEFI.

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