AM68A: U-boot splash screen on AM68A J721S2 over DSI display

Darko Alavanja

Part Number: AM68A
Other Parts Discussed in Thread: AM62P, AM68

Hello,

I'm looking into having a splash screen in u-boot while the board boots and loads the kernel I was following this very helpful guide www.ti.com/.../spradk8.pdf

I wanted to replicate the same setup on a custom AM68A based board, but I noticed the difference with AM62P-SK board used in the guide. In the guide, OLDI output was used to display the splash screen. On our custom board, DSI is used as an output.

The issue is that there's doesn't seem to be support for j721e-dsi IP, although it is prseent in the devicetree for AM68A/J721S2

dsi0: dsi@48000000 {
compatible = "ti,j721e-dsi";
...

Can someone confirm that it isn't supported and if not, if there are any plans to add support?

Thank you!
Darko

1 month ago

0 Mark L. 1 month ago

TI__Expert 5470 points

Hi Darko,

AM68A has two instances of DSI. I will defer to our software expert for appropriate software configuration.

0 Keerthy J 1 month ago in reply to Mark L.

TI__Guru**** 166080 points

Hi Darko,

We currently do not have a proof of concept similar to AM62A. Device tree is directly used from the Linux dts.

Best Regards,

Keerthy

0 Darko Alavanja 1 month ago in reply to Keerthy J

Prodigy 30 points

Hi, thank you for the info. Does that mean that the DSI driver needs to be added to U-boot sources?

0 Takuma Fujiwara 1 month ago in reply to Darko Alavanja

TI__Guru 54443 points

Hi Darko,

On the AM6x devices, only AM62 and AM62P has splash screen support within U-Boot.

Display driver/dts nodes, and some code changes in board files would be needed based on AM62P's SDK documentation: https://software-dl.ti.com/processor-sdk-linux/esd/AM62PX/11_01_16_13/exports/docs/linux/Foundational_Components/U-Boot/UG-Splash-Screen.html

We can create a new internal Jira requirement for our SDK team to look at to see if this can be a feature added for future releases.

Regards,

Takuma

0 Darko Alavanja 1 month ago in reply to Takuma Fujiwara

Prodigy 30 points

Hi Takuma.

please add it, thank you! As far as I can tell, there's no display support in U-boot for AM68, J721S2 and similar SoCs. Our use case is DSI MIPI panel.

Best regards,
Darko

0 Takuma Fujiwara 1 month ago in reply to Darko Alavanja

TI__Guru 54443 points

Hi Darko,

For TI internal purposes as you will not be able to access, but created Jira for our SDK team to look at: https://jira.itg.ti.com/browse/JACINTOREQ-9119

Regards,

Takuma

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AM68A: U-boot splash screen on AM68A J721S2 over DSI display