Support U-Boot splash screen to kernel in imx8MP for Linux NXP

[himanshu_bhavani]

Hi Team,

How can we maintain or keep U-Boot splash screen in kernel for imx8MP with DSI (may with other interfaces will also work) display with any BSP version?

From the below thread we can see that below are the patches that can be used but with imx6 (not active even with imx6 ), are there any patches/references that can be used for imx8MP ?

Thread Link : https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/Patch-to-support-uboot-logo-keep-from-ub...

Also as far as I understand, in imx8 family frame buffer is not supported.

Ref Link : https://community.nxp.com/t5/i-MX-Processors/Yocto-IMX8M-GA-release-dropped-support-for-the-Linux-Fr...

So any alternative approach available for the same ?

Regards,

Himanshu Bhavani

[Wilson_S]

Dear @Zhiming_Liu:

I use imx8mp with LVDS interface and had already bringup display in bootloader and see boot logo.

Can you provide LVDS version of patches for the feature (keep boot logo from bootloader to kernel)? We use single panel with dual LVDS channel (one channel is odd data the other channel is even data). and Android version is Android 11.0.0_2.6.0 (Linux 5.10.72 kernel)

Many patches use mxsfb.c but the latest uboot code does not use *video_hw_init function, or patches for lcdif1 mipi but LVDS is lcdif2. Can you provide the latest patches for lcdif2 LVDS? 

This function(keep boot logo from bootloader to kernel) involves the frame buffer, so it is difficult to solve it by ourself.

Thanks!

Wilson

[Zhiming_Liu]

Hi @Wilson_S 

We don't have such patch for LVDS, but the idea is that you can delay LVDS clk_enable before entering rootfs.

[Wilson_S]

Dear @Zhiming_Liu :

Display seamless is a very important feature, can you tell us how to develop it for LVDS interface ? Can you suggest the relevant NXP documentation?

Or can we get support from an agent?

Thanks!

Wilson

[Zhiming_Liu]

Hi @himanshu_bhavani 

Send you the demo code on i.MX8MN

The implementation principle is same 

[himanshu_bhavani]

@Zhiming_Liu ,

Thanks for the reply.

I will apply the patches and will let you know.

From the above patches it seems like, the patches can be applied for DSI Display, will it also work for LVDS of HDMI display? If not can you suggest the changes required for LVDS and HDMI display?

[Zhiming_Liu]

@himanshu_bhavani 

You can't apply it directly, this is for i.MX8MN, you need change some code in this patch for i.MX8MP

 will it also work for LVDS of HDMI display?

-->No, you need LVDS divier which you can use this patch: https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/Add-i-MX8MP-LVDS-driver-in-uboot/ta-p/14...

And we don't support HDMI in uboot driver.

[himanshu_bhavani]

@Zhiming_Liu ,

I do have imx8m mini evk board, with ADV bridge( For DSI to HDMI).

Can I use these patches for this imx8m mini evk board with minimal changes required in the patches?

Changing patches to test on imx8m mini will be good or changing it for imx8mp.

Can you suggest which evk should I use to have near implementation for this.

imx8m mini or imx8mp?

[Zhiming_Liu]

i.MX8MM and i.MX8MPlus is very similiar,  you can use i.MX8MM