i.MX6: How to solve the flash screen when switching from uboot to kernel based on the Linux

[zjgchenzhen]

When switching from uboot to kernel based on the Linux, the LCD screen will flash. How to keep the logo display continuously？

Note: I know the reason The LCD is initialized again in the kernel, which results in a flash screen.

Addtionally, I find some patch on the NXP Community, but I don't know how to use the patch and which patch I should use. Moreover, I don't find the i.MX6ull's patch which can solve the problem of flash screen on the NXP official website.

Note: Linux version 4.1.15 (root@cz-VirtualBox) (gcc version 4.9.4 (Linaro GCC 4.9-2017.01) )

The second problem:

where can I download the latest i.mx6ull Linux version from NXP website

[igorpadykov]

Hi zjgchenzhen

ipu patches can be found on below link:

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

For i.MX6UL which has not ipu, unfortunately I am not aware of similar patches, sorry.

Best regards
igor

[zjgchenzhen]

Hi  igorpadykov,

I think the article which is for Android kernel_imx, because I can't follow the above method to use the patch.(I use the NXP Linux, and I don't find the routine,such as ../kernel_imx, uboot-imx)

[igorpadykov]

kernel_imx:

https://source.codeaurora.org/external/imx/linux-imx/tree/?h=imx_4.1.15_2.0.0_ga

uboot-imx:

https://source.codeaurora.org/external/imx/uboot-imx/tree/?h=nxp%2Fimx_v2015.04_4.1.15_1.0.0_ga

as android is based on linux, modifications are similar for both.

Best regards
igor

[zjgchenzhen]

Hi igor,

Thank you for your support.

After reading Qiang's article which you provide the link, I think the patch can't work on the i.MX6ULL, Qiang say that "The iMX6UL has no IPU hardware, so this patch will not work on it.

The iMX6UL used LCDIF, it is a simple display controller, you just need enable it in Uboot and avoid kernel re-initialize it."

Do you konw how to avoid kernel re-initializing?

[igorpadykov]

Hi zjgchenzhen

unfortunately I am not aware of such patches, sorry.

If you have special task you can try to apply to NXP Professional Services for

helping with developing such solution:

https://contact.nxp.com/new-prof-svcs-sw-tech

Best regards
igor

[igorpadykov]

Hi zjgchenzhen

unfortunately I am not aware of such patches, sorry.

If you have special task you can try to apply to NXP Professional Services for

helping with developing such solution:

https://contact.nxp.com/new-prof-svcs-sw-tech

Best regards
igor

[zjgchenzhen]

Hi Igor

Can you help me ask your colleague who knows how to solve the problem that "The iMX6UL used LCDIF, it is a simple display controller, you just need enable it in Uboot and avoid kernel re-initialize it to solve the the phenomenon when switching from uboot to kernel based on the Linux, the LCD screen will flash. How to keep the logo display continuously？"

B.R.

Ted.Chen

[zjgchenzhen]

Hi Igor,

Can you help me ask your colleague who knows how to solve the problem that "<span>The iMX6UL used LCDIF, it is a&nbsp;simple display controller, you just need enable it in Uboot and avoid kernel re-initialize it to solve the the phenomenon when switching&nbsp;from uboot to kernel based on the Linux, the LCD screen will&nbsp;flash. How to keep the logo&nbsp;display continuously？"

B.R.

Ted.Chen