IMX8QXP custom board u-boot issue

[jakos]

Hi,

We are working on a project which consists of IMX8QXP MEK board + custom expansion board. Previously a Yocto based image was created and tested on MEK itself. Now in order to 'unify' everything with our custom board, which is to arrive next week, we have decided to make a custom machine definition with some small U-Boot and kernel changes. 

First things first to get started we have patched U-Boot with custom board definitions. For starters imx8qxp-mek files were copied and basically renamed to something like imx8qxp-custom. U-boot was build succesfully, Yocto image was built but console gives no output whatsoever. Upon some debugging we have found that if we change default device tree inside imx8qxp_custom_defconfig to fsl-imx8qxp-mek everything is working. 

Previously our device tree (fsl-imx8qxp-custom) was a copy of fsl-imx8qxp-mek with changes in compatibility (fsl, imx8qxp-mek to fsl, imx8qxp-custom). We are sort-of unfamiliar wit SCFW concept so we have thought that this might cause an issue. So we took SCFW for MEK, renamed it to custom and added to Yocto build (with BOARD_TYPE set to "custom") inside Yocto machine file. The system was built properly but with the same output.

We are using Yocto with nxp layers (zeus). 

What are we missing? 

Thanks in advance.

[joxborrow]

Hello@jakos ,

I am very new to Yocto but have managed to figure out quite a bit from the documentation. What I have not figured out is how to do what you did. I have the same boot issue you were facing. and would love to know in more detail exactly how you included your .dtsi file in, what I am assuming was a kernel provided .dts file)

For my scenario I have created a custom layer for our OS with a custom image and I have now created a custom machine which includes the fslc imx8qxp-mek machine from the meta-fslc layer as that is the processor on the SOM I have. I also have a .dtsi file that is specific to the SOM (on a side note the manufacturer of the SOM has not updated the layer in long enough that I have no desire to create an nyting with their exact BSP as it is not on Yocto v4.x so the syntax is not correct and have no signs of realising a new BSP) so my question to you is how you integrated your custom machine and .dtsi file to create a bootable image.

Thank you,

Jordan

[joxborrow]

Hi, @jakos Sorry this is over a year old, but I am fairly new to Yocto and need to create a custom image and have been having the same problem you had. Can you explain where and how you included your .dtsi file? I have a .dtsi that I have been told is for our board but am not sure how to make it work with my custom machine that I am including the IMx8qxp-mek machine from the fslc layer in.

Thank you

[jakos]

Hi,

Sorry for such later answer.

The integration issue which You are having consists of uboot or kernel ? Intergrating custom machine consists of porting bot uboot and kernel.

Perhaps message me on priv so that we do not create unnecessary spam here within this topic



BR
Jakub

[jakos · Accepted solution]

Found a solution.

Turns out i was missing fsl-imx8qxp-custom-u-boot.dtsi in my .dts file

Thanks for all the help and resources.

[igorpadykov]

Hi Jakub

for porting may be useful to look at attached socument and below links

https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/i-MX8-Boot-process-and-creating-a-bootab...

https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/MX8X-4-19-35-ga-BootLoader-V6-20200217-c...

SCFW Porting Kit​

Best regards
igor

[jakos]

Thank You very much I will get into it.

Attached file relates to linux 4.19 whilst we are using 5.4. Will this be compatibles?

BR

[igorpadykov]

general approaches and porting rules are the same.

Best regards
igor

[jakos]

Thanks. I am reading through this document but so far i can't find any logical explanation why simply renaming DTS causes the board not to boot? We have no external hardware nor any changes on our IMX8QXP MEK board.