u-boot with custom dts name won't boot

[BillR]

OpenStLinux 5.4 Dunfell 06 22 20

Boot chain of TF-A, U-Boot and kernel.

I had forked the three .dts files with custom board names. TF-A starts fine.

But in u-boot, hangs before it starts.

With exact same dts contents just using original dts name as the DEVICE_TREE then u-boot runs fine.

I have heard that the "compatible" property needs to be the same, which it is, but that seems to have no effect.

Example u-boot build:

make DEVICE_TREE=my-device-tree-name #won't boot

make DEVICE_TREE=original-device-tree-name #boots

Any ideas?

[Kevin HUBER · Accepted solution]

Hello @BillR​ ,

I made some test on my 157c-dk2 board and it works.

The name of my new dts is "stm32mp157c-dk2-test.dts", it is just a copy of "stm32mp157c-dk2.dts".

I didn't modified the "compatible" property, it is still:

	compatible = "st,stm32mp157c-dk2", "st,stm32mp157";

Please can you verify that you also made a copy of the u-boot.dtsi file with the same name?

[osboxes@osboxes ...es/arm-ostl-linux-gnueabi/u-boot-stm32mp-v2020.10-stm32mp-r2-r0/u-boot-stm32mp-v2020.10-stm32mp-r2/arch/arm/dts]
$ ll stm32mp157c-dk2*
-rw-rw-r-- 1 osboxes osboxes 119378 Apr 15 06:47 stm32mp157c-dk2.dtb
-rw-r--r-- 1 osboxes osboxes   2918 Apr 14 14:10 stm32mp157c-dk2.dts
-rw-rw-r-- 1 osboxes osboxes 119378 Apr 15 07:22 stm32mp157c-dk2-test.dtb
-rw-r--r-- 1 osboxes osboxes   2918 Apr 14 14:10 stm32mp157c-dk2-test.dts
-rw-r--r-- 1 osboxes osboxes    139 Apr 15 06:46 stm32mp157c-dk2-test-u-boot.dtsi
-rw-r--r-- 1 osboxes osboxes    139 Oct 18 13:27 stm32mp157c-dk2-u-boot.dtsi

You can see in the ls -l above that I have a:

• stm32mp157c-dk2-test.dts
• stm32mp157c-dk2-test-u-boot.dtsi

The u-boot.dtsi file is important because it is automatically included in the dts file with the same name.

This behavior is explained in the wiki: https://wiki.st.com/stm32mpu/wiki/STM32MP15_U-Boot#STM32MP15x_lines_support

-----------------------

You can use the command dtc, to verify that your dtb is correct without flashing your board.

dtc arch/arm/dts/stm32mp157c-dk2.dtb > dtc-stm32mp157c-dk2.dts
dtc arch/arm/dts/stm32mp157c-dk2-test.dtb > dtc-stm32mp157c-dk2-test.dts

The command "dtc" convert a generated dtb in a big dts file. This command is very helpful to verity the content of your final DTB, because all the include files have already been processed.

Once converted your two DTB files in dts, you can then verify that they are identical:

diff dtc-stm32mp157c-dk2.dts dtc-stm32mp157c-dk2-test.dts

or by using a diff tool like "meld".

Hope it helps,

Regards,

Kevin

[Kevin HUBER]

Hello @BillR​ ,

Did it solves your issue?

Regards,

Kevin

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[BillR]

Kevin, since it wasn't currently a show stopper I have not tried this yet. It does sound like that is likely the issue, about the dtsi file. I will getting back into this work maybe this week and try it out - I'll let you know, Thanks!

[BillR]

Kevin, yes that was it!

Because I didn't generate our DTs with CubeMX, but rather modified from existing files (an Octavo ref. design) I didn't realize the corresponding dtsi file was required since I didn't see it included in the dts.

Thanks again, Bill

[Kevin HUBER]

Hi @BillR​ ,

Thank you for the feedback ;)

Regards,

Kevin