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Where to find the device trees (*-a7-examples.dts or *-m4-examples.dts) ?

AHayo.1
Associate II

Hi,

I'm developping an application where we want the cortex-M doing some power management (with OpenAMP) and the cortex-A taking picture and saving it on SD card.

I have the STM32MP157A-EV1.

I used the OpenAMP_TTY_echo_wakeup sample that I modified for my need to do the power management. Everything is working fine if I boot in third mode (ie. stm32mp157c-ev1-m4-examples). However, I don't have any camera input as it's saying that /dev/video0 doesn't exist.

If I boot in second mode (ie. stm32mp157c-ev1-a7-examples), I've got a camera but I couldn't suspend at first (systemctl suspend), because I would get the following error :

PM: Device 40017000.dac:dac@1 failed to suspend: error -16

So, I commented every line of code linked to DAC and it worked (ie. I could have the OpenAMP and camera running at the same time). But it's not that great of a workaround. Ideally, I would want to update the device tree. Where could I find the initial device trees used so that I just can quickly modify them ?

I know they are stored in <path>/Developer-Package/stm32mp1-openstlinux-5-4-dunfell-mp1-20-11-12/sources/arm-ostl-linux-gnueabi/linux-stm32mp-5.4.56-r0/linux-5.4.56/arch/arm/boot/dts but I think it's the default one and I would like the stm32mp157c-ev1-m4-examples.dts and stm32mp157c-ev1-a7-examples.dts to make these minimal changes.

Note : I tried to get the dts from the /boot/dtb with dtc command but it's saying me there is a syntax error.

Best regards !

1 ACCEPTED SOLUTION

Accepted Solutions
Olivier GALLIEN
ST Employee

Hi @AHayo.1​ ,

stm32mp157c-ev1-m4-examples.dts and stm32mp157c-ev1-a7-examples.dts are indeed in the <path>/Developer-Package/stm32mp1-openstlinux-5-4-dunfell-mp1-20-11-12/sources/arm-ostl-linux-gnueabi/linux-stm32mp-5.4.56-r0/linux-5.4.56/arch/arm/boot/dts ... once you have applied the ST patches.

Refer to README_HOW_To file in <path>/Developer-Package/stm32mp1-openstlinux-5-4-dunfell-mp1-20-11-12/sources/arm-ostl-linux-gnueabi/linux-stm32mp-5.4.56-r0 for complete installation of sources.

Hope it help,

Olivier

Olivier GALLIEN
In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question.

View solution in original post

2 REPLIES 2
Olivier GALLIEN
ST Employee

Hi @AHayo.1​ ,

stm32mp157c-ev1-m4-examples.dts and stm32mp157c-ev1-a7-examples.dts are indeed in the <path>/Developer-Package/stm32mp1-openstlinux-5-4-dunfell-mp1-20-11-12/sources/arm-ostl-linux-gnueabi/linux-stm32mp-5.4.56-r0/linux-5.4.56/arch/arm/boot/dts ... once you have applied the ST patches.

Refer to README_HOW_To file in <path>/Developer-Package/stm32mp1-openstlinux-5-4-dunfell-mp1-20-11-12/sources/arm-ostl-linux-gnueabi/linux-stm32mp-5.4.56-r0 for complete installation of sources.

Hope it help,

Olivier

Olivier GALLIEN
In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question.

Yes, thank you very much !

Nice day !