Skip the 3A current verification in the boot process. STM32MP157F-DK2

[obedPH]

Hello,

I am using the STM32MP157F-DK2 board, I also developed a carrier board in order to use external peripherals. I am using a 5V external power supply and I supply it through pin headers CN2 expansion, since I don't want to use the USB type C connector. I would like to skip the current verification in the boot process in software, maybe from the device tree or a recipe. I am using yocto to develop my custom image. If I connect first the USB-type-C and the external power supply at the same time, the boot process finishes correctly, if I disconnect the USB-Type-C after that, the operating system can run correctly with the external power supply, but the USB-type-C is needed in order to finish the boot process. Is it possible to skip that 3A verification on software? 

I am in the kirkstone branch, 5.15.67 kernel version.

Regards, @obedPH 

[PatrickF]

HI @obedPH ,

please have a look to this post.

Regards.

[obedPH]

Hello @PatrickF , thanks for reading.

I saw the post, however , I cannot find the uBoot devicetree.

This is the list of all the available devicetree for the stm32mp157f-dk2.

I would like to mention that I am not using the stm32mp157f-dk2.dts devicetree, I am using one that I compiled in the STM32CubeMX, this devicetree is working until now. How can I find the uboot devicetree and be sure that it's working in my custom devicetree?

I will attach the devicetree.

I would appreciate any help, 

Regards, @obedPH 

[PatrickF]

Hi,

I'm more HW expert, maybe these links could help:
https://wiki.st.com/stm32mpu/wiki/How_to_compile_the_device_tree_with_the_Developer_Package
https://wiki.st.com/stm32mpu/wiki/How_to_configure_U-Boot_for_your_board

Regards.

[obedPH]

Hi @PatrickF 

I already found the folder with all the uBoot devicetree, however, i am not yet able to compile that device tree. I updated the line and nothing happened.

Do you know someone here in the community who is maybe an expert compiling in Yocto? If you do, I would appreciate if you  could tag him here or something like that, I think I am close to skip the verification, but I can't find more information about the compilation process for the u-boot devicetree.

Regards.

[PatrickF · Accepted solution]

Hi @obedPH ,

not expert, but maybe the answer is in this page: https://wiki.st.com/stm32mpu/wiki/How_to_compile_the_device_tree_with_the_Developer_Package

Regards.

[obedPH]

Hii @PatrickF ,

Thank you for your help. I was finally able to recompile the uboot in Yocto.

if anyone needs this in the future, this is what I did:

I modified the meta-st-stm32mp/recipes-bsp/u-boot/u-boot-stm32mp/0004-ARM-v2021.10-stm32mp-r1-DEVICETREE.patch file.

Be careful with the tabs or spaces, because if this line is not the same as the line in the destination file the compilation process will fail. After that, I compiled the image again with bitbake.

After this compilation, I excecuted the command ```devtool modify u-boot-stm32mp``` in order to  modify my u-boot. Finally, I compiled the image again with bitbake. I don't know if all these steps are necessary, but it worked for me.

I appreciate your help,

Regards