How to update the boot chain (basic mode) for a "custom" device tree.

[HMasu.1]

Hi,

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I want to update the boot chain (basic mode) for a "custom" device tree.

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Following the wiki page below, I understood how to update the boot chain (trusted mode) for a "custom" device tree.

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https://wiki.st.com/stm32mpu/wiki/How_to_compile_the_device_tree_with_the_Developer_Package

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On the other hand, I don't know​ how to update the boot chain (basic mode) for a "custom" device tree.

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In basic mode, should I compile the device trees in the following steps?

==U-boot==

make stm32mp15_basic_defconfig

make DEVICE_TREE=<device tree> all

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==TF-A==

make -f ../../sources/arm-ostl-linux-gnueabi/tf-a-stm32mp-2.0-r0/Makefile.sdk TFA_DEVICETREE=<device tree> TF_A_CONFIG=basic all

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In this case, which files should I copy into the 'fsbl1', 'fsbl2' and 'ssbl' partition of the target​?

Best Regards.

H. Masuda

[Olivier GALLIEN]

Hi @HMasu.1​ 

Seems you made some confusion regarding what is "basic" boot.

Please refer to https://wiki.st.com/stm32mpu-ecosystem-v1/wiki/Boot_chains_overview ( archived wiki aligned with V1 ecosystem delivery ) to clarify difference between so called "trusted" and "basic" boot chain.

Anyway "basic" boot chain was already not recommended in ecosystem V1 and is now deprecated/removed in ecosystem V2.

ST will not provide any further support for it.

We fully recommend to switch to Trusted boot chain.

Olivier

[HMasu.1]

Hi @Community member​ 

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Thank you for your answer.

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I read the page you taught me, and I have understood that the basic boot chain is only provided to support the DDR Tuning Tool and the U-Boot developments.

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On the other hand, ​I was explained by Real Time OS vendor that I need to use "basic" boot chain when I want to attach MDK-ARM(ULINK) debugger to Cortex-M4.

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I want to use ​"basic" boot chain for above reason.

Does it mean that ​the basic boot chain is not supported/promoted to make products, but I can use only for debugging?

Or, is the explanation of ​Real Time OS vendor wrong?

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Best Regards.

H. Masuda

[Olivier GALLIEN]

Hi @HMasu.1​ 

Can you point me resource from your Real Time OS vendor about this topic.

I don't see obvious relation between M4 debugger attachment and Linux boot scheme.

Olivier

[HMasu.1]

Hi @Community member (ST Employee)​ 

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Thank you for your answer.

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​I was explained by e-mail from Real Time OS vendor that, by using "trusted" boot chain , ARM Trusted Firmware seems to block the ports required for JTAG access, so I need to use "basic" boot chain when I want to attach MDK-ARM(ULINK) debugger to Cortex-M4.

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Is the explanation of ​Real Time OS vendor wrong?

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In any case, I will use "trusted" boot chain because I have understood that ST recommend to switch to Trusted boot chain.

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Best Regards.

H. Masuda

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[SMich.1]

if it helps, i using GDB debugger that came with STM32CubeIDE to debug m4 firmware with linux and with IS_ENGINEERING_BOOT_MODE you can search for this option on st wiki . works grate .

[HMasu.1]

Hi @SMich.1​ 

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Thank you for your valuable information.

I will search STM32CubeIDE GDB debugger option on ST Wiki.

Thank you.

H. Masuda

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