Build u-boot brick IOT2050-ADV

I was build u-boot image form "master" git branch. 

./kas-container build kas-iot2050-boot-advanced.yml

Then I flash image to SPI Flash S25FL128K over X17 connector with Segger j-Link and "SPI-Flash" program.

When I was try to start device nothing is happend on debug port X14. And STAT led turn to red.

It is look like device is bricked.

I have lucky that I have another IOT2050-ADV. I was read SPI Flash form good device with same tool and reflash bricked device. It is work now.

Could some one from SIEMENS check what is wrong with build tool that u-boot image not work.

I can send bad image.

Best regards,

Robert

That command line is supposed to reproduce the currently released firmware, while appending :kas/opt/upstream.yml should generate a working version with upstream U-Boot and newer TF-A / OP-TEE. The latter is supposed to work, but we might have regressed regarding the former.

What is your reason to rebuild the firmware?

I would like to test CPU core clock at 800MHz or lower. To see if I could lower temperature of aluminium body.

Because CPU core clock is defined in u-boot DT, i need to rebuild u-boot.

That was alredy question in my earlier post.

Hi Jan,

Did you maybe check is there any problem with building u-boot image.

I can confirm that we have a regression with master for the legacy boot loaders. I just built the basic version, but the result does not boot here as well. Not sure if we will fix that anymore - you can always go back to V01.00.01 (I can confirm that this works).

But what exactly would you then edit in the control DT of U-Boot? Are you sure it has influence on the max CPU frequency of the cores, and not Linux with its own DT?

Please correct me if I'm wrong.

u-boot aplication also use own linux kernel.

DT from u-boot kernel is also using (transfer to) in main linux kernel. With modification from main linux DT.

How could I create patch for main linux kernel to change CPU frequency?

Patch for frequency update is defined in:

/recipes-bsp/u-boot/files/0002-am654x-frequency-update-for-both-arm-clusters-and-bu.patch

I belive that his patch is valid only for u-boot build.

In our setup, U-Boot loads the kernel DT from the rootfs. The DTs are widely aligned but not technically identical. Therefore, you could define what the kernel should use by updating /usr/lib/linux-<version>/... (paths differ between downstream and upstream kernels).

Now, the problem is that this U-Boot patch - even if it would allow setting something upfront during boot - is not used on our hardware. We have a separate first-stage loader on the R5 cores, not U-Boot. Also, I don't think what is set there is actually the core frequency, likely rather its timer rate. See also https://github.com/u-boot/u-boot/commit/ea3f5348063ebe4f41be7d1ba3ef0afe56a04a40.

What you could try is if offlining some CPU cores or disabling unused devices helps to bring down the temperature a bit. But power management is not in good shape with this revision of the SOC. The next one (SR2.x) will be better, but I have no exact data on how much in °C.

I'm set CPU frequency in u-boot to 800MHz with version V01.00.02. And there was no temperature drop. It seems that something else is power hungry. But at least unit was not bricked.

Reason for doing that is, we want to use IOT2050 in our products. Our enclosure with IOT2050 will be installed in environment where outside temperatures can wary between -20C up to 50C. And enclosure is IP65 protected.

So til now we are in big trouble if IOT2050 is so hot.

Do you have any date when SR2.0 will be released?

Is it better to use IOS2.0 for that?

Could we get access to IOS2.0 git and participate code?

Best regards,

Robert