Load U-Boot into RAM of CCMP13 and start it for development

Embedded Devices Linux
1

I’m customizing U-Boot 2021.10 (part of DEY Yocto 4.0 r5.1) to run on our ConnectCore MP133 based board.

During this development phase I would like to avoid flashing every new U-Boot into the NAND flash, just in case it would have an error which prevents further starts.

So - in the first time - I want to stay with the originally delivered FSBL and U-Boot, because they do not conflict with our hardware (it only does not support all things).
Then from this running U-Boot, I would like to load (from the already supported USB stick) my own U-Boot build into RAM and start it from there.

Is this possible? Ideally it would be like:

=> usb start
=> fatload usb 0 $loadaddr fib.bin
=> go $loadaddr

But that fails. Could it be done somehow? Would I have to modify something in U-Boot to achieve that? What would be appropriate load and start addresses?

I know, I also could use the “STM32-Bootloader” mechanism via the USB and BOOTMODE, but that is a bit inconvenient, therefore I’d rather start the U-Boot-under-test from within the currently running U-Boot.

Any help appreciated!

Reagrds,
Wolfram

2

doesn’t that do exactly what you want?
https://www.digi.com/resources/documentation/digidocs/embedded/dey/4.0/ccmp13/yocto-recover-device_t_ccmp1.html

3

That is indeed what I’m doing now.

However I was looking for an easier way to start into a new U-Boot version without going over the “disaster recovery” method via USB/dfu-util.

If that’s the only way to start U-Boot without flashing the NAND, then it’s OK.
Thanks for your reply!

4

it is not just a disaster recovery method, we use it for the getting started guide as well: Step 3 - Program the Yocto firmware | ConnectCore MP13 . It is quite easy and popular. Once you get it working once, it is very ease to continue testing.

5

Ok, I will stay with this method.