User interface test verification part 20

FOUND A DIFFERENT UBOOT ARCHIVE FOR DE10-NANO

Somebody had uploaded a U-boot set up for my board. I pulled it from github in the hope that this will accomplish the three things necessary - it must bring up U-boot, it must enable the bridges, and it must support launching my Linux kernel to fit my design. 

As a quick initial test I did an install of their prebuilt U-Loader, one that most likely doesn't support the bridge or pin muxing configuration from my design, just to validate that it will successfully start U-boot. It did.

The next step is to build the customized U-boot from that distributions sources. If the updated U-boot will also load to the command prompt it would be a promising sign that I can move on to Linux boot and resume my testing. 

STUMBLING OVER OLD PROBLEMS AGAIN

The source for U-Boot includes an error with duplicate definitions of a label yylloc to which there are many google hits. However, the resolution in all those hits is to assert that one has to have the correct version of gcc versus Ubuntu versus U-boot all without ever stating ANYWHERE what all the versions are that should work together properly. 

AND ANOTHER BRICK WALL

Fortunately I could just comment out one of the duplicates so that the loader can link all the references to the same location. With that the preloader and U Boot images were created. Now all I had to do is to update the SD card, presumably, and it would boot up. 

It did not! 

The bottom line is that nothing I do to generate U-boot and the preloader can create something that will start up on the DE10-Nano board. I have several versions of premade U-boot but they have various problems. The earliest one does not properly activate the bridges I need. The newer one appears to activate the bridges, although I can't test that and only assume so because there are no error messages during the activation process. However, my Linux image will not boot up on that preloader.

Clearly I have to debug the startup of Linux hoping to get a clue to why this process is failing. My guess is that the U-boot versions are not activating key functions that my design uses and Linux is hanging trying to work with those functions.