HPS startup debugging with custom board based on Cyclone V

Hi,

I am quite new in SoC development and I would like to ask for some guidance.

We build custom board based on 5CSEBA5U23I7S.

I compile Preloader/Uboot/Kernel/DevTree/RootFS and create sdCard for first boot.

But I would like to ask how can I start to debug first BootRom and preloader initialization steps.

I tried to use DS-5 the same way as it is in Workshop labs on rocketboards.org but I cannot connect to HPS.

"Failed to connect to the device

Unable to connect to the device Cortex-A9_0

Failed to write register 0 on device CTI_0_2

General error on memory or register access"

We have direct output for HPS jtag and I can see HPS device in Quartus programmer through Altera USB blaster.

Secondly we have UART/RS485 transfeiver connected to HPS UART0 but I guess uart needs to be first initialized to stream some output.

Could you help me to find possible way to get some output I can start to debug Preloader->Bootloader->OS->etc. Some listning I can stick to and step by step debug it.

Thank you very much,

Michal