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Altera_Forum's avatar
Altera_Forum
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15 years ago

Problem debugging after bootloader loades

I have an Arria II GX device with an EPCS device attached. On this EPCS device I'm storing both the configuration and the application for NIOS. I'm able to use the NIOS default bootloader in the EPCS...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

I never found a solution from Altera that worked out of the box for me. We actually ended up writing a custom boot loader that copied the NIOS application from the EPCS flash and put it in the external SRAM. The boot loader was placed in an internal ram (not rom) and therefore you can debug the application just like normal since the reset vector can be overwritten by the debugger.

You will have to create the boot loader as a new application and make sure that all the linker sections are pointing to the internal memory. Once you have built your boot loader convert it to .hex file using the elf2hex utility. Rebuild the FPGA with the .hex file as your internal memory initialization file.

The tricky thing in all this is to debug the boot loader. We struggled a bit with that.

Hope this helped

/Boris