Programmable Devices
CPLDs, FPGAs, SoC FPGAs, Configuration, and Transceivers
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JTAG UART output to GDB


I've been developing a project of mine which has an Intel FPGA running a NIOS processor. I've been using printf() for debugging from the NIOS side to the PC. This works ok when using the "NIOS 2 Software Build Tools for Eclipse". However after updating the toolchain to the newest 20.1 there seems to be some kind of bug causing me to not be able to do "run as" preventing me from running the code via Eclipse. The "Run configurations" menu correctly shows my programming cable but the "run" button stays grayed out no matter what I do. The old version of the toolchain (17.1 I think) I had before had the same bug but I could get around it by replugging the cable but it doesn't seem to work anymore...

Anyway I'm not too attached to using the Eclipse for anything and I can run everything else from the CLI except I cannot get the JTAG UART printf() output to appear in gdb. Since this worked when run from Eclipse I'm sure my project and code are configured correctly so I think I am just missing some command to gdb or gdb-server telling it to display/print the JTAG UART data. I know for some GDBs/processors this command is "monitor semihosting enable" but the NIOS gdb does not seem to know this command. Does anyone know what I need to do to get the printf() stuff to appear in gdb?

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Hi Kalle!


First of all, thank you for reaching us.

regarding your issue, you can try by using the nios2-terminal and nios2-download commands to be able of having a debugging option from the console. Please take a look at the following documentation section Altera Command-Line Tools for Software Development and Debug and let me know any queries you may have.






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