Pynq on ZCU104 hangs when JTAG is used

[cathalmccabe]

I think this is a known issue. For debug, you need to disable cpuidle
Try the solution here:

Problem with Using integrated logic analyzer (ILA) for Debugging with PYNQ

OK, it looks like it’s possible to fix this without recompiling PYNQ. Add a new file “uEnv.txt” to the SD card with the following line: bootargs=root=/dev/mmcblk0p2 rw earlyprintk rootfstype=ext4 rootwait devtmpfs.mount=1 uio_pdrv_genirq.of_id="generic-uio" clk_ignore_unused cpuidle.off=1 This adds cpuidle.off=1 to the rest of the default bootargs found from PYNQ/pynq_bootargs.dtsi at master · Xilinx/PYNQ · GitHub Now the hardware manager seems to work and so does the Jupyter Notebook interfa…

This will result in the CPU clock running at full speed constantly. When you are finished debug, you probably want to turn this off for lower power. This is why this setting is turned ‘on’ by default.

Cathal