The official way to port PYNQ to a new board is to download the framework from Git create a custom board file that uses the custo board BSP and the board parameters.
To boot the board on the ZC702 we have to customize the default kernel of the PYNQ V2.5 image which targets the 400 pin version of ZC7020 to the 484 pin SOC on the ZC702.
Once all the settings are correct issue:
petalinux-package --boot --fsbl --fpga --u-boot
bram_test.txt.zip 1.0 KB