It's now time to decode some radio ham digital modes, starting from FT8, which I'm very fond of!

The idea is to transfer the PCM audio stream from the PL to the PS, where a "standard" linux audio driver lets consume the stream using the FT8 software WSJT-X. See Overview block diagram. 

Regarding the WSJT-X specific implementation on PetaLinux, I modified JTDX adapting it to the different software environment (without a windows manager) obtaining myjtdx

The Linux Audio Driver is described here Xilinx ALSA audio I2S driver

A Vivado project with an I2S Receiver and Transmitter, DMA and Linux Device Driver is very well described here:

In part 1 and 2 of Audio Linux Device Driver for (*) Zedboard - hardware implementation you can read the Vivado hardware implementation, while In part 3  you can read the PetaLinux building.

(*) Zedboard is an AVNET board based on Xilinx Zynq-7000