I was lost… here is what I were doing

AXI DMA

I work on https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/1027702787/Linux+DMA+From+User+Space+2.0

I will run petalinux then modprobe user space dma driver then the application following this https://www.kernel.org/doc/html/v4.15/driver-api/dmaengine/dmatest.html

Problem