The ARM peripherals need to be assigned to I&#x2F;O pins which happens in the FPGA (PL in Zynq terms). The ARM subsystem has bus connections to programmable logic which happens entirely in the FPGA (e.g., you connect a 16550 UART to the ARM via AXI bus, etc). I&#x27;d say Zynq is a far more complex bitstream than just a vanilla FPGA.