FELIX: the new ATLAS readout system from Run 3 to High Luminosity LHC

<!--HTML-->The Front-End Link eXchange (FELIX) system is a new ATLAS DAQ component designed to for detector readout in the High-Luminosity LHC era. FELIX acts as the interface between the data acquisition, detector and trigger timing systems. FELIX routes data between custom serial links from front-end electronics to data collection and processing components via a commodity switched network. This presentation covers the current design of FELIX and its evolution for High-Luminosity LHC, including the development of a new hardware platform based on a Xilinx Versal Prime FPGA, incorporating PCIe Gen4 and a new 25Gbps optical link standard.