EMP: a common infrastructure firmware framework for the CMS phase-2 upgrades

In its phase-2 upgrades, all of the CMS experiment's off-detector electronics systems will be replaced by ATCA boards featuring Xilinx UltraScale+ FPGAs and high-speed optical modules. The various off-detector electronics systems have different high-level purposes and I/O requirements, e.g. requiring different combinations of lpGBT links to/from detector modules, higher-speed data transfer links between off-detector boards, and readout links. The EMP framework provides common infrastructural firmware components, top-level designs and associated software for multiple CMS phase-2 boards and systems. It implements and integrates high-speed serial link engines, data capture and playback buffers, clocking components, and readout. In this paper, we present the EMP framework, along with its testing and validation, and associated build tooling.