Embedded FPGAs (eFPGA) are increasingly being used in SoCs, enabling post-silicon hardware specialization. Existing CPU-eFPGA SoCs have three deficiencies. First, their low core count hinders efficient execution of thread-level-parallel workloads. Second, noncoherent or partially coherent CPU-eFPGA integration inhibits dynamic, random memory sharing. Third, the use of full-custom circuits makes proprietary eFPGAs technology-dependent, inflexible in physical layout, and lacking architectural customizability.