What: /sys/class/fpga_region//compat_id Date: June 2018 KernelVersion: 4.19 Contact: Wu Hao Description: FPGA region id for compatibility check, e.g. compatibility of the FPGA reconfiguration hardware and image. This value is defined or calculated by the layer that is creating the FPGA region. This interface returns the compat_id value or just error code -ENOENT in case compat_id is not used.