When Go code is generated, a standard directory structure is created to hold the generated files which form a Go module. At the root level, the main.go and go.mod files are generated. Under that is asn1gen subdirectory, in which the generated Go files are stored. Below the asn1gen subdirectory is an asn1rt subdirectory, in which the required base run-time source files are stored. Executing “go build” will build the full package.