[seL4] Combined Ada and C project with Kbuild

I'm currently working on a project that is using the old Kbuild system. The project has been primarily implemented in C, however we would like to integrate some Ada code into the project. I am familiar with how to use gcc and makefiles to build polyglot projects on linux, however, I have no idea how to do so with the Kbuild system, as I cannot find out how to build anything other than .c or .h files with the makefile. How would I go about adding ada code to the project? Is there any way for me to build .ads and .adb, or .a files with the makefile?