Hello Bob and Liming,<br />I am coming back to you after re-reading Bob's answer:<br />&gt; I meet another problem related to .asl file. In one of platforms build process, there is a step which need to compile a .asl file a .h file firstly and that .h file will be included by a module&rsquo;s source code.<br />&gt; That step cannot be handled in edk2 build since the compilation command use different build option, so it&rsquo;s done in a pre-build script. I want to make edk2 build be able to handle such case. So together with your case,&nbsp; I think we may need a solution that can do:<br />&gt; 1.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Create a module which contains the .asl file and the build option to compile that .asl file.<br />&gt; 2.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Find a way to describe the dependency relation between the module contains .asl and the corresponding module contains .c file<br /><br />I split my module into one module containing the .asl file, and a second module containing .c source files. However I could not find a way to describe a dependency between the two modules (as suggested in the second step).<br />This part of Bob's answer makes me think it's not possible using current edk2 build system:<br />&gt; That step cannot be handled in edk2 build since the compilation command use different build option, so it&rsquo;s done in a pre-build script.<br /><br />I will have to reproduce the solution to multiple folders and for multiple platforms. Using a pre-build script would not be a scalable solution.<br />I would need to create a dependency between file extensions (or between modules which are edk2 library classes) using the build system.<br />Would you have an idea of how to do it, or if this is currently not possible and this implies modification in the build system, is there a way I could help?<br /><br />Regards,<br />Pierre