ali hagigat wrote:
Starting from top makefile, what is first rule that is executed?
I think this depends on which target you are building. Why do you ask?
How this makefile causes other makefiles inside the subdirectories are called? Please mention the line which does this.
It's not one line. coreboot uses a Makefile scheme which was inspired by the Linux kernel Makefile scheme and rules. By studying the Makefile rules in coreboot you'll see that it's not as simple as you may expect.
In any case, a starting point for studying the Makefile rules might be the line starting with:
includemakefiles=
in the top level Makefile.
//Peter