HelenOS sources

nm_fault          218 kernel/arch/amd64/src/interrupt.c 	exc_register(VECTOR_NM, "nm_fault", true, (iroutine_t) nm_fault);
nm_fault          240 kernel/arch/ia32/src/interrupt.c 	exc_register(VECTOR_NM, "nm_fault", true, (iroutine_t) nm_fault);
HelenOS homepage, sources at GitHub