This reverts commit b9ace36fcc.
This change was added by PR 625 but has a serious logic flaw. It removes all occurrences of INCDIROPT and replaces it with a definition in tools/Config.mk:
else ifeq ($(WINTOOL),y)
DEFINE = "$(TOPDIR)/tools/define.sh"
INCDIR = "$(TOPDIR)/tools/incdir.sh" -w
This logic flaw is the Config.mk is included in all Make.defs files BEFORE WINTOOL is defined. As a result, the definition is wrong in many places when building under Cygwin with a Windows native toolchain.
In the two pass build, the application logic is built during the first phase, pass 1. In that phase, the application may generate and install source files in the pass1/directory. The operating system is built during phase 2 of the build. At that time, those source files in the pass1/ directory will be built and incorporated into the kernel address space.
The primary purpose of the pass1/ directory is to such application-generated kernel symbol tables. For an example of the use of this feature, look at apps/examples/module/drivers/Makefile. Kernel symbol tables are needed to support kernel modules. Of course, addition board-specific logic in, say, configs/<board>/src would have to be included to make use of the application-installed symbol tables.
