• when you use the MSYS environment you can feel like under Linux (shell, basic programs: grep, awk, sed, itp.) - it provides great flexibility in automation of file processing tasks (e.g. automatic package creation, version numbering and marking, etc.),
• the GNU make provides more options, is newer, better tested than the Borland make (included in C++ Builderze 6.0),
• the GNU make is very popular, used by many programmers, in the Internet there is a lot of descriptions of different problem solutions,
• the GNU make is well known standard
• The transformation into the MSYS/GNU-make may be first step toward moving whole building process to GCC (the compiler that is more modern and better than Borland one)

• different format of paths specification (Borland expects DOS-like format, e.g. c:\directory\file, while GNU tools (i.e. MSYS) uses Linux-like, e.g. /c/directory/file)
• Borland uses a set of options with semicolon as separator of its items (e.g. symbol definition or paths in included folders)

Because the Borland provides .autodepend directive, all dependencies are determined automatically by make. The GNU make requires to enter dependencies, although they can be created with significant help of the GCC compiler, that can generate them (options -MM).

There is number of methods how the dependencies are created and used, I choose following way:
- the files containing dependencies in a rule format (generated by GCC) - files with extension .d
- in order to have correct extension of image files (obj) the extension in dependency rules is changes from .o to .obj
- inclusion dependency files in project makefile by -include directive (they are treated as additional rules)
- dependencies generation on request (target deps)

Examplar dependencies (main1.d file):

main1.obj: main1.cpp main1.h ../firmware/fclock.h ../firmware/protocol.h

In order to build (update) dependencies you should execute (in windows command line console):

build_by_gnumake.bat deps

or in the MSYS console:

make -f hello1_gnu.mak deps

Dependencies update is performed not very often and is required when new header files are included or new module is added. It is possible to add automatic dependencies build and refresh.

Of course, you can manage files location also in GNU makefile, just by defining and using a prefix:

$(BUILD_PREFIX)/%.obj : %.cpp 
	$(BCC32) $(CFLAG1) $(WARNINGS) "-I$(INCLUDEPATH)" "-D$(USERDEFINES);$(SYSDEFINES)" $< -o$@

• change conditional directives - they are mostly symbol definition, that are undefined
• provide dependencies
• use double path formats (DOS and Linux) - that matches shell or arguments requirement
• envelop DOS paths with double quotation - just to suppress interpretation of semicolon and backslashes by the MSYS shell
• replace temporary files usage by list of commands