mkmk Files

With the mkmk tool, you can write portable description files. The files are independent of both the host system you use and the target for which the system you are creating is destined. The mkmk tool also provides high level abstraction rules which ensure the portability of the application build files.

The mkmk command uses three types of build description files, suffixed by .df, .bf, and .mf, to produce Makefiles and generate all.dp dependencies. With mkmk, you create a .mf file for each host. In this way the mkmk tool ensures portability during cross compilation and so ensures the portability of hosts and targets.

.df Files

The .df files are used as shell scripts that are launched when the Makefile is created to adjust variables before they are written into the Makefile. The .df files define the following variables:

• The cpp symbols

• The header file directories

• The list of subdirectories

The .df files have similar properties to the Project.tmpl files of the imake tool. See ChorusOS 4.0 Introduction for further information. They affect the building of the Makefiles for all the subdirectories. With mkmk, you can have several .df files in each directory of the source tree. This contrasts with the imake tool, which has only one Project.tmpl file per component.

The inheritance mechanism of the mkmk tool is different from that of the imake tool. With mkmk, every Makefile is dependent on the Makefile present in the parent directory. However, with imake, every Makefile is dependent on the Project.tmpl file present in the top-level of the component and on the few variables which are inherited from the parent directory. The variable and macros are defined in the production tools. Table 4-2 lists those which you must not modify and Table 4-3 lists those which you may modify.

Table 4-2 Variables for the .df files, that must not be changed

TARGETMKRULES	<bin_dir>/tools/tgt-make/mktgt.rf
MKRULES	<bin_dir>/tools/tgt-make/mktgt.rf
DTL	<bin_dir>/tools/host/bin/
GROOT	../../
BDIR	<bin_dir>
BNAME	kern
HOST	LINUX
FAMILY	PowerPC
COMPILER	gcc
BFILES	List of .bf files found in your work directory
MFILES	List of .lf files found in your work directory
DFILES	kern.df

Table 4-3 Variables in the .df files that you can modify

DEFINES	List of macro definitions to use in every compilation rule
INCLUDES	List of directories to search for header files
VARIABLES	The list of user defined variables to export in Makefiles produced in subdirectories
SUB_DIRS	The list of directories to use when compiling; these are usually the subdirectories of your work directory
EXTRA_DIRS	A list of directories to use, in addition to SUB_DIRS, when creating libraries or linking actors (usually empty)
MODULES	The name of the module to which the object in your work directory (and subdirectories) belong; this is only useful in configurable actors
FEXCEPTION	(ON/OFF); Compile with exception support
FFPU	(ON/OFF): Compile with FPU support
FOPTIM	(ON/OFF): Compile with optimization
FPROF	(ON/OFF): Support for profiling
FREMOTEDEB	(ON/OFF): Compile with debug options, to enable debug with XRAY
FVERBOSE	(ON/OFF): Verbose compilations
FWARN	(STRICT/ON/OFF): Enable warnings production during compilation; with STRICT, warnings are treated as errors, the NUCLEUS component uses STRICT

.bf Files

The .bf files are equivalent to the Imakefiles. They define source files, binary files and compilation options. The .bf files contain link directives and source definitions, such as C__SRCS. You can have several .bf files per directory. The mkmk tool concatenates the .bf files inside the Makefile product. The .bf file is preprocessed by the macro processor m4(1).

Table 4-4 lists the macros used in a .bf file. Actor, ConfigurableActor, Library and BigObject, either directly, or indirectly use getExport to get the list of object files. DistFile and Export are defined in $(DEVTOOLS_DIR)/tgt-make/mkrules.m4.

Table 4-4 Macros used in .bf files.

Actor(actor, libs)	build 'actor' using libs
ConfigurableActor(actor, libs)	build 'actor' using libs
Library(lib)	build 'lib'
BigObject(obj)	build a relocatable object file
DistFile(file,dir)	copy 'file' into 'dir'
Export(file,dir)	same as DistFile

.mf Files

The .mf files contain lists of source files. The .mf files are used when the binary file to be built uses many subdirectories, each subdirectory containing a variable number of files to be compiled.

Another form of .mf files are .lf files. The variables and macros used in the .mf and .lf files are listed in Table 4-5.

Table 4-5 Variables and macros used in .mf and .lf files

C++SRCS	C++ source files
C__SRCS	C source files
AS_SRCS	assembly code source files
M4_SRCS	M4 source files (assembly code source files preprocessed with m4).
OF_SRCS.	C++ source files used to produce offset files