Compile and Link with the Build Tool (Compact 2013)
The Windows Embedded Compact 2013 build system uses the Build Tool (Build.exe) to make (compile and link) code. This program makes code in multiple directories as indicated by dirs files and sources files. A dirs file is a list of directories in which build.exe will make code; a sources file lists the files to compile.
Recursive Operation and Dirs Files
The first step that build.exe takes is to produce a list of all directories in which it will compile and link code. It does this as follows:
- It adds the directory from which it is called to the directory list.
- It searches that directory for a dirs file. If it does not find one, the process is complete, and the directory list contains only one entry.
- If it does find a dirs file, it searches, in turn, all of the directories listed in that file. For each such directory, it does the following:
- Adds it to the directory list.
- Determines whether it contains a dirs file. If it finds a dirs file, it treats each of the directories listed in that file just as it treats the directory that contains the dirs file; that is, it adds it to the directory list and searches it for a dirs file.
This process is recursive — each directory examined can potentially provide another dirs file that contains a list of directories to examine. The process ends when all directories listed in all of the discovered dirs files have been handled.
In the following example of a dirs file, the entries in the DIRS list (
SDHCLib, etc.) are the directories that build.exe will search.
DIRS= \ SDHCLib \ SDCard_Lib \ SDCardLib \ SDBus \ SDBus_dll \ SDHCDrivers \ SDClientDrivers
You can use Cesysgen conditional statements in your dirs file to build only the components that your OS will use. In the following excerpt from a dirs file, the battery driver code is included only if the battery module is needed.
DIRS= \ SDHCLib \ SDCard_Lib \ … # \@CESYSGEN IF CE_MODULES_BATTDRVR battery \ # \@CESYSGEN ENDIF CE_MODULES_BATTDRVR …
After build.exe creates the directory list, it returns to each directory in turn to make code. It checks each directory for a sources file.
In the following example of a sources file (Platform\Common\Src\Common\Bldr\Log\Sources), the .c files listed under SOURCES= \ are the files that will be compiled:
TARGETNAME=boot_log TARGETTYPE=LIBRARY INCLUDES=..\inc;$(INCLUDES); SOURCES= \ format.c \ log.c \ dump.c \ oalLog.c \ debugLog.c \ kitlLog.c WARNLEVEL=4 WARNISERROR=1
Build.exe processes this file as follows:
- Compiles all of the .c files listed in the file, including headers from the standard include path and from the ..\inc directory.
- Links the output file boot_log.lib, using the highest level of compiler warnings and throwing an error if any warnings are found during compilation.
For more information about the contents of a sources file, see Sources Macros.
The build.exe tool takes a number of arguments, but is most often used in one of the following ways:
- If build.exe is called with no arguments, it compiles and links only files that have changed since the last time it was called.
- If build.exe is called with the -c argument (the so-called “clean” option), it compiles and links files regardless of their time stamps.
Build.exe compiles and links source code based on the following types of input:
- Makefile.def — the standard makefile for the components of the Windows Embedded Compact project.
- Sources.cmn — a common environment file that is found in the build directory.
- The sources file in the directory that build.exe is compiling and/or linking.
- Makefile.inc — an optional file that is used for defining custom rules for custom targets.
- Environment variables in the local environment.
Build.exe starts executing in the directory in which it is called. There, it creates the following log files, which describe what occurred during execution:
- build.err — for errors only.
- build.wrn — for warnings.
- build.log — for all output, including errors and warnings.
Build.exe also provides the compiled and linked code to a variety of locations.
In This Section
- Sources Macros
Describes some of the more common macros you encounter during normal development.
- A Build Example
Provides an example of build.exe at work.