@c @c @c COPYRIGHT (c) 1988-2002. @c On-Line Applications Research Corporation (OAR). @c All rights reserved. @c @c $Id$ @c @chapter Building RTEMS @section Obtain the RTEMS Source Code This section provides pointers to the RTEMS source code and Hello World example program. These files should be placed in your @code{archive} directory. @subheading @value{RTEMSVERSION} @example FTP Site: @value{RTEMSFTPSITE} Directory: @value{RTEMSFTPDIR} File: @value{RTEMSTAR} @ifset use-html @c URL: @uref{ftp://@value{RTEMSFTPSITE}@value{RTEMSFTPDIR}, Download RTEMS components} URL: ftp://@value{RTEMSFTPSITE}@value{RTEMSFTPDIR} @end ifset @end example @subheading RTEMS Hello World @example FTP Site: @value{RTEMSFTPSITE} Directory: @value{RTEMSFTPDIR} File: hello_world_c.tgz URL: @uref{ftp://@value{RTEMSFTPSITE}@value{RTEMSFTPDIR}/hello_world_c.tgz,,ftp://@value{RTEMSFTPSITE}@value{RTEMSFTPDIR}/hello_world_c.tgz} @end example @c @c Unarchive the RTEMS Source @c @section Unarchive the RTEMS Source Use the following command sequence to unpack the RTEMS source into the tools directory: @example cd tools tar xzf ../archive/@value{RTEMSTAR} @end example This creates the directory @value{RTEMSUNTAR}. @section Add /bin to Executable PATH In order to compile RTEMS, you must have the cross compilation toolset in your search path. The following command appends the directory where the tools were installed prior to this point: @example export PATH=$PATH:/bin @end example NOTE: The above command is in Bourne shell (@code{sh}) syntax and should work with the Korn (@code{ksh}) and GNU Bourne Again Shell (@code{bash}). It will not work with the C Shell (@code{csh}) or derivatives of the C Shell. @section Verifying the Operation of the Cross Toolset In order to insure that the cross-compiler is invoking the correct subprograms (like @code{as} and @code{ld}), one can test assemble a small program. When in verbose mode, @code{gcc} prints out information showing where it found the subprograms it invokes. In a temporary working directory, place the following function in a file named @code{f.c}: @example int f( int x ) @{ return x + 1; @} @end example Then assemble the file using a command similar to the following: @example m68k-rtems-gcc -v -S f.c @end example Where @code{m68k-rtems-gcc} should be changed to match the installed name of your cross compiler. The result of this command will be a sequence of output showing where the cross-compiler searched for and found its subcomponents. Verify that these paths correspond to your . Look at the created file @code{f.s} and verify that it is in fact for your target processor. Then try to compile the file @code{f.c} directly to object code using a command like the following: @example m68k-rtems-gcc -v -c f.c @end example If this produces messages that indicate the assembly code is not valid, then it is likely that you have fallen victim to one of the problems described in @ref{Error Message Indicates Invalid Option to Assembler} Don't feel bad about this, one of the most common installation errors is for the cross-compiler not to be able to find the cross assembler and default to using the native @code{as}. This can result in very confusing error messages. @section Building RTEMS for a Specific Target and BSP This section describes how to configure and build RTEMS so that it is specifically tailored for your BSP and the CPU model it uses. There is currently only one supported method to compile and install RTEMS: @itemize @bullet @item direct invocation of @code{configure} and @code{make} @end itemize Direct invocation of @code{configure} and @code{make} provides more control and easier recovery from problems when building. This section describes how to build RTEMS. @subsection Using the RTEMS configure Script Directly Make a build directory under tools and build the RTEMS product in this directory. The @code{../@value{RTEMSUNTAR}/configure} command has numerous command line arguments. These arguments are discussed in detail in documentation that comes with the RTEMS distribution. A full list of these arguments can be obtained by running @code{../@value{RTEMSUNTAR}/configure --help} If you followed the procedure described in the section @ref{Unarchive the RTEMS Source}, these configuration options can be found in the file tools/@value{RTEMSUNTAR}/README.configure. @b{NOTE}: The GNAT/RTEMS run-time implementation is based on the POSIX API. Thus the RTEMS configuration for a GNAT/RTEMS environment MUST include the @code{--enable-posix} flag. The following shows the command sequence required to configure, compile, and install RTEMS with the POSIX API, FreeBSD TCP/IP, and C++ support disabled. RTEMS will be built to target the @code{BOARD_SUPPORT_PACKAGE} board. @example mkdir build-rtems cd build-rtems ../@value{RTEMSUNTAR}/configure --target= \ --disable-posix --disable-networking --disable-cxx \ --enable-rtemsbsp=\ --prefix= make all install @end example Where the list of currently supported 's and 's can be found in tools/@value{RTEMSUNTAR}/README.configure. is typically the installation point for the tools and defaults to @code{@value{RTEMSPREFIX}}. BSP is a supported BSP for the selected CPU family. The list of supported BSPs may be found in the file tools/@value{RTEMSUNTAR}/README.configure in the RTEMS source tree. If the BSP parameter is not specified, then all supported BSPs for the selected CPU family will be built. @b{NOTE:} The POSIX API must be enabled to use GNAT/RTEMS. @b{NOTE:} The @code{make} utility used should be GNU make.