[xml] libxml2 on VxWorks 6.4+


<Resent with better Subject>

Here are my instructions for building on VxWorks.... I am very ashamed of how I did this because it is a complete hack, but it works great, so I can't complain too much.

General Information

1. The only way to build for VxWorks is to cross compile from a windows or linux system.  We use a RedHat 5.1 workstation system as our build environment.

2. VxWorks 6.X has two main types of executable, DKMs (dynamic kernel modules), and RTPs (real-time processes).  Kernel modules are the bread and butter of VxWorks, but they look nothing like processes/threads in normal UNIX/Windows systems.  RTPs are more like processes that have memory protection, threads, etc.  VxWorks 6.X also introduces some level of POSIX conformance to their environment.  The POSIX conformance was the key for us to be able to port libxml2.  We support accessing libxml2 from both DKMs and RTPs.

3. There are 2 compilers for VxWorks, the WindRiver compiler, and a port of the GNU toolchain, we have only tested and built with the GNU toolchain.

How To Build

1. Run the configure on your native linux system (this is the cheesy hack).  Since the VxWorks GNU toolchain is very close in version to the one in red hat, it generates a good config.h file.  We configured libxml2 with the following to keep the size down, (but we have done basic testing with everything compiled in).

./configure --with-minimum --with-reader --with-writer --with-regexps --with-threads --with-thread-alloc

2. Rename the libxml2 folder to "src".  This step is required for our replacement makefile to work.

3. Run the replacement makefile.  I wrote a new makefile that sets all the proper vxworks defines and uses the correct compilers.  The two defines on the make command line are to tell it which VxWorks Target (SH3.2 little endian), and the executable type.  We have tested this code on PENTIUM2gnu and SH32gnule.

This makefile creates a shared library that runs on VxWorks: (libxml2.so)
make -f Makefile.vxworks clean all VXCPU=SH32gnule VXTYPE=RTP

This makefile creates a kernel module that runs on VxWorks: (xml2.out)
make -f Makefile.vxworks clean all VXCPU=SH32gnule VXTYPE=DKM

Important Notes

1. There are several ways that this process could be improved, but at the end of the day, we make products, not port libraries, so we did a meets minimum for our needs.

2. VxWorks is the devil, give me embedded linux every day.

3. No matter what I tried, I couldn't get the configure to pick up the VxWorks toolchain, and in my investigation, it has something to do with automake/autoconf, not any individual package.  VxWorks doesn't play by the normal rules for building toolchains.

4. The PIC flag in VxWorks (especially for SH processors) is very important, and very troublesome.  On linux, you can liberally use the PIC flag when compiling and the compiler/linker will ignore it as needed, on VxWorks if must always be on for shared libraries, and always be off for static libraries and executables.

5. If anyone wants to work on a better way to do the build of libxml2 for VxWorks, I'm happy to help as much as I can, but I'm not looking to support it myself.

Attached Files

1. To use my Makefile for vxworks, you should enter the vxworks environment (/opt/windriver/wrenv.linux -p vxworks-6.4 for me).
2. Run: build.sh libxml2-2.6.32 SH32gnule RTP (where you have libxml2-2.6.32.tar.gz and the Makefile in the same directory as the script file).


Jim Wert Jr.
JWert ILSTechnology com

Attachment: Makefile
Description: Binary data

Attachment: build.sh
Description: Binary data

[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]