libxml2 on VxWorks 6.4+

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).

Thanks,

Jim Wert Jr.

JWert@ILSTechnology.com