1               libxml2 on VxWorks 6.4+
 2  
 3  Here are my instructions for building on VxWorks.... I am very ashamed of
 4  how I did this because it is a complete hack, but it works great, so I
 5  can't complain too much.
 6  
 7  General Information
 8  
 9  1. The only way to build for VxWorks is to cross compile from a windows or
10  linux system.  We use a RedHat 5.1 workstation system as our build
11  environment.
12  
13  2. VxWorks 6.X has two main types of executable, DKMs (dynamic kernel
14  modules), and RTPs (real-time processes).  Kernel modules are the bread
15  and butter of VxWorks, but they look nothing like processes/threads in
16  normal UNIX/Windows systems.  RTPs are more like processes that have
17  memory protection, threads, etc.  VxWorks 6.X also introduces some level
18  of POSIX conformance to their environment.  The POSIX conformance was the
19  key for us to be able to port libxml2.  We support accessing libxml2 from
20  both DKMs and RTPs.
21  
22  3. There are 2 compilers for VxWorks, the WindRiver compiler, and a port
23  of the GNU toolchain, we have only tested and built with the GNU
24  toolchain.
25  
26  How To Build
27  
28  1. Run the configure on your native linux system (this is the cheesy
29  hack).  Since the VxWorks GNU toolchain is very close in version to the
30  one in red hat, it generates a good config.h file.  We configured libxml2
31  with the following to keep the size down, (but we have done basic testing
32  with everything compiled in).
33  
34  ./configure --with-minimum --with-reader --with-writer --with-regexps
35  --with-threads --with-thread-alloc
36  
37  2. Rename the libxml2 folder to "src".  This step is required for our
38  replacement makefile to work.
39  
40  3. Run the replacement makefile.  I wrote a new makefile that sets all the
41  proper vxworks defines and uses the correct compilers.  The two defines on
42  the make command line are to tell it which VxWorks Target (SH3.2 little
43  endian), and the executable type.  We have tested this code on PENTIUM2gnu
44  and SH32gnule.
45  
46  This makefile creates a shared library that runs on VxWorks: (libxml2.so)
47  make -f Makefile.vxworks clean all VXCPU=SH32gnule VXTYPE=RTP
48  
49  This makefile creates a kernel module that runs on VxWorks: (xml2.out)
50  make -f Makefile.vxworks clean all VXCPU=SH32gnule VXTYPE=DKM
51  
52  Important Notes
53  
54  1. There are several ways that this process could be improved, but at the
55  end of the day, we make products, not port libraries, so we did a meets
56  minimum for our needs.
57  
58  2. VxWorks is the devil, give me embedded linux every day.
59  
60  3. No matter what I tried, I couldn't get the configure to pick up the
61  VxWorks toolchain, and in my investigation, it has something to do with
62  automake/autoconf, not any individual package.  VxWorks doesn't play by
63  the normal rules for building toolchains.
64  
65  4. The PIC flag in VxWorks (especially for SH processors) is very
66  important, and very troublesome.  On linux, you can liberally use the PIC
67  flag when compiling and the compiler/linker will ignore it as needed, on
68  VxWorks if must always be on for shared libraries, and always be off for
69  static libraries and executables.
70  
71  5. If anyone wants to work on a better way to do the build of libxml2 for
72  VxWorks, I'm happy to help as much as I can, but I'm not looking to
73  support it myself.
74  
75  Attached Files
76  
77  1. To use my Makefile for vxworks, you should enter the vxworks
78  environment (/opt/windriver/wrenv.linux -p vxworks-6.4 for me).
79  2. Run: build.sh libxml2-2.6.32 SH32gnule RTP (where you have
80  libxml2-2.6.32.tar.gz and the Makefile in the same directory as the script
81  file).
82  
83  Thanks,
84  
85  Jim Wert Jr.
86  JWert@ILSTechnology.com