Re: [xml] Question about character encoding support

[Roumen Petrov <bugtrack roumenpetrov info>]

Can we assume that you are able to cross-compile sample "Hello world" 
program with gnu autotools without problems ?

Roumen



jwert ilstechnology com wrote:
> Daniel,
>
> 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
>
>
>
>
> Daniel Veillard <veillard redhat com> 
> 06/09/2008 06:23 AM
> Please respond to
> veillard redhat com
>
>
> To
> jwert ilstechnology com
> cc
> xml gnome org
> Subject
> Re: [xml] Question about character encoding support
>
>
>
>
>
>
> On Sun, Jun 08, 2008 at 05:46:20PM -0400, jwert ilstechnology com wrote:
> > List,
> >
> > We are using libxml-2.6.32 on VxWorks 6.4.  It is far from being a posix 
>
> > system.  I compiled libxml2 without too many issues, but porting iconv 
> is 
> > proving to be a lot more difficult.  What options do I have for 
> supporting 
> > various character encodings when parsing XML?  98% of our customers use 
> > UTF-8 encoding, but I don't want to limit them if I don't have to.  For 
> > other parts of our product, I have written my own layer to convert 
> between 
> > character sets.
> >
> > What is the default behavior for libxml2 if it doesn't have iconv 
> > available?
>
>   By default you will have UTF-8 and UTF-16 which are mandatory, and also
> the full set of ISO-8859-x (see xmlRegisterCharEncodingHandlersISO8859x
> in encoding.c), plus the possibility to connect new handlers at runtime
>   http://xmlsoft.org/html/libxml-encoding.html#xmlNewCharEncodingHandler
>
> How did you build on VxWorks ? Does configure work ? If not could you
> post some kind of Howto so that others can benefits too ?
>
>   thanks,
>
> Daniel