Wireshark · Wireshark-users: Re: [Wireshark-users] Crosscompiling TSHARK to run on embedded linux on ppc440!

[Guy Harris <guy@xxxxxxxxxxxx>]

On Feb 11, 2009, at 1:09 PM, Andrew Hood wrote:

> The real qustion being are those cross compliation tools or native  
> tools
> for the target platform?
>
> Aren't bison/yacc/flex outputs platform independent?

In theory, although if "platform" includes "operating system", it's  
conceivable that there might be differences in the #includes.  In  
practice, the output of those tools should work on all UN*Xes, but, as  
I remember, at least with some versions of flex, the output includes  
<unistd.h> on UN*X, which means the output *won't* work on Windows.

That's not the issue here, however, as we're talking about two UN*Xes  
(the Linux on which he's compiling and the embedded Linux he's using  
as the target).

What I'm trying to determine is whether the programs under /opt/eldk/ 
ppc_4xx are

	1) cross-tools to run on the development machine - yes, perhaps some  
tools don't have to be cross-tools, but it might be that they supply a  
complete set of cross-tools, so that, for example, /opt/eldk/ppc_4xx/ 
usr/bin/gcc runs a cross-compiler that generates code for PPC 4xx  
processors while /opt/eldk/ppc_4xx/usr/bin/flex just runs whatever  
version of Flex they happen to supply

or

	2) programs to run on the *target* machine, in case you were thinking  
of doing all your compilation on the target machine.

According to

	http://www.denx.de/wiki/DULG/ELDK

"The Embedded Linux Development Kit (ELDK) includes the GNU cross  
development tools, such as the compilers, binutils, gdb, etc., and a  
number of pre-built target tools and libraries necessary to provide  
some functionality on the target system."

So the question is where the cross-development tools are?  Are they  
under /opt/eldk/ppc_4xx/usr/bin?  Or are programs under there part of  
the "number of pre-built target tools and libraries necessary to  
provide some functionality on the target system" and, if so, why  
exactly is the functionality of reading Flex input and emitting C code  
to be compiled into a lexical analyzer functionality they've decided  
to provide?  (I.e., it seems a bit bizarre for them to provide a PPC  
binary of flex - I suspect most embedded PPC boxes aren't used to  
compile source code.)