[ELDK] 4.2 vs 5.x

[Michael Steiger]

On 16.11.2012 21:38 Wolfgang Denk said the following:
> Dear Michael,
> 
> In message <50A63EBE.4010008 at infoworks.at> you wrote:
>>
>> I have a question regarding the use of ELDK 5.x.
> 
> You are welcome.
Thanks

>> I still use a hardware device containing a ppc85xx board which is
>> preloaded by the supplier with a 2.6.24 ELDK 4.2 based Linux.
>>
>> Shall/Can I use ELDK 5.x to generate binaries for this platform?
>> I have not looked at the newer ELDK versions but I assume that they use
>> newer libraries which are not compatible with this old system.
> 
> I'm not sure what exactly you mean by "generate binaries".  Depending
> on how standard-conforming your code is, you may or may not see some
> new compiler warnings or even errors when switching to ELDK 5.2 - this
> is the result from moving from GCC 4.2.2 to 4.6.3 with ELDK 5.2 (or
> even gcc 4.7.2 with ELDK 5.3); these newer versions of GCC provide not
> only much better optimizations, but also much strikter code checking.

"generate binaries" means creating new executables and/or shared
libraries for this system.

> Assuming you have well written code, switching to the new tool chain
> should be a very smooth operation.  Also, usually you don't have to be
> afraid when using the newer tool chain with such an old kwernel
> version.  Yes, certain features are not supported by that old kernel
> yet, but you should not notice this - your code doesn't use any of
> these, as otherwise it would not work with this old kernel now.
> 
> 
> But you have to keep in mind that you must rebuild _all_ your code,
> i. e. all the libraries and binaries in your root file system.  You
> cannot expect to just build one or a few applications with the new
> tool chain and run these in the context of your old root file system
> using the old libraries.  [Sometimes this may even work, but I would
> not rely on it; investing the effort for a full rebuild now is
> definitely better spoent time than tracking down any nasty bugs caused
> by incompatible library versions later.]
And this is exactly the problem I have.
The appliance is shipped preinstalled with this root filesystem and I
can not/should not change it in any way.

Is was the reason to ask if I can use the newer ELDK with the old system.

Thanks for the confirmation that this is not easily possible.

Regards,
Michael

> 
> Best regards,
> 
> Wolfgang Denk
>