[ELDK] What's the main difference between official Linux and DENX Linux ?

[Gao Ya'nan]

2009/12/10 Detlev Zundel <dzu at denx.de>:
> Hello Gao Ya'nan,
>
> as a general guideline, we want to stay as close to the upstream Linux
> kernel as possible, yet still decouple our customers from the upstream
> time schedule.  This effectively allows the customers to develop their
> applications concurrently with the kernel changes going into mainline.
>
> So in effect the DENX linux tree can be seen as a "staging" tree for our
> custom specific additions.  In the past this for example allowed
> customers with MPC5200 CPUs to participate in kernel development while
> the transfer from arch=ppc to arch=powerpc when the 5200 support in
> mainline needed time to regain the level of support that it had before.
>
> The reasoning here is that up to today we always saw that back-ports
> into old Linux trees or board support packages for a single specific
> kernel version turned out to be a waste of effort, time and thus money.
> Thus we we always suggest working with a mainline linux kernel which
> also allows for a relatively smooth upgrade path during the long product
> cycle which is typical in embedded projects.
>

I think I will meet these problems.

>> I compared the whole source tree, but it was beyond my knowledge.
>
> Well this is understandable and we're actually actively working on
> reducing the differences.
>
>> why should I use DENX Linux instead of official Linux ?
>
> If the CPU you are developing for is supported in mainline, then we
> suggest to use mainline.  When on the other hand you need additional
> items not yet supported there, you may either contract us to develop
> them and publish them for your perusal in our tree as stated above or
> you may be lucky and someone else did just this, so that our tree has
> (at some point in time) better support for your hardware.
>
> In the long run, it is always be a smooth process to use the mainline
> tree once it has all the features you need.
>

Now I use MPC875 and MPC8313, and I think I'm very lucky.

> Best wishes
>  Detlev Zundel

Thanks for your guide, and I think I'm clear.

>
> --
> Question    : If you were redesigning UNIX, what would you do differently?
> Ken Thompson: I'd spell creat with an e.
> --
> DENX Software Engineering GmbH,      MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich,  Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu at denx.de
>