Re: [microblaze-uclinux] RE: [PATCH v3] Device tree bindings for Xilinx devices

[Michal Simek]

Hi Grant,

>> Hi Steve and all,
>> >Here's a full .dts generated using an updated version of
>> >gen_mhs_devtree.py, following the proposal.
>> >It happens to be a microblaze system, but you get the idea.
>>
>> I think that is no good idea generate dts with all information.
>> Especially information about PVR - number 2 means - Full PVR and you can
>> obtain information directly from PVR. It is waste of memory space.
>>                         xilinx,pvr = <2>;
>>
>> In my opinion will be better generate only parameters which you want not all.
>> That smells with unusable parameters.
>
>That is the hard part about crafting the dts; deciding which
>parameters the OS is going to care about and which ones are
>irrelevant.  The goal is to sufficiently and uniquely describe the
>board so that the OS can easily figure out what exactly what it needs
>to do to drive the board, but not to try and describe every aspect
>which it knows about.  Anything that is pollable (ie. USB devices)
>doesn't need to be in the tree.
>
>It's also important to remember that the device tree will *never* be
>perfect.  Eventually something will come up that the device tree
>doesn't describe well(a bug/quirk, something described poorly, etc).
>In this case, as long as the device tree is specific enough to
>identify which version of the board it is running on; we can alwasy
>add platform specific fixups for that unique system.
>

yes, but I think that is the right time to specify which parameters are relevant.
I will focus on in EDK renerator.

Michal Simek