[U-Boot] [PATCH] dfu: initial implementation

[Detlev Zundel]

Hi Andrzej,


[...]

>> > > If my assumption is correct, then what would it take to split off
>> > > protocol part and make it independent of the actual driver
>> interface?
>> >
>> > I guess that in the situation given it would be of little use.
>> 
>> What do you think would be of little use?
>> 
>
> As far as I understand you correctly, you would like the state
> machine code extracted from the initial DFU implementation posted
> on this mailing list. And then you would like the DFU implemented
> in terms of this abstract state machine. This means actually
> more code, probably not a desired thing. The generic state machine
> would also require some accompanying generic data structures,
> and this would also mean code to translate back and forth between
> USB/DFU (DFU _is_ USB) and state machine's data structures.
> All in all, this means adding more complexity and code. This looks
> like a premature optimization (which is widely known to be the root
> of all evil), while at the moment, there are no use cases
> to justify it. Should the use cases appear, the code can be reworked
> based on the needs of both USB/DFU and new state machine users.

Just to add my personal opinion here - I am occassionally lobbying for a
long time on this mailing list that mainline U-Boot gains DFU support,
so please let's get this working with the existing tools and in the
existing contexts, i.e. USB.  Personally I consider it to be completely
out of scope to dis-entangle DFU from its specification and abstract it
into something which it _could_ be, but really _isn't_.

When the implementation for USB is here, we all have much better grounds
to discuss possible generalizations (although I doubt that there are
many).

Cheers
  Detlev

-- 
Perfecting oneself is as much unlearning as it is learning. 
                                        -- Edsger Dijkstra 
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