Re: [ECOS] Re: PC targets and ethernet

[Nick Garnett <nickg@ecoscentric.com>]

Gary Thomas <gary@mlbassoc.com> writes:

> On Thu, 2004-08-12 at 02:49, John Dallaway wrote:
> > Hi Andrew
> > 
> > Andrew Lunn wrote:
> > 
> > >>>Question: Why should hardware packages not be removable?
> > >>
> > >>This was a design decision intended to prevent users from modifying 
> > >>their configuration to such an extent that it was effectively targetting 
> > >>a different board. The eCos Configuration Tool uses the selected 
> > >>"Hardware Template" (target) for more than just package selection. For 
> > >>example, the "Run Tests" feature requires knowledge of the selected board.
> > > 
> > > OK. 
> > > 
> > > This leads to the counter question. Is ecosconfig broken? Should it
> > > also not allow hardware targets to be removed?
> > 
> > ecosconfig has no need to impose the restriction detailed above. It 
> > could be argued that the GUI and CLUI tools should be consistent in this 
> > respect. However, there may be objections to imposing such a restriction 
> > on ecosconfig users.
> 
> Perhaps devices like this (which may or not be present) should just not
> be marked as "hardware" in the database.  Would that not work?

While that might solve the problem for PCs, it would then make these
packages optional for all other targets that use them. Which we don't
want to do.

The base problem is that the PC is an unusual target as far as eCos is
concerned. Most boards that have ethernet have the MAC in the
microcontroller or soldered quite firmly to the board. So there is no
question of it being changeable. The PC is different in that any PCI
card can be plugged in. So far we have coped with this quite
successfully by defining different targets for each supported ethernet
card. This is not particularly hard to do -- the ecos.db changes are
trivial compared with creating the target specific package and maybe
modifying the driver to work.

I'm not sure I really like the idea of compromising the functionality
of eCos simply to make a specific, unusual, target slightly more
convenient to use.

-- 
Nick Garnett                    eCos Kernel Architect
http://www.ecoscentric.com/     The eCos and RedBoot experts


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