Re: Self defining CDL interfaces

[Jonathan Larmour <jifl at eCosCentric dot com>]

Gary Thomas wrote:
> There are many examples of CDL which have comments like this:
>
>         # FIXME: This really belongs in the NS DP83902A package
>         cdl_interface CYGINT_DEVS_ETH_NS_DP83902A_REQUIRED {
>             display   "NS DP83902A ethernet driver required"
>         }
>
> These appear in target/platform instance CDL files.
>
> Does anyone remember why this interface is not defined in the
> common/platform-independent CDL file?

Because those platform-independent CDL files are generally active_if that 
interface themselves. It's catch-22: the parent is active_if a 
cdl_interface, but if the parent contains that cdl_interface itself it can 
never be enabled because it's inactive!

I'd like to know what Bart's idea of a real solution would be though. The 
only thing I can imagine is having a CYGPKG_DEVS_ETH_NS_DP83902A_REALLY 
within CYGPKG_DEVS_ETH_NS_DP83902A where the latter (the parent) contains 
the cdl_interface, but it's the latter that has the active_if. But this is 
icky fluff that just makes the whole lot more confusing.

My preference would be for cdl_interfaces always to be active in the sense 
of being able to be implemented; so if their parent is inactive, then 
that's similar to having a no_define.

Jifl
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