EGCS __interrupt__ attribute

[Brendan Simon]

I wish to add support for the __interrupt__ attribute for the powerpc
family (and probably the 68k at a later stage).  I think
__interrupt__ is the standard (pseudo standard) attribute name to use.

Does anyone out there have any documentation, notes or advice on how to
achieve this ?
What files need changing ?  What problems to lookout for ?
Does binutils need any modifications or just the egcs sourcetree ?

Thanks,
Brendan Simon.