Ease of administration

[Jonathan S. Shapiro]

> We can do better than this, I think; new EROS programs will know what
> kinds of capabilities they need, and part of the process of making
> factories for them will be sealing the right capabilities into the
> factory, analogous to linking with libraries.  (In fact, linking with
> libraries could be accomplished by exactly this mechanism.)

Indeed, the process of building a bootable EROS image has much the flavor of
a link editing phase that link edits across processes. In builing the
mkimage tool I was frequently struck by functional similarities between it
and the original prototype ELF linker. I had a hand in ELF, so I suppose
this isn't entirely accidental. :-)

> Therefore,
> trying to build a factory for a program that needs a serial-line
> capability, without supplying either a serial-line capability or a
> simulator thereof, will give you a link-time error.

There is a third case, which is building a factory for a program that needs
a serial-line capability in such a way that this serial-line capability must
be supplied by the invoker.  That is, it is the factory's job to initiate a
program. The program may elect to initialize itself and then negotiate with
the client for further authority. This can be part of the program's
documented startup protocol if necessary, and need not imply a type error.