[coyotos-dev] Storage Objects

[Neal H. Walfield]

I sent this message last night but I neither got a copy nor have I
seen it appear in the message archives.  Hence, I'm resending it.



A GPT object contains an object ID.  The named object contains 16
capability slots (256 bytes).  A process object also contains an
object ID.  The named object contains a number of capability slots.
One slot if for a schedule object, another for a page object for the
UPCB and a thing for a cappage object for the capability registers.
There is also normal data: the protected payload, the fault code and
the fault info.  This totals about 200 bytes.

I thought a storage object was the size of a hardware page.  Since
these objects use much less than 4kb what happens to the rest of the
storage in the object?  Do we just not care that it is wasted because
these objects are rare relative to data and cappages?

Since there are only two types of objects on backing store, pages and
cappages, how do we get both data and capabilities in a single object
(e.g. the process)?  In EROS, I would have said that we'd use a number
capability but Coyotos doesn't have such a beast.

Thanks,
Neal