[coyotos-dev] Status and roadmap

[Jonathan Adams]

On Fri, 2007-01-19 at 10:48 -0500, Jonathan S. Shapiro wrote:
> On Fri, 2007-01-19 at 10:29 -0500, Jonathan Adams wrote:
> > On Fri, 2007-01-19 at 14:28 +0000, Sam Mason wrote:
> > > On Thu, Jan 18, 2007 at 04:57:41AM -0500, Jonathan S. Shapiro wrote:
> > > > The kernel specification has been public for quite some time, and the
> > > > implementation is already underway.
> > > 
> > > The work is showing, section 3.3.2 (or was it 3.3.3) only documented
> > > what happened when the Activated field was in one state---I see this has
> > > been filled out to both now.
> > > 
> > > One thing that worries me now is where the kernel gets the memory to
> > > "synthesize a message to be delivered" when the userland scheduler is
> > > activated.  In fact where does this memory come from in the general
> > > case?
> > 
> > The message is a "short" message, which any non-blocked FCRB can receive
> > without needing additional storage.
> 
> Oh. Perhaps I misunderstood Sam's question.

I should have provided the context;  my understanding, based on the
"synthesize a message to be delivered" text quoted in Sam's e-mail, was
that he was asking about the following part of
http://www.coyotos.org/docs/ukernel/spec.html:

--- cut here ---
3.3.3 Exception Handling
...
Execution exception handling depends on the current setting of the
Activated field.

* If the Activated field is 0, ...
* If the Activated field is non-zero, then the exception has occurred 
in the activation handler itself. In this case the kernel will
synthesize a message to be delivered as if by invoking the handler
capability stored in the process structure. The fault code and 
auxiliary fault information will be passed as arguments to 
this invocation in w0 and w1 respectively. ...
--- cut here ---

since this is the only place the document refers to "synthesizing" a
message.  

Cheers,
- jonathan