Re: Getting Started with Hurd-L4

[Sam Mason]

Marcus Brinkmann wrote:
>Well, I will write a smallish task server any day now, which should be
>good enough to create new tasks and allocate threads.  The physmem
>server definitely needs more than the current dummy container,
>although it turns out good enoough to run the task server and allocate
>some anonymous memory (with a frightening dumb interface).

It'll be interesting to see what the difference is!  Everything is
pretty new at the moment, so I don't really know what's
incomplete/broken at the moment.

>Then we need some fake/dummy device access server [. . .]  That's
>another couple of days easy hacking.

Assuming you know where to put it!

>At that point, user level stuff can start (porting the C library, etc).

I think my wording of "user level" was probably a bit off!  Not sure
how to describe what I mean though.  I guess I'll just hang around a
bit and see how everything moves on!  I was expecting things like the
C library to be a *long* way of yet though.

>For real usability, much more work is needed of course.

That's kind of what I was expecting. . .

>It's only dictated as much as we want to port the Hurd to it, so, we
>have to provide the right primitives.  But as you can read in the doc/
>document, it's quite radically different from Mach.

I didn't know much about OS development when I investigated
Hurd before.  I just about got it booting and was proud of that!
I've done a bit of reading/coding since then and I think I'm a bit
more knowledgeable now though.  The internals of Mach were beyond
me then and I haven't attempted to look at them since, so I can't
really appreciate how different everything is now. . .

I know that it looks like quite a nice design now - which is
probably why I'm getting a bit more interested.  It also seems to
be converging significantly with my own ideas on how things should
be designed and I was hoping to have some interesting banter with
people about it.

>We are not trying to port the Hurd with minimal changes, so we feel
>free to deal in the Hurd as much as needed, and that is quite a lot on
>the surface, but surprisingly little on the overall design (not
>surprising to the original designers of the Hurd, of course :).

Sounds like the right way to going about things - pick up the good
bits and try and push the rest forward as much as you can.

>It sounds like you are not scared of technical details.

They're generally the interesting parts!

>I'd recommend
>to read the design notes in the doc/hurd-on-l4.pdf document.

I've already been reading that; I've also been trying to get my head
around the code, and I've been dipping into mailing list archives
a bit to try and get a bit of an idea of how everything fits together.

>The TODO list is just the "working set" for
>things to keep track of so they don't get lost.  The real stuff is in
>our brains and in that document.  Ask questions, you'll need the answers ;)

OK, I'll carry on reading a bit so I don't make too much of a fool of
myself, and I'll see what gets committed to CVS over the next few
days.

Cheers,
  Sam