Jerry Bell wrote:
> 
> I'm new to the list, but I've found some references to 'bare-metal' Squeak
> implementations.  Is anyone working on this?
> 
> What would be the ideal kind of kernel to run Squeak on top of?  I know
> portability would be on the top of the list.  How about single vs.
> multithreaded? Maybe even something completely different to take advantage
> of the unique needs of a smalltalk environment?
> 
> I assume that a goal would be to eventually make Squeak classes that could
> generate the low-level kernel code for a given platform, much like the
> interpreter generator.  Then, to port to another platform you would simply
> define the characteristics of that specific platform.  All from within
> Squeak.  That would be.... nice.
> 
> I don't have much experience with Smalltalk, and even less with OS design.
> But it seems that one way to approach this would be to build something
> quickly using simple, existing tools.  Then, when there is a working system
> we could factor parts of the original low-level code out and replace them
> with code generated by Squeak.  At that point, we could make refinements in
> speed, portability, etc. from within Squeak itself.
> 
> Specifically, I've started looking at FreeDOS's kernel, dos-c, as a
> possible starting point.  There is already a DOS port of Squeak out there,
> and it seems as if it would not be too terribly complicated to take dos-c
> and the DOS port of Squeak and kinda mash them together to make a booting
> SqueakOS.  Plus, the dos-c kernel is supposed to be pretty portable, and is
> written mostly in C so it shouldn't be not TOO hard to work with.  It
> should also be simpler than a more advanced kernel.  And, it's GPL'd.

I would rather try a Linux port to ggi (http://synergy.foo.net/~ggi/).
Some (older) stripped down Linux kernels seem to run in 1MB. If you
would
throw out the file system and replace it by something simpler, I guess
you would gain again some memory. 

> 
> I've just started looking at dos-c, I'm reading the author's book now.
> Unfortunately, it doesn't look like the current version of dos-c will
> handle the DPMI stuff that the DOS port of Squeak needs, but maybe that
> would be easy to fix for someone who knows what they are doing?

I guess it's not that easy because Squeak assumes a 32bit memory model. 


Markus

-- 
Markus Kohler  mailto:markus_kohler at hp.com