[Vm-dev] Simulating the Cog V3 VM

[David T. Lewis]

On Wed, May 11, 2016 at 04:46:32PM -0700, tim Rowledge wrote:
> 
> 
> > On 11-05-2016, at 4:17 PM, Levente Uzonyi <leves at caesar.elte.hu> wrote:
> > 
> > Spur support has been added to SystemTracer a while ago.
> > http://www.squeaksource.com/SystemTracing.html
> 
> Excellent; looks like other-Tim got to it and seems to have made something working. So, why isn???t that the solution to migrating Cuis?
>

Because it is not just a matter of converting the existing object memory,
there are also changes in the image.

Regarding SystemTracer, this is a nice light-weight approach to doing
the conversion, but Eliot's bootstrap process that uses the simulation
machinery in VMMaker has a lot of advantages too.

In addition to Eliot's documentation of the image bootstrap process, you
can also get a rough idea of the image-side differences by looking at
the four packages in this repository from your up to date trunk Spur
image:

  MCHttpRepository
	location: 'http://www.squeaksource.com/TrunkUpdateStreamV3'
	user: ''
	password: ''

This overstates the differences needed for bootstrapping a V3 image
to Spur, but it does give a sense of where the differences lie.

Dave