[Vm-dev] Simulating the Cog V3 VM

[tim Rowledge]

> On 17-05-2016, at 6:01 AM, Juan Vuletich <JuanVuletich at zoho.com> wrote:
> 
> On 5/11/2016 9:05 PM, David T. Lewis wrote:
>> 
>> 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.
> 
> I understand. But in any case, have you, Levente, David or anyone else produced a spur image that can start, using SystemTracer?

The submit comments in the history of the SystemTracer2 package claim it has been used to trace a working Spur image. I imagine it would have been a contemporary v3 trunk image loaded with SystemTracer2.

Unless some very big changes have been made in Cuis that completely break the concept of a system tracer I have trouble imagining how it could be unable to produce a proper spur version. I don’t doubt there might be some interesting details to solve.
In the past I know the tracer has been used to convert bytecode sets, object formats, word sizes,  and method formats, as well as to create application specific images etc. I know from personal experience that it can be made to do a lot of interesting things.

tim
--
tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
"Bother" said Pooh, as he flunked the the sobriety test.