Hi Jecel


On Nov 5, 2008, at 11:43 PM, Jecel Assumpcao Jr wrote:

> Eliot Miranda wrote on Thu, 30 Oct 2008 18:15:24 -0700
>>     I wonder if anyone has any 32-bit processor implementations,
>> either in Smalltalk or in some other, preferrably easy-to-parse,
>> formal semantics.
>
> I have a simulator for the 16 bit stack processor in Squeak, but I  
> don't
> think it would be very interesting for you.

Where did you publish it?


> For Smalltalk compatible
> formal semantics there is IDaSS (http://www.xs4all.nl/~averschu/ 
> idass/)
> on VisualWorks but all their examples are 8 bit.
>
> You can find many processor implementations in VHDL, Verilog and other
> hardware design languages but the effort of dealing with any of these
> languages would far outweigh just writting a new simulator in  
> Smalltalk.
> And they would probably be too low level for your needs in any case.  
> You
> can find more suitable simulators in C, Java and similar languages.
>
>>  In implementing the new JIT VM I would like to continue developing
>> in Smalltalk using VMMaker/Slang,
>
> Good plan!
>
>> but this implies having a processor simulation in Smalltalk to  
>> produce
>> actual machine code for.  Ideally this would be an x86 of some  
>> description
>> (doesn't need to be bang up to date, 386 would be fine).  I'd also  
>> welcome
>> an ARM.
>
> I wrote simulators for the 8086 and ARM2 back in 1988 and can tell you
> that the first is much more troublesome. Both architectures have grown
> more complicated since then but the x86 has done so exponentially.  
> Just
> to give you an idea of how bad things are now, the RAMP people
> (http://ramp.eecs.berkeley.edu/) had initially planned to have a x86
> implementation as one of their core options but even with all their
> resources they eventually had to give up and now run QEMU on Sparc  
> cores
> instead!
>
> One processor that has been implemented many times and has many formal
> descriptions floating around on the web is the MIPS-like academic DLX
> design presented in the Hennessy & Patterson textbook.
>
> -- Jecel
>
>
>