hardware for eToys

tim Rowledge tim at rowledge.org
Tue Nov 14 16:41:48 UTC 2006


On 14-Nov-06, at 6:44 AM, Klaus D. Witzel wrote:

> Hi Jecel,
>
> nice find, perhaps they learned the eToys name from the OLPC  
> project ;-)
>
> Question to the VM guru: are there any opcodes in the instruction  
> set of ARM9 which allow a *fast* VM? A *small* VM is addressed by  
> the thumb thing, IIRC. But what about speed. And what VM  
> technology, (direct) threaded bytecode, or what does ARM9 support  
> best.
Well ARM is a generically nice little RISC cpu and the ARM9 is just  
one variation (actually ARM9 is a family designation for a range of  
actual chips) among many.
Things that are good for running a squeakish vm include good fast  
integer handling,  a barrel shifter, and perhaps most interesting the  
very fast call / return from subroutines that can reduce the use of  
inlining and save memory traffic. The fast interrupt handling can be  
useful too.
bad things include the almost non-existent cache and no FPU.

I still think that a maxed out ARM11 with the fully 4mb cache and 4mb  
TCM and the FPU would be a very fast system. But nobody is banging  
onmy door to offer me one.:-(

tim
--
tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
Strange OpCodes: MAW: Make Aggravating Whine





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