[squeak-dev] Raspberry Pi (was: Squeak Community Hangout - some notes)

tim Rowledge tim at rowledge.org
Fri Nov 9 02:01:26 UTC 2012


On 08-11-2012, at 2:29 PM, Open Slate <openslateproj at gmail.com> wrote:
> 
> Why would the port "just work?" Does the Freescale chip execute i86 instruction set? (I feel like I am in over my head here.) My thinking is that the ARM chip will require its own vm, then an image will "just work."

To expand upon Bert's comment, the 'ordinary' VM is a simple (for certain values of 'simple') interpreter and has no particular dependence upon the exact cpu when one is looking from the Smalltalk side. Obviously, the VM program must be compiled for the cpu upon which it will run. And the ARM most definitely does not run x86 instructions. Well, except for the small number that were built  that did in fact run x86 as well as ARM. But that was a long time ago and in a galaxy far, far, away. It had nothing to do with them being radiation hardened as well. Really.

ARMs up to architecture v7 are 32 bit (OK the A15 is kinda-sorta 40 bit addresses but we'll do our best to ignore that outburst of insanity) and the new and exciting v8 is 64 bit and likely to crush intel. When there are real A57 cpu based units to play with we'll see what happens.

At some point I will probably have a go at doing the CogVM stuff needed for ARM cpus. Enormous amounts of money deposited into my bank account would speed up that process, as well as Squeak, Pharo & Scratch. ARM v8 would be a quite separate job since it is an almost completely new ISA.

I'd also like to have a chance to re-do some ancient self-compiling bitBLT stuff since it made a huge difference to graphics performance - in '88 an 8MHz ARM2 machine could bitBLT faster than any other Smalltalk implementation of the time.

Ah, Abba is on the radio; "money, money, money…."

tim
--
tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
Strange OpCodes: HEM: Hide Evidence of Malfunction




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