Re: Transmeta ;)

[Alastair Donlon <nospam [at] netsoc.ucd.ie>]

On Thu, Jan 20, 2000 at 02:30:30PM +0000, Al Hudson wrote:
> sheflug - http://www.sheflug.co.uk
>
> On Thu, 20 Jan 2000, Alastair Donlon wrote:
>
> > From my reading of their docs, the translation software which morphs
> > instructions on the fly will be on a Rom, which will mean that you
> > won't be able to _easily_ shift between different instruction sets.
> > It will require a FLASH upgrade.
>
> Not quite. Firstly, the morphing software only morphs x86 code, so
> currently the question is pretty academic. But, there is no reason for the
> code to be in flash ROM. The 3120 is ROM-based, because it is designed for
> an embedded system: Mobile Linux is ROM based, and talks to the morphing
> software at boot time. However, remapping is done all the time, as is
> shadowing. Your video card, for instance, has a rom in it. That ROM is
> almost certainly shadowed into main memory. With an MMU, it doesn't matter
> whether the address is different, because the RAM pages can be mapped in
> over the ROM pages.
>

There is a reason for the code to be in ROM - it's the first thing that
runs when the processor is switched on. Before the BIOS even. Doesn't
mean that it has to stay in ROM, in fact it's copied to memory for
exactly the performance reasons you mention.