Re: [Syllable-kernel] upcoming Syllable patches..

[Maritimus <rea...@ih...>]

> > The NexGen Nx586, AMD/Cyrix 5x86s, 486s etc, don't have it at all. Not that
> > Syllable can currently run on those because of a couple of lines of Kurt's
> > i586 assembler enthusiasm, but someone's going to want to sooner or later :)
>
> Besides the code which assumes the presence of the cpuid instruction, is
> there any other assembly language code that anyone knows of that is
> keeping it from working on 486s?

From AtheOS.cx (thanks to archive.org):


""" Here is a list of supported hardware:
CPU:
 Pentium or better (Yes AtheOS use Pentium only instructions and will
 crash and burn on a 486). """


As far as I remember, there were a couple of i586 opcodes in the assembler (I
think it was only a few lines) because Kurt owned a Pentium. This was probably
talked about on the AtheOS mailing list, if anyone can search their old mailbox. I
guess it'd be possible to make the system's utilisation of these instructions
dependent on an Intel Pentium or fully compatible having been CPUID'ed, though I
don't know whether they're of any benefit or Kurt was just experimenting.



>  I know how to fix the cpuid code to
> detect if the machine doesn't support cpuid,

Like so?
http://www.paradicesoftware.com/specs/cpuid/
http://www.sandpile.org/ia32/cpuid.htm



> but how many people these
> days have access to a 486-class machine with math coprocessor that they
> want to run Syllable on?  If you do, let me know and I may be able to
> work something out.  Otherwise, it's probably never going to get fixed.

I've got a couple of 80486 boxes next to me =)

Though it isn't just 486s, as it was a long time after the Pentium was released
before all the non Intel x86s had fully implemented the i586 instructions. There
is little way Syllable's going to be usable on an SX25, but some of these older
chips best a Pentium 100, so it's probably as 'enabling' to Syllable's hardware
bredth as adding another video driver or two more or less.