Jeremy Jackson <jeremy.jackson@sympatico.ca> writes:
> Jaswinder Singh wrote:
>
> > Dear Sirs,
> >
> > Thanks for your help,
> >
> > I see . The biggest negative point of running kernel from ROM is that ROM
> > speed is slow :(
>
> Also, the PCI specification forbids executing code from ROMs over the PCI bus.
> The system BIOS in a PC is not on the PCI bus, bus, but everything else is.
No it forbids executing boot roms that way, by a standard pc bios.
The system BIOS in a PC is normally on the ISA bus which is reached
across via the PCI bus with a PCI->ISA bridge.
The thing is slow it really doesn't matter, all you need to do is
enable caching on that area of the physical address space. You can't
do this on the alpha currently but only because the alpha sucks that
way. You can on practically everything else.
As for ROM being slow on x86 you can enable the MTRR to speed things
up. Usually though ROMs are at least as expensive as RAM, so it is
pointless.
Eric
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Fri Feb 23 2001 - 21:00:20 EST