[LinuxBIOS] Fun easy question. 512Kb or 256Kb

Adam Talbot talbotx at comcast.net
Tue Feb 7 18:18:41 CET 2006

Wow, that is allot of really good info.  Thank you Ron, Peter and Bari.
This all just sounds like over clocking the bios :-) 
So let me take the path of messing with Linuxbios code instead of 
messing with hardware access times that may or may not effect my system 
and will be almost impossible to tell.

Ron stated:
"Sending a byte out the serial port at 115200 is approx 80 times slower 
than a ISA bios fetch. So you will have the most dramatic speed up by 
nuking anything that writes to the serial port"

So if I turn off any serial console, that is fixed?  Does VGA bios have 
the same problem?

> Adam Talbot wrote:
>> Speed in ns:
>> What controls that? Can I set/change the access speed to my "bios chip"?
> The timing of the Flash BIOS read and write cycles are hardwired into 
> the chipset and clock synthesizer. At most there is a pinstrap 
> (Pinstrap = A signal line on a chipset that is read only after RESET 
> that is used to configure the chipset. The line is either tied to a 
> High or Low via a resistor.) to chose the type of firmware interface, 
> x8, x16, LPC or FWH.
> For an example, see page #3 of this schematic: 
> http://www.amd.com/epd/desiging/evalboards/8.am186ccev/22002_1/22002_1.pdf 
>> I have a few boards that had Eon chips(120ns), I have replaced them 
>> with SST's(45ns), they work fine.  Are they running faster? 
> No. The chipset spec may just require a flash device of 120ns or less. 
> Dropping in a faster flash device doesn't change the read access 
> speed, since the speed is driven by the chipset.
> -Bari

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