[LinuxBIOS] bios addressing

Peter Stuge stuge-linuxbios at cdy.org
Wed Jun 7 19:41:55 CEST 2006

On Wed, Jun 07, 2006 at 09:09:18AM -0700, Tyler Pohl wrote:
> What is the first instructions address in a 2Mb bios chip ?  I'm not very
> familiar with i386 processors obviously because i assumed the first
> instruction on power up was 0h but i don't think thats the case now.  Is
> there a good flow chart somewhere on the web I don't know about ?

x86 always boot at 0xfffffff0 and BIOS ROM ends at 4GB with very few
exceptions, if any.

For a 2Mbit BIOS chip (256kbyte) that means the BIOS ROM is at
0xfffc0000 and x86 will boot from 0x3fff0 in the chip.


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