[SeaBIOS] seabios: About the reset mem address

[Amos Kong]

----- Original Message -----
> Amos Kong wrote:
> >  [CS base address = CS segment selector * 16]
> >        F000H * 16 = F0000H
> >                     ^^^^^^ (it's not 0xFFFF0000)
> > 
> > ==> "CS base address" is not "base address in CS register" ?
> 
> Study real mode vs. protected mode. x86 starts in real mode. For
> backwards compatibility, 386 CPUs (the first with full 32-bit
> addressing) and later also start in real mode, but with CS in a
> twilight state, so that the first instruction is actually fetched
> from near top of 4GB, where the boot flash chip is decoded.

Understood.
Thanks for the reply of kevin of peter :)

> > 2. If I only compile seabios, and load the bios.bin to qemu,
> > coreboot will not be used?
> 
> Of course not. If you compile Linux, and load bzImage from LILO, will
> gPXE be used? coreboot is one project and SeaBIOS is another. They
> can both be used together and separately.
> 
> 
> > what's the relationship between coreboot and seabios ?
> 
> coreboot picks SeaBIOS as default payload, if the person building
> coreboot does not explicitly provide a payload.
> 
> On qemu the initialization done by coreboot is simple, and has been
> included into SeaBIOS instead, probably for convenience, I don't
> know.
> 
> 
> //Peter
>