Flash mapped to lower address?

[Devi Priya]

If i have my Flash memory mapped to the lower address (0x0000-0x3FFFFF), 
then what modification should be made to linux bios?

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"Devi Priya" <[e-mail]> writes:
> If i have my Flash memory mapped to the lower address
> (0x0000-0x3FFFFF), then what modification should be made to linux bios?

If this is x86 and that is your only flash address then
you can't boot.  x86 cpus start at address 0xfffffff0.
Unless there are some embedded variants I am not familiar with.

If this is ARM where flash is normally mapped to 0 that
makes sense but currently we don't have an arm port.  I don't
think it would be too difficult though.

So I really can't answer without more information.

Eric

[ron minnich]

On Tue, 23 Dec 2003, Devi Priya wrote:
> If i have my Flash memory mapped to the lower address (0x0000-0x3FFFFF), 
> then what modification should be made to linux bios?

why on earth would you map flash to this address? it makes no sense to me.

ron

[Bari Ari]

Devi Priya wrote:
> If i have my Flash memory mapped to the lower address (0x0000-0x3FFFFF), 
> then what modification should be made to linux bios?

If you have you Flash mapped to 0x0000 - 0x3FFFF then you can't use your 
Flash as a Boot Device since the "SCx200 Core Logic module positively 
decodes memory addresses 000F0000h-000FFFFFh (64 KB) and 
FFFC0000h-FFFFFFFFh (256 KB) at reset".

Why don't you just get the application note "AMD Geode™ SC1200/SC2200/
SC3200 Processors: External NAND Flash Memory Circuit" and the Geode 
data sheet from AMD? They explain how all this works.

-Bari

[Bari Ari]

Devi Priya wrote:
> If i have my Flash memory mapped to the lower address (0x0000-0x3FFFFF), 
> then what modification should be made to linux bios?

Are you using NAND Flash or DOC or both ? Are you trying to boot from 
the DOC?

You may also want to look at the

Geode™ IA on a Chip Devices: Booting from the M-Systems DiskOnChip 
Millennium Application Note

http://www.m-sys.com/files/documentation/doc/App_Note_047_Des_DOC_FD_Boot_Re...

http://www.m-sys.com/files/documentation/doc/App_Note_031_PC_Rev_2.2.pdf

-Bari