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Date: Thu, 5 Apr 2012 03:20:31 +0200
From: Peter Stuge <peter AT stuge DOT se>
To: geda-user AT delorie DOT com
Subject: Re: [geda-user] Re: [coreboot] Dual SPI Flash adapter
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Colin D Bennett wrote:
> Do existing motherboards include a _single_ SPI flash IC already?

Yes. Sometimes soldered down, sometimes in a socket. The PCB is to go
into the socket, with the original chip on the PCB, and a second SO8
flash chip selectable with a jumper, instead of the original.


> What is stored on the SPI flash,

A BIOS or coreboot.


> and who reads data from it?

The CPU reset vector decodes into the end of the flash minus 16
bytes, so this is where the machine starts executing code.


> Is your module designed to mount on a stock motherboard and
> transparently emulate a single SPI flash IC, or does it use a
> modified interface (presumably requiring the party accessing
> it to be modified?

It's a mux on the CS/ line of two SPI flash chips.


//Peter