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Date: Thu, 20 Apr 2006 23:17:26 +0200
From: Fabrice Bellard <fabrice@bellard.org>
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Subject: [Qemu-devel] Flash devices
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To: qemu-devel@nongnu.org

Schwarz, Konrad wrote:
>>Date: Tue, 18 Apr 2006 21:54:42 +0200
>>From: Stefan Weil <weil@mail.berlios.de>
>>Subject: [Qemu-devel] Flash simulation
>>To: qemu-devel@nongnu.org
>>Message-ID: <44454402.7030404@mail.berlios.de>
>>Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>
>>A typical embedded system (and also most standard PCs) 
>>contains flash memory. Full system emulation should also 
>>emulate flash behaviour - not only read accesses but also 
>>flash type discovery and flash programming.
>>
>>Is there an easy way to realise flash memory emulation with 
>>Qemu? Must I write this emulation from scratch?
>>Hints how this might be done are welcome.
> 
> 
> The QEMU memory interface is capable of supporting Flash emulation.
> As far as I know, no ready solutions exist, so you need to do this from
> scratch.
> 
> The data sheet of the Flash device you want to emulate documents the
> commands the
> device understands.  You need to implement the finite state machine
> which interprets those commands.
> 
> A high-fidelity emulation will also simulate Flash erase and programming
> times.

There is already an implementation of a flash device made by Jocelyn 
Mayer but I have not merged it yet because it needs an architectural 
change in QEMU concerning memory mapped I/Os. I'll try to make this 
change ASAP.

Fabrice.