Re: [Qemu-devel] Flash devices

[Stefan Weil <weil@mail.berlios.de>]

Fabrice Bellard schrieb:

> 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
>>>
>>> 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.
>
Hello Fabrice,

I noticed the new code in QEMU HEAD and tried to use it, but my flash 
memory still behaves like
ordinary RAM even on write access.

Do you have a working example which uses the new flash driver or some 
hints which might help?

Thank you
Stefan