Re: [Qemu-devel] Simtec BAST emulation

[Daniel Silverstone]

On Tue, 2007-04-03 at 01:04 +0200, andrzej zaborowski wrote:
> We have also implemented emulation of the S3C2410x SoC. I hope we can
> merge both implementations to come up with better emulation. Our tree
> is accessible at http://svn.openmoko.org/trunk/src/host/qemu-neo1973/
> and our main target machine is the FIC Neo1973 which you mention
> above. The tree is still heavily a work-in-progress but the processor
> part (S3C2410 with on-chip preripherals) is quite mature.

Perhaps we should work together to get your processor core merged into
QEMU proper? I could work on patching our BAST stuff against your core
and then together we could look at getting it merged.

> All of the on-chip peripherals described in the S3C2410A User Manual
> rev 1.0 except the Watchdog timer and USB Slave are emulated with high
> level of detail. The OHCI USB uses the same routine as the PXA2xx
> emulator.

That sounds excellent. Far further than we had gotten thus-far.

> Things that are tested to work:
> OpenMoko firmware from the real device boots as a NAND Flash image.

Cool. Is the NAND format with, or without OOB?

> The OpenMoko rootfs can also be booted off the emulated SD card. We
> use the u-boot and kernel images from the original device. Input is
> through GPIO buttons or touchscreen connected to the on-chip ADC,
> output through on-chip UARTs and LCD. Audio through a codec connected
> to on-chip I2C and I2S busses.

Out of interest, which codec is it?

> There is also an SPI-connected
> peripheral (can be driven either through the on-chip SPI interface or
> GPIO bit-banging).

*nod*

> S3C2410 idle mode is supported.

Aha, this is wonderful news.

> There's no save/restore support.

Hmm, perhaps we could work on that together.

> Apparently there's some code duplication, which is sad but I hope we
> can get both machines (BAST and Neo1973) to use common code. Briefly
> looking at your patch, the openmoko tree seems to have a more
> complete/specs-conformant S3C2410 part.

Yes, our S3C2410 part was only as far as we needed to get Linux and ABLE
booting on the emulator. Yours is much more mature and really deserves
to be merged once we can get a system emulation in place which you're
happy to offer for merging.

I assume you too have noticed that the longer you leave it before
offering patches for merging, the scarier the diff becomes.

I will take a look at your tree and at how hard it will be to merge the
Simtec board emulation into it.

Thanks,

Daniel.

-- 
Daniel Silverstone                              http://www.simtec.co.uk/
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