Re: [Qemu-devel] Re: [4215] Nokia N800 machine support (ARM).

[andrzej zaborowski]

Hi,

On 18/04/2008, Anderson Lizardo <address@hidden> wrote:
> On Thu, Apr 17, 2008 at 7:03 PM, andrzej zaborowski <address@hidden> wrote:
>  >  The firmware kernel is very quiet, so if it's unable to mount the
>  >  initfs, it'll hang at the blank screen.  A kernel built from sources
>  >  will dump logs on the third serial port.  To boot Linux you'll need to
>  >  provide the kernel and a flash image with at least two of the five
>  >  partitions present on it.  The flash is supplied with "-mtdblock
>  >  filename" and the file should be of 276824064 bytes (256 MB of data +
>  >  OOB data at the end).  You'll need to have the initfs and the rootfs
>  >  present in this image, and for Maemo also the "config" partition (not
>  >  my fault). Poky (pokylinux.org) boots fine with just the stock initfs
>  >  + Poky rootfs.
>
> A nice feature would be to allow the host to communicate with nolo
>  running inside qemu (e.g. through a TCP server or something), then
>  modify the free 0xFFFF flasher (http://nopcode.org/0xFFFF/) to be able
>  to communicate with this server. In practice, this would allow to
>  "flash" the emulated device like we do for the real hardware.

That should be possible, I think the easiest communication channel
would be serial - I didn't find the "cold-flashing" over serial option
in 0xFFFF but it can be added. However several things in 0xFFFF are
outdated since 770 (I'm using version 0.3.2), so it may take a bit of
work.

You can also boot-up a small rootfs that contains the images to flash,
and use "nandwrite" from mtd-utils to write the images like on the
real heardware.

Another possibility I found is using NOLO console interface.  I don't
know if there is a way to access this console on the real hardware,
but in Qemu you can type commands into NOLO on the serial port and it
even has help messages and stuff, and also allows you to flash an
image from RAM like U-boot. Judging from no google hits for any of the
NOLO commands, I think it may be only possible in qemu :)

Flashing the emulated device like the real hardware would still assume
that the config partition is already present in flash and stays there
though.  In addition to the config partition Nokia stores some
information about the unit in the OneNAND's One-Time-Programmable
area, fortunately this is not critical for booting Maemo.

I uploaded at http://folks.o-hand.com/andrew/qemu-n800/ a tiny script
that creates an empty mtdblock image for qemu and can also write the
jffs2 / config partitions from images.  It can use dd (very fast) or
it can use qemu to boot up the zImage which contains nandwrite in an
initramfs, and will read the images to flash from an SD generated by
the script (this is slower but independent of the file format used by
qemu).

Regards
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