qemu: generating ext3 images including activities

[Erik Garrison]

I am trying to generate an image usable in Qemu for use by the Peru team
in the production of a series of videos about the XO.

I am generating this image because the existing ones are out of date
with respect to the current Peru deployment's software, and they have
requested if it would be possible to create a new image.  It would be
sufficient to use an existing ext3 image [1] but I wanted to drop the
customization key activities which Peru has into the image.

Just mounting and doing this was not sufficient, as the image file
lacked free space for all the needed activities, so I had to first build
a new, larger sparse image file, which I did using this script (hacked
out of pilgrim) [2].

Then I mounted the sparse and existent image files via loopback devices
and copied the directory tree over, and then unzipped the activity
bundles I wanted into the new image file.

Currently I am stuck because I do not know how to write grub to an image
file.  Here is what happens when I try to write the bootloader [3] on a
loopback (produced via losetup /dev/loop0 os.img).

Any ideas?  Someone out there constructed the qemu-bootable ext3 image
in the past.  Would you please step forward and advise?

Best,
Erik


[1] http://download.laptop.org/xo-1/os/official/708/ext3/xo-1-olpc-stream-update.1-build-708-20080604_1540-devel_ext3.img.bz2
[2] http://dev.laptop.org/~erik/code/make_ext3_image_file
[3] http://pastebin.com/f7dc65ff9