Emulating the XO
Simulating an XO
Emulators allow you to run a "virtual machine" on a (reasonably powerful) host machine. There are a number of emulator systems available which can be used to run a simulated OLPC-XO. The three listed here provide either Open Source or Gratis players to run images:
- VirtualBox
- VMWare
- Qemu (with or without kqemu)
As of official build 557, VirtualBox and VMWare are both able to load converted images with networking support. VirtualBox also provides sound support. At the moment, these converted images are the recommended practise for simulating an XO, both for testing out the environment and developing activities.
As of the same date, Qemu is able to run the official images, but networking must be restarted (/etc/init.d/network restart) from the developer's console to have any networking support. Sound doesn't yet appear to be working.
Simulating a Developer's Desktop
Most core developers use Fedora 7 or Ubuntu Feisty desktops which are running sugar-jhbuild to track the latest developments in the code-base. This allows you to integrate into the core development process, but can be a considerable maintenance headache due to the fragile nature of the build process.
You can readily run a simulated Fedora/Ubuntu desktop in VMWare. This setup is not substantially different from running a regular Linux desktop using sugar-jhbuild.
Note: This approach is really only recommended for those who want to work on core components of the environment, activity developers are probably better off using an official image.
Note: Previously we have attempted to provide LiveCD and Developer Images for download. Manpower issues have meant that these images have fallen far behind the official images, thus they are no longer a recommended approach for developers.
Qemu
(We should move this tool-specific instruction stuff over to the Qemu page, likely).
Install QEMU and kernel acceleration as described in Emulating the XO/Quick Start. See the /Help_and_tips "Development" section.
505 is the most recent build known to work. Builds after 541 run, but collaboration is broken (you can't see other laptops).
Many builds between 541 and 505, including 531, 529, and 525, didn't boot. However, some of the later 50x may work.
- Actually build 542, the Trial 2 build, introduced a "feature": the configuration is no longer hardcoded to use the server olpc.collabora.co.uk, and has no server prepopulated. You can set the server yourself by editing ~olpc/.sugar/default/config and setting server = olpc.collabora.co.uk and restarting. This should mean that 542 is the preferred image for developing with, since 505 and other 50x are quite old. --morgs 03:54, 21 August 2007 (EDT)
- I've added seting the server to the instructions below. Thanks! :) But for now, we're still stuck at 505, because the workaround for #1977 stopped working. MitchellNCharity 23:25, 22 August 2007 (EDT)
- #1977 is now marked fixed. Hopefully once #2981 is fixed, emulation of current builds will again work. MitchellNCharity 10:33, 24 August 2007 (EDT)
Overview
One way to run oplc software is using an emulator on your pc. See Getting started programming for other options.
Note Category:Emulation and Help and tips.
For play, you can use LiveCd or Quick Start.
For development, you can use LiveCd, or qemu (as in quick start, but with a different image), or perhaps one of the Developer Images other than the LiveCd. An alternate approach is to attempt installing sugar. See Getting started programming for a comparison.
A common development approach is to use QEMU with kqemu acceleration. See Quick Start for the basics. Though for development, we will use a different .img, one with a few extra utility programs. See OS images, including latest stable build.
Instead of qemu, you can run VMware, and there are additional options on a Mac.
Please report your experiences in User Feedback on Images. There is a Virtualization Common Room.
There are limitations with XO disk images.
The LATEST-STABLE-BUILD versus LATEST build distinction is mostly of interest to people running on actual XO's. In emulation, developers should usually use LATEST. And when STABLE is old, non-developers probably should too.
Comparison of alternatives
An OLPC laptop is custom hardware, running a stripped-down Red Hat linux, running Sugar. But what if you don't have a real olpc laptop? There are a several options, which can each be used in a couple of ways.
recommendations
| platform | purpose | recommendation |
|---|---|---|
| Windows | development | emulated xo disk image; or emulated Ubuntu with sugar-jhbuild; (or develoepr CD or LiveCD)?. (need your reports) |
| Mac | development | emulated xo disk image; or emulated Ubuntu with sugar-jhbuild; (or developer CD or LiveCD)?. (need your reports) |
| Mac with Parallels | development | install Ubuntu 32-bit, and Sugar on Ubuntu Linux. See /Mac. |
| Ubuntu 32-bit | development | Sugar with sugar-jhbuild and Sugar on Ubuntu Linux |
| 32-bit linux | development | Sugar with sugar-jhbuild |
| 64-bit linux | development | xo disk images under qemu; or LiveCd once it gets updated (currently it's April) |
- I don't really believe the development option of Windows/Mac developer/live CD. I've not yet heard of it actually being used. They are months out of date (April). But Mcfletch said (in May) it's an option, so I added it. MitchellNCharity 09:19, 23 June 2007 (EDT)
Mcfletch It's probably no longer an option, Red Hat seems to have stopped releasing them. Even the developer's CDs are getting too old to be usable.
background
| option | updated | sound? | camera? | library? | etoys? | R/W? | development software? | net? | comments |
|---|---|---|---|---|---|---|---|---|---|
| Installing Sugar | continuous | yes | yes? | yes? | yes | yes | your own | yes | On some platforms, it takes time and space (hours and ~3GB), but "just works". On others, it is quite difficult to install. |
| Installing Sugar, on a virtual 32-bit Ubuntu, running in an emulator (qemu, parallels, or vmware) | |||||||||
| LiveCd | April | yes(boot) yes?(qemu) | yes?(boot) no(qemu) | no | yes | no | toolchain, Gnome | yes? | Alternative Quick Start. Can both be booted from, and used in qemu. Problems: A. |
| XO disk images: | |||||||||
| LATEST-STABLE-BUILD http://olpc.download.redhat.com/olpc/streams/development/LATEST-STABLE-BUILD/ | |||||||||
| ...development-ext3.img | ~monthly | yes/B | no | yes | yes | yes | no | after config | Quick Start for getting a look at Sugar. |
| ...development-devel_ext3.img | ~monthly | yes/B | no | no | yes | yes | a little | after config | |
| LATEST http://olpc.download.redhat.com/olpc/streams/development/LATEST/ | |||||||||
| ...development-ext3.img | ~daily | yes/B | no | yes | yes | yes | no | after config | |
| ...development-devel_ext3.img | ~daily | yes/B | no | no | yes | yes | a little | after config | Good for new developers (requires some command-line comfort). |
| OTHER | |||||||||
| FC6+Sugar | April | yes? | ? | ? | no | yes | Full Fedora Softare Dev. | yes | 6GB (April version: no etoys) |
Key:
- library: A library of sample content is included (english version). Ie, pretty text to web browse without having to get network.
- R/W (writable): With an .img, you can save things between sessions. With a .iso, your environment is the same each time you start.
- development software: are development tools included?
- Net (network): does the network "just work" or "manual" steps are required?
Problems:
- A: LiveCd (April) on fc6 x86_64, kernel panics under kqemu. A squashfs problem.
- B: Tam Tam is silent (though EToys makes noise). Cause unknown.
Notes:
- re "does sugar-jhbuild support camera/mic?": "yes, if the camera uses v4l2 and 640x480, I'd suspect so." Can someone confirm this? (#olpc, now) MitchellNCharity 00:16, 2 June 2007 (EDT)
Doables:
- Remove LiveCd's "?" above.
- Find out what's going on with Tam Tam sound. It would be nice for the xo disk images to all be sound-yes.
- Add a microphone column? Reconsolidate sound/camera/mic into a H/W column?
Example step-by-step instructions
Here, in one place, are assembled all the steps to get you to a working emulated XO. Assuming you are running on linux, and have already installed qemu and kqemu.
The following will not work on your virtual xo: sound, camera. The first because no one has gotten around to figuring out why it isn't working[1]. The second because qemu doesn't yet support them.
Go to http://olpc.download.redhat.com/olpc/streams/development/LATEST/devel_ext3/ and obtain the numbered -devel_ext3.img.bz2 and its md5. For this example I used build 485.
md5sum -c olpc-redhat-stream-development-build-485-20070703_0249-devel_ext3.img.bz2.md5 bzcat olpc-redhat-stream-development-build-485-20070703_0249-devel_ext3.img.bz2 > xo-485a.img
The resulting file is 1 GB.
export PORT=2221 qemu-system-x86_64 -soundhw es1370 -serial `tty` -kernel-kqemu -redir tcp:$PORT::22 -hda xo-485a.img
Unless you have a x86_64 cpu, use qemu instead of qemu-system-x86_64.
The screen will very briefly be black, and then show the blue "GNU GRUB" screen. If it stays black, that's a qemu bug. Kill qemu and try again.
The boot messages will scroll by, and you should eventually see the normal XO first-time login. We'll save that for later.
In the window where you started qemu, you should now see a login: prompt.
- Enter root
- Then:
/etc/rc5.d/S98NetworkManager stop
mv /etc/rc3.d/S98NetworkManager /etc/rc3.d/DISABLED-S98NetworkManager
mv /etc/rc5.d/S98NetworkManager /etc/rc5.d/DISABLED-S98NetworkManager
echo ifup eth0 >> /etc/rc.local
cp -p /home/olpc/.sugar/default/config /home/olpc/.sugar/default/config.old
gawk '/^server/ {print "server = olpc.collabora.co.uk"} !/^server/ {print}' /home/olpc/.sugar/default/config.old > /home/olpc/.sugar/default/config
ifup eth0
killall X
Killing X should restart sugar.
If you want to enter a name with diacritics, you need to wait for X to restart, and then do:
su olpc -c"DISPLAY=:0 xmodmap -e 'keycode 77 = Multi_key'"
This sets up Num_lock as Multi_key. Unfortunately, the next time X is restarted, you will lose it. A better solution is needed.
At this point you could just proceed to use your new XO. However, the screen resolution is wrong (1024x768). So for development, or to get a more accurate feel for how things really look, some extra steps are required.
Once you reach the main sugar screen, you should check the Neighborhood view (F1). If you can't see other people, either the we are having problems with the presence server, you are behind an unusually picky firewall, or networking on qemu is broken again in the build number you are using. (Remember that ping doesn't work inside of qemu).
While this next step is not strictly required, it will enable you to use ssh and scp, which can be handy to move stuff back and forth between your host and xo.
Still as root on the xo,
1. Change the root password.
passwd
Don't worry if it says something like "BAD PASSWORD: ", and complains about the password you picked. It will still work.
2. Change the olpc password.
passwd olpc
Now you can use ssh and scp.
The current released version of QEMU doesn't support 1200x900, so we use a Xephyr remote X server. Each time you boot the xo, if you want 1200x900, you'll need to do these next steps again, except for the ones marked "(First time only)".
1. Still as root on the xo:
init 3 sleep 5 ifup eth0 su olpc grep export /usr/bin/sugar > ~/env source ~/env
If the ifup eth0 fails with an "already running" message, that's ok. Perhaps it is no longer needed.
2. Back on the host, prepare Xephyr (First time only)
mcookie > xephyr-cookie export COOKIE=`cat xephyr-cookie` rm -f xephyr-xauth; echo "add :1 . $COOKIE" | xauth -f xephyr-xauth echo $COOKIE
3. On the xo, still as "su olpc", record the cookie: (First time only)
echo "add 10.0.2.2:1 . " PUT-THE-COOKIE-HERE | xauth
4. Back on the host, start a Xephyr:
Xephyr :1 -auth xephyr-xauth -reset -screen 1200x900x16 -dpi 200
You will probably want to do this in its own window, as it periodically dies and needs to be restarted.
5. On the xo, still as "su olpc", start sugar:
DISPLAY=10.0.2.2:1 sugar
Actually, I usually ssh in from the host, and run sugar that way:
a. On the host,
ssh -o NoHostAuthenticationForLocalhost=yes -p 2222 olpc@localhost
b. in the resulting shell,
source ~/env export DISPLAY=10.0.2.2:1 sugar
You may also want to run
xmodmap -e 'keycode 77 = Multi_key'
to be able to enter diacritics with the Num_lock key. But I find doing it first thing tends to kill Xephyr. :(
You should now see the XO first-login screen in correct resolution. You can use Num_lock to enter diacritics. Congratulations. Sorry it was so much bother.
To run multiple xo's (to play with collaboration, for instance), you
can repeat the above steps. Create a xo-485b.img, and use a different
PORT number (like 2222). If you are using Xephyr, start a second
Xephyr, which will be 10.0.2.2:2, use that instead of ...:1 in
the instructions. You should now be able to see yourself, and
collaborate in Write.
The following will save you having to periodically type your xo password, but is optional, and can just as easily be done later.
Back on the host,
1. Create an ssh key if you don't already have one. See /Help_and_tips#SSH into qemu, using a key.
2. Copy it to the xo,
scp -o NoHostAuthenticationForLocalhost=yes -P $PORT ~/.ssh/id_rsa.pub root@localhost:~/
3. On the xo, as root, spread the key around:
mkdir ~root/.ssh mkdir ~olpc/.ssh cat ~root/id_rsa.pub >> ~root/.ssh/authorized_keys cat ~root/id_rsa.pub >> ~olpc/.ssh/authorized_keys
You can now ssh and scp without retyping your password.
Links
- Tutorial Written by IBM on how to get this working.