qemu (tummy.com, ltd. Journal Entry)
tummy.com: we do linux

Tuesday January 04, 2005 at 21:27
Subject: qemu
Keywords: Emulator, Tech, Testing
Posted by: Kevin Fenzi

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I have been working on putting together a Morphix based live cd/distro recently. I found that instead of burning lots of cd's for testing changes, there is a VERY handy emulator out there called qemu. Here's some handy information on it:

If you are running a Fedora based system, you can grab a qemu rpm from the DAG rpm repository , HERE.

Once you install the pretty tiny rpm, you are ready for some testing.

You can run qemu with various flags (see 'man qemu' for the list), but the handy ones in testing are:

  • qemu -cdrom (cdrom-bootable-image-file.iso)
  • qemu -fda (bootable floppy image.img)

Basically what those do is pop up a window and boot an emulator and show you just what it would look like if you had burned the cd, or written the floppy and booted it on your handy pc. Networking is supported, as are mouse/video, etc. It's pretty fast too. You can see in a few seconds if the boot image you just added looks right, or if the cdrom boots the morphix module you just added to it.

You can also add '-monitor stdio' and get a qemu console in the terminal you started it from. This is very handy for doing things like sending a 'control-alt-f1' to the linux instance. In the case of morphix you can then see whats on the virtual console after X has started.

I have used qemu with morphix cd's, morphix cd's boot.img floppy boot files, knoppix cd's, fedora cd's. They all seem to boot just fine and come up fast and nifty. Qemu is definitely going to be a tool I use a lot now.
(Post Reply)

Comment
Joe VanAndel
Subject: instructions for building bootable Linux CDs
Qemu sounds very useful. Where can I find instructions on how to build my own bootable Linux CD with custom utilities on it? For example, I might want to build a bootable CD with 'kdar' on it, for restoring my system after a crash.
Comment
Author: Sean Reifschneider
Subject: Use Morphix?
Kevin just gave a presentation to the Boulder LUG about using Morphix to build custom bootable/live CDs. His presentation can be found at http://www.tummy.com/Community/Presentations/, if you just want to look at the slides. Morphix has fairly complete documentation, though sometimes it's hard to find exactly the pieces you need to get the build environment working as you'd like. The Morphix site should be able to get you started though. If you just want a live CD with a particular package on it, it's real easy to do with Morphix. Just drop the appropriate Debian package into the appropriate directory on the CD image and burn it.

Sean