Downloading UML Source

Before you can build UML from source, you need some sources to build. UML is in the mainline 2.6 kernel tree. The process of releasing patches to mainline is done so as to make the main releases as stable and as functional as possible. Patches are considered ready to submit from my development tree to mainline when they have been sufficiently tested. For an obvious bug fix, this can involve just booting and running a UML with the patch. Other, more intrusive patches have stayed for many months in my development tree before being sent to mainline.

So, one of the main 2.6 kernel releases, normally the later the better, is a good place to start for UML. The "stable" kernel tree maintained by Greg Kroah-Hartman and Chris Wright is another good choice. This tree is the same as the corresponding release from Linus, except for a few additional small, critical bug fixes. There normally aren't any additional UML bug fixes in this tree, so it is usually identical to the release from Linus as far as UML is concerned. Occasionally, there is a UML fix here, which will be clear from the change log, and then this would be the recommended kernel tree to start with.

Both of these kernel trees are available from http://www.kernel.org and its mirrorsthe stable tree is actually more accessible than Linus' releases. When there is a stable version of the latest kernel, it is available from the main page of http://www.kernel.org, while in order to get the corresponding Linus release, you need to go digging. Successful digging will produce the directory http://www.kernel.org/pub/linux/kernel/v2.6, where you will find all of Linus' kernels.

Whichever tree you decide to use, it is one download away:

host% wget http://kernel.org/pub/linux/kernel/v2.6/\    linux-2.6.12.5.tar.bz2 --22:49:05-- http://kernel.org/pub/linux/kernel/v2.6/\    linux-2.6.12.5.tar.bz2            => `linux-2.6.12.5.tar.bz2'    Resolving kernel.org... 204.152.191.37, 204.152.191.5    Connecting to kernel.org[204.152.191.37]:80... connected.    HTTP request sent, awaiting response... 200 OK    Length: 37,398,284 [application/x-bzip2]    100%[====================================>] 37,398,284 \       471.35K/s ETA 00:00    22:50:08 (580.21 KB/s) - `linux-2.6.12.5.tar.bz2' saved \       [37,398,284/37,398,284]

This is a compressed tar file, so it needs to be uncompressed and unpacked:

host% bunzip2 linux-2.6.12.5.tar.bz2 host% tar xf linux-2.6.12.5.tar

At this point, we have a linux-2.6.12.5 subdirectory in which there is a kernel tree.

host% cd linux-2.6.12.5 host% ls COPYING        MAINTAINERS REPORTING-BUGS drivers init   \   lib  scripts   usr CREDITS        Makefile    arch           fs      ipc    \   mm   security Documentation  README      crypto         include kernel \   net  sound

Now the UML tree is ready to be configured and built.