Autarchy of the Private Cave

Topologilinux ‘BSOD at launch’ problem solution is at the end of this post.

Topologilinux is a special linux flavour, which is especially fit for the newcomers to the *nix world. The motto of Topologilunux is ‘Running Linux inside Windows’ – and that is what it does. Even more – you can run it inside windows, or you can boot into it and work Linux-only – in both cases the system is the same.
Personally, I consider this kind of setup extremely useful for users who are strongly used to working in Windows (or just stuck with windows for too long), but at the same time are inclined to script a bit (be it bash, Perl, PHP or Python), to run server applications, write cross-platform programs, to test something or just play with software. With Topologilunux, it’s perfectly fine to work in DreamWeaver on your windows machine, and launch Topologilinux with apache+php+mysql to serve as a testing server – on that same machine. You can easily replicate the needed server config, and play with it the way you wouldn’t if that was the production server.

Or, in another scenario, you may launch Topologilinux to write the script you need for your data (for example, Bioconductor package for R statistics environment has many packages available only for *nix systems) without leaving your nearly perfectly set up windows environment; then, when you need to run that CPU-intensive you wrote, you can boot into real-mode Topologilunux, run your analysis, and get back to Windows

All of this is available without the need to re-partition your hard drive – Topologilinux fits into a single image file on your FAT32/NTFS drive of choice. Both installation and removal are very simple (common click-through), with a bit more effort in the networking part (sufficient documentation is available, if not with Topologilinux, then with coLinux).

The only problem I had with Topologilinux was BSOD (Blue Screen Of Death) every time I tried to launch Topologilinux from within Windows. The error was DRIVER_IRQL_NOT_LESS_OR_EQUAL. Searching for troubleshooting required some time and was not evident, so here is what fixed my problem.

The conflict seems to arise from the Data Execution Prevention (DEP) feature of the modern computers, which is intended to protect from the various ‘buffer overrun’-based exploits and hacks. By default, it is enabled for system files and services (equal to /noexecute=optin option in boot.ini). I tried setting it to ‘All files, except chosen below’, then adding colinux-daemon to exceptions, but that didn’t help either. The only option which helped was disabling DEP from boot.ini by adding ‘/noexecute=alwaysoff’ after the line identifying your Windows installation.

Here is a sample line from my boot.ini before modification:

multi(0)disk(0)rdisk(0)partition(1)\WINDOWS=”WinXP Pro” /fastdetect

and after modification:

multi(0)disk(0)rdisk(0)partition(1)\WINDOWS=”WinXP Pro (DEP off)” /noexecute=alwaysoff /fastdetect

Hope this helps you.

Update: since I’ve moved to Debian, I’m no longer using Topologilinux.