Download and unpack UML and a root filesystem, from here or from the UML project page. UML lives in an executable named 'linux' - type this to run it in debug mode:
/path/to/linux ubd0=/path/to/root_fs debug
It takes a minute to start up, and it may hang on some of the boot prompts. Be patient, and if it's really taking a long time try doing a ^C on the main UML window to skip the current startup item. If you still have problems, experiement with different root_fs's from the UML homepage. Eventually a gdb session should automatically start in one of the terminals, stopped at start_kernel.
Alternatively, rename your root_fs* to just root_fs, and run the UML executable from the directory you put root_fs in. The ubd0= thing is to tell UML where it should find the root_fs when its not in the current directory.
NOTE: UML likes to run under X windows, because it pops up two xterms that are connected to UML. There are also ways to connect consoles to UML - see the homepage for details.
| linux.bz2 | |
| uml 2.4.3, compiled with debugging support. | |
| root_fs_debian2.2_small.bz2 | |
| A root filesystem that worked with my UML. Unfortunately, it doesn't include any developement tools - you'll have to compile things under your normal system, and then run them under UML. | |
| User Mode Linux Homepage | |
| The excellent UML project webpage, with a HOWTO and sample debugging sessions. | |