1. Build the Kernel# wget http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.39.tar.gz # bunzip2 linux-2.6.39.tar.gz Build the Kernel # make ARCH=um defconfig # make ARCH=um
2. Download Root-fs filesystem for Debian # wget http://fs.devloop.org.uk/filesystems/Debian-Squeeze/Debian-Squeeze-AMD64-root_fs.bz2 # bunzip2 Debian-Squeeze-AMD64-root_fs.bz2
3. Run it!!! Voila!! # ./vmlinux ubda=/root/Debian-Squeeze-AMD64-root_fs mem=128m umid=debian Core dump limits : soft - 0 hard - NONE Checking that ptrace can change system call numbers...OK Checking syscall emulation patch for ptrace...OK Checking advanced syscall emulation patch for ptrace...OK Checking for tmpfs mount on /dev/shm...OK Checking PROT_EXEC mmap in /dev/shm/...OK Checking for the skas3 patch in the host: - /proc/mm...not found: No such file or directory - PTRACE_FAULTINFO...not found - PTRACE_LDT...not found UML running in SKAS0 mode Adding 5627904 bytes to physical memory to account for exec-shield gap Linux version 2.6.39 (root@instructor.example.com) (gcc version 4.4.6 20120305 (Red Hat 4.4.6-4) (GCC) ) #1 Wed Jan 30 11:49:25 PST 2013 Built 1 zonelists in Zone order, mobility grouping on. Total pages: 33675 Kernel command line: ubda=/root/Debian-Squeeze-AMD64-root_fs mem=128m root=98:0 PID hash table entries: 1024 (order: 1, 8192 bytes) Dentry cache hash table entries: 32768 (order: 6, 262144 bytes) Inode-cache hash table entries: 16384 (order: 5, 131072 bytes) Memory: 123904k available NR_IRQS:15 Calibrating delay loop... 525.92 BogoMIPS (lpj=2629632) pid_max: default: 32768 minimum: 301 Mount-cache hash table entries: 256 Checking that host ptys support output SIGIO...Yes Checking that host ptys support SIGIO on close...No, enabling workaround Using 2.6 host AIO NET: Registered protocol family 16 bio: create slabat 0 Switching to clocksource itimer NET: Registered protocol family 2 IP route cache hash table entries: 2048 (order: 2, 16384 bytes) TCP established hash table entries: 8192 (order: 5, 131072 bytes) TCP bind hash table entries: 8192 (order: 4, 65536 bytes) TCP: Hash tables configured (established 8192 bind 8192) TCP reno registered UDP hash table entries: 128 (order: 0, 4096 bytes) UDP-Lite hash table entries: 128 (order: 0, 4096 bytes) NET: Registered protocol family 1 mconsole (version 2) initialized on /root/.uml/debian/mconsole Checking host MADV_REMOVE support...OK VFS: Disk quotas dquot_6.5.2 Dquot-cache hash table entries: 512 (order 0, 4096 bytes) msgmni has been set to 242 io scheduler noop registered io scheduler deadline registered io scheduler cfq registered (default) TCP cubic registered NET: Registered protocol family 17 Initialized stdio console driver Console initialized on /dev/tty0 console [tty0] enabled Initializing software serial port version 1 console [mc-1] enabled ubda: detected capacity change from 0 to 1073741824 ubda: unknown partition table Switched to NOHz mode on CPU #0 EXT3-fs: barriers not enabled kjournald starting. Commit interval 5 seconds EXT3-fs (ubda): mounted filesystem with ordered data mode VFS: Mounted root (ext3 filesystem) readonly on device 98:0. modprobe: FATAL: Could not load /lib/modules/2.6.39/modules.dep: No such file or directory INIT: version 2.88 booting Using makefile-style concurrent boot in runlevel S. .udev/ already exists on the static /dev! ... (warning). Starting the hotplug events dispatcher: udevd. Synthesizing the initial hotplug events...udevd-work[272]: kernel-provided name 'hw_random' and NAME= 'hwrng' disagree, please use SYMLINK+= or change the kernel to provide the proper name done. Waiting for /dev to be fully populated...done. hostname: the specified hostname is invalid Activating swap...done. EXT3-fs (ubda): using internal journal Cleaning up ifupdown.... Setting up networking.... Loading kernel modules...done. Activating lvm and md swap...done. Checking file systems...fsck from util-linux-ng 2.17.2 done. Mounting local filesystems...failed. Activating swapfile swap...done. Cleaning up temporary files.... Configuring network interfaces...Internet Systems Consortium DHCP Client 4.1.1-P1 Copyright 2004-2010 Internet Systems Consortium. All rights reserved. For info, please visit https://www.isc.org/software/dhcp/ modprobe: FATAL: Could not load /lib/modules/2.6.39/modules.dep: No such file or directory modprobe: FATAL: Could not load /lib/modules/2.6.39/modules.dep: No such file or directory SIOCSIFADDR: No such device modprobe: FATAL: Could not load /lib/modules/2.6.39/modules.dep: No such file or directory modprobe: FATAL: Could not load /lib/modules/2.6.39/modules.dep: No such file or directory eth0: ERROR while getting interface flags: No such device modprobe: FATAL: Could not load /lib/modules/2.6.39/modules.dep: No such file or directory modprobe: FATAL: Could not load /lib/modules/2.6.39/modules.dep: No such file or directory eth0: ERROR while getting interface flags: No such device Bind socket to interface: No such device Failed to bring up eth0. done. Cleaning up temporary files.... Setting kernel variables ...done. startpar: service(s) returned failure: hostname.sh ... failed! INIT: Entering runlevel: 2 Using makefile-style concurrent boot in runlevel 2. Starting enhanced syslogd: rsyslogd. Starting periodic command scheduler: cron. Serial line 0 assigned device '/dev/pts/0' Debian GNU/Linux 6.0 (none) tty0 (none) login: root Last login: Wed Jan 30 19:57:33 UTC 2013 on tty0 Linux (none) 2.6.39 #1 Wed Jan 30 11:49:25 PST 2013 x86_64 The programs included with the Debian GNU/Linux system are free software; the exact distribution terms for each program are described in the individual files in /usr/share/doc/*/copyright. Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent permitted by applicable law. root@(none):~# whoami root
