logIt » virtualization

That Handy Tap Interface on Mac OSX

Arif — Fri, 04 Jan 2013 09:04:46 +0000

Ubuntu has been my desktop for some years. I’ve become so attached in a way that I no longer know how to work without. Then of course, the pain of moving to Mac is one foreseeable future. Unlike my usual repository where everything is on the table and for free, this one is a little tougher to handle. Well, if I were to cut to the chase, tap interface for instance, was nowhere near to be found. My VirtualBox depends a lot on these virtual networks as I’m used to try things out.

..you’ll always have love-hate relationship with the tools you work with.. blindly turning yourself into devoted-fanatic is another thing..

Enough bragging (let’s spare that). First we need to have /dev/tap0, /dev/tap1, etc., available using TunTap kernel extension.

I modify the small script from this post to have it available on background instead of keeping a shell open all the time:

I saved it as /usr/local/bin/setup-tap1.py

#!/usr/bin/python
 
import os
while 1:
	try:
		file_path = '/dev/tap1'
		dev_file = os.open(file_path, os.O_RDWR)
		interface = 'tap1'
		while 1:
			pass
	except:
		print "tap interface is closing"
		exit()
		break

Let the shell takes care of putting it to background (daemon):

[root]$ /usr/local/bin/setup-tap1.py &

and there you have one working tap interface:

VirtualBox tap interface in Mac OSX Lion 10.7

[Moving-in would probably be easier if I started life with FreeBSD. More posts to come]

Ubuntu ARM on QEMU Processor Emulator

Arif — Sun, 27 Nov 2011 04:14:55 +0000

There are times when you need to try things on virtualized environment before hand e.g. 1) checking application functionality or 2) actual device shipment is still on its long way. Those were also my cases with ARM Linux. Unlike virtualization in production environment however, putting software to emulate CPU architecture will slow down the guest machine a lot.

Ready-to-use image for from the old Ubuntu 9.10 Karmic is avalaible as suggested in RootStock Wiki .

To run Ubuntu 10,04 Lucid you can create similar .img filled by RootStock generated root file system as described in this post generating lucid-arm.img. Boot image is obtained from Lucid port page, of which I saved with the name vmlinuz-lucid-current-ports which is actually linux kernel 2.6.32-21. Running QEMU is then:

qemu-system-arm -M versatilepb -cpu cortex-a8 \
  -kernel vmlinuz-lucid-current-ports \
  -hda lucid-arm.img -m 256 -append "root=/dev/sda mem=256M devtmpfs.mount=0 rw"

However, adding -redir tcp:3232::22 isn’t directly working (although telnet is showing both directions are functional). This redirection is working with the Karmic image which gives instant ssh on my host laptop as in:

ssh localhost -oPort=3232 -l ubuntu

Note: successful QEMU machine image probably won’t boot successfully with the real board. I can’t use kernel 2.6.38-10 for Lucid rootfs on QEMU, but successfully boot that on DevKit8500D board.

QEMU console of Ubuntu 10.04 VM