new dev vm for debian and raspbian

[plugwash]

Note: crossposting this in both debian and raspbian forums as it's relavent to both groups.

I've just put together a new virtualbox dev vm for debian and raspbian.

This vm uses qemu in "user" mode, this is far more efficient than using qemu in "system" mode as it avoids emulating the hardware kernel and drivers.

The vm is configured with 1 gigabyte of ram but I would reccomend increasing this if you have lots of ram. The kernel supports PAE so it should have no problem with large ammounts of ram..

There are three chroots, /chroots/squeeze-armel /chroots/wheezy-armel and /chroots/wheezy-raspbian, /proc and /dev/pts are mounted in all chroots, build-essential and debhelper are installed, a policy-rc.d is in place and locales are configured sensiblly.

to login use username: root password: root

The host system is ubuntu precise and was chosen because it's a LTS release and it ships with a nice modern qemu (unlike debian squeeze which is getting rather long in the tooth).

http://archive.raspbian.org/qemu/rpi-qe ... ev.tar.bz2

Does this mean that we can build any packages on this VM and they will be identical to those built on the pi? But with more ram available for compiling. What if any are the difficulties with this? Can you do apt-get update in the Raspbian chroot? Finnaly what is the compile speed compared to the pi?

Thank you for doing this.

Am I right in thinking the switch to user mode emulation means the host has to be Linux (and not windows) ?

[plugwash]

Does this mean that we can build any packages on this VM and they will be identical to those built on the pi? But with more ram available for compiling.

That is the idea yes.

What if any are the difficulties with this?

The main potential issue is that some system calls may be missing from qemu which may break some programs the build process tries to run. Also build processes that use ill-advised detection techniques may also break or do the wrong thing (that issue also applies to building on higher hardware than the target though).

Can you do apt-get update in the Raspbian chroot?

Yes

Finnaly what is the compile speed compared to the pi?

dunno yet.

Am I right in thinking the switch to user mode emulation means the host has to be Linux (and not windows) ?

Yes, that is why I set things up inside a virtualbox VM.

[plugwash]

I found an issue with this image on newer virtualbox (the image worked fine on the version of virtualbox I used to set it up). Afaict the machine boots but nothing comes up on the display.

To fix this

hold down shift during boot to display the grub menu
leave the first entry in the menu selected but rather than pressing enter press "e"
remove "$vt_handoff" from the end of the kernel command line
press F10
login with username root and password root
now open /etc/default/grub2 in your favorite editor and remove quiet and splash from GRUB_CMDLINE_LINUX_DEFAULT
now run update-grub2

[plugwash]

Finnaly what is the compile speed compared to the pi?

I'm not masochistic enough to compile on a Pi but based on a test build of apt on my pentium G system this seems to be slightly slower than building on an imx.

The real value of a VM like this will come with apps that need lots of memory and would swap heavily on virtually all arm boards (that aren't made of unobtanium).

I've just put together a new virtualbox dev vm for debian and raspbian.

.....

The host system is ubuntu precise and was chosen because it's a LTS release and it ships with a nice modern qemu (unlike debian squeeze which is getting rather long in the tooth).

http://archive.raspbian.org/qemu/rpi-qe ... ev.tar.bz2

Is there a link for this (should there be?) anywhere on the Raspbian website?

I did not see one, but that may be by intent, of course...

Some benchmarks building ioquake3.

I5-2500k overclocked to 4.5Ghz, running Windows 7 x64.
1Gb RAM + 1 CPU given to virtual box and running XFCE4 desktop enviroment.

Code: Select all

real   22m31.630s
user   19m34.157s
sys    0m24.718s


RPi overclocked to 800 Mhz, SDRAM 500, Core Freq 275, emmc clock 100000000.
Running XChat and openbox WM.

Code: Select all

real    59m52.982s
user    57m31.910s
sys     0m55.460s

ok, logged in as root..... what next? the earlier emulator had instructions on running qemu...

[plugwash]

chroot into one of the build chroots (under /chroots ) and start using it like you would any other chroot.

also, how do i change the system to a US keyboard?.... methods used for previous vbox images don't work on this one...

answered second question... changed /etc/default/keyboard from "gb" to "us". thanks for including mc, as it makes finding the files i'm looking for a whole lot easier.

There's something strange...
I downloaded the VM, booted it with VirtualBox (on a Mac Host) but I can't get the network to work ! It kind of defeats the purpose since I can't git xbmc in order to build it in chroot...
Anyone can help me ?

ps: when doing a ifconfig, the only interface available is lo.

[plugwash]

There's something strange...
I downloaded the VM, booted it with VirtualBox (on a Mac Host) but I can't get the network to work ! It kind of defeats the purpose since I can't git xbmc in order to build it in chroot...
Anyone can help me ?

ps: when doing a ifconfig, the only interface available is lo.

remember normal ifconfig only shows interfaces that are up, do "ifconfig -a" to show all interfaces. If you don't have an eth0 but do have an eth1 or so then you probablly want to clear out /etc/udev/rules.d/70-persistent-net.rules

Also make sure the network is set up correctly on the host side.