Senaste inläggen som handlar om Ubuntu

Hej å hå!
På den här bloggen kommer jag att skriva en del om Linuxdistributionen Ubuntu, vilket är ett perfekt operativsystem som många fler borde testa.

Återkommer...

A couple of months ago I wrote about how to install 9.04 on Macbook Air 2,1. I never really got it to work well but I knew Karmic Koala was coming soon so I did not spend time on it.

Now it is out and unfortunately it does not work perfect out of the box. Installing from the normal desktop 32-bit CD I got read errors (might have been the external drive's fault). Instead I went for the alternative install CD and it worked better.

The newly installed system got a kernel boot option acpi=off and with that I managed to boot, but only after first booting OSX.

I also noticed that only one core was detected by the kernel and it had no support for frequency scaling.

After reading up on more kernel boot options and testing about 100 times (reboots) I finally found the holy combination that fixes all problems:

• Boot Ubuntu direct w/o need to first boot OSX
• Both CPU cores are detected
• CPU freq scaling works
• Shutdown turns off power
• Suspend to RAM works

So, where is the magic? Here it is: acpi=noirq and pnpacpi=off. Enjoy!

Update 2009-11-11: This post is about old version 9.04, please consider the better-working 9.10 I am writing about here instead.

My brand new little Macbook Air arrived the other day and I spent quite some time getting Ubuntu 9.04 (Jaunty) to run on it. Since I could not find alot of info on the web I thought I would switch to English for today and scribble down some notes that might help others out there!

First of all, I don't know if it is possible to set up netboot for the installation, I could not be bothered and my colleague was kind enough to lend me a USB CD drive so I went for the 32-bit CD install.

The Bootcamp app in Macos can be used to resize and make space for the Ubuntu partition. Holding the alt key during the DOOOOOOH sound at boot time gives a boot menu where the USB CD drive is recognised. However, just booting the plain vanilla Ubuntu disc reboots the computer and the USB port dies.

It can be healed by doing an SMB reset (google it). I did not know what that was so I ended up calling support and the guy told me to unplug the USB drive and hold left shift + ctrl + alt + power button for 12 seconds. Sometimes that works but sometimes I also have to do and additional 5 sec powerbutton... whatever that does?

To get the installation (or just live session) going, add noapic and remove quiet and splash from the kernel command line (F6 to add noapic and then arrow keys and backspace to edit the commandline).

I started a live session and installed cryptsetup before I started the installation. This makes is possible to create an encrypted partition that can be used as root during installation. (_cryptsetup luksFormat /dev/sda3_ and cryptsetup luksOpen /dev/sda3 cryptoroot and mkfs.xfs /dev/mapper/cryptoroot, note that you need to save about 200 meg for a separate /boot partition if you opt for the encrypted root).

During the installation it is a good idea to click Advanced and make sure Grub is only installed to the beginning of the Ubuntu partition, or it will fail. To get a nice start menu for MBR check out rEFIt.

There are some Macbook specific packages to enable most of the hardware available from the Mactel Support Team.

The only problem I have now is that Ubuntu only boots about half of the times I try. The other half of times the laptop just reboots again. The trick I have found so far is to have noapic and acpi=force on the command line.

Will update this post when I know a better way of booting :-)

And a final word about the Macbook Air -- it is a really nice piece of hardware that I can really recommend. Using it together with Ubuntu gives me the best of both worlds: world class hardware and OS at the same time!

...släpptes härom veckan och för ovanlighetens skull gick en del saker sönder i uppgraderingen. Bland annat verkar regioninställningarna för wifi helt trasiga (eller ignorerade?). Drivisen laddas med restriktiva amerikanska inställningar utan bland annat kanal 12-13 som är vanligt förekommande i Sverige.

iwlist interface channel

...visar om du är drabbad. Saknas kanal 12-13 kan du köra:

sudo echo "options cfg80211 ieee80211_regdom=EU" >> /etc/modprobe.d/options

...för att få tillbaka de förlorade kanalerna (efter nästa uppstart).

Min dual core Intel växlar inte längre ner till lågenergiläge när datorn går på batteri och det går inte heller längre att manuellt ställa läge via panelikonen för processorn. Om någon har en bra fix på det problemet, säg gärna till! Tills vidare använder jag två små skript:

#!/bin/sh
sudo echo powersave > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
sudo echo powersave > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor

@#!/bin/sh
sudo echo ondemand > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
sudo echo ondemand > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor