I recently got a Raspberry Pi from RS online store. I wanted one so bad and it took so long before I got to play with it that by the time I got it, I was pretty much drooling over it. I started off by installing Raspbian which worked out of the box (what fun it is! :( ). I then moved on to try Arch and the fun began. Arch Linux install guide at elinux is pretty good but it only helps you to get bare bones Arch up and running. After that you are on your own. So here I am going to discuss how I managed to get Arch up and running with XFCE, a login manager and a web browser.
First off, download the Arch Linux from Raspberry Pi downloads page. Raspberry Pi's processor is ARMv6 so you cannot just use any Arch variant. Once you are done with the download, you need to extract it and transfer the .img file to a sd card. Either use dd command for this or use a tool like ImageWriter. There are more options available. Check out elinux more choices. I'll use dd command here:
# dd bs=4M if=~/archlinux-hf-2012-09-18.img of=/dev/mmcblk0
No, cp command is not supposed to be used here because cp copies over the file system and we have to do something at much more lower level. In case you are wondering how I got the /dev/mmcblk0 bit, I just mounted the sd card and check the output of df -h command. If you are using a sd card of more than 2G memory, then I recommend using gparted or anything else and expand the size of the file system since by default it'll be just about 2G and rest of your space will go unused. Once you are done here, insert the sd card into your Pi and fire it up.
Now you can see the awesome black login screen. The default password for root user is 'root'. Login as root and create pacman, the Arch Package Manager, database.
# pacman-key --init
Some randomness would be helpful here. So hit ALT+F2 to go to another tty and execute some random commands like ls and echo and cd etc. Switch back to the previous tty by hitting ALT+F1 and wait till the initialization of db is done. Now you can update your repositories:
# pacman -Syu
Now first we will install the xorg libraries:
# pacman -S xorg-xinit xorg-server xorg-server-utils
This will install the X server and pull some common dependencies.
To install XFCE now, fire:
# pacman -S xfce4
It'll ask you to "Enter a selection" after giving some packages. I installed all of them since they looked quite necessary like Thunar and the top panel etc but you can be choosy if you want.
Is your GUI working? You may be missing display drivers. Install them:
# pacman -S mesa xf86-video-fbdev xf86-video-vesa
We still need a login manager. I used SLiM, the Simple Login Manager. Remember it is Pi, so we are trying to do everything lightweight.
# pacman -S slim
Reboot after this and you will be shown a GUI interface to enter your user id and password to login. Do that and open a terminal. We'll install a web browser now. You might be tempted to install Firefox or Chrome but remember, this is ARMv6 and none of the main stream browsers support this architecture out of the box. So either you can compile the binary from Firefox or Chromium code or install a browser like Midori or Arora. I installed Midori because I am more familiar with it.
# pacman -S midori
That is it. You got Arch in quite usable state with a working XFCE. Have fun!
PS: The memory footprint with XFCE up and running is about 140m for my Pi.