Real-Time Kernel for RaspberryPi

After installing and running ArchLinuxARM on my RaspberryPi, I tried to compile a real-time kernel.
With the help of moonman, following this ArchLinuxARM forum thread, I downloaded the RT patch:
https://www.kernel.org/pub/linux/kernel/projects/rt/3.6/patch-3.6.11.4-rt36.patch.gz
and the PKGBUILD:
# git clone https://github.com/archlinuxarm/PKGBUILDs.git
following this, I updated pacman:
# pacman -Syy
and installed some packages:
# pacman -S kernel26-headers file base-devel abs
next
# cd PKGBUILDs/core/linux-raspberrypi
and edit the PKGBUILD file to include the patch in the source array:

source=('config'
        'change-default-console-loglevel.patch'
        'usb-add-reset-resume-quirk-for-several-webcams.patch'
        'args-uncompressed.txt'
        'boot-uncompressed.txt'
        'imagetool-uncompressed.py'
        'https://raspy-juice.googlecode.com/svn/trunk/linux-rtc/0001-rtc-pcf8523.patch'
        'https://raspy-juice.googlecode.com/svn/trunk/linux-rtc/0002-pcf8523-i2c-register-dt.patch'
        'patch-3.6.11.4-rt36.patch')

add a patch line:

patch -Np1 -i "${srcdir}/patch-3.6.11.4-rt36.patch"

and add md5sums at the end of the PKGBUILD file. to get the correct number run:

# md5sum patch-3.6.11.4-rt36.patch

next for the build:

# makepkg --asroot -Acs

The process has failed with some rejections of patches. So we need to manually apply the patches:

first look for rejections:

# find . -name "*.rej"

then edit the file and the .rej file:

# vim XXX.c XXX.c.rej

replacing XXX with the file path and name.

Then use :split to split the screen :next to change one screen to .rej file and ctrl+ww to switch between files.

add the lines marked by + and remove lines marked by - (lines with no +- sign are used for orientation.

after manually patching all files, edit the PKGBUILD file to ignore the kernel git and the patches (adding # at the start of the line)
add a line to src/linux/security/apparmor/sid.c:
"#include <linux/cache.h>"

re-run:

# makepkg --asroot

Now for the installation part:
# pacman -U linux-headers-raspberrypi-3.6.11-11-armv6h.pkg.tar.xz linux-raspberrypi-3.6.11-11-armv6h.pkg.tar.xz

And reboot.

Well, it didn't work.

RaspberryPi initial steps

I initiated a new project involving low-cost micro-computer RaspberryPi.
In order to begin I ordered some basic parts (costs are in USD for Israeli market, should be cheaper elsewhere):
a RaspberryPi (55$)
5v charger with microusb adapter (10$)
8GB SD card (12$)
HDMI cable (8$)

and some extra parts:
3.5" LCD screen (45$)
micro-keyboard (62$)
micro-sd low profile adapter (11.9$)
wifi dongle (18.6$)

Not so cheap but might be worth it.

after I got a couple of RaspberryPi (model B rev2 512MB RAM) devices for a project I'm working on (details about the project will come later if it will work).
I bought a SD 8GB card and hooked it to the my desktop computer.
I downloaded the ARCLinux image unzipped it and followed the instructions:

Replacing sdX with the location of the SD card, run:
dd bs=1M if=/path/to/archlinux-hf-2013-06-15.img of=/dev/sdX

In order to increase the SD space to it's full 8GB I used gparted.

upgrade system:
> pacman -Sy pacman
> pacman-key --init
> pacman -Syu
sync (3 times):
# sync
reboot:
# reboot
Now I can add packages using pacman. to look for a package use:
> pacman -Ss <package name>
then select the one you need and install by:
> pacman -S <package name>

I am currently testing the Pi with the screen and 8 AA batteries to see how long it can work. I plan to build a case with a built-in 3.5" screen and a miniature keyboard so I can have a control unit for other RaspberryPi devices. My initial thoughts of using an old Gamboy case are now switched (with the encouragement of my electronic tec. guy David Shtibelman) to build a costume made case. Of course, David is the one to build it, since I have no skills to do that.