compile_cm9_cm_galaxymtd-userdebug

This is how I compiled cm9 for galaxysmtd.
For sure there is better ways but this is the only way I know, and it works for me.
I use Linux Mint 12.

Follow this guide until you have synced source. (Step 4D)
http://forum.xda-developers.com/showthread.php?t=1505006

setup ccache
http://source.android.com/source/initializing.html

New terminal
cd ~/android/system/device/samsung
git clone git://github.com/teamhacksung/android_device_samsung_galaxysmtd.git -b ics galaxysmtd

then
git clone git://github.com/teamhacksung/android_device_samsung_aries-common.git -b ics aries-common

go to android/system/vendor/cm
edit file vendorsetup.sh
add this in between any of the lines

add_lunch_combo cm_galaxysmtd-userdebug

New terminal
cd ~/android/system/device/samsung/galaxysmtd/
./extract-files.sh

New terminal
cd ~/android/system/vendor/cm/
./get-prebuilts

New terminal
cd ~/android/system repo sync

clone this somewhere
git clone git://github.com/teamhacksung/buildscripts.git

New terminal
cd into your working directory
drag the build.sh file into the terminal and type galaxysmtd and enter

When compiled add a working kernel and modem, as I dont know how to compile kernels yet.
(I tried to flash with the boot.img that builds in the update zip, and lost recovery and it did not boot)

Should be it. Enjoy!