I created a kernel (based on fugumod) which supports all filesystems and has only one purpose, rooting any SGS stock ROM.
It also removes annoying boot and shutdown sounds.
Is it safe to use
It is safer than rooting using speedmod or whatever other all purpose kernel as it does not try to start android after rooting, so there is no fs corruption possible. It works even for very new leaks.
How to use:
1: Flash the stock rom
2: Download the image for Heimdall or for Odin
3: Flash it with either Odin or Heimdall
4: Boot once, it will install root and crash/shutdown (it is preferred to let the phone connected to usb so it does not loop boot)
5: Reflash the original kernel
How to reflash the original kernel on windows using Odin
1: install 7zip if don't have it already. It has been reported that IZarc or PeaZip may be more reliable.
2: unpack zImage which is in the PDA tar or tar.md5
3: with 7zip, IZarc or PeaZip create a new tar which contains only zImage and save
4: flash the the new tar using Odin
Does it work on ROM XXXXX?
It should work on every ROM since it recognizes all filesystems and does not try to start android.
Busybox was not installed on my device
Please download the updated version and retry, it will work fine.
Odin flashable stock kernel zImages
no image available yet, use samfirmware or google to get one