What are the steps to root this phone?
As I understand, Samsung has been using an internal counter that will void your guarantee if you install a custom kernel, I'd like to avoid that.
You have a prety good tutorial right here: [GT-I9070] [ROOT] Rooting your Galaxy S Advance without increasing the Binary Counter
Solution for at least I9070 / I9070P on Linux:
Flashing only system.img with Odin or Heimdall (use 1.3.1 version) does not increase the counter.
So download an official stock ROM for your phone, extract it,
convert the system.img (sparse ext4 image) to an normal ext4 image as described here. Loop-mount it, add a su binary to the
At the end install the Superuser or SuperSu app which belongs to the su binary you added to the system image.