All postinstalls should be able to run at do_rootfs time.
Patches merged: http://git.yoctoproject.org/cgit.cgi/poky/commit/?id=aab3c1306ff99d593966a192ad7c4678b605b8bd http://git.yoctoproject.org/cgit.cgi/poky/commit/?id=9129102aee5ad264a978dbefb4b40943d4b1e068 http://git.yoctoproject.org/cgit.cgi/poky/commit/?id=bdb52d2e56f48cbbf8c13151f221fbdffe4246ca
Verified on master branch. Commit ID: 9ffee9add2d0380f4025e7a678a166f25a7d659e