[oe] bootimg.bbclass not works

[Patrick Fischer]

On dependence on the dosfstools problem I will ask if anybody use the 
bootimg.bbclass

First there was/is a problem with the dosfstool, but that will be 
discussed in an other post.

my problem is now that i want to create a boot iso from my oe system.
So i will inherit from the bootimg.bbclass

In my opinion there is the following line missing in the bootimg.bbclass

IMAGE_POSTPROCESS_COMMAND += "build_boot_bin"
But this can be done in my image.bb

The build_boot_bin need so extern variables like:
${INITRD} - indicates a filesystem image to use as an initrd (optional)
${AUTO_SYSLINUXCFG} - set this to 1 to enable creating an automatic config
${LABELS} - a list of targets for the automatic config
${APPEND} - an override list of append strings for each label
${SYSLINUX_OPTS} - additional options to add to the syslinux file ';' 
delimited


The initrd is not realy optional if you look into the source.
But how to create an initrd with oe? Is there an class for?


Best regard
Patrick