[yocto] Removing rootfs from SDK

[John Ernberg]

Hi

We're trying to optimize the SDK generated by bitbake -c populate_sdk.
Currently we're trying to remove the kernel, modules and other 
executables which we have no use for, most of it could be removed using 
IMAGE_INSTALL = "" and IMAGE_FEATURES = "".

Due to us using 2 different kernel module sets, we're using 
IMAGE_INSTALL_append_[machine] additions to IMAGE_INSTALL which are not 
cleared by the IMAGE_INSTALL = "" setting.

I've tried to do IMAGE_INSTALL_remove using the same variable that we 
use to populate the IMAGE_INSTALL_append, but that doesn't work. I can 
however remove each individual package added by IMAGE_INSTALL_append.
Due to the number of packages added by IMAGE_INSTALL_append this is not 
really feasible.

Is there a way to clear IMAGE_INSTALL_append without doing an 
IMAGE_INSTALL_remove per package? Alternatively clearing it using a 
python loop without needing to know the name of each package.

We're also seeing busybox getting included into the SDK without anything 
showing a dependency on it from running bitbake -g -c populate_sdk.

What could be going on with that?

We're using poky daisy 11 and Yocto 1.6.1.

Thank you in advance.

Best regards // John Ernberg