If you need to include other packages in your embedded rootfs (i.e. apache, openssh, etc.), you need only to use the portage to compile them:
Searching a package:
# emerge search packagename |
Check required dependancies needed by the package:
# emerge -pv packagename
|
Compile the package:
# emerge packagename
|
Install the package into the embedded_rootfs:
# ROOT=/embedded_rootfs emerge -K packagename
|