[gentoo-alt] prefixed gentoo for cross-compile (question)

[Piergiorgio Beruto]

Hi,
I'm an embedded sw developer already used to gentoo and portage.

I am wondering whether gentoo prefix could help me in the following: I
would like to use portage to cross compile some base linux packages
plus some board specific applications for a different number of boards
each requiring their own patches and packages, with a huge amount of
code to be shared among them.
I was lookong at crossdev but the big problem is that I CAN'T get
administrative priviledges on the development machine, in fact each
user at the moment builds the packages in their own home.

To be more precise I wish I could use portage installed in my home
directory and have it use some cross-toolchain (either pre-built or
built through portage) to actually download, patch, configure, build
and install packages to some directory which will eventually be turned
into a target filesystem someway.
I've tried to use crossdev inside prefixed gentoo but failed to have
it working and I'm not sure it's the correct approach anyway.

Have you guys any suggestion about my problem? That would save a lot
of users to keep developing new build systems and re-inventing the
wheel each time! Also they would never come to something as good and
featured as portage.

Thank you in advance!