[oe-users] how to make OE work with source files downloaded by other package manager

[Michal Panczyk]

Hello all,
I am looking for a tip how to make openembedded work with gentoo's
portage in the field of downloaded source files.
I am not sure how may OE uses use gentoo linux, so I will make some
short introduction.
>From my, user's point of view, gentoo's pakage management system works
similar to OE - it takes care of dependencies, compiles packages from
the source, and what is most important for this massage - downloads
the souce files and checks the signatures....
The source files are kept in /usr/portage/distfiles/ dir which belongs to root.
  When OE builds a package it downloads the source file, compares its
md5 sum and stores it in directory from the local.conf. Additional
thing that OE does it leaves a footprint that a job of downloading a
file has been done - by creating PACKAGE.do_fetch file in proper
tmp/stamps/xxx/ directory. Without that file bitbake try's to fetch
the source even it the file was already downloaded by bitbake.
My question is - how to make OE work with files that were already
downloaded (in this case by gentoo' portage) to:
1) save time/bandwidth, by not downloading the same files twice,
2) save space by keeping all the source files in one place ?

I would be grateful for some tips.....

Regards,
Michal