Re: [gentoo-user] Compiling Gentoo for Raspberry Pi (Was: List of base system packages)

[Yohan Pereira <yohan.pereira@gmail.com>]

On 04/02/13 at 11:13am, Nilesh Govindrajan wrote:
> Nah, I don't need berkdb, I'll do without it.
> Did you install emerge/portage on the Pi yet?
> Python cannot be cross compiled (it's a hot topic since ages, but very
> few people have been successful with that).
> So I guess Python would have to be compiled on the Pi itself... the
> question is, emerge needs python and python needs emerge?!!?

I recently got a minimal gentoo running on the pi (without running
emerge/compiling on the pi), here's what I've learned.

Cross compilation is FUN <\sarcasm>. Lots of packages (like python)
don't like being cross compiled. A good number of  failures occurred 
because of missing build time dependencies on the host, Some times I had
to copy certain files need at build-time from the host to the arm
sysroot (mainly for the x11-proto/* packages).

For the really adamant packages (like python) I used the method
described here [1] to build binary packages using a native arm chroot +
qemu-user (a rather interesting way to go about it). 

However I've not compared the performance (wrt compilation time) to 
running a full blown arm qemu vm so you may want to try that and see 
what works better for you. But I reckon any of these methods should be 
faster than compiling on the pi on a modern CPU. 

Also note cross-compiling is way faster than this method so I preferred
cross-compiling and only resorted to this for packages like python.  

In the end I got it to boot. Then I decided I wanted to try xbmc, after
seeing the long list of dependencies, I went ahead and installed
openELEC :D. Which works great BTW (Still trying to find some indian
news streams).

[1] http://www.gentoo.org/proj/en/base/embedded/handbook/?part=1&chap=5
(Note that page is a bit dated, app-emulation/qemu-user is masked in the
tree. Use app-emulation/qemu instead)

-- 

- Yohan Pereira

The difference between a Miracle and a Fact is exactly the difference
between a mermaid and a seal.
                -- Mark Twain