Re: [gentoo-mips] profiles

[Kumba]

Stephen P. Becker wrote:
> Hi folks,
>
> With the somewhat recent introduction of support for a wide variety of
> SGI machines under gentoo, expanding to include all of Indy/Indigo2,
> Origin, Octane, Indigo2 Impact (ip28), and O2, I've noticed more than
> just a handful of new users have had problems when getting to the kernel
> compile phase of the install.  The problem is that on systems that only
> run 64-bit kernels, you need a mips64-unknown-linux-gnu toolchain to
> build the kernel.  Since the userland is all 32-bit, the native
> toolchain isn't good enough to compile the kernel.  However, we do
> provide a proper toolchain via the gcc-mips64 ebuild.  Furthermore,
> binutils supports mips64 by default, but symlinks must exist such that
> we have mips64-unknown-linux-gnu-ld -> ld, etc.  Both of these are
> automatically provided during emerge system if you use the correct
> profile, which is default-linux/mips/mips64/2005.0 currently.
>
> The problem is that all of our stages ship with
> default-linux/mips/2005.0 as the default profile, which does *not*
> provide gcc-mips64 and the binutils symlinks.  Therefore if a user
> didn't know any better and didn't change their profile appropriately,
> they would be stuck while trying to build their kernel because the
> native 32-bit toolchain in the userland will just spit out errors and
> die when compiling the kernel.  Of course, this is easily fixed by
> emerging gcc-mips64 and running "binutils-config --mips", which will set
> up a proper toolchain.  However, by that time, the user is discouraged a
> bit and inevitably finds our irc channel and whines that Gentoo is broken.
>
> Now, I have a few ideas for getting around this.  Obviously whatever is
> decided should be added to the documentation, but here are some ideas:
>
> A) Do nothing...document in the handbook that if your machine is 64-bit,
> you *must* select the mips64 sub-profile. (I don't like this because
> some folks may be confused as to why everything still works just fine
> with the mips profile, and/or they will just skim over that and keep going)
>
> B) Similar to A, except ship stages without the profile set.  That way,
> folks really are stuck until they set the proper profile.  (I don't like
> this because they could still be confused and set the mips profile)
>
> C) Make default-linux/mips/ provide all the 64-bit stuff and get rid of
> the mips64 sub-profile, since all of the SGI machines we support can run
> 64-bit kernels if you so choose (ip22 is the only system that supports a
> 32-bit kernel at this time).
>
> D) (Kumba's idea here...) Have machine specific profiles, e.g.
> default-linux/mips/ip22, default-linux/mips/ip32, etc.  (This could be
> really useful because it would allow us to do some other machine
> specific voodoo in the profile).
>
> Any thoughts?
>
> -Steve


So people have an idea of what's being proposed in regards to Item #D, Attached 
to this message are two text files.  The first shows the current profile setup 
as of today.  The second file shows the proposed reorganization, starting with 
2005.1, of the profiles.

The upside to re-organizing under machine-specific categorization is better 
control for us developers, and easier to follow layout for the users.  Downside 
is, it requires more upkeep on our end (although that upkeep should be 
relatively trivial, and it's unoptimized; an optimized version will likely be 
simpler.).

And as a sidenote, the proposed variant lacks the multilib layout until we 
figure out where it goes.


--Kumba

-- 
Gentoo/MIPS Team Lead
Gentoo Foundation Board of Trustees

"Such is oft the course of deeds that move the wheels of the world: small hands 
do them because they must, while the eyes of the great are elsewhere."  --Elrond