Cross-compiling problem on SGI O2

iMike

I have successfully installed gentoo on an SGI O2 awhile back, but apparently have forgotten a trick or two. I was following the manual, so installed sys-devel/kgcc64-4.1.2, made sure cross-compile was turned OFF in the kernel configure, but then got the following when trying to build the most recent mips-sources (linux-2.6.20.18-20070902):

Redhatter · Posted: Tue Jan 01, 2008 10:38 am Post subject:

This is apparently caused by a broken version of binutils-config. Update that, then use it to re-select your cross-binutils and try again.
_________________
Stuart Longland (a.k.a Redhatter, VK4MSL)
I haven't lost my mind - it's backed up on a tape somewhere...

Gentoo/MIPS Cobalt developer, Mozilla herd member.

iMike · Posted: Wed Jan 02, 2008 2:44 pm Post subject:

I think you are right about the broken binutils-config, and now my entire install seems to be borked. This was a fresh install that worked after following the steps of the manual up to and including the point of booting into the kernel (arcload) and then starting an update of the entire system. I was doing this on a couple of O2s and I know that one died during an overall update (emerge -vauDN world) after updating openssl. On that machine I get floating point exception when trying to do env-update. This traces to a python dload of an ssl .so file, which I suspect was incorrectly compiled in the wrong ENDIAN. Perhaps an ENDIAN problem also got the machine where I tried to install the 2.6.20 kernel (as detailed earlier).

I had picked the profile

Redhatter · Posted: Wed Jan 02, 2008 9:57 pm Post subject:

I doubt endianness is the problem here. While yes, passing -LE to gcc will possibly yield a little endian binary, by default, a mips-unknown-linux-gnu compiler is big endian.

You can confirm this by running file /usr/lib/libssl.so.*, you'll see it's a "MSB" executable (Most Significant Byte first, aka big endian).

Floating-point exceptions are caused by broken compilers/assemblers and such. I'm not sure what's happened in your case, but you may be able to recover it by manually unpacking a tbz2 of openssl (tar -C / -xjvf foo.tbz2) from a known working BE MIPS system. Such binaries can be produced using quickpkg.
_________________
Stuart Longland (a.k.a Redhatter, VK4MSL)
I haven't lost my mind - it's backed up on a tape somewhere...

Gentoo/MIPS Cobalt developer, Mozilla herd member.

iMike · Posted: Thu Jan 03, 2008 4:14 pm Post subject:

OK, thank you for the tip. I will try it.

Just to make it crystal clear for me.... when I emerge mips-sources-2.6.20.18, I get the message below. The question I have about that is the following: is the ugly hack referred to kgcc64, which implies we should be using plain old gcc for compiling the kernel (instead of kgcc), as on other platforms, or is it really just about the version of kgcc64, and thus implies that we should only use >= kgcc64-4.1.1 when compiling more recent kernels? Clarification would be helpful.

Although I have thus far just compiled the kernel on the O2, it would of course be much nicer to use a nearby and faster gentoo x86 or ppc32 for the job. Thus a different, but related question, would be: do I have to install kgcc64 on the x86 or ppc32 to cross-compile the kernel? If you only have time to answer one of these two questions, then this one is definitely secondary, as to work through the strange problem I had earlier I would just as soon keep all compiling on the O2 at least for starters.

Redhatter · Posted: Fri Jan 04, 2008 11:28 pm Post subject:

Okay, that message actually refers to kgcc64, the plain old gcc is 32-bit, and won't compile a 64-bit kernel correctly.

As for kgcc64 on other architectures. If you merge it on x86, AFAIK it generates a x86_64-pc-linux-gnu compiler, or on ppc32, it'd generate a ppc64 compiler. Not much use.

If you want a cross-compiler on your x86 box, look into a package called crossdev. crossdev -t mips64-unknown-linux-gnu -s1 should yield a toolchain similar to that produced by kgcc64 on the O2.
_________________
Stuart Longland (a.k.a Redhatter, VK4MSL)
I haven't lost my mind - it's backed up on a tape somewhere...

Gentoo/MIPS Cobalt developer, Mozilla herd member.

ddc · Guru Joined: 29 Aug 2006 Posts: 522

(I hope the soonest I can) I will be given by an O2 R5K as gift, so i will have to load gentoo to an O2, too

armanox · n00b Joined: 03 Jan 2008 Posts: 36 Location: Baltimore, MD

I've got the same problem listed above on an SGI Octane. Now that I know how to fix the issue, it should be smooth sailing for it.

iMike · Posted: Mon Jan 07, 2008 3:49 pm Post subject:

It's gonna be interesting to see where this problem sneaks in. I was doing as standard (i.e., by-the-manual) an install as possible. Thanks to emerge's logging I know what got updated and when things started going south.

Taking redhatter's advice, I braved it and got my system back to running. Without his advice, I'm sure I would have just started over, since having a broken toolchain seems like too bad a starting point for me without some expert advice. Specifically that I did was test a few commands and see what clearly wasn't working. I then did a quickpkg of these on a correctly working O2: