SGI O2 boot hang with latest kernels

I was testing my r5k, 256 Mb ram SGI O2 again after some inactivity, and found what latest kernel (from LMO git, up to commit 9368a0777aa3eaab13dcbd7038041df54885dc32
MIPS: Fix __vmalloc() etc. on MIPS for non-GPL modules ) compiled with my
usual kernel toolchain (binutils-2.19.1/gcc 4.3.3) will lock up/hang very early, even before clearing screen.

Git bisect point me at some bootmem changes, last working commit for me is

commit a626b46e17d0762d664ce471d40bc506b6e721ab
Merge: c1dcb4b dce46a0
Author: Linus Torvalds <[email protected]>
Date: Wed Mar 3 08:15:05 2010 -0800

Merge branch 'x86-bootmem-for-linus' of
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

and bad one:

commit fb7b096d949fa852442ed9d8f982bce526ccfe7e
Merge: a626b46 fad5399
Author: Linus Torvalds <[email protected]>
Date: Wed Mar 3 08:15:37 2010 -0800

Merge branch 'x86-apic-for-linus' of
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

Sorry for annoy you all on IRC, i'll try to add more interesting details about this hang as fast as my O2 finished some compile job i have running on it currently