* Kyle Moffett | 2011-03-09 00:22:11 [-0500]: >On Tue, Mar 8, 2011 at 23:39, Segher Boessenkool ><segher@xxxxxxxxxxxxxxxxxxx> wrote: >>> The problem is not with the kernel compile itself, but with the 2.12 >>> "dssall" binutils test. ??Basically, recent binutils treats e500 as >>> effectively a separate architecture that happens to share *most* of >>> the opcodes with regular PowerPC. ??Any opcode which is not understood >>> by the e500 chip is either convert to an equivalent opcode which is >>> understood (IE: lwsync => sync), or failed with an error. ??This means >>> that the kernel compile aborts early telling me to upgrade to a newer >>> version of binutils. >> >> $ echo dssall | powerpc-linux-as -many -me500 >> $ powerpc-linux-objdump -d a.out | grep 0: >> ?? 0: ?? 7e 00 06 6c ?? ?? dssall >> $ powerpc-linux-as --version | head -1 >> GNU assembler (GNU Binutils) 2.21.51.20110309 >> >> What version of binutils does not work? ??(I also checked with >> -me500x2, -me500mc, -mspe, and various combinations. ??lwsync >> is indeed converted to a regular sync (well, "msync") for e500 >> and e500x2). > >Hmm, something's fishy here. Did I break anything? Not sure if mc and x2 are the same thing. One of those e500 thingy has a the "classic FPU" if I remember correctly. Anyway, -me500 enables a certain range of opcodes -many enables all of them (or the remaining few). So without -many this test will fail. The auto conversion of lwsync => sync or msync should be performed due to -me500. >Just going based on this changeset, the floating point and AltiVec >opcodes are *supposed* to generate hard errors: > http://sourceware.org/ml/binutils-cvs/2010-06/msg00070.html > >Oh... that patch only disables the opcodes if "-many" is not specified. To some degree yes. If you specify -me500 -maltivec you can still use AltiVec opcodes because you enabled them. So for that reason there are scripts on buildds to prevent passing mcpu to gcc among other things :) >Cheers, >Kyle Moffett Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
