From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751893AbbKJA3k (ORCPT ); Mon, 9 Nov 2015 19:29:40 -0500 Received: from ozlabs.org ([103.22.144.67]:46384 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751062AbbKJA3i (ORCPT ); Mon, 9 Nov 2015 19:29:38 -0500 Message-ID: <1447115377.13889.7.camel@ellerman.id.au> Subject: Re: [PATCH] powerpc: allow cross-compilation of ppc64 kernel From: Michael Ellerman To: Laurent Vivier , Scott Wood Cc: paulus@samba.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Date: Tue, 10 Nov 2015 11:29:37 +1100 In-Reply-To: <563DE203.6030001@vivier.eu> References: <1446724029-10884-1-git-send-email-laurent@vivier.eu> <1446844180.11597.13.camel@freescale.com> <563D2813.80302@vivier.eu> <1446852296.11597.53.camel@freescale.com> <563DE203.6030001@vivier.eu> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.16.5-1ubuntu3 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 2015-11-07 at 12:35 +0100, Laurent Vivier wrote: > Le 07/11/2015 00:24, Scott Wood a écrit : > > On Fri, 2015-11-06 at 23:22 +0100, Laurent Vivier wrote: > > > Le 06/11/2015 22:09, Scott Wood a écrit : > > > > On Thu, 2015-11-05 at 12:47 +0100, Laurent Vivier wrote: > > > > > When I try to cross compile a ppc64 kernel, it generally > > > > > fails on the VDSO stage. This is true for powerpc64 cross- > > > > > compiler, but also when I try to build a ppc64le kernel > > > > > on a ppc64 host. > > > > > > > > > > VDSO64L fails: > > > > > > > > > > VDSO64L arch/powerpc/kernel/vdso64/vdso64.so.dbg > > > > > /usr/bin/powerpc64-linux-gnu-ld: arch/powerpc/kernel/vdso64/sigtramp.o: > > > > > file class ELFCLASS64 incompatible with ELFCLASS32 > > > > > /usr/bin/powerpc64-linux-gnu-ld: final link failed: File in wrong format > > > > > > > > > > This fails because gcc calls "collect2" with > > > > > "--oformat elf32-powerpcle" with ppc64 objects, without the > > > > > "--oformat" ld works well because it use the format of the > > > > > first object as output format. > > > > > > > > > > As this case is correctly managed to build the other kernel > > > > > objects, this patch replaces $(GCC) by $(LD) to generate the > > > > > VDSO objects. > > > > > So at this point, I can: > > > > > > 1- either fix my compiler, > > > 2- or fix the vdso64 linker command. > > > Thank you Scott. With the help of the comment from Segher, I can choose > #1 now :) What distro/toolchain did you hit this on? I actually wrote this same patch a while back, but from memory it broke in some configurations. So I never merged it. I'll see if I can find my notes and work out exactly why it didn't work, maybe we should merge it anyway, even though the real bug is a toolchain bug. cheers