From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-iw0-f179.google.com (mail-iw0-f179.google.com [209.85.214.179]) by ozlabs.org (Postfix) with ESMTP id C5C57B70AF for ; Fri, 1 Oct 2010 17:13:21 +1000 (EST) Received: by iwn4 with SMTP id 4so3599724iwn.38 for ; Fri, 01 Oct 2010 00:13:19 -0700 (PDT) MIME-Version: 1.0 Sender: geert.uytterhoeven@gmail.com In-Reply-To: <1285916771-18033-3-git-send-email-imunsie@au1.ibm.com> References: <1285916771-18033-1-git-send-email-imunsie@au1.ibm.com> <1285916771-18033-3-git-send-email-imunsie@au1.ibm.com> Date: Fri, 1 Oct 2010 09:13:19 +0200 Message-ID: Subject: Re: [PATCH 02/18] powerpc: Add CROSSBE_COMPILE to build big endian boot wrapper From: Geert Uytterhoeven To: Ian Munsie Content-Type: text/plain; charset=UTF-8 Cc: Michal Marek , Sam Ravnborg , Albert Herranz , linux-kernel@vger.kernel.org, paulus@samba.org, Andrew Morton , linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, Oct 1, 2010 at 09:05, Ian Munsie wrote: > From: Ian Munsie > > Since the boot wrapper must be built by a big endian 32bit toolchain > regardless of what the rest of the kernel is using introduce a new > parameter to specify that toolchain - CROSSBE_COMPILE. > > We already have CROSS32_COMPILE which is already used for the boot > wrapper, but it is also used to build the 32bit vdso which should be > build in the same endianness as the rest of the kernel, so it is > necessary to be able to specify the toolchain to build the boot wrapper > separately from that used to build the vdso and again separately from > that used to build the main kernel. > > CROSSBE_COMPILE should be pointed to a toolchain capable of targeting > 32bit big endian powerpc, either specifically targetted at 32bit or > bi-arch 64 and 32bit. If CROSSBE_COMPILE is not specified it will fall > back to CROSS32_COMPILE to maintain compatibility with big endian > targets. Shouldn't the help text added by [PATCH 01/18]: +++ b/arch/powerpc/platforms/Kconfig.cputype @@ -329,3 +329,19 @@ config CHECK_CACHE_COHERENCY bool endmenu + +config ARCH_SUPPORTS_LITTLE_ENDIAN + bool + +config CPU_LITTLE_ENDIAN + bool "Build little endian kernel" + depends on ARCH_SUPPORTS_LITTLE_ENDIAN && EXPERIMENTAL + default n + help + This option selects whether a big endian or little endian kernel = will + be built. + + Note that if building a little endian kernel, CROSS_COMPILE must + point to a toolchain capable of targetting little endian powerpc, + while the toolchain specified by CROSS32_COMPILE must be capable = of + targetting *BIG* endian PowerPC. be updated here as well? Gr{oetje,eeting}s, =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 =C2=A0 Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k= .org In personal conversations with technical people, I call myself a hacker. Bu= t when I'm talking to journalists I just say "programmer" or something like t= hat. =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 =C2=A0 =C2=A0 =C2=A0=C2=A0 =C2=A0=C2=A0 -- Linus Torvalds