From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from kirsty.vergenet.net (kirsty.vergenet.net [202.4.237.240]) by lists.ozlabs.org (Postfix) with ESMTP id 1A6D51A1E15 for ; Wed, 2 Sep 2015 11:11:56 +1000 (AEST) Date: Wed, 2 Sep 2015 10:02:51 +0900 From: Simon Horman To: Samuel Mendoza-Jonas Cc: kexec@lists.infradead.org, mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH] purgatory/arch/ppc64: Reset primary cpu endian to big-endian Message-ID: <20150902010251.GC30886@verge.net.au> References: <1440125476-9420-1-git-send-email-sam.mj@au1.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1440125476-9420-1-git-send-email-sam.mj@au1.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , [CC linuxppc-dev] On Fri, Aug 21, 2015 at 12:51:16PM +1000, Samuel Mendoza-Jonas wrote: > Older big-endian ppc64 kernels don't include the FIXUP_ENDIAN check, > meaning if we kexec from a little-endian kernel the target kernel will > fail to boot. > Returning to big-endian before we enter the target kernel ensures that > the target kernel can boot whether or not it includes FIXUP_ENDIAN. > > This mirrors commit 150b14e7 in kexec-lite. > > Signed-off-by: Samuel Mendoza-Jonas I would value a review from one of the PPC folks. > --- > purgatory/arch/ppc64/v2wrap.S | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) > > diff --git a/purgatory/arch/ppc64/v2wrap.S b/purgatory/arch/ppc64/v2wrap.S > index dc5034f..179ade9 100644 > --- a/purgatory/arch/ppc64/v2wrap.S > +++ b/purgatory/arch/ppc64/v2wrap.S > @@ -114,10 +114,16 @@ master: > LOADADDR(6,run_at_load) # the load flag > lwz 7,0(6) # possibly patched by kexec-elf-ppc64 > stw 7,0x5c(4) # and patch it into the kernel > - li 5,0 # r5 will be 0 for kernel > - mtctr 4 # prepare branch too > mr 3,16 # restore dt address > > + mtsrr0 4 # prepare branch to > + > + mfmsr 5 > + clrrdi 5,5,1 # clear MSR_LE > + mtsrr1 5 > + > + li 5,0 # r5 will be 0 for kernel > + > # skip cache flush, do we care? > > - bctr # start kernel > + rfid # update MSR and start kernel > -- > 2.5.0 >