From mboxrd@z Thu Jan 1 00:00:00 1970 From: vijay.kilari@gmail.com (Vijay Kilari) Date: Fri, 12 Jul 2013 17:26:59 +0530 Subject: v3.10 - big endian core support In-Reply-To: <20130712134726.0a909165@skate> References: <20130712134726.0a909165@skate> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Jul 12, 2013 at 5:17 PM, Thomas Petazzoni wrote: > Dear Vijay Kilari, > > On Fri, 12 Jul 2013 17:09:12 +0530, Vijay Kilari wrote: > >> > Ben Dooks has a separate branch on top of this base branch for >> > big-endian support, that adds atags compat code to convert the ATAGs >> > data from LE to BE. See the baserock/311/be/atags branch in >> > git://git.baserock.org/delta/linux. Or >> > http://git.baserock.org/cgi-bin/cgit.cgi/delta/linux.git/log/?h=baserock/311/be/atags. >> >> ARM VE TC2 board, enabling CONFIG_THUMB2_KERNEL failed to boot in BE mode >> It hangs at very early stage of boot > > Yeah, the Thumb2 code is not supported by Ben Dooks patches, it's part > of the TODO-list. I think Ben said he would probably not have much time > to work on this. I might be able to spare some time on this, so just > let me know if I should start working on this. If I remember correctly, > it's mainly the fixup_pv_table code that needed some Thumb2/BE love. In fact, I tried with below changes.. still it fails diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 2de1114..7df64c7 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -592,8 +592,14 @@ __fixup_a_pv_table: b 2f 1: add r7, r3 ldrh ip, [r7, #2] +#ifdef CONFIG_CPU_ENDIAN_BE8 + rev ip, ip +#endif and ip, 0x8f00 orr ip, r6 @ mask in offset bits 31-24 +#ifdef CONFIG_CPU_ENDIAN_BE8 + rev ip, ip +#endif strh ip, [r7, #2] 2: cmp r4, r5 ldrcc r7, [r4], #4 @ use branch for delay slot > > Will, is getting Thumb2 working a requirement to get the BE support > merged, or can we for now make the BE option depends on !THUMB2_KERNEL ? > > Thanks! > > Thomas > -- > Thomas Petazzoni, Free Electrons > Kernel, drivers, real-time and embedded Linux > development, consulting, training and support. > http://free-electrons.com