From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Sun, 09 Oct 2011 13:35:31 +0200 Subject: [PATCH 17/26] ARM: pxa: pxa95x is incompatible with earlier pxa In-Reply-To: References: <1317499438-14058-1-git-send-email-arnd@arndb.de> <1499585.ED4ktnBDpX@wuerfel> Message-ID: <5678343.s7jMIvu0rV@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sunday 09 October 2011 14:21:35 Haojian Zhuang wrote: > > If we move it to arch/arm/Kconfig, I would prefer making it a global option, > > not a pxa specific one. If we introduce a top-level CONFIG_CPU_V6PLUS > > option, we can make a number of decisions inside of Kconfig depend on that, > > especially as we move to allow building multiple v6/v7 platforms together, > > or multiple v5 platforms for that matter. I believe we don't need to > > worry about v5+v7 at this point and can instead assume that won't ever > > happen. > > > Nobody is using PJ4 as v6 architecture now. CPUv6 is used in old stepping > of Dove and MMP2. CPU_PJ4 only enables CPU_v7 in the mainline code. > > If we used ARCH_PXA_V7 in arch/arm/Kconfig, we would have two ARCH for > pxa. One is ARCH_PXA, and the other is ARCH_PXA_V7. Those v5 machine > should be based on ARCH_PXA. And the saarb, tavorevb3 should be based > on ARCH_PXA_V7. So we can avoid to define PXA_V7_MACH_AUTO. I think > the logic of Kconfig could be easier. I was referring to building different subarchitectures together. We want to eventually be able to build a single kernel that works on e.g. pxa95x (ARMv7) and omap2 (ARMv6), and we hope to get there within the next few release. This is completely unrelated to building a combination of old-world (ARMv3/v4/v5) and new-world (ARMv6/v7) in a single kernel, which is something that we decided not to try supporting in the forseeable future. Arnd