On 23/09/16 14:13, Stuart Yoder wrote: > > >> -----Original Message----- >> From: Robin Murphy [mailto:[email protected]] >> Sent: Friday, September 23, 2016 7:17 AM >> To: Alison Wang <[email protected]>; [email protected]; >> [email protected]; Fabio Estevam >> Estevam <[email protected]>; [email protected]; >> [email protected]; linux- >> [email protected]; Scott Wood <[email protected]>; Stuart Yoder >> <[email protected]>; Leo Li >> <[email protected]> >> Cc: Jason Jin <[email protected]> >> Subject: Re: [PATCH 1/2] armv8: aarch32: Execute 32-bit Linux for LayerScape >> platforms >> >> Hi Alison, >> >> On 23/09/16 03:19, Alison Wang wrote: >>> The ARMv8 architecture supports: >>> 1. 64-bit execution state, AArch64. >>> 2. 32-bit execution state, AArch32, that is compatible with previous >>> versions of the ARM architecture. >>> >>> LayerScape platforms are compliant with ARMv8 architecture. This patch >>> is to support running 32-bit Linux kernel for LayerScape platforms. >>> >>> Verified on LayerScape LS1043ARDB, LS1012ARDB, LS1046ARDB boards. >>> >>> Signed-off-by: Ebony Zhu <[email protected]> >>> Signed-off-by: Alison Wang <[email protected]> >>> --- >>> arch/arm/Kconfig | 9 +++++++++ >>> arch/arm/mach-imx/Kconfig | 14 ++++++++++++++ >>> arch/arm/mach-imx/Makefile | 4 +++- >>> arch/arm/mach-imx/mach-layerscape.c | 23 +++++++++++++++++++++++ >>> 4 files changed, 49 insertions(+), 1 deletion(-) >>> create mode 100644 arch/arm/mach-imx/mach-layerscape.c >>> >>> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig >>> index f0c8068..e8d470e 100644 >>> --- a/arch/arm/Kconfig >>> +++ b/arch/arm/Kconfig >>> @@ -294,6 +294,15 @@ config PGTABLE_LEVELS >>> default 3 if ARM_LPAE >>> default 2 >>> >>> +config ARCH_AARCH32_ES_SUPPORT >>> + def_bool n >>> + help >>> + The ARMv8 architecture supports 64-bit execution state, AArch64 >>> + and 32-bit execution state, AArch32, that is compatible with >>> + previous versions of the ARM architecture. >>> + >>> + Enable AArch32 execution state support for ARMv8 architecture. >> >> What's this supposed to do, exactly? I've been running 32-bit kernels on >> my Juno with very little issue (beyond a couple of DT tweaks, and some >> firmware hacks with a corresponding bit of A64 assembly tacked on the >> front of the zImage to switch into AArch32 state). > > Which arch/arm/mach-* platform are you using for Juno?
I don't even know! :) I just start with a multi_v7_defconfig plus a few extra bits (LPAE, KVM, sil24, sky2, etc.) and it works. I guess it's the combination of mach-vexpress and mach-virt. Robin. > > Thanks, > Stuart >
