From: arnd@arndb.de (Arnd Bergmann)
Date: Thu, 18 Sep 2014 19:38:46 +0200
Subject: [PATCH] ARM: zImage: add support for ARMv7-M
In-Reply-To: <1411057343-20861-1-git-send-email-manabian@gmail.com>
References: <1411057343-20861-1-git-send-email-manabian@gmail.com>
Message-ID: <201409181938.46996.arnd@arndb.de>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Thursday 18 September 2014, Joachim Eastwood wrote:
>   ARM(          mov     pc, r4  )               @ call kernel
> - THUMB(                bx      r4      )               @ entry point is always ARM
> +#ifdef CONFIG_CPU_V7M
> +               add     r4, r4, #1              @ enter in Thumb mode for ARMv7M
> +#endif
> + THUMB(                bx      r4      )               @ entry point is always ARM for non ARMv7M CPUs
>  

I think it would be much nicer to avoid sprinkling #ifdefs here. We already
have the ARM() and THUMB() macros to deal with the two cases we support, which
are booting in ARM mode vs ARMv7-A with THUMB2 mode. We can probably add
another macro like this to deal with the ARMv7-M case that does not have
ARM mode.

	Arnd