From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Date: Sun, 13 Sep 2015 10:21:36 +0200 Subject: [Buildroot] [PATCH 2/3] New entry for the Cortex-M4 processor In-Reply-To: <1442127768-26447-2-git-send-email-cjwfirmware@vxmdesign.com> References: <1442127768-26447-1-git-send-email-cjwfirmware@vxmdesign.com> <1442127768-26447-2-git-send-email-cjwfirmware@vxmdesign.com> Message-ID: <20150913102136.01d94129@free-electrons.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Chris, On Sun, 13 Sep 2015 03:02:47 -0400, Chris Wardman wrote: > I created a new entry for the Cortex-M4 processor in the processor list. Don't use "personal" formulations in commit log. It should be something like: "This commit adds a new entry..." > Right now it is being tested against a STM32F4disovery board. > This is technically an M4F. I will add that entry with the floating point in the future Ditto here. And the title of the commit log should be: arch: add entry for the ARM Cortex-M4 processor > diff --git a/arch/Config.in.arm b/arch/Config.in.arm > index 4d10f4c..2692402 100644 > --- a/arch/Config.in.arm > +++ b/arch/Config.in.arm > @@ -156,6 +156,11 @@ config BR2_cortex_m3 > bool "cortex-M3" > select BR2_ARM_CPU_HAS_THUMB > select BR2_ARM_CPU_HAS_THUMB2 > +config BR2_cortex_m4 > + bool "cortex-M4" > + select BR2_ARM_CPU_HAS_THUMB > + select BR2_ARM_CPU_HAR_THUMB2 > + select BR2_ARM_CPU_ARMV7M Please use tab for indentation. Also, while Cortex-M3 also does it, I think selecting both Thumb and Thumb-2 is not correct: Cortex-M3/M4 only support Thumb-2, no? Or at least, gcc only provides a -mthumb option that will generate Thumb-2 code, so there is no way to generate classic Thumb code on ARMv7-M platforms. Though since the problem already exists for Cortex-M3, we can keep it this way for Cortex-M4 as well for now. Also, you're selecting the BR2_ARM_CPU_ARMV7M option, but this option does not exist. Since there is a BR2_ARM_CPU_ARMV7A, I believe it makes sense to create this option, so probably you should have three patches here: * One option that adds BR2_ARM_CPU_ARMV7M * One patch that makes Cortex-M3 select it * One patch that adds Cortex-M4 Other than that, looks good to me. Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com