From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Sun, 19 Aug 2012 14:05:24 +0000 Subject: [PATCH 0/6] Integrator devicetree support In-Reply-To: References: <1345119317-22600-1-git-send-email-linus.walleij@linaro.org> <201208161344.55723.arnd@arndb.de> Message-ID: <201208191405.25048.arnd@arndb.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Saturday 18 August 2012, Linus Walleij wrote: > Since we already have CONFIG_USE_OF I think > CONFIG_USE_ATAGS is more apropriate, but I get the > idea. There is both CONFIG_USE_OF and CONFIG_OF. The former is what a platform selects and it turns on a few other options as well, while the latter is the one that you typically check in #ifdef. We might need both of them for ATAG as well, but I think if we have just one, CONFIG_ATAGS or CONFIG_ATAG would be nicer because it's slightly shorter. > So it begins like this: > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index e91c7cd..0764ef7 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -1907,6 +1907,12 @@ endmenu > > menu "Boot options" > > +config USE_ATAGS > + bool "ATAGS support" > + default y > + help > + Include support for ATAGS-based machine descriptions. > + > config USE_OF > bool "Flattened Device Tree support" > select OF > @@ -2110,6 +2116,7 @@ config KEXEC > > config ATAGS_PROC > bool "Export atags in procfs" > + depends on USE_ATAGS > depends on KEXEC > default y > help > > But then we hit #ifdeffing and compiling out a lot of dangerous stuff > in arch/arm/kernel and then I get the creeps. I can try, but I think > this is typical Nico territory for example... We don't have to enclose every single usage of ATAGS with this, but I think it's helpful in platforms that you want to migrate away from ATAG to DT-only. I think we should also use this method in mach-ux500, for instance. Putting MACHINE_START and DT_MACHINE_START inside of CONFIG_ATAG and CONFIG_OF respectively would help ensure that we don't accidentally build support for a board that cannot work. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH 0/6] Integrator devicetree support Date: Sun, 19 Aug 2012 14:05:24 +0000 Message-ID: <201208191405.25048.arnd@arndb.de> References: <1345119317-22600-1-git-send-email-linus.walleij@linaro.org> <201208161344.55723.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Linus Walleij Cc: Russell King , Nicolas Pitre , devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, Will Deacon , arm-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On Saturday 18 August 2012, Linus Walleij wrote: > Since we already have CONFIG_USE_OF I think > CONFIG_USE_ATAGS is more apropriate, but I get the > idea. There is both CONFIG_USE_OF and CONFIG_OF. The former is what a platform selects and it turns on a few other options as well, while the latter is the one that you typically check in #ifdef. We might need both of them for ATAG as well, but I think if we have just one, CONFIG_ATAGS or CONFIG_ATAG would be nicer because it's slightly shorter. > So it begins like this: > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index e91c7cd..0764ef7 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -1907,6 +1907,12 @@ endmenu > > menu "Boot options" > > +config USE_ATAGS > + bool "ATAGS support" > + default y > + help > + Include support for ATAGS-based machine descriptions. > + > config USE_OF > bool "Flattened Device Tree support" > select OF > @@ -2110,6 +2116,7 @@ config KEXEC > > config ATAGS_PROC > bool "Export atags in procfs" > + depends on USE_ATAGS > depends on KEXEC > default y > help > > But then we hit #ifdeffing and compiling out a lot of dangerous stuff > in arch/arm/kernel and then I get the creeps. I can try, but I think > this is typical Nico territory for example... We don't have to enclose every single usage of ATAGS with this, but I think it's helpful in platforms that you want to migrate away from ATAG to DT-only. I think we should also use this method in mach-ux500, for instance. Putting MACHINE_START and DT_MACHINE_START inside of CONFIG_ATAG and CONFIG_OF respectively would help ensure that we don't accidentally build support for a board that cannot work. Arnd