From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg Ungerer Subject: Re: Support for ARM940T core Samsung S3C2510A MCU under Linux Date: Wed, 23 Mar 2011 23:18:42 +1000 Message-ID: <4D89F332.1050700@snapgear.com> References: <4D87363A.7090209@snapgear.com> <4D89E270.1080001@snapgear.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from sncsmrelay2.nai.com ([67.97.80.206]:60951 "EHLO sncsmrelay2.nai.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932600Ab1CWNUq convert rfc822-to-8bit (ORCPT ); Wed, 23 Mar 2011 09:20:46 -0400 In-Reply-To: Sender: linux-arch-owner@vger.kernel.org List-ID: To: Madhavi Manchala Cc: linux-arch@vger.kernel.org Hi Madhavi, On 23/03/11 22:36, Madhavi Manchala wrote: > Hi Greg, > > Thanks for your information. > > On Wed, Mar 23, 2011 at 5:37 PM, Greg Ungerer wro= te: >> Hi Madhavi, >> >> On 22/03/11 22:43, Madhavi Manchala wrote: >>> >>> Thank you very much for your valuable information and suggestions. >>> >>> On Mon, Mar 21, 2011 at 4:57 PM, Greg Ungerer =C3= =A1wrote: >>>> >>>> On 19/03/11 01:54, Madhavi Manchala wrote: >>>>> >>>>> I have one basic question about the architecture files in Linux >>>>> kernels. We have a board with Samsung S3C2510A MCU (ARM940T core) >>>>> which is a no-mmu based CPU. I heard that "there was not a lot of= ARM >>>>> no-mmu support at the moment" from Ben Dooks. >>>> >>>> The core is there, but there is very little specific machine suppo= rt. >>>> The one I use for testing is non-MMU ARM is the Atmel/AT91X40 (tha= t is >>>> CONFIG_ARCH_AT91X40). I don't run it on real hardware, but on the >>>> SkyEye emulator. >>> >>> I saw the mach-at91/at91x40.c and mach-at91/at91x40_time.c file >>> sources. There is a few lines of code is available in these two fil= es. >>> I guess, some of the common files are there for all Atmel boards an= d >>> that is also included as a part of at91x40 board. Am I correct? >> >> Yes, exactly. Much of the code is shared by all type of at91 parts, >> irrespective of whether they have the MMU or not. (Most of the >> internal peripherals at either the same or very similar - so >> things like interrupts, etc). >> >> >>> I found only at91_aic_init() function only called from at91x40.c fi= le. >>> What about other initialization like serial etc.? =C3=A1Is this inc= luded >>> from common files for Atmel boards? >> >> Serial is a problem for this target, it is a little different >> on the old at91x40 series to most of the newer at91 parts. Currently >> it requires a different driver than the standard at91 serial driver. >> (And that driver is not in mainline, and is not a platform type >> driver either). >> >> >>>>> So, I started developing the architecture files for my Samsung >>>>> S3C2510A MCU (ARM940T core) by looking at the existing S3C2410A >>>>> (ARM920 core) architecture files. Is this my porting (developing = the >>>>> architecture files) correct? >>>> >>>> Would make sense to start on something similar, yes. >>> >>> I downloaded the latest uClinux sources from >>> http://sourceforge.net/projects/uclinux/files/uClinux%20Stable/ and >>> the name of the file is uClinux-dist-20101026.tar.bz2. In this >>> distribution, I found mach-s3c24a0, mach-s3c3410, s3c44b0x and >>> mach-s5c7375 sources in linux-2.6.x/arch/arm/ directory. (Arnd aske= d >>> me to see these sources as a reference, only). So, I am looking at >>> these sources and especially s3c3410 sources as remaining are >>> different like s3c24a0 is a MMU based etc. >>> >>>> >>>>> How can I port the Linux on to my board which has a Samsung S3C25= 10A >>>>> MCU (ARM940T core) which is a NO-MMU based CPU? >>>>> >>>>> Thanks for your suggestions / hints / comments. >>>> >>>> You can look at what I did with the AT91X40 for an example. >>>> Or look at the patches that Ithamar Adema sent to the ARM linux >>>> mailing list in the last few days for supporting the NXP LPC2K >>>> family as another example (they are also non-MMU parts). >>> >>> As I said above, there are only two files which are related to at91= x40 >>> board. However, I found some sources for the Ithamar Adema patches = at >>> the following link. >>> http://www.spinics.net/lists/arm-kernel/msg118932.html >>> >>> These sources (patches) are similar to samsung sources which are >>> available in uClinux-dist. So, I will look into the Ithamar Adema >>> patches and uClinux-dist samsung machine directory sources. Please >>> suggest me. >> >> Looking at all of these will be useful. The AT91 changes where quite >> simple due to the high degree of similarity. > > Do you mean similarity between AT91 and S3C2510A processors? Am I > understand your statement correct? No, I meant the similarity between the non-MMU AT91x40 and the other MMU AT91 parts. Regards Greg > Thanks and Regards, > Madhavi M. > >> >>> My final question, All these samsung machines (s3c24a0, s3c3410, >>> s3c44b0x and s5c7375) are ARM7TDMI core based MCUs. My MCU (Samsung >>> s3c2510A) is a ARM9TDMI core based. So, is this porting will help? >>> >>> I am extreamly sorry, If I asked silly questions here. >>> >>> Once again, thanks for your suggestions and valuable inforamtion. >> >> No problem, glad to help. >> >> Regards >> Greg >> >> >> --------------------------------------------------------------------= ---- >> Greg Ungerer =C3=A1-- =C3=A1Principal Engineer =C3=A1 =C3=A1 =C3=A1 = =C3=A1EMAIL: =C3=A1 =C3=A1 gerg@snapgear.com >> SnapGear Group, McAfee =C3=A1 =C3=A1 =C3=A1 =C3=A1 =C3=A1 =C3=A1 =C3= =A1 =C3=A1 =C3=A1 =C3=A1 =C3=A1PHONE: =C3=A1 =C3=A1 =C3=A1 +61 7 3435 2= 888 >> 8 Gardner Close =C3=A1 =C3=A1 =C3=A1 =C3=A1 =C3=A1 =C3=A1 =C3=A1 =C3= =A1 =C3=A1 =C3=A1 =C3=A1 =C3=A1 =C3=A1 =C3=A1 FAX: =C3=A1 =C3=A1 =C3=A1= =C3=A1 +61 7 3217 5323 >> Milton, QLD, 4064, Australia =C3=A1 =C3=A1 =C3=A1 =C3=A1 =C3=A1 =C3=A1= =C3=A1 =C3=A1WEB: http://www.SnapGear.com >> > > > --=20 -----------------------------------------------------------------------= - Greg Ungerer -- Principal Engineer EMAIL: gerg@snapgear.co= m SnapGear Group, McAfee PHONE: +61 7 3435 288= 8 8 Gardner Close FAX: +61 7 3217 532= 3 Milton, QLD, 4064, Australia WEB: http://www.SnapGear.co= m