From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from moutng.kundenserver.de ([212.227.126.171]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Ti0he-0003nC-1r for linux-mtd@lists.infradead.org; Mon, 10 Dec 2012 10:35:16 +0000 Message-ID: <50C5BAD6.2010500@corscience.de> Date: Mon, 10 Dec 2012 11:35:02 +0100 From: =?UTF-8?B?QW5kcmVhcyBCaWXDn21hbm4=?= MIME-Version: 1.0 To: jean-philippe francois Subject: Re: U-boot bch4_sw vs omap bch4_hw References: <20121208082935.GA17392@parrot.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: Ivan Djelic , "linux-mtd@lists.infradead.org" List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi Ivan Djelic and Jean-Philippe Francois, On 10.12.2012 10:41, jean-philippe francois wrote: > 2012/12/8 Ivan Djelic : >> On Fri, Dec 07, 2012 at 03:26:06PM +0000, jean-philippe francois wrote= : >>> Hi Ivan, >>> >>> I have applied your patches for hardware bch ecc support on >>> OMAP. On the linux side, everything is fine. However I have some trou= ble >>> when it comes to u-boot and kernel interoperability. >>> >>> A nand page written with bch4_sw ecc by U-boot fails the ecc step whe= n >>> read by the kernel. Looking at a nanddump, OOB placement and size of >>> the ecc data are the same. >>> >>> Do you know of any patch for u-boot that would make the bch4_sw ecc >>> identical to the kernel one ? can you both please have a loot at http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/147698 >> Hi Jean-Philippe, >> >> If you point me to a git repo with the exact u-boot version you are us= ing, >> I can probably provide a patch (or at least understand the problem). >> BR, >> -- >> Ivan > I am using an u-boot from the arago project : > http://arago-project.org/git/projects/?p=3Du-boot-omap3.git;a=3Dtags >=20 > So it is quite old. > I will probably have to modify x-loader, too. current u-boot do not need x-loader any more. > Both implementation use very similar file for hardware assisted > bch decoding. >=20 > If this code is too old for you to look at, could you help me find an o= map > project that "new ecc" all the way up from x-loader to u-boot + kernel = ? >=20 > If I understands things correctly, I have two options if I want to use > Nand that needs > 4-bit ecc : > - Stick with the old ecc scheme in x-loader and u-boot, and use > software 4-bit bch in the kernel. > Is this compatible with using ubifs ? > - Implement new ecc scheme in x-loader and u-boot, and use hardware > assisted bch-4 in the kernel. > Is this correct ? * use 1-bit hamming 'ROM-layout' for SPL mtd and 4-bit BCH8 in all other sections, see my u-boot patches. Would be great to have some testers for these patches. Best regards Andreas Bie=C3=9Fmann