Dear Steffen Arendt, you could test the tricorder configuration. It does work with Pekon's patchset mentioned in your mail. I haven't tested Pekon's changes when they where included. But my regular tests before each U-Boot release showed a change in OOB layout, therefore commit 1b82491ee6ee1e986e5521b33692a00e1f38fe75 was generated. It seems my first attempt to implement OMAP3 HW supported BCH in u-boot was buggy :( Sorry for that!
On 07/11/2014 10:27 AM, Steffen Arendt wrote: > Dear Pekon, > > thanks for your mail. This ECC topic is of some complexity. :( > > I am close to solve a huge problem here, switching boards from > 1bit-SW-ECC to BCH4. > The only missing part is, that OMAP xloader and uboot calculates the > BCH4 ECC values than Sitara XLoader > (although the x-loader binaries are identical). > Main problem is not that this is different to Linux - this is not nice, > but not a problem. I solved this by implementing a > second linux compatible BCH4 in uboot (which works on both platforms). > Problem is, that BCH4 (as it is implemented in aragos xloader) seems > not to work on OMAP3503. > And it is not understood by me, why this is not working, or what can > the reason for this. There is an issue in GPMC for AM37xx up to revision 1.0 (Advisory 1.54 'GPMC Has Incorrect ECC Computation for 4-Bit BCH Mode'). I think this includes the OMAP35xx variants. > You suggestions address kernel/uboot changes. For this I have already > a solution. > I am running into other troubles if I shift to your suggestions, and I > can't see an improvement for > the xloader problem. > I know, nowadays the xloader is SPL and is derived from uboot. But I > haven't the power to completely change everything again. > Frankly speaking, I afraid another nightmare here. > Unfortunatly TI doesn't have an newer SDK for OMAP3503/AM3703. > Is it true, that in this Arago or TI SDK the only functional ECC scheme > are 1 bit SW and 1 bit HW (for xloader)? U-Boot had also only 1 bit Hamming with two different OOB-schemes before my attempt to support BCH. Since X-Loader is outdated I think nobody cared to port these changes. Sorry, I never worked with X-Loader so I can't tell anything about it. You should really migrate to U-Boot! > For me it seems (if you check my logs) that in xloader the > omap_calculate_ecc_bch4() uses hardware GPMC registers. > Main question: why this doens't work or give different results in > OMAP? I think it is because of the errata mentioned above. You should switch to BCH8 on OMAP3 devices in favor of BCH4. > The version I take over for uboot and kernel (according to Technical > Note from Micron tn2971_software_bch_ecc_on_linux.pdf), > this functions. The counterpart for this seems to me in bch.c > encode_bch(), which seems to run completly independent on hardware. > > Please understand my situation. At TI forum I asked since monthes with > no real help. So I started my work and succeeded 90%. U-Boot BCH8 support for OMAP3 is working, one example is tricorder board. Best regards Andreas Bießmann _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
