On Tuesday 12 May 2009, Nicolas Pitre wrote: > On Tue, 12 May 2009, David Brownell wrote: > > > On Tuesday 12 May 2009, Nicolas Pitre wrote: > > > The Kirkwood bootrom expects 4-bit ECC from NAND. This adds > > > 4-bit ECC computation to the NAND support and uses it with SheevaPlug. > > > > Hmm, from the outside this sounds like the 4-bit ECC in some > > TI DaVinci family chips: 10 bytes ECC per 512 bytes data, > > delivered as eight 10-bit values. > > Isn't ECC on the Davinci computed in hardware by the NAND controller?
Yes, on newer chips like DM335/355/365, DA830 (and OMAP-L137). Older chips just have 1-bit HW ECC. > But otherwise it is a Reed-Solomon implementation using a x^10 + x^3 + 1 > polinomial. Anyone with the same ECC characteristics may reuse this > code quite trivially. Stay tuned for Linux support soon as well. Linux *software* support? Patches for the DaVinci 4-bit ECC hardware are slowly wending their way to mainline ... the issue that's not quite resolved is how to use it with large page chips (since there seems to be agreement that clobbering badblock markers via ECC_HW_SYNDROME is Not Good). > > Maybe some of this should share code ... probably not the > > "compute backwards" part though! > > No comment ... > > > Nicolas > _______________________________________________ Openocd-development mailing list Openocd-development@lists.berlios.de https://lists.berlios.de/mailman/listinfo/openocd-development
