On Fri, Jul 27, 2012 at 11:24:48AM +1000, Marc Reilly wrote: > Hi Juergen, > > Thanks for your ideas. > > I managed to clear the BBT, it was a bit of a hack... the saga is below for > anyone who runs into similar problem. > > On Thursday, July 26, 2012 11:27:48 AM Juergen Beisert wrote: > > The flash blocks which contains the "bad block table" are protected by > > the "bad block table" aware MTD layer. > > > > So, the ugly way: run a bootloader which does not use the in-flash bad block > > table. Then the tables are regular blocks in the flash and can be erased. > > After that run again the bad block table aware bootloader and it will > > re-create the in-flash table. But be careful: In this case the generic > > functions scans all blocks in the NAND to collect the bad block markers in > > each NAND block's OOB. If this information is already destroyed somehow, > > this solution does not help. > > Recompiling barebox with bbt support disabled stopped the all the bad block > messages, however erasing the nand didn't clear the BBT for subsequent > reboots... > The issue was that the erase commands and functions skip erasing bad blocks, > and the blocks that held the actual BBT were being considered bad, so they > weren't getting erased. After commenting out calls to nand_block_checkbad() in > nand_write.c and block_isbad() in mtd_erase()/core.c I was able to manually > erase the blocks. (erasing actual bad blocks results in I/O error) > Next restart of barebox the BBT was regenerated with the two actual bad > blocks. > > After all that, I noticed imx_low_erase() in nand_imx.c. Probably would have > been easier to make up a command around that. This problem comes up regularly. I remember Wolfram implemented a nand 'scrub' command. He was working on i.MX28. I don't know wether his command was i.MX28 specific, but it would be nice to have such a command around. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
