Hi, Huang Shijie wrote: > 于 2014年03月26日 16:51, Lothar Waßmann 写道: > > I don't see why this should not be supported on i.MX28 (i.MX23 doesn't > > do byteswapping anyway, so this wouldn't change anything for i.MX23). > > The partitions used by Linux need not necessarily be accessible for the > > Boot ROM code (and vice versa). > But the first partition used to store the u-boot is accessible for the ROM. > Whether this partition is available to Linux depends on the partition table passed in the DT. > Please see "Figure 12-13" in the 12.12.1.12: > "In order to preserve the BI (bad block information), flash updater > or gang programmer > applications need to swap Bad Block Information (BI) data to byte 0 of > metadata area for > every page before programming NAND Flash. ROM when loading firmware, > copies back > the value at metadata[0] to BI offset in page data. The following figure > shows how the > factory bad block marker is preserved." > The inspection of the BB markers is only a fallback for the case that there is no DBBT. From the same chapter that you quoted above: | ROM uses DBBT to skip any bad block that falls within firmware data | on NAND Flash device. | If the address of DBBT Search Area in FCB is 0, ROM will rely on | factory marked bad block markers to find out if a block is good or bad. Thus, even the boot ROM of i.MX28 can well live without blockmark swapping. Lothar Waßmann -- ___________________________________________________________ Ka-Ro electronics GmbH | Pascalstraße 22 | D - 52076 Aachen Phone: +49 2408 1402-0 | Fax: +49 2408 1402-10 Geschäftsführer: Matthias Kaussen Handelsregistereintrag: Amtsgericht Aachen, HRB 4996 www.karo-electronics.de | info@xxxxxxxxxxxxxxxxxxx ___________________________________________________________ -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
