Hello everyone, I have a question regarding the Barebox checksum verification on NAND- partitions. To verificate that the Barebox has been flashed correctly, we do a crc32 check on the nand.bb-partition. The offsets for the slots are derived from the max partition, so that the slots are equally sized. The bb-partitions are badblock-aware partitions, meaning that the bad-marked blocks are just skipped. This means, that the overall size of the bb-partition also decreases relative to the number of bad- blocks. Our problem here is, in case a badblock occurs on a block prior to the slots, the offset to the slots where the Barebox-code resides in the bb-partition also changes. Here an example: The startpage of slot1 is 0x240000. This is the real address, where Barebox is flashed into and can also be dumped using the original nand0-partition. Now, when a bad-block occurs prior to the startpage of slot1, let's take for example the block at 0x140000, then offset of slot1 changes also in the nand0.bb partition. In the original partition nand0, slot1 is still at 0x240000, but on nand0.bb, slot1 has been moved one block prior to the original offset and changed to 0x220000. Taking into account that with time the NAND cells will worn out and degrate even more, we need to calculate the offset for every board to- be tested and perform the crc32 check after that. Using the original nand0-partition is also out of option, since the verification would also fail when a badblock would occur somewhere in the slot-area (in case of the above example, 0x260000). Is there a proper way to do a checksum verification on NAND-flash, which I'm not familiar with? Can the size of the partitions be somehow determined dynamically? How do the experts handle this? Thank you in advance. -- With Regards, Yunus Bas -Software Engineer- PHYTEC Messtechnik GmbH Robert-Koch-Str. 39 55129 Mainz Germany Tel.: +49 (0)6131 9221- 466 Web: www.phytec.de Sie finden uns auch auf: Facebook, LinkedIn, Xing, YouTube PHYTEC Messtechnik GmbH | Robert-Koch-Str. 39 | 55129 Mainz, Germany Geschäftsführer: Dipl.-Ing. Michael Mitezki, Dipl.-Ing. Bodo Huber | Handelsregister Mainz HRB 4656 | Finanzamt Mainz | St.Nr. 266500608, DE 149059855 This E-Mail may contain confidential or privileged information. If you are not the intended recipient (or have received this E-Mail in error) please notify the sender immediately and destroy this E-Mail. Any unauthorized copying, disclosure or distribution of the material in this E-Mail is strictly forbidden. _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
