Hello,
When using the nand, with regards to its implementation in U-boot or linux, does a good strategy would be to map Nand to areas with *space* between the end of one area to the start on another ? It seems a good ideas becuase of the bad block issue and the skipping of bad blocks. I did not find information about the Nand usage.
Best Regards,
Ran
Dear Ran Shalit,
In message AANLkTimCUE1ZbFB3eupKYcO_9=Ls4hKbqW=U4v8XfBXU@mail.gmail.com you wrote:
When using the nand, with regards to its implementation in U-boot or linux, does a good strategy would be to map Nand to areas with *space* between the end of one area to the start on another ? It seems a good ideas becuase of the bad block issue and the skipping of bad blocks. I did not find information about the Nand usage.
Your question makes no sense. NAND is not a memory device that could be mapped to some address range - insted,itis a strage device that can be accessed only through some controller interface, similar to the ATA controller on a harddisk.
Best regards,
Wolfgang Denk
Hello,
I think my question was not very well expressed. I ment to ask about the mapping of the partitions inside the NAND: Does each partitions need some spare blocks (padding block) becuase of the bad block skipping in the Nand ? As I said, I did not find any information about the strategy of mapping partitions in the Nand.
Best Regards,
Ran
Dear ran shalit,
In message 31183736.post@talk.nabble.com you wrote:
I think my question was not very well expressed. I ment to ask about the mapping of the partitions inside the NAND: Does each partitions need some spare blocks (padding block) becuase of the bad block skipping in the Nand ? As I said, I did not find any information about the strategy of mapping partitions in the Nand.
As you are talking about partitions, I assume you refert to the MTD partitioning. In this case the bad block handling needs to be done in by the file system code, when you create a file system insinde one of the partitions.
[Note that this differs from UBI, where bad block handling is done for the whole device, independent of the volumes that you create on top of it.]
Best regards,
Wolfgang Denk
wd wrote:
I think my question was not very well expressed. I ment to ask about the mapping of the partitions inside the NAND: Does each partitions need some spare blocks (padding block) becuase of the bad block skipping in the Nand ? As I said, I did not find any information about the strategy of mapping partitions in the Nand.
As you are talking about partitions, I assume you refert to the MTD partitioning. In this case the bad block handling needs to be done in by the file system code, when you create a file system insinde one of the partitions.
[Note that this differs from UBI, where bad block handling is done for the whole device, independent of the volumes that you create on top of it.]
Sorry, I probably use the wrong terms in my question. I do not mean partition using file system, but just saving files using the u-boot interface, for example saving the kernel file in some space in the NAND and for the u-boot file in another space in the NAND, and all done with the given write command in the uboot (nand write...). And again with this u-boot interface I still need some strategy for deciding where to put each file.
Thanks again,
Ran
On Fri, 18 Mar 2011 11:54:43 -0700 ran shalit ranshalit@gmail.com wrote:
wd wrote:
I think my question was not very well expressed. I ment to ask about the mapping of the partitions inside the NAND: Does each partitions need some spare blocks (padding block) becuase of the bad block skipping in the Nand ? As I said, I did not find any information about the strategy of mapping partitions in the Nand.
As you are talking about partitions, I assume you refert to the MTD partitioning. In this case the bad block handling needs to be done in by the file system code, when you create a file system insinde one of the partitions.
[Note that this differs from UBI, where bad block handling is done for the whole device, independent of the volumes that you create on top of it.]
Sorry, I probably use the wrong terms in my question. I do not mean partition using file system, but just saving files using the u-boot interface, for example saving the kernel file in some space in the NAND and for the u-boot file in another space in the NAND, and all done with the given write command in the uboot (nand write...). And again with this u-boot interface I still need some strategy for deciding where to put each file.
Yes, when placing raw files in NAND, you want to leave some space for bad blocks.
-Scott
participants (4)
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Ran Shalit -
ran shalit
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Scott Wood -
Wolfgang Denk