LXR uboot/drivers/mtd/ubi/Kconfig

   1menu "UBI support"
   2
   3config CONFIG_UBI_SILENCE_MSG
   4        bool "UBI silence verbose messages"
   5        default ENV_IS_IN_UBI
   6        help
   7          Make the verbose messages from UBI stop printing. This leaves
   8          warnings and errors enabled.
   9
  10config MTD_UBI
  11        bool "Enable UBI - Unsorted block images"
  12        select CRC32
  13        select RBTREE
  14        select MTD_PARTITIONS
  15        help
  16          UBI is a software layer above MTD layer which admits of LVM-like
  17          logical volumes on top of MTD devices, hides some complexities of
  18          flash chips like wear and bad blocks and provides some other useful
  19          capabilities. Please, consult the MTD web site for more details
  20          (www.linux-mtd.infradead.org).
  21
  22if MTD_UBI
  23
  24config MTD_UBI_WL_THRESHOLD
  25        int "UBI wear-leveling threshold"
  26        default 4096
  27        range 2 65536
  28        help
  29          This parameter defines the maximum difference between the highest
  30          erase counter value and the lowest erase counter value of eraseblocks
  31          of UBI devices. When this threshold is exceeded, UBI starts performing
  32          wear leveling by means of moving data from eraseblock with low erase
  33          counter to eraseblocks with high erase counter.
  34
  35          The default value should be OK for SLC NAND flashes, NOR flashes and
  36          other flashes which have eraseblock life-cycle 100000 or more.
  37          However, in case of MLC NAND flashes which typically have eraseblock
  38          life-cycle less than 10000, the threshold should be lessened (e.g.,
  39          to 128 or 256, although it does not have to be power of 2).
  40
  41config MTD_UBI_BEB_LIMIT
  42        int "Maximum expected bad eraseblock count per 1024 eraseblocks"
  43        default 20
  44        range 0 768
  45        help
  46          This option specifies the maximum bad physical eraseblocks UBI
  47          expects on the MTD device (per 1024 eraseblocks). If the underlying
  48          flash does not admit of bad eraseblocks (e.g. NOR flash), this value
  49          is ignored.
  50
  51          NAND datasheets often specify the minimum and maximum NVM (Number of
  52          Valid Blocks) for the flashes' endurance lifetime. The maximum
  53          expected bad eraseblocks per 1024 eraseblocks then can be calculated
  54          as "1024 * (1 - MinNVB / MaxNVB)", which gives 20 for most NANDs
  55          (MaxNVB is basically the total count of eraseblocks on the chip).
  56
  57          To put it differently, if this value is 20, UBI will try to reserve
  58          about 1.9% of physical eraseblocks for bad blocks handling. And that
  59          will be 1.9% of eraseblocks on the entire NAND chip, not just the MTD
  60          partition UBI attaches. This means that if you have, say, a NAND
  61          flash chip admits maximum 40 bad eraseblocks, and it is split on two
  62          MTD partitions of the same size, UBI will reserve 40 eraseblocks when
  63          attaching a partition.
  64
  65          This option can be overridden by the "mtd=" UBI module parameter or
  66          by the "attach" ioctl.
  67
  68          Leave the default value if unsure.
  69
  70config MTD_UBI_FASTMAP
  71        bool "UBI Fastmap (Experimental feature)"
  72        default n
  73        help
  74           Important: this feature is experimental so far and the on-flash
  75           format for fastmap may change in the next kernel versions
  76
  77           Fastmap is a mechanism which allows attaching an UBI device
  78           in nearly constant time. Instead of scanning the whole MTD device it
  79           only has to locate a checkpoint (called fastmap) on the device.
  80           The on-flash fastmap contains all information needed to attach
  81           the device. Using fastmap makes only sense on large devices where
  82           attaching by scanning takes long. UBI will not automatically install
  83           a fastmap on old images, but you can set the UBI module parameter
  84           fm_autoconvert to 1 if you want so. Please note that fastmap-enabled
  85           images are still usable with UBI implementations without
  86           fastmap support. On typical flash devices the whole fastmap fits
  87           into one PEB. UBI will reserve PEBs to hold two fastmaps.
  88
  89           If in doubt, say "N".
  90
  91config MTD_UBI_FASTMAP_AUTOCONVERT
  92        int "enable UBI Fastmap autoconvert"
  93        depends on MTD_UBI_FASTMAP
  94        default 0
  95        help
  96          Set this parameter to enable fastmap automatically on images
  97          without a fastmap.
  98
  99config MTD_UBI_FM_DEBUG
 100        int "Enable UBI fastmap debug"
 101        depends on MTD_UBI_FASTMAP
 102        default 0
 103        help
 104          Enable UBI fastmap debug
 105
 106endif # MTD_UBI
 107endmenu # "Enable UBI - Unsorted block images"
 108