2 tristate "Enable UBI - Unsorted block images"
5 UBI is a software layer above MTD layer which admits of LVM-like
6 logical volumes on top of MTD devices, hides some complexities of
7 flash chips like wear and bad blocks and provides some other useful
8 capabilities. Please, consult the MTD web site for more details
9 (www.linux-mtd.infradead.org).
13 config MTD_UBI_WL_THRESHOLD
14 int "UBI wear-leveling threshold"
18 This parameter defines the maximum difference between the highest
19 erase counter value and the lowest erase counter value of eraseblocks
20 of UBI devices. When this threshold is exceeded, UBI starts performing
21 wear leveling by means of moving data from eraseblock with low erase
22 counter to eraseblocks with high erase counter.
24 The default value should be OK for SLC NAND flashes, NOR flashes and
25 other flashes which have eraseblock life-cycle 100000 or more.
26 However, in case of MLC NAND flashes which typically have eraseblock
27 life-cycle less than 10000, the threshold should be lessened (e.g.,
28 to 128 or 256, although it does not have to be power of 2).
30 config MTD_UBI_BEB_RESERVE
31 int "Percentage of reserved eraseblocks for bad eraseblocks handling"
35 If the MTD device admits of bad eraseblocks (e.g. NAND flash), UBI
36 reserves some amount of physical eraseblocks to handle new bad
37 eraseblocks. For example, if a flash physical eraseblock becomes bad,
38 UBI uses these reserved physical eraseblocks to relocate the bad one.
39 This option specifies how many physical eraseblocks will be reserved
40 for bad eraseblock handling (percents of total number of good flash
41 eraseblocks). If the underlying flash does not admit of bad
42 eraseblocks (e.g. NOR flash), this value is ignored and nothing is
43 reserved. Leave the default value if unsure.
46 tristate "MTD devices emulation driver (gluebi)"
48 This option enables gluebi - an additional driver which emulates MTD
49 devices on top of UBI volumes: for each UBI volumes an MTD device is
50 created, and all I/O to this MTD device is redirected to the UBI
51 volume. This is handy to make MTD-oriented software (like JFFS2)
52 work on top of UBI. Do not enable this unless you use legacy
61 This option enables UBI debugging.