1menu "UBI - Unsorted block images" 2 depends on MTD 3 4config MTD_UBI 5 tristate "Enable UBI" 6 depends on MTD 7 select CRC32 8 help 9 UBI is a software layer above MTD layer which admits of LVM-like 10 logical volumes on top of MTD devices, hides some complexities of 11 flash chips like wear and bad blocks and provides some other useful 12 capabilities. Please, consult the MTD web site for more details 13 (www.linux-mtd.infradead.org). 14 15config MTD_UBI_WL_THRESHOLD 16 int "UBI wear-leveling threshold" 17 default 4096 18 range 2 65536 19 depends on MTD_UBI 20 help 21 This parameter defines the maximum difference between the highest 22 erase counter value and the lowest erase counter value of eraseblocks 23 of UBI devices. When this threshold is exceeded, UBI starts performing 24 wear leveling by means of moving data from eraseblock with low erase 25 counter to eraseblocks with high erase counter. 26 27 The default value should be OK for SLC NAND flashes, NOR flashes and 28 other flashes which have eraseblock life-cycle 100000 or more. 29 However, in case of MLC NAND flashes which typically have eraseblock 30 life-cycle less than 10000, the threshold should be lessened (e.g., 31 to 128 or 256, although it does not have to be power of 2). 32 33config MTD_UBI_BEB_RESERVE 34 int "Percentage of reserved eraseblocks for bad eraseblocks handling" 35 default 1 36 range 0 25 37 depends on MTD_UBI 38 help 39 If the MTD device admits of bad eraseblocks (e.g. NAND flash), UBI 40 reserves some amount of physical eraseblocks to handle new bad 41 eraseblocks. For example, if a flash physical eraseblock becomes bad, 42 UBI uses these reserved physical eraseblocks to relocate the bad one. 43 This option specifies how many physical eraseblocks will be reserved 44 for bad eraseblock handling (percents of total number of good flash 45 eraseblocks). If the underlying flash does not admit of bad 46 eraseblocks (e.g. NOR flash), this value is ignored and nothing is 47 reserved. Leave the default value if unsure. 48 49config MTD_UBI_GLUEBI 50 tristate "MTD devices emulation driver (gluebi)" 51 default n 52 depends on MTD_UBI 53 help 54 This option enables gluebi - an additional driver which emulates MTD 55 devices on top of UBI volumes: for each UBI volumes an MTD device is 56 created, and all I/O to this MTD device is redirected to the UBI 57 volume. This is handy to make MTD-oriented software (like JFFS2) 58 work on top of UBI. Do not enable this unless you use legacy 59 software. 60 61source "drivers/mtd/ubi/Kconfig.debug" 62endmenu 63