1# drivers/mtd/ubi/Kconfig
2
3menu "UBI - Unsorted block images"
4	depends on MTD
5
6config MTD_UBI
7	tristate "Enable UBI"
8	depends on MTD
9	select CRC32
10	help
11	  UBI is a software layer above MTD layer which admits of LVM-like
12	  logical volumes on top of MTD devices, hides some complexities of
13	  flash chips like wear and bad blocks and provides some other useful
14	  capabilities. Please, consult the MTD web site for more details
15	  (www.linux-mtd.infradead.org).
16
17config MTD_UBI_WL_THRESHOLD
18	int "UBI wear-leveling threshold"
19	default 4096
20	range 2 65536
21	depends on MTD_UBI
22	help
23	  This parameter defines the maximum difference between the highest
24	  erase counter value and the lowest erase counter value of eraseblocks
25	  of UBI devices. When this threshold is exceeded, UBI starts performing
26	  wear leveling by means of moving data from eraseblock with low erase
27	  counter to eraseblocks with high erase counter. Leave the default
28	  value if unsure.
29
30config MTD_UBI_BEB_RESERVE
31	int "Percentage of reserved eraseblocks for bad eraseblocks handling"
32	default 1
33	range 0 25
34	depends on MTD_UBI
35	help
36	  If the MTD device admits of bad eraseblocks (e.g. NAND flash), UBI
37	  reserves some amount of physical eraseblocks to handle new bad
38	  eraseblocks. For example, if a flash physical eraseblock becomes bad,
39	  UBI uses these reserved physical eraseblocks to relocate the bad one.
40	  This option specifies how many physical eraseblocks will be reserved
41	  for bad eraseblock handling (percents of total number of good flash
42	  eraseblocks). If the underlying flash does not admit of bad
43	  eraseblocks (e.g. NOR flash), this value is ignored and nothing is
44	  reserved. Leave the default value if unsure.
45
46config MTD_UBI_GLUEBI
47	bool "Emulate MTD devices"
48	default n
49	depends on MTD_UBI
50	help
51	   This option enables MTD devices emulation on top of UBI volumes: for
52	   each UBI volumes an MTD device is created, and all I/O to this MTD
53	   device is redirected to the UBI volume. This is handy to make
54	   MTD-oriented software (like JFFS2) work on top of UBI. Do not enable
55	   this if no legacy software will be used.
56
57source "drivers/mtd/ubi/Kconfig.debug"
58endmenu
59