1menu "UBI support"
2
3config 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	depends on MTD
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_BLOCK
25	def_bool n
26
27config MTD_UBI_MODULE
28	def_bool y
29	help
30	  ubi_init() disables returning error codes when built into the Linux
31	  kernel so that it doesn't hang the Linux kernel boot process.  Since
32	  the U-Boot driver code depends on getting valid error codes from this
33	  function we just tell the UBI layer that we are building as a module
34	  (which only enables the additional error reporting).
35
36config MTD_UBI_WL_THRESHOLD
37	int "UBI wear-leveling threshold"
38	default 4096
39	range 2 65536
40	help
41	  This parameter defines the maximum difference between the highest
42	  erase counter value and the lowest erase counter value of eraseblocks
43	  of UBI devices. When this threshold is exceeded, UBI starts performing
44	  wear leveling by means of moving data from eraseblock with low erase
45	  counter to eraseblocks with high erase counter.
46
47	  The default value should be OK for SLC NAND flashes, NOR flashes and
48	  other flashes which have eraseblock life-cycle 100000 or more.
49	  However, in case of MLC NAND flashes which typically have eraseblock
50	  life-cycle less than 10000, the threshold should be lessened (e.g.,
51	  to 128 or 256, although it does not have to be power of 2).
52
53config MTD_UBI_BEB_LIMIT
54	int "Maximum expected bad eraseblock count per 1024 eraseblocks"
55	default 20
56	range 0 768
57	help
58	  This option specifies the maximum bad physical eraseblocks UBI
59	  expects on the MTD device (per 1024 eraseblocks). If the underlying
60	  flash does not admit of bad eraseblocks (e.g. NOR flash), this value
61	  is ignored.
62
63	  NAND datasheets often specify the minimum and maximum NVM (Number of
64	  Valid Blocks) for the flashes' endurance lifetime. The maximum
65	  expected bad eraseblocks per 1024 eraseblocks then can be calculated
66	  as "1024 * (1 - MinNVB / MaxNVB)", which gives 20 for most NANDs
67	  (MaxNVB is basically the total count of eraseblocks on the chip).
68
69	  To put it differently, if this value is 20, UBI will try to reserve
70	  about 1.9% of physical eraseblocks for bad blocks handling. And that
71	  will be 1.9% of eraseblocks on the entire NAND chip, not just the MTD
72	  partition UBI attaches. This means that if you have, say, a NAND
73	  flash chip admits maximum 40 bad eraseblocks, and it is split on two
74	  MTD partitions of the same size, UBI will reserve 40 eraseblocks when
75	  attaching a partition.
76
77	  This option can be overridden by the "mtd=" UBI module parameter or
78	  by the "attach" ioctl.
79
80	  Leave the default value if unsure.
81
82config MTD_UBI_FASTMAP
83	bool "UBI Fastmap (Experimental feature)"
84	help
85	   Important: this feature is experimental so far and the on-flash
86	   format for fastmap may change in the next kernel versions
87
88	   Fastmap is a mechanism which allows attaching an UBI device
89	   in nearly constant time. Instead of scanning the whole MTD device it
90	   only has to locate a checkpoint (called fastmap) on the device.
91	   The on-flash fastmap contains all information needed to attach
92	   the device. Using fastmap makes only sense on large devices where
93	   attaching by scanning takes long. UBI will not automatically install
94	   a fastmap on old images, but you can set the UBI module parameter
95	   fm_autoconvert to 1 if you want so. Please note that fastmap-enabled
96	   images are still usable with UBI implementations without
97	   fastmap support. On typical flash devices the whole fastmap fits
98	   into one PEB. UBI will reserve PEBs to hold two fastmaps.
99
100	   If in doubt, say "N".
101
102config MTD_UBI_FASTMAP_AUTOCONVERT
103	int "enable UBI Fastmap autoconvert"
104	depends on MTD_UBI_FASTMAP
105	default 0
106	help
107	  Set this parameter to enable fastmap automatically on images
108	  without a fastmap.
109
110config MTD_UBI_FM_DEBUG
111	int "Enable UBI fastmap debug"
112	depends on MTD_UBI_FASTMAP
113	default 0
114	help
115	  Enable UBI fastmap debug
116
117config UBI_BLOCK
118	bool "Enable UBI block device support"
119	select BLK
120	help
121	  Enable UBI block device support using blk_ops abstraction.
122
123endif # MTD_UBI
124endmenu # "Enable UBI - Unsorted block images"
125