64 lines
2.4 KiB
Plaintext
64 lines
2.4 KiB
Plaintext
# drivers/mtd/ubi/Kconfig
|
|
|
|
menu "UBI - Unsorted block images"
|
|
depends on MTD
|
|
|
|
config MTD_UBI
|
|
tristate "Enable UBI"
|
|
depends on MTD
|
|
select CRC32
|
|
help
|
|
UBI is a software layer above MTD layer which admits of LVM-like
|
|
logical volumes on top of MTD devices, hides some complexities of
|
|
flash chips like wear and bad blocks and provides some other useful
|
|
capabilities. Please, consult the MTD web site for more details
|
|
(www.linux-mtd.infradead.org).
|
|
|
|
config MTD_UBI_WL_THRESHOLD
|
|
int "UBI wear-leveling threshold"
|
|
default 4096
|
|
range 2 65536
|
|
depends on MTD_UBI
|
|
help
|
|
This parameter defines the maximum difference between the highest
|
|
erase counter value and the lowest erase counter value of eraseblocks
|
|
of UBI devices. When this threshold is exceeded, UBI starts performing
|
|
wear leveling by means of moving data from eraseblock with low erase
|
|
counter to eraseblocks with high erase counter.
|
|
|
|
The default value should be OK for SLC NAND flashes, NOR flashes and
|
|
other flashes which have eraseblock life-cycle 100000 or more.
|
|
However, in case of MLC NAND flashes which typically have eraseblock
|
|
life-cycle less then 10000, the threshold should be lessened (e.g.,
|
|
to 128 or 256, although it does not have to be power of 2).
|
|
|
|
config MTD_UBI_BEB_RESERVE
|
|
int "Percentage of reserved eraseblocks for bad eraseblocks handling"
|
|
default 1
|
|
range 0 25
|
|
depends on MTD_UBI
|
|
help
|
|
If the MTD device admits of bad eraseblocks (e.g. NAND flash), UBI
|
|
reserves some amount of physical eraseblocks to handle new bad
|
|
eraseblocks. For example, if a flash physical eraseblock becomes bad,
|
|
UBI uses these reserved physical eraseblocks to relocate the bad one.
|
|
This option specifies how many physical eraseblocks will be reserved
|
|
for bad eraseblock handling (percents of total number of good flash
|
|
eraseblocks). If the underlying flash does not admit of bad
|
|
eraseblocks (e.g. NOR flash), this value is ignored and nothing is
|
|
reserved. Leave the default value if unsure.
|
|
|
|
config MTD_UBI_GLUEBI
|
|
bool "Emulate MTD devices"
|
|
default n
|
|
depends on MTD_UBI
|
|
help
|
|
This option enables MTD devices emulation on top of UBI volumes: for
|
|
each UBI volumes an MTD device is created, and all I/O to this MTD
|
|
device is redirected to the UBI volume. This is handy to make
|
|
MTD-oriented software (like JFFS2) work on top of UBI. Do not enable
|
|
this if no legacy software will be used.
|
|
|
|
source "drivers/mtd/ubi/Kconfig.debug"
|
|
endmenu
|