| # 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 |