[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / mtd / ubi / Kconfig

menuconfig MTD_UBI
	tristate "Enable UBI - Unsorted block images"
	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).

if MTD_UBI

config MTD_UBI_WL_THRESHOLD
	int "UBI wear-leveling threshold"
	default 4096
	range 2 65536
	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 than 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
	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
	tristate "MTD devices emulation driver (gluebi)"
	help
	   This option enables gluebi - an additional driver which emulates MTD
	   devices 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 unless you use legacy
	   software.

config MTD_UBI_DEBUG
	bool "UBI debugging"
	depends on SYSFS
	select DEBUG_FS
	select KALLSYMS_ALL if KALLSYMS && DEBUG_KERNEL
	help
	  This option enables UBI debugging.

endif # MTD_UBI
Commit	Line	Data
1dd78632 HS	1	menuconfig MTD_UBI
1dd78632 HS	2	tristate "Enable UBI - Unsorted block images"
801c135c AB	3	select CRC32
	4	help
	5	UBI is a software layer above MTD layer which admits of LVM-like
	6	logical volumes on top of MTD devices, hides some complexities of
	7	flash chips like wear and bad blocks and provides some other useful
	8	capabilities. Please, consult the MTD web site for more details
	9	(www.linux-mtd.infradead.org).
	10
1dd78632 HS	11	if MTD_UBI
1dd78632 HS	12
801c135c AB	13	config MTD_UBI_WL_THRESHOLD
	14	int "UBI wear-leveling threshold"
	15	default 4096
	16	range 2 65536
801c135c AB	17	help
	18	This parameter defines the maximum difference between the highest
	19	erase counter value and the lowest erase counter value of eraseblocks
	20	of UBI devices. When this threshold is exceeded, UBI starts performing
	21	wear leveling by means of moving data from eraseblock with low erase
6e0c84e3 AB	22	counter to eraseblocks with high erase counter.
	23
	24	The default value should be OK for SLC NAND flashes, NOR flashes and
	25	other flashes which have eraseblock life-cycle 100000 or more.
	26	However, in case of MLC NAND flashes which typically have eraseblock
3f502622	27	life-cycle less than 10000, the threshold should be lessened (e.g.,
6e0c84e3	28	to 128 or 256, although it does not have to be power of 2).
801c135c AB	29
	30	config MTD_UBI_BEB_RESERVE
	31	int "Percentage of reserved eraseblocks for bad eraseblocks handling"
	32	default 1
	33	range 0 25
801c135c AB	34	help
	35	If the MTD device admits of bad eraseblocks (e.g. NAND flash), UBI
	36	reserves some amount of physical eraseblocks to handle new bad
	37	eraseblocks. For example, if a flash physical eraseblock becomes bad,
	38	UBI uses these reserved physical eraseblocks to relocate the bad one.
	39	This option specifies how many physical eraseblocks will be reserved
	40	for bad eraseblock handling (percents of total number of good flash
	41	eraseblocks). If the underlying flash does not admit of bad
	42	eraseblocks (e.g. NOR flash), this value is ignored and nothing is
	43	reserved. Leave the default value if unsure.
	44
	45	config MTD_UBI_GLUEBI
2ba3d76a	46	tristate "MTD devices emulation driver (gluebi)"
801c135c	47	help
2ba3d76a DP	48	This option enables gluebi - an additional driver which emulates MTD
	49	devices on top of UBI volumes: for each UBI volumes an MTD device is
	50	created, and all I/O to this MTD device is redirected to the UBI
	51	volume. This is handy to make MTD-oriented software (like JFFS2)
	52	work on top of UBI. Do not enable this unless you use legacy
	53	software.
801c135c	54
28237e45 AB	55	config MTD_UBI_DEBUG
	56	bool "UBI debugging"
	57	depends on SYSFS
	58	select DEBUG_FS
	59	select KALLSYMS_ALL if KALLSYMS && DEBUG_KERNEL
	60	help
	61	This option enables UBI debugging.
1dd78632 HS	62
1dd78632 HS	63	endif # MTD_UBI