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authorHeiko Schocher <hs@denx.de>2014-06-24 10:10:04 +0200
committerTom Rini <trini@ti.com>2014-08-25 19:25:55 -0400
commitff94bc40af3481d47546595ba73c136de6af6929 (patch)
tree858119077e2ca8a992589185c36bd431e4a8c80e /README
parent0c06db59836746c5caf397e642cd0f2bf1cc20a6 (diff)
mtd, ubi, ubifs: resync with Linux-3.14
resync ubi subsystem with linux: commit 455c6fdbd219161bd09b1165f11699d6d73de11c Author: Linus Torvalds <torvalds@linux-foundation.org> Date: Sun Mar 30 20:40:15 2014 -0700 Linux 3.14 A nice side effect of this, is we introduce UBI Fastmap support to U-Boot. Signed-off-by: Heiko Schocher <hs@denx.de> Signed-off-by: Tom Rini <trini@ti.com> Cc: Marek Vasut <marex@denx.de> Cc: Sergey Lapin <slapin@ossfans.org> Cc: Scott Wood <scottwood@freescale.com> Cc: Joerg Krause <jkrause@posteo.de>
Diffstat (limited to 'README')
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diff --git a/README b/README
index 14d6b227d68..1e63f048efe 100644
--- a/README
+++ b/README
@@ -3338,6 +3338,9 @@ FIT uImage format:
Adds the MTD partitioning infrastructure from the Linux
kernel. Needed for UBI support.
+ CONFIG_MTD_NAND_VERIFY_WRITE
+ verify if the written data is correct reread.
+
- UBI support
CONFIG_CMD_UBI
@@ -3351,6 +3354,64 @@ FIT uImage format:
Make the verbose messages from UBI stop printing. This leaves
warnings and errors enabled.
+
+ CONFIG_MTD_UBI_WL_THRESHOLD
+ 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).
+
+ default: 4096
+
+ CONFIG_MTD_UBI_BEB_LIMIT
+ This option specifies the maximum bad physical eraseblocks UBI
+ expects on the MTD device (per 1024 eraseblocks). If the
+ underlying flash does not admit of bad eraseblocks (e.g. NOR
+ flash), this value is ignored.
+
+ NAND datasheets often specify the minimum and maximum NVM
+ (Number of Valid Blocks) for the flashes' endurance lifetime.
+ The maximum expected bad eraseblocks per 1024 eraseblocks
+ then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
+ which gives 20 for most NANDs (MaxNVB is basically the total
+ count of eraseblocks on the chip).
+
+ To put it differently, if this value is 20, UBI will try to
+ reserve about 1.9% of physical eraseblocks for bad blocks
+ handling. And that will be 1.9% of eraseblocks on the entire
+ NAND chip, not just the MTD partition UBI attaches. This means
+ that if you have, say, a NAND flash chip admits maximum 40 bad
+ eraseblocks, and it is split on two MTD partitions of the same
+ size, UBI will reserve 40 eraseblocks when attaching a
+ partition.
+
+ default: 20
+
+ CONFIG_MTD_UBI_FASTMAP
+ Fastmap is a mechanism which allows attaching an UBI device
+ in nearly constant time. Instead of scanning the whole MTD device it
+ only has to locate a checkpoint (called fastmap) on the device.
+ The on-flash fastmap contains all information needed to attach
+ the device. Using fastmap makes only sense on large devices where
+ attaching by scanning takes long. UBI will not automatically install
+ a fastmap on old images, but you can set the UBI parameter
+ CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
+ that fastmap-enabled images are still usable with UBI implementations
+ without fastmap support. On typical flash devices the whole fastmap
+ fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
+
+ CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
+ Set this parameter to enable fastmap automatically on images
+ without a fastmap.
+ default: 0
+
- UBIFS support
CONFIG_CMD_UBIFS