From abb7a31b4d8f8f60a19637031e68b6c296aeb07d Mon Sep 17 00:00:00 2001
From: Brian Norris
Lets introduce symbols:
+Let's introduce symbols:
0xFF
's to these pages, so they will be
-written to twice! However, many NAND flashes require NAND pages to be written
-only once, even if the data contains only 0xFF
bytes.
+from the fourth one as free, and will write data there. If the flasher program
+has already written 0xFF
's to these pages, then any new UBIFS data
+will cause a second write. However, many NAND flashes require NAND pages to be
+written only once, even if the data contains only 0xFF
bytes.
To put it differently, writing 0xFF
bytes may have side-effects.
What the flasher has to do is to drop all empty NAND pages from the end of the
diff --git a/doc/ubifs.xml b/doc/ubifs.xml
index 44405d6..c1f54b5 100644
--- a/doc/ubifs.xml
+++ b/doc/ubifs.xml
@@ -666,7 +666,7 @@ NOTES
This is true for UBIFS (except of the "some buggy implementations" part, -because UBIFS does reserves space for cached dirty data). This is also true for +because UBIFS does reserve space for cached dirty data). This is also true for JFFS2, as well as for any other Linux file system.
However, some (perhaps not very good) user-space programmers do not take diff --git a/faq/nand.xml b/faq/nand.xml index e142de8..05f0fbf 100644 --- a/faq/nand.xml +++ b/faq/nand.xml @@ -92,7 +92,7 @@ necessary before you copy a filesystem image to the chip.
Technically yes, as long as this MTD partition does not contain bad blocks. But
-it is generally a bad idea. For bad block aware copying, batter use nandwrite
+it is generally a bad idea. For bad block aware copying, use nandwrite
from the mtd-utils
package.
On NAND devices that support sub-page accesses, ubiformat
may choose a different location for the
-VID header to the kernel UBI driver
+VID header to the kernel UBI driver.
This can result in the following error when attaching to a UBI device:
@@ -559,7 +559,7 @@ ubi.mtd=0,2048What is a sub-page?
-Please, refer this section.
+Please, refer to this section.
@@ -857,7 +857,7 @@ is a similar table for UBI.Extra self-checks
UBI contains various internal self-check functions which are often -very useful for debugging or testing. Please, refer the corresponding +very useful for debugging or testing. Please, refer to the corresponding UBIFS self-checks section for more information, because UBI extra self-checks are very similar, just a bit simpler. Here is a similar table for UBI.
diff --git a/faq/ubifs.xml b/faq/ubifs.xml index 0274b52..8b61fc7 100644 --- a/faq/ubifs.xml +++ b/faq/ubifs.xml @@ -188,7 +188,7 @@ by running themtdinfo
tool with-u
parameter. Of course, the tool has to be run on the target system. -Please, refer this for more +
Please, refer to this for more information about how to find these parameters.
And optionally, you should decide which compression algorithm you want @@ -264,7 +264,7 @@ vol_flags=autoresize
The ubinize
utility requires volumes description file. Please,
-refer this section for more
+refer to this section for more
ubinize
usage information.
In the example, the ubinize.cfg
file tells ubinize
@@ -628,7 +628,7 @@ provably want the file-system doing inode updates every time they are read.
Not, it does not, which means you cannot export UBIFS file-system via NFS. +
No, it does not, which means you cannot export UBIFS file-systems via NFS. We did make an attempt to support NFS, but the support was not exactly correct so it was dropped, and we have never found time to come back to that. Please, refer to this thread @@ -682,15 +682,15 @@ compression, write-back, space wastage at the end of logical eraseblocks, garbage-collection, etc. Please, refer this section for details.
-Note, JFFS2 also has problems with free space predictions, but in average, -it reports much more accurate amount of free space. However, JFFS2 may lie and +
Note, JFFS2 also has problems with free space predictions, but on average, +it reports free space much more accurately. However, JFFS2 may lie and report more free space than it actually has. For example, we experienced situations when JFFS2 reported 8MiB free space, while we were able to write only 2 MiB of data. This makes some user-space applications very unhappy.
-UBIFS also lies, but it always report less space that user may +
UBIFS also lies, but it always reports less space than the user may actually write. For example, it may report 2MiB of free space, but if you -start writing to it, may be able to write 4MiB there (even if you have +start writing to it, you may be able to write 4MiB (even if you have compression disabled).
Thus, the only way to find out precise amount of free space is to -- 2.49.0