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| author | Scott Wood <scottwood@freescale.com> | 2008-06-12 13:13:23 -0500 | 
|---|---|---|
| committer | Scott Wood <scottwood@freescale.com> | 2008-08-12 11:31:27 -0500 | 
| commit | 984e03cdf1431bb593aeaa1b74c445d616f955d3 (patch) | |
| tree | 9ca147809a8266bd016050a0789d4b19913d7e40 /doc/README.nand | |
| parent | e1c3dbada349992875934575c97b328ab2cb33ca (diff) | |
| download | olio-uboot-2014.01-984e03cdf1431bb593aeaa1b74c445d616f955d3.tar.xz olio-uboot-2014.01-984e03cdf1431bb593aeaa1b74c445d616f955d3.zip | |
NAND: Always skip blocks on read/write/boot.
Use of the non-skipping versions was almost always (if not always)
an error, and no valid use case has been identified.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Diffstat (limited to 'doc/README.nand')
| -rw-r--r-- | doc/README.nand | 35 | 
1 files changed, 11 insertions, 24 deletions
| diff --git a/doc/README.nand b/doc/README.nand index 647a6b8e6..0ad5e18dd 100644 --- a/doc/README.nand +++ b/doc/README.nand @@ -57,14 +57,9 @@ Commands:        Print information about all of the NAND devices found.     nand read addr ofs|partition size -      Read `size' bytes from `ofs' in NAND flash to `addr'. If a page -      cannot be read because it is marked bad or an uncorrectable data -      error is found the command stops with an error. - -   nand read.jffs2 addr ofs|partition size -      Like `read', but the data for blocks that are marked bad is read as -      0xff. This gives a readable JFFS2 image that can be processed by -      the JFFS2 commands such as ls and fsload. +      Read `size' bytes from `ofs' in NAND flash to `addr'.  Blocks that +      are marked bad are skipped.  If a page cannot be read because an +      uncorrectable data error is found, the command stops with an error.     nand read.oob addr ofs|partition size        Read `size' bytes from the out-of-band data area corresponding to @@ -73,17 +68,15 @@ Commands:        for bad blocks or ECC errors.     nand write addr ofs|partition size -      Write `size' bytes from `addr' to `ofs' in NAND flash. If a page -      cannot be written because it is marked bad or the write fails the -      command stops with an error. +      Write `size' bytes from `addr' to `ofs' in NAND flash.  Blocks that +      are marked bad are skipped.  If a page cannot be read because an +      uncorrectable data error is found, the command stops with an error. -   nand write.jffs2 addr ofs|partition size -      Like `write', but blocks that are marked bad are skipped and the -      data is written to the next block instead. This allows writing -      a JFFS2 image, as long as the image is short enough to fit even -      after skipping the bad blocks. Compact images, such as those -      produced by mkfs.jffs2 should work well, but loading an image copied -      from another flash is going to be trouble if there are any bad blocks. +      As JFFS2 skips blocks similarly, this allows writing a JFFS2 image, +      as long as the image is short enough to fit even after skipping the +      bad blocks.  Compact images, such as those produced by mkfs.jffs2 +      should work well, but loading an image copied from another flash is +      going to be trouble if there are any bad blocks.     nand write.oob addr ofs|partition size        Write `size' bytes from `addr' to the out-of-band data area @@ -215,12 +208,6 @@ JFFS2 related commands:    using both the new code which is able to skip bad blocks    "nand erase clean" additionally writes JFFS2-cleanmarkers in the oob. -  "nand write.jffs2" -  like "nand write" but skip found bad eraseblocks - -  "nand read.jffs2" -  like "nand read" but skip found bad eraseblocks -  Miscellaneous and testing commands:    "markbad [offset]"    create an artificial bad block (for testing bad block handling) |