diff options
Diffstat (limited to 'doc/README.nand')
| -rw-r--r-- | doc/README.nand | 39 |
1 files changed, 13 insertions, 26 deletions
diff --git a/doc/README.nand b/doc/README.nand index 647a6b8..171380e 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. - - 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. + 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. + + 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 @@ -191,7 +184,7 @@ We now use a complete rewrite of the NAND code based on what is in The old NAND handling code has been re-factored and is now confined to only board-specific files and - unfortunately - to the DoC code (see below). A new configuration variable has been introduced: -CFG_NAND_LEGACY, which has to be defined in the board config file if +CONFIG_NAND_LEGACY, which has to be defined in the board config file if that board uses legacy code. The necessary changes have been made to all affected boards, and no @@ -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) |