mtd nand issue

mtd nand issue

[syed riyaz]

Hi I use a 2K page size 1 GB nand chip on a mx31 ads basd board. At redboot level, read and write happpen perfectly. Even in kernel, flash_eraseall is fine. Then i did nanddump -p and saw 0xff on all addresses. So i believe the nand driver is fine.I am trying to use a nand partition as my rootfilesystem. I have partioned nand into 4 mtd blocks. 60 MB for the first 3 and and the remaining 820 in the 4th block. I created a 8 MB jffs2 file system named rootfs.jffs2 with the proper erase size. Wrote to mtd block 6 usingnandwrite /dev/mtd/6 rootfs.jffs2When linux mounted this block, i went in fine for the first time. But subsequent booting returned lot of CRC errors until the file system was hopelessly currupted. Any help appreciated.The messages are likemtd->read:0x100 bytes from block 0 CRC error.I read somewhere that the factory information about bad blocks is stores in first block and if erased will lead to errors. Pleas elaborate if you know.Please
 answer my queries so i understand things a litle better.1) Is it ok to flash a 8 MB image on a 60 MB partion. Are the errors because the remaining partition doesnt match?2) If i specify "root=/dev/mtdblock6" while booting, does the kernel see only mtd7 as available space or will mtd5 and mtd7 and mtd8 will also be available as user space.3)What does nandwrite -a -p mean?

 Thanking you


      

Re: mtd nand issue

[Nils Faerber]

syed riyaz schrieb:
> Hi
Hi!

> I use a 2K page size 1 GB nand chip on a mx31 ads basd board. At
redboot level, read and write happpen perfectly. Even in kernel,
flash_eraseall is fine. Then i did nanddump -p and saw 0xff on all
addresses. So i believe the nand driver is fine.I am trying to use a
nand partition as my rootfilesystem. I have partioned nand into 4 mtd
blocks. 60 MB for the first 3 and and the remaining 820 in the 4th
block. I created a 8 MB jffs2 file system named rootfs.jffs2 with the
proper erase size. Wrote to mtd block 6 usingnandwrite /dev/mtd/6
rootfs.jffs2When linux mounted this block, i went in fine for the first
time. But subsequent booting returned lot of CRC errors until the file
system was hopelessly currupted. Any help appreciated.The messages are
likemtd->read:0x100 bytes from block 0 CRC error.I read somewhere that
the factory information about bad blocks is stores in first block and if
erased will lead to errors. Pleas elaborate if you know.Please
>  answer my queries so i understand things a litle better.1) Is it ok to flash a 8 MB image on a 60 MB partion. Are the errors because the remaining partition doesnt match?2) If i specify "root=/dev/mtdblock6" while booting, does the kernel see only mtd7 as available space or will mtd5 and mtd7 and mtd8 will also be available as user space.3)What does nandwrite -a -p mean?

Did you give proper option to mkfs.jffs2 for eraseblockzize and such?
If not, do it - it should improve the situation ;)

>  Thanking you
Cheers
  nils faerber

-- 
kernel concepts GbR        Tel: +49-271-771091-12
Sieghuetter Hauptweg 48    Fax: +49-271-771091-19
D-57072 Siegen             Mob: +49-176-21024535
http://www.kernelconcepts.de