A solution for a particular "Magic bitmask 0x1985 not found" error

Brian T. btuch at usa.net
Fri May 23 12:11:26 EDT 2003


I have seen this also, but it was caused by uploading the jffs2 image to the
unit using xmodem, which annoyingly pads the last (128 - (SIZE % 128)) of
the file being uploaded with 0x1A.  I fixed this by padding the end of the
file with 0xFF prior to upload to make it look erased instead.

Funny, we actually just found this 1/2 hour ago.

Regards,

-Brian


> Chuck Meade wrote:
>
> >Hello,
> >
> >Regarding this error message sequence at boot time:
> >
> >...
> >jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00040000:
0x2003 instead
> >jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00040004:
0x000c instead
> >jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00040008:
0xdc6d instead
> >jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00080000:
0x2003 instead
> >jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00080004:
0x000c instead
> >jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00080008:
0xdc6d instead
> >...
> >
> >I had this happen for a long time each time I booted Linux.
> >I finally found a solution which stopped it, and maybe this
> >will help anyone else out there who is getting it.  I have
> >seen it mentioned in the archives, so I know I am not the
> >first to get this error "triplet".
> >
> >The solution was to simply make the jffs2 filesystem with a
> >newer version of mkfs.jffs2.  I had been using version 1.9
> >(see output of your "mkfs.jffs2 --version") when I got the
> >errors, and it stopped when I began using version 1.35.  So
> >it looks like this message is due to compatibility issues
> >between the jffs2 support in your kernel and the version of
> >mkfs.jffs2 that you use.
> >
> >One thing of note is that the filesystem did work OK after
> >spewing all these msgs, they were just a nuisance -- I guess
> >that's why I lived with them for a while before seeking the
> >answer. :)
> >
> >Chuck Meade
> >
> >
> >______________________________________________________
> >Linux MTD discussion mailing list
> >http://lists.infradead.org/mailman/listinfo/linux-mtd/
> >
> >
> >
> It seems that we are having similiar experiences. I have also
> experienced a similiar problem. The addresses were different but the
> values returned were the same.  When I updated to the latest snapshot of
> the mkfs.jffs2 utility and started with a fresh file system, the
> messages went away but only briefly.  After I had been exercising the
> file system, the messages returned again when powering up.
>
> I investigated further and came to the conclusion that the file system
> was unable to "reclaim" the first node on an erase block. In my case
> these are the nodes at addresses on a multiple of 0x20000.  I verified
> this by completing filling my file system, then erasing the entire
> contents, then rebooting the system.  When I did this, the message:
> jffs2_scan_eraseblock(): Magic bitmask 0x1985 not .... at 0x.....20000:
> 0x2003 instead ... occurred for every eraseblock boundary in the mounted
> partition.
>
> This problem is just another non-critical item on my open issues list. I
> will be returning to it at a later date. I expect that your problem has
> just been masked by the creation of the new file system. It may be
> worthwhile to test for this problem in a manner similiar to mine.
>





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