On September 6, 2006 07:10 am, Guillermo Prandi wrote:
> > P.S. I really don't understand why TS didn't just define the FIS
> > directory as follows:
> >
> > TS-BOOTROM 0x6000-0000 - 0x6000-3fff
> > LinuxFS 0x6000-4000 - 0x6....
> > RedBoot 0x6....
> > zimage ...
> > RedBoot config ...
> >
> > If they did it that way, it would be very easy to use RedBoot to
> > replace the LinuxFS with whatever you wanted. Instead of course
> they
> > grouped the TS-BOOTROM and the LinuxFS under "(reserved)" and you
> > can't touch it with RedBoot. So we have to become RedBoot source
> > hackers to do anything non-standard with the board.
> >
>
> Perhaps being a NAND Flash the explanation comes from the fact that
> they normally have (and develop new) bad blocks. In the TS-7260 I've
> got, the (reserved) area holds a yaffs filesystem, which is aware of
> NAND Flash "problems" (or more likely "particular characteristics")
> and performs active realocation of blocks when they become
> suspicious. If you would have a normal RedBoot block, some people
> wouldn't resist to try to load an ext2/ext3 image on the partition,
> which is very unadvisable. This policy is very restrictive of course.
>
> Another reason may come from the fact that the MTD driver on the TS
> kernel does not parse the RedBoot partition at all, but has a
> hardcoded map of the partitions instead. If you would change the
> partition layout, the /dev/mtd devices would stop working (At least
> on the TS-11 kernel version I'm using).
>
> Guille
>
TS loads the 256KB RedBoot partition into memory with no ECC correction. Thats
pretty risky. The SerialBlaster bootloader loads Redboot with ECC.
Redboot seems to have jffs2. Maybe that could be used to store the linux
kernel or BSD kernels. But it looks like it need some work:
ecos/packages/fs/jffs2
I'd also consider updating the SerialBlaster NAND flash code to skip bad
blocks. So an equivalent RedBoot NAND driver (based on the SerialBlaster
code) could write an image that skipped bad blocks. The whenever Redboot
wrote and image it would skip bad blocks. And the SerialBlaster or Redboot
would know how to read these images. I don't need to worry about
wear-leveling because these images are seldom updated.
-Curtis.
>
>
>
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/ts-7000/
<*> To unsubscribe from this group, send an email to:
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
|