Bootloader support for UBI images
dedekind at infradead.org
Wed Jul 2 05:02:58 EDT 2008
On Wed, 2008-07-02 at 08:57 +0100, Richard Titmuss wrote:
> Right, I was thinking that it would allow any number of volumes for
> renaming. I am also not sure about the interface, and was hoping to get
> some suggestions here. I will think about it and propose something in a
> few days.
Do you absolutely need multiple renames? Could you live with one at
> > So you use the sub-page read patch BTW?
> No, I'd missed that. Where is it?
Here is the relevant thread. Some people already use that patch. dwmw2
was positive about it and told he would accept it.
> Ok, that is possible. This would also have to include the bad block and
> bit flip status for each PEB. At the moment the Redboot flash api does
> not make this available, so it would mean extending Redboot or writing
> custom flash drivers to access this information.
Well, bit-flip information is not mandatory and may be done later as
an improvement. Bad-block information have to be available.
> > I did not actually catch the second part (LER and PER) tables - this is
> > something I am not aware of. UBI has only volume table on flash, the
> > other things are in-memory and build by scanning.
> It was a proposal to _add_ an addition table, that provided a LER to PER
> mapping for static volumes.
Ah, this is s/LER/LEB/, s/PER/PEB/.
> If this table was stored near the beginning
> of the flash, then it could be accessed without a full scan. This could
> only be used if the UBI volume was mounted read-only, any write
> operations would require scanning all the flash blocks. This is an
> alternative approach to passing data from the bootloader to the kernel.
Well, may be done, but the R/O limitation seems to be too hard.
Artem Bityutskiy (Битюцкий Артём)
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