[U-Boot] [PATCH v2] sunxi_nand_spl: Be smarter about where to look for backup u-boot.bin

[Ian Campbell <ijc+uboot@hellion.org.uk>]

On Mon, 2015-09-21 at 13:24 +0200, Hans de Goede wrote:
> Hi,
> 
> On 21-09-15 12:22, Ian Campbell wrote:
> > On Sun, 2015-09-20 at 15:39 -0400, Hans de Goede wrote:
> > > We know when u-boot is written to its own partition, in this case the
> > > layout always is:
> > > 
> > > eb 0 spl
> > > eb 1 spl-backup
> > > eb 2 u-boot
> > > eb 3 u-boot-backup
> > > 
> > > eb: erase-block
> > > 
> > > So if we cannot load u-boot from its primary offset we know exactly
> > > where
> > > to look for it.
> > 
> > Is it worth noting here (or perhaps in a code comment?) that the code
> > currently assumes that the first four ebs are of uniform size?
> 
> The eraseblock size is a property of the nand, given a certain nand chip,
> all eraseblocks on that chip always have the same size.

So they never have "boot erase zones" at either the start or end, which
divide one of the erase zones into more fine-grained sizes?

e.g. it used to be the case with NOR that with, say, a 128KB device you
would have zones of 3x32K, 1x16K, 2x8K or something like that rather than
simply 4x32K.

They don't do this with NAND then?

Ian.