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

[Hans de Goede]

Hi,

On 21-09-15 14:19, Ian Campbell wrote:
> 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?

To the best of my knowledge no.

Regards,

Hans