[U-Boot] [PATCH 1/5] nand: sunxi: change BLOCK_SIZE in mksunxiboot to match NAND block size

[Ian Campbell]

On Tue, 2015-05-05 at 11:02 +0200, Daniel Kochmański wrote:
> Ian Campbell writes:
> 
> > On Wed, 2015-04-29 at 17:02 +0200, Daniel Kochmański wrote:
> >> This change is necessary to calculate correct checksum for NAND
> >> boot. Works both for MMC and NAND. Without it BROM rejects boot image
> >> as invalid (bad checksum). (Changes block size from 0x200 to 0x2000).
> >
> > I'm inferring here that for MMC boot this checksum is ignored by the
> > BROM? If that is the case then I think it should be explicitly
> > mentioned.
> 
> It isn't ignored, just larger block is taken into checksum and put in
> header (which is read by BROM). I think, that in NAND case BROM just
> ignores length field in header, and calculates checksum for whole page
> (8KB), while on MMC it respects this field, hence 0x2000 works for
> both.

OK, please add an explanation along these lines to the commit message.

> I've tried to put garbage into checksum field, and MMC doesn't boot if
> checksum isn't correct.
> >
> > As well as the checksum this also changes the header's length field,
> > FWIW.
> >
> 
> Yes, this is true. Should I change it to set block size conditionally
> depending on defines - if it's SPL NAND boot, then use 0x2000, in other
> occasion use 0x200?

I don't think that is necessary assuming...

>  Whole `u-boot-sunxi-with-spl.bin` size doesn't
> increase tough (probably because of space between spl and proper
> u-boot).

... this is actually the case, then you could just say it in the commit
log.