[U-Boot] [U-Boot,3/3] mmc: support writing sparse images

[Alex Kiernan]

On Mon, May 14, 2018 at 9:50 PM Tom Rini <trini at konsulko.com> wrote:

> On Mon, May 14, 2018 at 05:14:42PM +0100, Alex Kiernan wrote:
> > On Mon, May 14, 2018 at 3:47 PM Tom Rini <trini at konsulko.com> wrote:
> >
> > > On Mon, May 14, 2018 at 06:42:41PM +0530, Jassi Brar wrote:
> > > > Hi Tom,
> > > >
> > > > On Tue, May 8, 2018 at 10:45 PM, Tom Rini <trini at konsulko.com>
wrote:
> > > > > On Fri, Apr 06, 2018 at 12:05:24PM +0530, jassisinghbrar at gmail.com
> > wrote:
> > > > >
> > > > >> From: Jassi Brar <jaswinder.singh at linaro.org>
> > > > >>
> > > > >> Provide an alternate path for sparse-images to be
> > > > >> written to MMC. For example, via tftp on platforms
> > > > >> that don't support fastboot protocol. Or when an
> > > > >> image is to written at some offset, rather than the
> > > > >> start of a partition.
> > > > >>
> > > > >> Signed-off-by: Jassi Brar <jaswinder.singh at linaro.org>
> > > > >
> > > > > Applied to u-boot/master, thanks!
> > > >
> > > > I see you modified the patch to protect the feature with
> > > > CONFIG_FASTBOOT_FLASH, which kills the purpose -- this feature is
for
> > > > platforms that don't support fastboot.
> > > >
> > > > Do you want me to send the patch to revert the protection?
> >
> > > Sorry, I guess maybe things weren't clear enough all around, and we
> > > should (functionally) revert patches 2 and 3 and try something
> > > different.  It is OK to say "lets make writing sparse images more
widely
> > > available".  It's not OK to make every platform with MMC write grow a
> > > decent bit in binary size.  Making a quick pass at re-enabling things
on
> > > a platform without fastboot support already grew things by nearly
2KiB.
> > > The other part which is I believe got me down this path was that
without
> > > a change to common/Makefile to always (outside of SPL) include
> > > common/image-sparse.o things don't link.
> >
> > > In sum, a new patch to add an option to allow people to opt-in for
> > > swrite would be good.  And please make sure to do something like:
> > > diff --git a/common/Makefile b/common/Makefile
> > > index d0681c7dd96a..92b2aa1ca8f0 100644
> > > --- a/common/Makefile
> > > +++ b/common/Makefile
> > > @@ -120,6 +120,7 @@ ifdef CONFIG_FASTBOOT_FLASH_NAND_DEV
> > >       obj-y += fb_nand.o
> > >       endif
> > >       endif
> > > +obj-$(CONFIG_MMC_WRITE) += image-sparse.o
> > >       endif
> >
> > Isn't this just move image-sparse to lib and add a separate guard for it
> > (LIB_IMAGE_SPARSE?) which can be selected by both FASTBOOT and a new
> > command symbol (CMD_MMC_SWRITE)?
> >
> > This is all overlapping with the UDP fastboot code I've been posting, so
> > I'd kinda like it to fit nicely with that, rather than have to refactor
it
> > to fit something different!

> That sounds like a good idea to me, thanks!


I'll work it into that patch series... having just had a quick look at it,
it's going to be easiest part way through it after I've done most of the
Kconfig reworking.

-- 
Alex Kiernan