[PATCH V2] mkimage: fit: Do not tail-pad fitImage with external data

[Alex Kiernan]

On Mon, May 4, 2020 at 12:28 PM Tom Rini <trini at konsulko.com> wrote:
>
> On Fri, May 01, 2020 at 05:40:25PM +0200, Marek Vasut wrote:
>
> > There is no reason to tail-pad fitImage with external data to 4-bytes,
> > while fitImage without external data does not have any such padding and
> > is often unaligned. DT spec also does not mandate any such padding.
> >
> > Moreover, the tail-pad fills the last few bytes with uninitialized data,
> > which could lead to a potential information leak.
> >
> > $ echo -n xy > /tmp/data ; \
> >       ./tools/mkimage -E -f auto -d /tmp/data /tmp/fitImage ; \
> >       hexdump -vC /tmp/fitImage | tail -n 3
> >
> > before:
> > 00000260  61 2d 6f 66 66 73 65 74  00 64 61 74 61 2d 73 69  |a-offset.data-si|
> > 00000270  7a 65 00 00 78 79 64 64                           |ze..xydd|
> >                    ^^       ^^ ^^
> > after:
> > 00000260  61 2d 6f 66 66 73 65 74  00 64 61 74 61 2d 73 69  |a-offset.data-si|
> > 00000270  7a 65 00 78 79                                    |ze.xy|
> >
> > Signed-off-by: Marek Vasut <marex at denx.de>
> > Reviewed-by: Simon Glass <sjg at chromium.org>
> > Cc: Heinrich Schuchardt <xypron.glpk at gmx.de>
> > Cc: Tom Rini <trini at konsulko.com>
>
> Applied to u-boot/master, thanks!
>

This breaks booting on my board (am3352, eMMC boot, FIT u-boot,
CONFIG_SPL_LOAD_FIT). Not got any useful diagnostics - if I boot it
from eMMC I get nothing at all on the console, if I boot over ymodem
it stalls at 420k, before continuing to 460k. My guess is there's some
error going to the console at the 420k mark, but obviously it's lost
in the ymodem... I have two DTBs in the FIT image, 420k would about
align to the point between them.

-- 
Alex Kiernan