On Tue, May 05, 2020 at 06:39:58PM +0200, Marek Vasut wrote: > On 5/5/20 6:37 PM, Alex Kiernan wrote: > > On Tue, May 5, 2020 at 2:28 PM Marek Vasut <ma...@denx.de> wrote: > >> > >> On 5/5/20 3:22 PM, Alex Kiernan wrote: > >>> On Mon, May 4, 2020 at 12:28 PM Tom Rini <tr...@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 <ma...@denx.de> > >>>>> Reviewed-by: Simon Glass <s...@chromium.org> > >>>>> Cc: Heinrich Schuchardt <xypron.g...@gmx.de> > >>>>> Cc: Tom Rini <tr...@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. > >> > >> My bet would be on some padding / unaligned access problem that this > >> patch uncovered. Can you take a look ? > > > > Seems plausible. With this change my external data starts at 0x483 and > > everything after it is non-aligned: > > Should the beginning of external data be aligned ?
If in U-Boot we revert e8c2d25845c72c7202a628a97d45e31beea40668 does the problem go away? If so, that's not a fix outright, it means we need to dig back in to the libfdt thread and find the "make this work without killing performance everywhere all the time" option. -- Tom
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