From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Date: Tue, 5 May 2020 18:39:58 +0200 Subject: [PATCH V2] mkimage: fit: Do not tail-pad fitImage with external data In-Reply-To: References: <20200501154026.79169-1-marex@denx.de> <20200504112749.GE12564@bill-the-cat> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 5/5/20 6:37 PM, Alex Kiernan wrote: > On Tue, May 5, 2020 at 2:28 PM Marek Vasut wrote: >> >> On 5/5/20 3:22 PM, Alex Kiernan wrote: >>> On Mon, May 4, 2020 at 12:28 PM Tom Rini 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 >>>>> Reviewed-by: Simon Glass >>>>> Cc: Heinrich Schuchardt >>>>> Cc: Tom Rini >>>> >>>> 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 ?