From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Roese Date: Tue, 1 Sep 2015 14:52:21 +0200 Subject: [U-Boot] [PATCH] tools/kwboot.c: Support UART fallback mode In-Reply-To: <1441052989-14603-1-git-send-email-kevin.smith@elecsyscorp.com> References: <1441052989-14603-1-git-send-email-kevin.smith@elecsyscorp.com> Message-ID: <55E59F85.40008@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Kevin, (Added Luka to Cc, as the Marvell / MVEBU custodian) On 31.08.2015 22:30, Kevin Smith wrote: > On some processors such as Armada 38x, if the hardware- > configured boot mode fails, the CPU falls back to booting over > UART. When this happens the chip prints a failure message, waits > for the magic sequence and, when it is received, prints a > "(boot)" message, then sends a NAK to start the transfer. > > This breaks the current kwboot behavior because the xmodem > transfer only tries to read one character after the magic > sequence, looking for the NAK. Instead it gets the "(boot)" > text, and retries the magic sequence. The CPU thinks the > repeated sequence is part of the packet, stops NAKing, and one > side or another eventually times out. > > This patch adds support for a fallback mode which continues to > scan for a NAK in the characters received after the sequence, > printing out any non-NAK characters. This allows kwboot to skip > the "(boot)" message, find the NAK, and start the transfer > successfully. > > Signed-off-by: Kevin Smith I've not seen this "(boot)" yet. But the patch looks good. So: Reviewed-by: Stefan Roese BTW: Please always keep Luka on MVEBU related patches on Cc. Thanks, Stefan