From e2de305f11864a92cd1ce6ce6a7a42f098f754b6 Mon Sep 17 00:00:00 2001 From: Uwe Kleine-König Date: Fri, 30 Jun 2017 11:51:45 +0200 Subject: docs: mvebu: describe -n more accurately in the sphinx document MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Uwe Kleine-König Signed-off-by: Sascha Hauer --- Documentation/boards/mvebu.rst | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/Documentation/boards/mvebu.rst b/Documentation/boards/mvebu.rst index 8e5612283e..b28fd443b6 100644 --- a/Documentation/boards/mvebu.rst +++ b/Documentation/boards/mvebu.rst @@ -37,9 +37,15 @@ Booting from UART The mvebu SoCs support booting from UART. For this there is a tool available in barebox called ``kwboot``. Quite some mvebu boards are reset once more when -they already started to read the first block of the image to boot. If you want -to boot such a board, use the parameter ``-n 15`` for ``kwboot``. (The number -might have to be adapted per board.) +they already started to read the first block of the image to boot which +obviously results in a failure to boot this image. If you want to boot such a +board, use the parameter ``-n 15`` for ``kwboot`` to delay uploading the image +and try to hit the right (i.e. second) window harder. +(The number might have to be adapted per board. The semantic is that the magic +string is sent until the 15th NAK is seen and only then the image is sent.) A +typical commandline is: + + kwboot -b barebox.img -n 15 -B 115200 -t /dev/ttyUSB mvebu boards ------------ -- cgit v1.2.3