From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: barebox@lists.infradead.org
Subject: [PATCH 2/2] docs: move kwboot description to generic mvebu section
Date: Fri, 2 Jun 2017 20:22:04 +0200 [thread overview]
Message-ID: <20170602182204.32309-2-u.kleine-koenig@pengutronix.de> (raw)
In-Reply-To: <20170602182204.32309-1-u.kleine-koenig@pengutronix.de>
Expand the generic part about kwboot to the mvebu page and advertise the
parameter -n to make it simpler to boot some machines.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
Documentation/boards/mvebu.rst | 5 ++++-
Documentation/boards/mvebu/Netgear-ReadyNAS-2120.rst | 13 ++-----------
2 files changed, 6 insertions(+), 12 deletions(-)
diff --git a/Documentation/boards/mvebu.rst b/Documentation/boards/mvebu.rst
index 4dfdc4a8f761..18a5c150bb95 100644
--- a/Documentation/boards/mvebu.rst
+++ b/Documentation/boards/mvebu.rst
@@ -35,7 +35,10 @@ Booting from UART
-----------------
The mvebu SoCs support booting from UART. For this there is a tool available in
-barebox called kwboot.
+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.)
mvebu boards
------------
diff --git a/Documentation/boards/mvebu/Netgear-ReadyNAS-2120.rst b/Documentation/boards/mvebu/Netgear-ReadyNAS-2120.rst
index 5bee03af9d38..488af2d7acfe 100644
--- a/Documentation/boards/mvebu/Netgear-ReadyNAS-2120.rst
+++ b/Documentation/boards/mvebu/Netgear-ReadyNAS-2120.rst
@@ -6,14 +6,5 @@ This is a rack mountable 4 bay NAS using an Armada XP dual-core processor.
UART booting
------------
-The first UART hides behind a sticker on 4 pins.
-
-The machine seems to do two resets at power on which makes UART booting hard. A
-trick to work around this is::
-
- scripts/kwboot -d /dev/ttyUSB0; kwboot -b images/barebox-netgear-rn2120.img -t /dev/ttyUSB0
-
-This way the first window in which the CPU accepts the magic string is taken by
-the first invokation which blocks until the second reset happens. The second
-window is then hit with the image to boot. This is not 100% reliable but works
-most of the time.
+The UART that can be used to boot via RS232 (using ``kwboot``) hides behind a
+sticker on the backside of the machine. It uses TTL levels.
--
2.11.0
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next prev parent reply other threads:[~2017-06-02 18:22 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-02 18:22 [PATCH 1/2] docs: mvebu can do 2nd stage booting Uwe Kleine-König
2017-06-02 18:22 ` Uwe Kleine-König [this message]
2017-06-06 5:56 ` Sascha Hauer
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