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authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>2017-06-02 20:22:04 +0200
committerSascha Hauer <s.hauer@pengutronix.de>2017-06-06 09:17:00 +0200
commitebaa911f2da5206a2f750fd3708de14f35398692 (patch)
treed50e6017639015e851c3bdc0057f189d29690dba
parentba97a1c1365195e5a76c71355fc5e471d92382b7 (diff)
downloadbarebox-ebaa911f2da5206a2f750fd3708de14f35398692.tar.gz
docs: move kwboot description to generic mvebu section
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> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
-rw-r--r--Documentation/boards/mvebu.rst5
-rw-r--r--Documentation/boards/mvebu/Netgear-ReadyNAS-2120.rst13
2 files changed, 6 insertions, 12 deletions
diff --git a/Documentation/boards/mvebu.rst b/Documentation/boards/mvebu.rst
index 42dcdb8..8e56122 100644
--- a/Documentation/boards/mvebu.rst
+++ b/Documentation/boards/mvebu.rst
@@ -36,7 +36,10 @@ 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 5bee03a..488af2d 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.