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authorAhmad Fatoum <ahmad@a3f.at>2019-10-30 10:27:31 +0100
committerSascha Hauer <s.hauer@pengutronix.de>2019-11-06 11:22:36 +0100
commitd510bd6e5746dcba23c11fd03494c2f9114e0ac7 (patch)
treea83ac5a4f3a1dc0501d813ba3c08fd16c134a53a /Documentation
parentcc5c3ad060a219cb8c2964946f1bae67f712e262 (diff)
downloadbarebox-d510bd6e5746dcba23c11fd03494c2f9114e0ac7.tar.gz
Documentation: boards: stm32mp: document boot mode strap pins
The evaluation kits have 2P DIP-Switches for boot mode selection. Document them. Signed-off-by: Ahmad Fatoum <ahmad@a3f.at> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/boards/stm32mp.rst19
1 files changed, 19 insertions, 0 deletions
diff --git a/Documentation/boards/stm32mp.rst b/Documentation/boards/stm32mp.rst
index d4429aa..f93ec04 100644
--- a/Documentation/boards/stm32mp.rst
+++ b/Documentation/boards/stm32mp.rst
@@ -62,3 +62,22 @@ An appropriate image for the boot media can be generated with following
}
Image can then be flashed on e.g. a SD-Card.
+
+Boot source selection
+---------------------
+
+The STM32MP BootROM samples three boot pins at reset. Usually BOOT1 is
+pulled down and BOOT0 and BOOT2 are connected to a 2P DIP switch::
+
+ +-------+
+ BOOT2 | O O-- |
+ BOOT0 | N O-- | <---- SDMMC
+ +-------+
+ +-------+
+ BOOT2 | O O-- |
+ BOOT0 | N --O | <---- QSPI-NOR Flash
+ +-------+
+ +-------+
+ BOOT2 | O --O |
+ BOOT0 | N --O | <---- DFU on UART and USB OTG
+ +-------+