doc: board: phytec: phycore-am6: Describe UART based boot
Describe how to boot via UART.
Signed-off-by: Wadim Egorov <w.egorov@phytec.de>
diff --git a/doc/board/phytec/phycore-am64x.rst b/doc/board/phytec/phycore-am64x.rst
index 2b9cd32..68d78ad 100644
--- a/doc/board/phytec/phycore-am64x.rst
+++ b/doc/board/phytec/phycore-am64x.rst
@@ -119,6 +119,25 @@
fatload mmc 1 ${loadaddr} u-boot.img
mtd write ospi.u-boot ${loadaddr} 0 ${filesize}
+UART based boot
+---------------
+
+To boot the board via UART, set the switches to UART mode and connect to the
+micro USB port labeled as "Debug UART". After power-on the build artifacts
+needs to be uploaded one by one with a tool like sz.
+
+Example bash script sequence for running on a Linux host PC feeding all boot
+artifacts needed to the device. Assuming the host uses /dev/ttyUSB0 as
+the main domain serial port:
+
+.. prompt:: bash $
+
+ stty -F /dev/ttyUSB0 115200
+ sb --xmodem tiboot3.bin > /dev/ttyUSB0 < /dev/ttyUSB0
+ # Resend tiboot3.bin a 2nd time due to ErrataID:i2331
+ sb --xmodem tiboot3.bin > /dev/ttyUSB0 < /dev/ttyUSB0
+ sb --ymodem tispl.bin > /dev/ttyUSB0 < /dev/ttyUSB0
+ sb --ymodem u-boot.img > /dev/ttyUSB0 < /dev/ttyUSB0
Boot Modes
----------