[bootlin/training-materials updates] master: labs/sysdev-u-boot-beagleplay: add detail (0c26c37f)

[Michael Opdenacker]

Repository : https://github.com/bootlin/training-materials
On branch  : master
Link       : https://github.com/bootlin/training-materials/commit/0c26c37f78aaf9bb96d2aec653804b995edabf41

>---------------------------------------------------------------

commit 0c26c37f78aaf9bb96d2aec653804b995edabf41
Author: Michael Opdenacker <michael.opdenacker at bootlin.com>
Date:   Mon Aug 7 16:13:59 2023 +0200

    labs/sysdev-u-boot-beagleplay: add detail
    
    Signed-off-by: Michael Opdenacker <michael.opdenacker at bootlin.com>


>---------------------------------------------------------------

0c26c37f78aaf9bb96d2aec653804b995edabf41
 labs/sysdev-u-boot-beagleplay/sysdev-u-boot-beagleplay.tex | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/labs/sysdev-u-boot-beagleplay/sysdev-u-boot-beagleplay.tex b/labs/sysdev-u-boot-beagleplay/sysdev-u-boot-beagleplay.tex
index 419ebb17..7c39d59f 100644
--- a/labs/sysdev-u-boot-beagleplay/sysdev-u-boot-beagleplay.tex
+++ b/labs/sysdev-u-boot-beagleplay/sysdev-u-boot-beagleplay.tex
@@ -740,8 +740,13 @@ partition.
   => mmc write 0x80000000 0 400
 \end{ubootinput}
 
-Now, we will make the user hardware partition accessible as USB Mass Storage
-on the host machine, in order to flash it. To do so type the following
+Now, we will make the user hardware partition accessible as USB Mass Storage on
+the host machine, in order to flash it. For this to work, you need the USB-C
+cable powering up the board to be connected to a port on your host machine, not
+to a USB power supply. Otherwise, the connection through USB won't possibly
+work.
+
+So, type the following:
 \code{ums} U-Boot command :
 \begin{ubootinput}
   => ums 0 mmc 0