doc: sl-mx8mm: Add note about using cross toolchain
This clarifies the usage of a cross toolchain to build U-Boot
and TF-A.
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
diff --git a/doc/board/kontron/sl-mx8mm.rst b/doc/board/kontron/sl-mx8mm.rst
index 57143b9..ff6f01d 100644
--- a/doc/board/kontron/sl-mx8mm.rst
+++ b/doc/board/kontron/sl-mx8mm.rst
@@ -20,6 +20,12 @@
- Build U-Boot
- Boot
+.. note::
+
+ To build on a x86-64 host machine, you need a GNU cross toolchain for the
+ target architecture (aarch64). Check your distros package manager or
+ download and install the necessary tools (``aarch64-linux-gnu-*``) manually.
+
Get and Build the Trusted Firmware-A (TF-A)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^