diff --git a/doc/board/sifive/unmatched.rst b/doc/board/sifive/unmatched.rst
index b52a1f690cc..24a889991c4 100644
--- a/doc/board/sifive/unmatched.rst
+++ b/doc/board/sifive/unmatched.rst
@@ -20,8 +20,11 @@ The support for following drivers are already enabled:
 4. SiFive SPI Driver.
 5. MMC SPI Driver for MMC/SD support.
 
-Booting from uSD using U-Boot SPL
----------------------------------
+Booting from micro SD card using U-Boot SPL
+-------------------------------------------
+
+Booting from an SD card requires that the boot mode selection DIP switches
+MSEL[3:0] are set to 1011.
 
 Building
 --------