diff --git a/systems/lctr-rpi/fs/boot/config.txt b/systems/lctr-rpi/fs/boot/config.txt
index f5a204f..a90164b 100644
--- a/systems/lctr-rpi/fs/boot/config.txt
+++ b/systems/lctr-rpi/fs/boot/config.txt
@@ -1,5 +1,18 @@
+# Core.
+arm_freq=1000
+
+# Disable BT on Rpi3.
+dtoverlay=pi3-disable-bt
+
 dtoverlay=uart1
 dtoverlay=uart0
 
+### EXTERNAL SDCARD OPTIONS
 # Activate external sdcard in CM3 [22 at 27]
-dtoverlay=sdio,poll_once=off
+#dtoverlay=sdio,poll_once=off
+
+#Activate external sdcard in CM3 [34 at 39]
+#dtoverlay=sdio34,poll_once=off,gpios_34_39
+#dtoverlay=sdio34,poll_once=off,bus_width=4,gpios_34_39
+#dtoverlay=sdio34,poll_once=off,bus_width=4,sdio_overclock=30
+#dtoverlay=sdio34,poll_once=off,bus_width=4,gpios_34_39,sdio_overclock=30