diff --git a/configs/ea3131/ostest/defconfig b/configs/ea3131/ostest/defconfig
index aa04a397da..86fa0ecdfe 100755
--- a/configs/ea3131/ostest/defconfig
+++ b/configs/ea3131/ostest/defconfig
@@ -105,6 +105,35 @@ CONFIG_LPC313X_MCI=n
 CONFIG_LPC313X_SPI=n
 CONFIG_LPC313X_UART=y
 
+#
+# Exernal memory available on the board (see also CONFIG_MM_REGIONS)
+#
+# CONFIG_LPC313X_EXTSRAM0 - Select if external SRAM0 is present
+# CONFIG_LPC313X_EXTSRAM0HEAP - Select if external SRAM0 should be
+#   configured as part of the NuttX heap.
+# CONFIG_LPC313X_EXTSRAM0SIZE - Size (in bytes) of the installed
+#   external SRAM0 memory
+# CONFIG_LPC313X_EXTSRAM1 - Select if external SRAM1 is present
+# CONFIG_LPC313X_EXTSRAM1HEAP - Select if external SRAM1 should be
+#   configured as part of the NuttX heap.
+# CONFIG_LPC313X_EXTSRAM1SIZE - Size (in bytes) of the installed
+#   external SRAM1 memory
+# CONFIG_LPC313X_EXTSDRAM - Select if external SDRAM is present
+# CONFIG_LPC313X_EXTSDRAMHEAP - Select if external SDRAM should be
+#   configured as part of the NuttX heap.
+# CONFIG_LPC313X_EXTSDRAMSIZE - Size (in bytes) of the installed
+#   external SDRAM memory
+#
+CONFIG_LPC313X_EXTSRAM0=n
+CONFIG_LPC313X_EXTSRAM0HEAP=n
+CONFIG_LPC313X_EXTSRAM0SIZE=(128*1024)
+CONFIG_LPC313X_EXTSRAM1=n
+CONFIG_LPC313X_EXTSRAM1HEAP=n
+CONFIG_LPC313X_EXTSRAM1SIZE=(128*1024)
+CONFIG_LPC313X_EXTSDRAM=n
+CONFIG_LPC313X_EXTSDRAMHEAP=n
+CONFIG_LPC313X_EXTSDRAMSIZE=(64*1024*1024)
+
 #
 # LPC313X specific device driver settings
 #