diff --git a/configs/rock2_defconfig b/configs/rock2_defconfig
index 1570a71..38a5f3a 100644
--- a/configs/rock2_defconfig
+++ b/configs/rock2_defconfig
@@ -17,6 +17,7 @@
 CONFIG_DEBUG_UART=y
 CONFIG_HAS_CUSTOM_SYS_INIT_SP_ADDR=y
 CONFIG_CUSTOM_SYS_INIT_SP_ADDR=0x100000
+CONFIG_SYS_MONITOR_LEN=614400
 # CONFIG_ANDROID_BOOT_IMAGE is not set
 CONFIG_USE_PREBOOT=y
 CONFIG_DEFAULT_FDT_FILE="rk3288-rock2-square.dtb"