diff --git a/libcpu/Kconfig b/libcpu/Kconfig
index 239fa58346bc95ad479f524d6b03129ad20483f4..3c8c73636dbbe9e4b2ea477e27283c6afec257c7 100644
--- a/libcpu/Kconfig
+++ b/libcpu/Kconfig
@@ -4,6 +4,10 @@ config ARCH_CPU_64BIT
 config ARCH_ARM
     bool
 
+config RT_USING_CPU_FFS
+    bool
+    default n
+
 config ARCH_ARM_CORTEX_M
     bool
     select ARCH_ARM
@@ -18,6 +22,7 @@ config ARCH_ARM_CORTEX_M0
 config ARCH_ARM_CORTEX_M3
     bool
     select ARCH_ARM_CORTEX_M
+    select RT_USING_CPU_FFS
 
 config ARCH_ARM_MPU
     bool
@@ -26,10 +31,12 @@ config ARCH_ARM_MPU
 config ARCH_ARM_CORTEX_M4
     bool
     select ARCH_ARM_CORTEX_M
+    select RT_USING_CPU_FFS
 
 config ARCH_ARM_CORTEX_M7
     bool
     select ARCH_ARM_CORTEX_M
+    select RT_USING_CPU_FFS
 
 config ARCH_ARM_CORTEX_R
     bool