diff --git a/sys/dev/psci/smccc.h b/sys/dev/psci/smccc.h
--- a/sys/dev/psci/smccc.h
+++ b/sys/dev/psci/smccc.h
@@ -56,12 +56,14 @@
 #define	SMCCC_STD_HYP_SERVICE_CALLS	5
 #define	SMCCC_VENDOR_HYP_SERVICE_CALLS	6
 
+#if !defined(__ASSEMBLER__)
 struct arm_smccc_res {
 	register_t a0;
 	register_t a1;
 	register_t a2;
 	register_t a3;
 };
+#endif
 
 /*
  * Arm Architecture Calls.
@@ -81,6 +83,7 @@
 #define	SMCCC_RET_NOT_SUPPORTED		-1
 #define	SMCCC_RET_NOT_REQUIRED		-2
 
+#if !defined(__ASSEMBLER__)
 void smccc_init(void);
 uint32_t smccc_get_version(void);
 int32_t smccc_arch_features(uint32_t);
@@ -149,4 +152,5 @@
     struct arm_smccc_1_2_regs *res);
 int arm_smccc_1_2_smc(const struct arm_smccc_1_2_regs *args,
     struct arm_smccc_1_2_regs *res);
+#endif /* __ASSEMBLER__ */
 #endif /* _PSCI_SMCCC_H_ */