Index: boot/arch/arm32/src/mm.c
===================================================================
--- boot/arch/arm32/src/mm.c	(revision 8a64320e304a59746f5987caeba986e6baf11dd7)
+++ boot/arch/arm32/src/mm.c	(revision 193d280c34f38846eccfa1ecce71975f9ad92398)
@@ -193,7 +193,8 @@
 }
 
-static void enable_paging()
-{
-	/* c3   - each two bits controls access to the one of domains (16)
+static void enable_paging(void)
+{
+	/*
+	 * c3   - each two bits controls access to the one of domains (16)
 	 * 0b01 - behave as a client (user) of a domain
 	 */
@@ -232,5 +233,6 @@
 
 /** Start the MMU - initialize page table and enable paging. */
-void mmu_start() {
+void mmu_start(void)
+{
 	disable_paging();
 #ifdef PROCESSOR_ARCH_armv7_a
Index: boot/arch/ppc32/include/asm.h
===================================================================
--- boot/arch/ppc32/include/asm.h	(revision 8a64320e304a59746f5987caeba986e6baf11dd7)
+++ boot/arch/ppc32/include/asm.h	(revision 193d280c34f38846eccfa1ecce71975f9ad92398)
@@ -35,5 +35,5 @@
 extern void jump_to_kernel(void *, void *, size_t, void *)
     __attribute__((noreturn));
-extern void real_mode();
+extern void real_mode(void);
 
 #endif
Index: boot/arch/sparc32/src/ambapp.c
===================================================================
--- boot/arch/sparc32/src/ambapp.c	(revision 8a64320e304a59746f5987caeba986e6baf11dd7)
+++ boot/arch/sparc32/src/ambapp.c	(revision 193d280c34f38846eccfa1ecce71975f9ad92398)
@@ -58,5 +58,5 @@
 static void ambapp_scan_area(uintptr_t, unsigned int);
 
-void ambapp_scan()
+void ambapp_scan(void)
 {
 	amba_fake = false;
@@ -104,5 +104,5 @@
 }
 
-void ambapp_qemu_fake_scan()
+void ambapp_qemu_fake_scan(void)
 {
 	/* UART */
@@ -134,10 +134,10 @@
 }
 
-bool ambapp_fake()
+bool ambapp_fake(void)
 {
 	return amba_fake;
 }
 
-void ambapp_print_devices()
+void ambapp_print_devices(void)
 {
 	printf("ABMA devices:\n");
Index: boot/arch/sparc32/src/mm.c
===================================================================
--- boot/arch/sparc32/src/mm.c	(revision 8a64320e304a59746f5987caeba986e6baf11dd7)
+++ boot/arch/sparc32/src/mm.c	(revision 193d280c34f38846eccfa1ecce71975f9ad92398)
@@ -76,5 +76,5 @@
 }
 
-static void mmu_disable()
+static void mmu_disable(void)
 {
 	uint32_t cr = asi_u32_read(ASI_MMUREGS, 0x000);