diff --git a/arch/xtensa/boot/lib/zmem.c b/arch/xtensa/boot/lib/zmem.c
index e3ecd743c515..b89189355122 100644
--- a/arch/xtensa/boot/lib/zmem.c
+++ b/arch/xtensa/boot/lib/zmem.c
@@ -4,13 +4,14 @@
 /* bits taken from ppc */
 
 extern void *avail_ram, *end_avail;
+void gunzip(void *dst, int dstlen, unsigned char *src, int *lenp);
 
-void exit (void)
+static void exit(void)
 {
   for (;;);
 }
 
-void *zalloc(unsigned size)
+static void *zalloc(unsigned int size)
 {
         void *p = avail_ram;