diff --git a/arch/mips/boot/compressed/dbg.c b/arch/mips/boot/compressed/dbg.c
index f6728a8fd1c3..2f1ac38fe1cc 100644
--- a/arch/mips/boot/compressed/dbg.c
+++ b/arch/mips/boot/compressed/dbg.c
@@ -9,6 +9,8 @@
 #include <linux/compiler.h>
 #include <linux/types.h>
 
+#include "decompress.h"
+
 void __weak putc(char c)
 {
 }
diff --git a/arch/mips/boot/compressed/decompress.c b/arch/mips/boot/compressed/decompress.c
index c5dd415254d3..adb6d5b0e6eb 100644
--- a/arch/mips/boot/compressed/decompress.c
+++ b/arch/mips/boot/compressed/decompress.c
@@ -19,6 +19,8 @@
 #include <asm/unaligned.h>
 #include <asm-generic/vmlinux.lds.h>
 
+#include "decompress.h"
+
 /*
  * These two variables specify the free mem region
  * that can be used for temporary malloc area
@@ -26,20 +28,6 @@
 unsigned long free_mem_ptr;
 unsigned long free_mem_end_ptr;
 
-/* The linker tells us where the image is. */
-extern unsigned char __image_begin[], __image_end[];
-
-/* debug interfaces  */
-#ifdef CONFIG_DEBUG_ZBOOT
-extern void puts(const char *s);
-extern void puthex(unsigned long long val);
-#else
-#define puts(s) do {} while (0)
-#define puthex(val) do {} while (0)
-#endif
-
-extern char __appended_dtb[];
-
 void error(char *x)
 {
 	puts("\n\n");
diff --git a/arch/mips/boot/compressed/decompress.h b/arch/mips/boot/compressed/decompress.h
new file mode 100644
index 000000000000..073b64593b3d
--- /dev/null
+++ b/arch/mips/boot/compressed/decompress.h
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef _DECOMPRESSOR_H
+#define _DECOMPRESSOR_H
+
+/* The linker tells us where the image is. */
+extern unsigned char __image_begin[], __image_end[];
+
+/* debug interfaces  */
+#ifdef CONFIG_DEBUG_ZBOOT
+extern void putc(char c);
+extern void puts(const char *s);
+extern void puthex(unsigned long long val);
+#else
+#define putc(s) do {} while (0)
+#define puts(s) do {} while (0)
+#define puthex(val) do {} while (0)
+#endif
+
+extern char __appended_dtb[];
+
+void error(char *x);
+void decompress_kernel(unsigned long boot_heap_start);
+
+#endif
diff --git a/arch/mips/boot/compressed/string.c b/arch/mips/boot/compressed/string.c
index 0b593b709228..f0eb251e44e5 100644
--- a/arch/mips/boot/compressed/string.c
+++ b/arch/mips/boot/compressed/string.c
@@ -7,6 +7,7 @@
 
 #include <linux/compiler_attributes.h>
 #include <linux/types.h>
+#include <asm/string.h>
 
 void *memcpy(void *dest, const void *src, size_t n)
 {