--- zzzz-none-000/linux-4.4.60/arch/arm/include/asm/system_misc.h	2017-04-08 07:53:53.000000000 +0000
+++ hawkeye-5590-729/linux-4.4.60/arch/arm/include/asm/system_misc.h	2022-03-30 14:21:51.000000000 +0000
@@ -21,6 +21,7 @@
 #define UDBG_BUS	(1 << 4)
 
 extern unsigned int user_debug;
+extern char* (*arch_read_hardware_id)(void);
 
 #endif /* !__ASSEMBLY__ */