diff --git a/src/include/bootblock_common.h b/src/include/bootblock_common.h
index b227cf47be..0985241590 100644
--- a/src/include/bootblock_common.h
+++ b/src/include/bootblock_common.h
@@ -16,6 +16,7 @@
 #ifndef __BOOTBLOCK_COMMON_H
 #define __BOOTBLOCK_COMMON_H
 
+#include <arch/cpu.h>
 #include <main_decl.h>
 #include <stdint.h>
 
@@ -36,6 +37,6 @@ void bootblock_soc_init(void);
  * This function assumes that the timer has already been initialized, so it
  * does not call init_timer().
  */
-void bootblock_main_with_timestamp(uint64_t base_timestamp);
+void asmlinkage bootblock_main_with_timestamp(uint64_t base_timestamp);
 
 #endif	/* __BOOTBLOCK_COMMON_H */
diff --git a/src/lib/bootblock.c b/src/lib/bootblock.c
index f16cb44df6..9dece0c373 100644
--- a/src/lib/bootblock.c
+++ b/src/lib/bootblock.c
@@ -29,7 +29,7 @@ __attribute__((weak)) void bootblock_soc_early_init(void) { /* do nothing */ }
 __attribute__((weak)) void bootblock_soc_init(void) { /* do nothing */ }
 __attribute__((weak)) void bootblock_mainboard_init(void) { /* do nothing */ }
 
-void bootblock_main_with_timestamp(uint64_t base_timestamp)
+void asmlinkage bootblock_main_with_timestamp(uint64_t base_timestamp)
 {
 	/* Initialize timestamps if we have TIMESTAMP region in memlayout.ld. */
 	if (IS_ENABLED(CONFIG_COLLECT_TIMESTAMPS) && _timestamp_size > 0)