emulation/qemu-i440fx qemu-q35: Asmlinkage for romstage main()

Change-Id: I66238525c5c4d97313a589373144741f1be97483
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/15226
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
Tested-by: Raptor Engineering Automated Test Stand <noreply@raptorengineeringinc.com>

src/mainboard/emulation/qemu-i440fx/cache_as_ram.inc

@@ -49,7 +49,7 @@ cache_as_ram:
 before_romstage:
 	post_code(0x29)
 	/* Call romstage.c main function. */
-	call	main
+	call	romstage_main
 
 	post_code(0x30)
 

src/mainboard/emulation/qemu-i440fx/romstage.c

@@ -21,14 +21,14 @@
 #include <pc80/mc146818rtc.h>
 #include <console/console.h>
 #include <cpu/x86/bist.h>
+#include <cpu/intel/romstage.h>
 #include <timestamp.h>
 #include <delay.h>
 #include <cpu/x86/lapic.h>
 
 #include "memory.c"
 
-#include <cpu/intel/romstage.h>
-void main(unsigned long bist)
+void * asmlinkage romstage_main(unsigned long bist)
 {
 	int cbmem_was_initted;
 
@@ -48,4 +48,6 @@ void main(unsigned long bist)
 	timestamp_init(timestamp_get());
 	timestamp_add_now(TS_START_ROMSTAGE);
 
+	/* Emulation uses fixed low stack during ramstage. */
+	return NULL;
 }

src/mainboard/emulation/qemu-q35/romstage.c

@@ -22,14 +22,14 @@
 #include <console/console.h>
 #include <southbridge/intel/i82801ix/i82801ix.h>
 #include <cpu/x86/bist.h>
+#include <cpu/intel/romstage.h>
 #include <timestamp.h>
 #include <delay.h>
 #include <cpu/x86/lapic.h>
 
 #include "../qemu-i440fx/memory.c"
 
-#include <cpu/intel/romstage.h>
-void main(unsigned long bist)
+void * asmlinkage romstage_main(unsigned long bist)
 {
 	int cbmem_was_initted;
 
@@ -50,4 +50,6 @@ void main(unsigned long bist)
 	timestamp_init(timestamp_get());
 	timestamp_add_now(TS_START_ROMSTAGE);
 
+	/* Emulation uses fixed low stack during ramstage. */
+	return NULL;
 }