soc/intel/common: Allow exporting the size of the VBT

Change-Id: Ib340aad846ea7cb61d650928b495efaa1fc2d641
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/26038
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/soc/intel/common/vbt.c

@@ -33,7 +33,7 @@ const char *mainboard_vbt_filename(void)
 static char vbt_data[8 * KiB];
 static int vbt_data_used;
 
-void *locate_vbt(void)
+void *locate_vbt(size_t *vbt_size)
 {
 	uint32_t vbtsig = 0;
 
@@ -48,6 +48,9 @@ void *locate_vbt(void)
 	if (file_size == 0)
 		return NULL;
 
+	if (vbt_size)
+		*vbt_size = file_size;
+
 	memcpy(&vbtsig, vbt_data, sizeof(vbtsig));
 	if (vbtsig != VBT_SIGNATURE) {
 		printk(BIOS_ERR, "Missing/invalid signature in VBT data file!\n");
@@ -72,5 +75,5 @@ void *vbt_get(void)
 		return NULL;
 	if (!display_init_required())
 		return NULL;
-	return locate_vbt();
+	return locate_vbt(NULL);
 }

src/soc/intel/common/vbt.h

@@ -27,8 +27,11 @@
  */
 const char *mainboard_vbt_filename(void);
 
-/* locate vbt.bin file. Returns a pointer to its content. */
-void *locate_vbt(void);
+/*
+ * locate vbt.bin file. Returns a pointer to its content.
+ * If vbt_size is non-NULL, also return the vbt's size.
+ */
+void *locate_vbt(size_t *vbt_size);
 /*
  * Returns VBT pointer and mapping after checking prerequisites for Pre OS
  * Graphics initialization