sunxi: board: Save the chosen DT name in the SPL header

This overwrites the name loaded from the SPL image. It will be different
if there was previously no name provided, or if a more accurate name was
determined by the board variant selection logic. This means that the DT
name in the SPL header now always matches the DT appended to U-Boot.

Acked-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
[Andre: move function under CONFIG_SPL_LOAD_FIT guard]
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/board/sunxi/board.c b/board/sunxi/board.c
index 3243e16..42fc602 100644
--- a/board/sunxi/board.c
+++ b/board/sunxi/board.c
@@ -903,9 +903,26 @@
 }
 
 #ifdef CONFIG_SPL_LOAD_FIT
+
+static void set_spl_dt_name(const char *name)
+{
+	struct boot_file_head *spl = get_spl_header(SPL_ENV_HEADER_VERSION);
+
+	if (spl == INVALID_SPL_HEADER)
+		return;
+
+	/* Promote the header version for U-Boot proper, if needed. */
+	if (spl->spl_signature[3] < SPL_DT_HEADER_VERSION)
+		spl->spl_signature[3] = SPL_DT_HEADER_VERSION;
+
+	strcpy((char *)&spl->string_pool, name);
+	spl->dt_name_offset = offsetof(struct boot_file_head, string_pool);
+}
+
 int board_fit_config_name_match(const char *name)
 {
 	const char *best_dt_name = get_spl_dt_name();
+	int ret;
 
 #ifdef CONFIG_DEFAULT_DEVICE_TREE
 	if (best_dt_name == NULL)
@@ -943,6 +960,15 @@
 	}
 #endif
 
-	return strcmp(name, best_dt_name);
+	ret = strcmp(name, best_dt_name);
+
+	/*
+	 * If one of the FIT configurations matches the most accurate DT name,
+	 * update the SPL header to provide that DT name to U-Boot proper.
+	 */
+	if (ret == 0)
+		set_spl_dt_name(best_dt_name);
+
+	return ret;
 }
 #endif