fdt: Record where the devicetree came from

Keep track of where the devicetree came from, so we can report this later.

Signed-off-by: Simon Glass <sjg@chromium.org>

3 files changed, 51 insertions, 5 deletions

diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h
index 99daa20c765..104282bd479 100644
--- a/include/asm-generic/global_data.h
+++ b/include/asm-generic/global_data.h
@@ -244,6 +244,10 @@ struct global_data {
 	 * @fdt_size: space reserved for relocated device space
 	 */
 	unsigned long fdt_size;
+	/**
+	 * @fdt_src: Source of FDT
+	 */
+	enum fdt_source_t fdt_src;
 #if CONFIG_IS_ENABLED(OF_LIVE)
 	/**
 	 * @of_root: root node of the live tree
diff --git a/include/fdtdec.h b/include/fdtdec.h
index 68a36f10583..09525ce510a 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -55,6 +55,31 @@ struct bd_info;
 #define SPL_BUILD	0
 #endif
 
+/**
+ * enum fdt_source_t - indicates where the devicetree came from
+ *
+ * These are listed in approximate order of desirability after FDTSRC_NONE
+ *
+ * @FDTSRC_SEPARATE: Appended to U-Boot. This is the normal approach if U-Boot
+ *	is the only firmware being booted
+ * @FDTSRC_FIT: Found in a multi-dtb FIT. This should be used when U-Boot must
+ *	select a devicetree from many options
+ * @FDTSRC_BOARD: Located by custom board code. This should only be used when
+ *	the prior stage does not support FDTSRC_PASSAGE
+ * @FDTSRC_EMBED: Embedded into U-Boot executable. This should onyl be used when
+ *	U-Boot is packaged as an ELF file, e.g. for debugging purposes
+ * @FDTSRC_ENV: Provided by the fdtcontroladdr environment variable. This should
+ *	be used for debugging/development only
+ * @FDTSRC_NONE: No devicetree at all
+ */
+enum fdt_source_t {
+	FDTSRC_SEPARATE,
+	FDTSRC_FIT,
+	FDTSRC_BOARD,
+	FDTSRC_EMBED,
+	FDTSRC_ENV,
+};
+
 /*
  * Information about a resource. start is the first address of the resource
  * and end is the last address (inclusive). The length of the resource will
@@ -1215,4 +1240,11 @@ int fdtdec_decode_ram_size(const void *blob, const char *area, int board_id,
 			   phys_addr_t *basep, phys_size_t *sizep,
 			   struct bd_info *bd);
 
+/**
+ * fdtdec_get_srcname() - Get the name of where the devicetree comes from
+ *
+ * @return source name
+ */
+const char *fdtdec_get_srcname(void);
+
 #endif
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index 31a509bc221..8cfa958fb96 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -1618,6 +1618,7 @@ static void setup_multi_dtb_fit(void)
 	if (blob) {
 		gd_set_multi_dtb_fit(gd->fdt_blob);
 		gd->fdt_blob = blob;
+		gd->fdt_src = FDTSRC_FIT;
 	}
 }
 
@@ -1626,22 +1627,31 @@ int fdtdec_setup(void)
 	int ret;
 
 	/* The devicetree is typically appended to U-Boot */
-	if (IS_ENABLED(CONFIG_OF_SEPARATE))
+	if (IS_ENABLED(CONFIG_OF_SEPARATE)) {
 		gd->fdt_blob = fdt_find_separate();
-	else /* embed dtb in ELF file for testing / development */
+		gd->fdt_src = FDTSRC_SEPARATE;
+	} else { /* embed dtb in ELF file for testing / development */
 		gd->fdt_blob = dtb_dt_embedded();
+		gd->fdt_src = FDTSRC_EMBED;
+	}
 
 	/* Allow the board to override the fdt address. */
 	if (IS_ENABLED(CONFIG_OF_BOARD)) {
 		gd->fdt_blob = board_fdt_blob_setup(&ret);
 		if (ret)
 			return ret;
+		gd->fdt_src = FDTSRC_BOARD;
 	}
 
+	/* Allow the early environment to override the fdt address */
 	if (!IS_ENABLED(CONFIG_SPL_BUILD)) {
-		/* Allow the early environment to override the fdt address */
-		gd->fdt_blob = map_sysmem(env_get_ulong("fdtcontroladdr", 16,
-			       (unsigned long)map_to_sysmem(gd->fdt_blob)), 0);
+		ulong addr;
+
+		addr = env_get_hex("fdtcontroladdr", 0);
+		if (addr) {
+			gd->fdt_blob = map_sysmem(addr, 0);
+			gd->fdt_src = FDTSRC_ENV;
+		}
 	}
 
 	if (CONFIG_IS_ENABLED(MULTI_DTB_FIT))