[PATCH v3 07/22] fdt: Redo devicetree setup

[Simon Glass]

The existing logic for handling receiving a devicetree from a previous
phase is quite complicated. Simplify it in preparation for introducing
standard passage.

Add a Kconfig called OF_PASSAGE which indicates that the devicetree
must come from standard passage.

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

Changes in v3:
- Add new patch to redo how a devicetree is set up

 dts/Kconfig  |  8 ++++++++
 lib/fdtdec.c | 34 ++++++----------------------------
 2 files changed, 14 insertions(+), 28 deletions(-)

diff --git a/dts/Kconfig b/dts/Kconfig
index c544f948a15..57101bddabb 100644
--- a/dts/Kconfig
+++ b/dts/Kconfig
@@ -159,6 +159,14 @@ config OF_EMBED
 	  and development only and is not recommended for production devices.
 	  Boards in the mainline U-Boot tree should not use it.
 
+config OF_PASSAGE
+	bool "DTB is provided by a standard passage, in a bloblist"
+	help
+	  Select this to read the devicetree using the standard passage
+	  mechanism, i.e. from a previous phase in bloblist using arch-specific
+	  register conventions. If enabled, the previous phase must provide
+	  the devicetree, or U-Boot will not function correctly.
+
 endchoice
 
 config OF_INITIAL_DTB_READONLY
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index f09c9926a7a..8559616873b 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -1689,35 +1689,13 @@ void fdtdec_setup_embed(void)
 
 int fdtdec_setup(void)
 {
-	int ret = -ENOENT;
-
-	/*
-	 * If allowing a bloblist, check that first. There was discussion about
-	 * adding an OF_BLOBLIST Kconfig, but this was rejected.
-	 *
-	 * The necessary test is whether the previous phase passed a bloblist,
-	 * not whether this phase creates one.
-	 */
-	if (CONFIG_IS_ENABLED(BLOBLIST) &&
-	    (xpl_prev_phase() != PHASE_TPL ||
-	     IS_ENABLED(CONFIG_TPL_BLOBLIST))) {
-		ret = bloblist_maybe_init();
-		if (!ret) {
-			gd->fdt_blob = bloblist_find(BLOBLISTT_CONTROL_FDT, 0);
-			if (gd->fdt_blob) {
-				gd->fdt_src = FDTSRC_BLOBLIST;
-				log_debug("Devicetree is in bloblist at %p\n",
-					  gd->fdt_blob);
-				ret = 0;
-			} else {
-				log_debug("No FDT found in bloblist\n");
-				ret = -ENOENT;
-			}
-		}
-	}
+	int ret;
 
-	/* Otherwise, the devicetree is typically appended to U-Boot */
-	if (ret) {
+	if (CONFIG_IS_ENABLED(OF_BLOBLIST)) {
+		printf("Previous phase failed to provide standard passage\n");
+		return -ENOENT;
+	} else {
+		/* The devicetree is typically appended to U-Boot */
 		if (IS_ENABLED(CONFIG_OF_SEPARATE)) {
 			gd->fdt_blob = fdt_find_separate();
 			gd->fdt_src = FDTSRC_SEPARATE;
-- 
2.43.0