fdt: Show a runtime warning based on devicetree source

When running, if the devicetree failed to come from the expected source,
show a warning, e.g:

   U-Boot ...

   DRAM:  128 MiB
   Core:  42 devices, 11 uclasses, devicetree: separate
   Warning: Unexpected devicetree source (not from a prior stage)
   Warning: U-Boot may not function properly
   Flash: 64 MiB
   ...

These warnings should only appear if the board config has been changed, or
the prior stage is broken.

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

diff --git a/common/board_r.c b/common/board_r.c
index 99adff1..6d52066 100644 (file)
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -598,6 +598,12 @@ static int dm_announce(void)
                if (CONFIG_IS_ENABLED(OF_REAL))
                        printf(", devicetree: %s", fdtdec_get_srcname());
                printf("\n");
+               if (IS_ENABLED(CONFIG_OF_HAS_PRIOR_STAGE) &&
+                   (gd->fdt_src == FDTSRC_SEPARATE ||
+                    gd->fdt_src == FDTSRC_EMBED)) {
+                       printf("Warning: Unexpected devicetree source (not from a prior stage)");
+                       printf("Warning: U-Boot may not function properly\n");
+               }
        }
 
        return 0;