[U-Boot] [PATCH] spl: fit: Add support for applying DT overlay

[Michal Simek]

doc/uImage.FIT/overlay-fdt-boot.txt is describing how to create FIT
image with DT overlays in it.
Add support for this feature to SPL.

Here is the ZynqMP fragment where dtb points to full DT and dtbo is
overlay which should be applied on the top of dtb.
config {
        description = "ATF with full u-boot overlay";
        firmware = "atf";
        loadables = "uboot";
        fdt = "dtb", "dtbo";
};

The whole feature depends on OF_LIBFDT_OVERLAY which is adding +4kB code
and 0 for platforms which are not enabling this feature.

Signed-off-by: Michal Simek <michal.simek at xilinx.com>
---

02: spl: fit: Add support for applying DT overlay
   aarch64: (for 1/1 boards) spl/u-boot-spl:all +4066.0
spl/u-boot-spl:rodata +206.0 spl/u-boot-spl:text +3860.0
            xilinx_zynqmp_zcu100_revC: spl/u-boot-spl:all +4066
spl/u-boot-spl:rodata +206 spl/u-boot-spl:text +3860
               spl-u-boot-spl: add: 11/0, grow: 1/0 bytes: 3860/0 (3860)
                 function                                   old     new  delta
                 fdt_overlay_apply                            -    1640  +1640
                 overlay_update_local_node_references         -     424   +424
                 fdt_get_path                                 -     364   +364
                 overlay_apply_node                           -     300   +300
                 overlay_get_target                           -     216   +216
                 overlay_adjust_node_phandles                 -     168   +168
                 overlay_phandle_add_offset                   -     144   +144
                 fdt_setprop_inplace                          -     136   +136
                 fdt_overlay_apply_verbose                    -     128   +128
                 fdt_get_max_phandle                          -     128   +128
                 spl_fit_append_fdt                         152     260   +108
                 fdt_setprop_inplace_namelen_partial          -     104   +104

---
 common/spl/spl_fit.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/common/spl/spl_fit.c b/common/spl/spl_fit.c
index db436268cbcd..ee38dfea7816 100644
--- a/common/spl/spl_fit.c
+++ b/common/spl/spl_fit.c
@@ -278,10 +278,10 @@ static int spl_fit_append_fdt(struct spl_image_info *spl_image,
 			      void *fit, int images, ulong base_offset)
 {
 	struct spl_image_info image_info;
-	int node, ret;
+	int node, ret, index = 0;
 
 	/* Figure out which device tree the board wants to use */
-	node = spl_fit_get_image_node(fit, images, FIT_FDT_PROP, 0);
+	node = spl_fit_get_image_node(fit, images, FIT_FDT_PROP, index++);
 	if (node < 0) {
 		debug("%s: cannot find FDT node\n", __func__);
 		return node;
@@ -303,8 +303,31 @@ static int spl_fit_append_fdt(struct spl_image_info *spl_image,
 #if !CONFIG_IS_ENABLED(FIT_IMAGE_TINY)
 	/* Try to make space, so we can inject details on the loadables */
 	ret = fdt_shrink_to_minimum(spl_image->fdt_addr, 8192);
+	if (ret < 0)
+		return ret;
 #endif
+#if defined(CONFIG_OF_LIBFDT_OVERLAY)
+	for (; ; index++) {
+		node = spl_fit_get_image_node(fit, images, FIT_FDT_PROP, index);
+		if (node < 0) {
+			debug("%s: No additional FDT node\n", __func__);
+			return 0;
+		}
 
+		ret = spl_load_fit_image(info, sector, fit, base_offset, node,
+					 &image_info);
+		if (ret < 0)
+			return ret;
+
+		ret = fdt_overlay_apply_verbose(spl_image->fdt_addr,
+						(void *)image_info.load_addr);
+		if (ret)
+			return ret;
+
+		debug("%s: DT overlay %s applied\n", __func__,
+		      fit_get_name(fit, node, NULL));
+	}
+#endif
 	return ret;
 }
 
-- 
1.9.1