[U-Boot] [PATCH v4 02/20] SPL: FIT: rework U-Boot image loading

[Andre Przywara]

Currently the SPL FIT loader always looks only for the first image in
the /images node a FIT tree, which it loads and later executes.

Generalize this by looking for a "firmware" property in the matched
configuration subnode, or, if that does not exist, for the first string
in the "loadables" property. Then using the string in that property,
load the image of that name from the /images node.
This still loads only one image at the moment, but refactors the code to
allow extending this in a following patch.
To simplify later re-usage, we also generalize the spl_fit_select_index()
function to not return the image location, but just the node offset.

Signed-off-by: Andre Przywara <andre.przywara at arm.com>
Reviewed-by: Lokesh Vutla <lokeshvuta at ti.com>
Reviewed-by: Simon Glass <sjg at chromium.org>
---
 common/spl/spl_fit.c | 46 ++++++++++++++++++++++++++++++++--------------
 1 file changed, 32 insertions(+), 14 deletions(-)

diff --git a/common/spl/spl_fit.c b/common/spl/spl_fit.c
index 67372ca..85af980 100644
--- a/common/spl/spl_fit.c
+++ b/common/spl/spl_fit.c
@@ -60,14 +60,25 @@ static int spl_fit_find_config_node(const void *fdt)
 	return -ENOENT;
 }
 
-static int spl_fit_select_index(const void *fit, int images, int *offsetp,
-				const char *type, int index)
+/**
+ * spl_fit_get_image_node(): By using the matching configuration subnode,
+ * retrieve the name of an image, specified by a property name and an index
+ * into that.
+ * @fit:	Pointer to the FDT blob.
+ * @images:	Offset of the /images subnode.
+ * @type:	Name of the property within the configuration subnode.
+ * @index:	Index into the list of strings in this property.
+ *
+ * Return:	the node offset of the respective image node or a negative
+ * 		error number.
+ */
+static int spl_fit_get_image_node(const void *fit, int images,
+				  const char *type, int index)
 {
 	const char *name, *str;
 	int node, conf_node;
 	int len, i;
 
-	*offsetp = 0;
 	conf_node = spl_fit_find_config_node(fit);
 	if (conf_node < 0) {
 #ifdef CONFIG_SPL_LIBCOMMON_SUPPORT
@@ -104,10 +115,7 @@ static int spl_fit_select_index(const void *fit, int images, int *offsetp,
 		return -EINVAL;
 	}
 
-	*offsetp = fdt_getprop_u32(fit, node, "data-offset");
-	len = fdt_getprop_u32(fit, node, "data-size");
-
-	return len;
+	return node;
 }
 
 static int get_aligned_image_offset(struct spl_load_info *info, int offset)
@@ -193,15 +201,22 @@ int spl_load_simple_fit(struct spl_image_info *spl_image,
 	if (count == 0)
 		return -EIO;
 
-	/* find the firmware image to load */
+	/* find the node holding the images information */
 	images = fdt_path_offset(fit, FIT_IMAGES_PATH);
 	if (images < 0) {
 		debug("%s: Cannot find /images node: %d\n", __func__, images);
 		return -1;
 	}
-	node = fdt_first_subnode(fit, images);
+
+	/* find the U-Boot image */
+	node = spl_fit_get_image_node(fit, images, "firmware", 0);
 	if (node < 0) {
-		debug("%s: Cannot find first image node: %d\n", __func__, node);
+		debug("could not find firmware image, trying loadables...\n");
+		node = spl_fit_get_image_node(fit, images, "loadables", 0);
+	}
+	if (node < 0) {
+		debug("%s: Cannot find u-boot image node: %d\n",
+		      __func__, node);
 		return -1;
 	}
 
@@ -243,10 +258,13 @@ int spl_load_simple_fit(struct spl_image_info *spl_image,
 	memcpy(dst, src, data_size);
 
 	/* Figure out which device tree the board wants to use */
-	fdt_len = spl_fit_select_index(fit, images, &fdt_offset,
-				       FIT_FDT_PROP, 0);
-	if (fdt_len < 0)
-		return fdt_len;
+	node = spl_fit_get_image_node(fit, images, FIT_FDT_PROP, 0);
+	if (node < 0) {
+		debug("%s: cannot find FDT node\n", __func__);
+		return node;
+	}
+	fdt_offset = fdt_getprop_u32(fit, node, "data-offset");
+	fdt_len = fdt_getprop_u32(fit, node, "data-size");
 
 	/*
 	 * Read the device tree and place it after the image. There may be
-- 
2.8.2