[U-Boot] [PATCH PATCH v6 13/13] spl: fit: Allow the board to tell if more images must be loaded from FIT

[Jean-Jacques Hiblot]

spl_fit_get_image_name() is used to get the names of the images that the
SPL must load from the FIT. It relies on the content of a property present
in the FIT. The list of images is thus statically defined in the FIT.
With this scheme, it quickly becomes hard to manage combinations of more
than a handful of images.
To address this problem, give the board driver code the opportunity to
add to the list of images. The images from the FIT property are loaded
first, and then the board_get_fit_loadable() is called to get more image
names.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot at ti.com>

---

Changes in v6:
- Instead of matching a overlay by the name of it's node. Try to match it
  first with the description, and then with the node's name. This allows
  to use makeimg to add the overlays to u-boot.img and not use a custom
  SPL_FIT_GENERATOR script

Changes in v5:
-reword commit log

Changes in v4:
- Use the board driver infrastructure to get the image names from the
board code.
- Remove a patch that passed the board name to the FIT generator. If needed
the generator can get it from elsewhere
- Add a fix to not load the firmware twice (once as a firmware and once as
a loadable)

Changes in v3:
- removed the RFC prefix. This work will be needed soon by TI's AM65x
platform. and can probably benefit other modular platforms
- removed the last patch that provided an example of how to use this with
on a DRA76.
- removed the patch that made u-boot.img a symlink to u-boot.itb because
it breaks the build of many platforms (because files required to build the
ITB are missing)
- removed the patch to reduce the footprint of the am335x SPL. (already
merged)
- Made the boot flow more permissive (don't fail immediately if an overlay
is not present) and more verbose when an error occures
- handle the dependencies of the FIT generation in a more generic way
- use a dedicated kconfig option to enable the application of the overlays
by the SPL.

Changes in v2:
- reworked board_fit_get_additionnal_images() and how it used in spl_fit.c
- removed dtbo generation from dtso files and use .dts extension for the
  overlays
- add dynamic allocation usage in a separate patch
- defconfig change for the am335x_evm

 common/spl/spl_fit.c | 65 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 62 insertions(+), 3 deletions(-)

diff --git a/common/spl/spl_fit.c b/common/spl/spl_fit.c
index 9001731303..ac69d8312e 100644
--- a/common/spl/spl_fit.c
+++ b/common/spl/spl_fit.c
@@ -6,6 +6,7 @@
 
 #include <common.h>
 #include <errno.h>
+#include <board.h>
 #include <fpga.h>
 #include <gzip.h>
 #include <image.h>
@@ -32,6 +33,29 @@ __weak ulong board_spl_fit_size_align(ulong size)
 	return size;
 }
 
+static int find_node_from_desc(const void *fit, int node, const char *str)
+{
+	int child;
+
+	if (node < 0)
+		return -EINVAL;
+
+	/* iterate the FIT nodes and find a matching description */
+	for (child = fdt_first_subnode(fit, node); child >= 0;
+	     child = fdt_next_subnode(fit, child)) {
+		int len;
+		const char *desc = fdt_getprop(fit, child, "description", &len);
+
+		if (!desc)
+			continue;
+
+		if (!strcmp(desc, str))
+			return child;
+	}
+
+	return -ENOENT;
+}
+
 /**
  * spl_fit_get_image_name(): By using the matching configuration subnode,
  * retrieve the name of an image, specified by a property name and an index
@@ -48,10 +72,12 @@ static int spl_fit_get_image_name(const void *fit, int images,
 				  const char *type, int index,
 				  const char **outname)
 {
+	struct udevice *board;
 	const char *name, *str;
 	__maybe_unused int node;
 	int conf_node;
 	int len, i;
+	bool found = true;
 
 	conf_node = fit_find_config_node(fit);
 	if (conf_node < 0) {
@@ -77,12 +103,45 @@ static int spl_fit_get_image_name(const void *fit, int images,
 	for (i = 0; i < index; i++) {
 		str = strchr(str, '\0') + 1;
 		if (!str || (str - name >= len)) {
-			debug("no string for index %d\n", index);
-			return -E2BIG;
+			found = false;
+			break;
+		}
+	}
+
+	if (!found && !board_get(&board)) {
+		int rc;
+		/*
+		 * no string in the property for this index. Check if the board
+		 * level code can supply one.
+		 */
+		rc = board_get_fit_loadable(board, index - i - 1, type, &str);
+		if (rc && rc != -ENOENT)
+			return rc;
+
+		if (!rc) {
+			/*
+			 * The board provided a name for a loadable.
+			 * Try to match it against the description properties
+			 * first. If no matching node is found, use it as a
+			 * node name.
+			 */
+			int node;
+			int images = fdt_path_offset(fit, FIT_IMAGES_PATH);
+
+			node = find_node_from_desc(fit, images, str);
+			if (node > 0)
+				str = fdt_get_name(fit, node, NULL);
+
+			found = true;
 		}
 	}
 
-	*outname = (char *)str;
+	if (!found) {
+		debug("no string for index %d\n", index);
+		return -E2BIG;
+	}
+
+	*outname = str;
 	return 0;
 }
 
-- 
2.17.1