From 6cf9953bfb9d849b4f617e54570a6fe0e5b824a9 Mon Sep 17 00:00:00 2001
From: Simon Glass
Date: Tue, 1 Sep 2020 05:13:59 -0600
Subject: binman: Support generating FITs with multiple dtbs

In some cases it is useful to generate a FIT which has a number of DTB
images, selectable by configuration. Add support for this in binman,
using a simple iterator and string substitution.

Signed-off-by: Simon Glass <sjg@chromium.org>
---
 tools/binman/README.entries | 48 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 47 insertions(+), 1 deletion(-)

(limited to 'tools/binman/README.entries')

diff --git a/tools/binman/README.entries b/tools/binman/README.entries
index 8999d5eb387..d2628dffd5d 100644
--- a/tools/binman/README.entries
+++ b/tools/binman/README.entries
@@ -339,6 +339,7 @@ For example, this creates an image containing a FIT with U-Boot SPL:
     binman {
         fit {
             description = "Test FIT";
+            fit,fdt-list = "of-list";
 
             images {
                 kernel@1 {
@@ -357,7 +358,52 @@ For example, this creates an image containing a FIT with U-Boot SPL:
         };
     };
 
-Properties:
+U-Boot supports creating fdt and config nodes automatically. To do this,
+pass an of-list property (e.g. -a of-list=file1 file2). This tells binman
+that you want to generates nodes for two files: file1.dtb and file2.dtb
+The fit,fdt-list property (see above) indicates that of-list should be used.
+If the property is missing you will get an error.
+
+Then add a 'generator node', a node with a name starting with '@':
+
+    images {
+        @fdt-SEQ {
+            description = "fdt-NAME";
+            type = "flat_dt";
+            compression = "none";
+        };
+    };
+
+This tells binman to create nodes fdt-1 and fdt-2 for each of your two
+files. All the properties you specify will be included in the node. This
+node acts like a template to generate the nodes. The generator node itself
+does not appear in the output - it is replaced with what binman generates.
+
+You can create config nodes in a similar way:
+
+    configurations {
+        default = "@config-DEFAULT-SEQ";
+        @config-SEQ {
+            description = "NAME";
+            firmware = "uboot";
+            loadables = "atf";
+            fdt = "fdt-SEQ";
+        };
+    };
+
+This tells binman to create nodes config-1 and config-2, i.e. a config for
+each of your two files.
+
+Available substitutions for '@' nodes are:
+
+    SEQ    Sequence number of the generated fdt (1, 2, ...)
+    NAME   Name of the dtb as provided (i.e. without adding '.dtb')
+
+Note that if no devicetree files are provided (with '-a of-list' as above)
+then no nodes will be generated.
+
+
+Properties (in the 'fit' node itself):
     fit,external-offset: Indicates that the contents of the FIT are external
         and provides the external offset. This is passsed to mkimage via
         the -E and -p flags.
-- 
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