binman: Add support for flashrom FMAP

Add an entry which can hold an FMAP region as used by flashrom, an
open-source flashing tool used on Linux x86 machines. This provides a
simplified non-hierarchical view of the entries in the image and has a
signature at the start to allow flashrom to find it in the image.

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

2 files changed, 66 insertions, 2 deletions

diff --git a/tools/binman/etype/fmap.py b/tools/binman/etype/fmap.py
new file mode 100644
index 0000000000..f1dd81ec49
--- /dev/null
+++ b/tools/binman/etype/fmap.py
@@ -0,0 +1,61 @@
+# SPDX-License-Identifier: GPL-2.0+
+# Copyright (c) 2018 Google, Inc
+# Written by Simon Glass <sjg@chromium.org>
+#
+# Entry-type module for a Flash map, as used by the flashrom SPI flash tool
+#
+
+from entry import Entry
+import fmap_util
+
+
+class Entry_fmap(Entry):
+    """An entry which contains an Fmap section
+
+    Properties / Entry arguments:
+        None
+
+    FMAP is a simple format used by flashrom, an open-source utility for
+    reading and writing the SPI flash, typically on x86 CPUs. The format
+    provides flashrom with a list of areas, so it knows what it in the flash.
+    It can then read or write just a single area, instead of the whole flash.
+
+    The format is defined by the flashrom project, in the file lib/fmap.h -
+    see www.flashrom.org/Flashrom for more information.
+
+    When used, this entry will be populated with an FMAP which reflects the
+    entries in the current image. Note that any hierarchy is squashed, since
+    FMAP does not support this.
+    """
+    def __init__(self, section, etype, node):
+        Entry.__init__(self, section, etype, node)
+
+    def _GetFmap(self):
+        """Build an FMAP from the entries in the current image
+
+        Returns:
+            FMAP binary data
+        """
+        def _AddEntries(areas, entry):
+            entries = entry.GetEntries()
+            if entries:
+                for subentry in entries.values():
+                    _AddEntries(areas, subentry)
+            else:
+                areas.append(fmap_util.FmapArea(entry.image_pos or 0,
+                                                entry.size or 0, entry.name, 0))
+
+        entries = self.section.GetEntries()
+        areas = []
+        for entry in entries.values():
+            _AddEntries(areas, entry)
+        return fmap_util.EncodeFmap(self.section.GetSize() or 0, self.name,
+                                    areas)
+
+    def ObtainContents(self):
+        """Obtain a placeholder for the fmap contents"""
+        self.SetContents(self._GetFmap())
+        return True
+
+    def ProcessContents(self):
+        self.SetContents(self._GetFmap())
diff --git a/tools/binman/etype/section.py b/tools/binman/etype/section.py
index 2e68f276f0..f5b2ed67cf 100644
--- a/tools/binman/etype/section.py
+++ b/tools/binman/etype/section.py
@@ -30,8 +30,8 @@ class Entry_section(Entry):
     hierarchical images to be created. See 'Sections and hierarchical images'
     in the binman README for more information.
     """
-    def __init__(self, image, etype, node):
-        Entry.__init__(self, image, etype, node)
+    def __init__(self, section, etype, node):
+        Entry.__init__(self, section, etype, node)
         self._section = bsection.Section(node.name, node)
 
     def ProcessFdt(self, fdt):
@@ -89,3 +89,6 @@ class Entry_section(Entry):
             fd: File to write the map to
         """
         self._section.WriteMap(fd, indent)
+
+    def GetEntries(self):
+        return self._section.GetEntries()