binman: Support marking FMAP areas as preserved

Add an entry flag called 'preserve' to indicate that an entry should be
preserved by firmware updates. Propagate this to FMAP too.

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

diff --git a/tools/binman/binman.rst b/tools/binman/binman.rst
index 2bcb7d3886f0dd005d04fc3b7c937041352ac75c..8af23fd0fab5341fa989ceec69634010d02c6f4f 100644 (file)
--- a/tools/binman/binman.rst
+++ b/tools/binman/binman.rst
@@ -838,6 +838,14 @@ offset-from-elf:
     is the symbol to lookup (relative to elf-base-sym) and <offset> is an offset
     to add to that value.
 
+preserve:
+    Indicates that this entry should be preserved by any firmware updates. This
+    flag should be checked by the updater when it is deciding which entries to
+    update. This flag is normally attached to sections but can be attached to
+    a single entry in a section if the updater supports it. Not that binman
+    itself has no control over the updater's behaviour, so this is just a
+    signal. It is not enforced by binman.
+
 Examples of the above options can be found in the tests. See the
 tools/binman/test directory.
 

diff --git a/tools/binman/entries.rst b/tools/binman/entries.rst
index 7a04a613992da6615949af28a73c0cf1b4aa3460..19659247cf02b49d0e69a4ed9c2f160fc9c1330d 100644 (file)
--- a/tools/binman/entries.rst
+++ b/tools/binman/entries.rst
@@ -887,6 +887,11 @@ before its contents, so that it is possible to reconstruct the hierarchy
 from the FMAP by using the offset information. This convention does not
 seem to be documented, but is used in Chromium OS.
 
+To mark an area as preserved, use the normal 'preserved' flag in the entry.
+This will result in the corresponding FMAP area having the
+FMAP_AREA_PRESERVE flag. This flag does not automatically propagate down to
+child entries.
+
 CBFS entries appear as a single entry, i.e. the sub-entries are ignored.
 
 

diff --git a/tools/binman/entry.py b/tools/binman/entry.py
index 5eacc5fa6c42a45692f87cf7ff7dfe17595a2c54..fd617e4f15f2a4e966e04b5a7351c8628aae32dd 100644 (file)
--- a/tools/binman/entry.py
+++ b/tools/binman/entry.py
@@ -100,6 +100,10 @@ class Entry(object):
             appear in the map
         optional (bool): True if this entry contains an optional external blob
         overlap (bool): True if this entry overlaps with others
+        preserve (bool): True if this entry should be preserved when updating
+            firmware. This means that it will not be changed by the update.
+            This is just a signal: enforcement of this is up to the updater.
+            This flag does not automatically propagate down to child entries.
     """
     fake_dir = None
 
@@ -148,6 +152,7 @@ class Entry(object):
         self.overlap = False
         self.elf_base_sym = None
         self.offset_from_elf = None
+        self.preserve = False
 
     @staticmethod
     def FindEntryClass(etype, expanded):
@@ -310,6 +315,8 @@ class Entry(object):
         self.offset_from_elf = fdt_util.GetPhandleNameOffset(self._node,
                                                              'offset-from-elf')
 
+        self.preserve = fdt_util.GetBool(self._node, 'preserve')
+
     def GetDefaultFilename(self):
         return None
 

diff --git a/tools/binman/etype/fmap.py b/tools/binman/etype/fmap.py
index 0c576202a48d165fdb50f553cef3b25fab81a83c..b35450fec9731df4bf6fd3b038c4bf09fae32ca1 100644 (file)
--- a/tools/binman/etype/fmap.py
+++ b/tools/binman/etype/fmap.py
@@ -33,6 +33,11 @@ class Entry_fmap(Entry):
     from the FMAP by using the offset information. This convention does not
     seem to be documented, but is used in Chromium OS.
 
+    To mark an area as preserved, use the normal 'preserved' flag in the entry.
+    This will result in the corresponding FMAP area having the
+    FMAP_AREA_PRESERVE flag. This flag does not automatically propagate down to
+    child entries.
+
     CBFS entries appear as a single entry, i.e. the sub-entries are ignored.
     """
     def __init__(self, section, etype, node):
@@ -48,6 +53,12 @@ class Entry_fmap(Entry):
             entries = entry.GetEntries()
             tout.debug("fmap: Add entry '%s' type '%s' (%s subentries)" %
                        (entry.GetPath(), entry.etype, to_hex_size(entries)))
+
+            # Collect any flag (separate lines to ensure code coverage)
+            flags = 0
+            if entry.preserve:
+                flags = fmap_util.FMAP_AREA_PRESERVE
+
             if entries and entry.etype != 'cbfs':
                 # Create an area for the section, which encompasses all entries
                 # within it
@@ -59,7 +70,7 @@ class Entry_fmap(Entry):
                 # Drop @ symbols in name
                 name = entry.name.replace('@', '')
                 areas.append(
-                    fmap_util.FmapArea(pos, entry.size or 0, name, 0))
+                    fmap_util.FmapArea(pos, entry.size or 0, name, flags))
                 for subentry in entries.values():
                     _AddEntries(areas, subentry)
             else:
@@ -67,7 +78,7 @@ class Entry_fmap(Entry):
                 if pos is not None:
                     pos -= entry.section.GetRootSkipAtStart()
                 areas.append(fmap_util.FmapArea(pos or 0, entry.size or 0,
-                                                entry.name, 0))
+                                                entry.name, flags))
 
         entries = self.GetImage().GetEntries()
         areas = []

diff --git a/tools/binman/fmap_util.py b/tools/binman/fmap_util.py
index 1ce63d1a8321c9ea88fbab1dfcffaa51db7fb1b4..82e0f74d50f22efe201498697ce58a50190f28e9 100644 (file)
--- a/tools/binman/fmap_util.py
+++ b/tools/binman/fmap_util.py
@@ -45,6 +45,9 @@ FMAP_AREA_NAMES = (
     'flags',
 )
 
+# Flags supported by areas (bits 2:0 are unused so not included here)
+FMAP_AREA_PRESERVE = 1 << 3  # Preserved by any firmware updates
+
 # These are the two data structures supported by flashrom, a header (which
 # appears once at the start) and an area (which is repeated until the end of
 # the list of areas)

diff --git a/tools/binman/ftest.py b/tools/binman/ftest.py
index 062f54adb0ed9393ab626708f904c8ab6de87fd4..df916ed602a837625809b66e2ed70b079e204f80 100644 (file)
--- a/tools/binman/ftest.py
+++ b/tools/binman/ftest.py
@@ -1702,7 +1702,7 @@ class TestFunctional(unittest.TestCase):
         self.assertEqual(b'SECTION0', fentry.name)
         self.assertEqual(0, fentry.offset)
         self.assertEqual(16, fentry.size)
-        self.assertEqual(0, fentry.flags)
+        self.assertEqual(fmap_util.FMAP_AREA_PRESERVE, fentry.flags)
 
         fentry = next(fiter)
         self.assertEqual(b'RO_U_BOOT', fentry.name)

diff --git a/tools/binman/test/067_fmap.dts b/tools/binman/test/067_fmap.dts
index 9c0e293ac83179fdf3217177afc47ceef4beb305..24fa6351ec3c0f6bce6656b931b92a1eb6414970 100644 (file)
--- a/tools/binman/test/067_fmap.dts
+++ b/tools/binman/test/067_fmap.dts
@@ -11,6 +11,7 @@
                        name-prefix = "ro-";
                        size = <0x10>;
                        pad-byte = <0x21>;
+                       preserve;
 
                        u-boot {
                        };