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authorSimon Glass <sjg@chromium.org>2018-07-06 19:27:41 +0300
committerSimon Glass <sjg@chromium.org>2018-07-09 18:11:00 +0300
commit078ab1a2f5a9901f5f9983163d4f98b8d94bfda0 (patch)
tree469e20126f5566717b8a0cd35395b1c029e42139 /tools/binman/README
parentecab89737a4eb58c043388b1ca1c0f1dfdaa3346 (diff)
downloadu-boot-078ab1a2f5a9901f5f9983163d4f98b8d94bfda0.tar.xz
binman: Add a SetCalculatedProperties() method
Once binman has packed the image, the position and size of each entry is known. It is then possible for binman to update the device tree with these positions. Since placeholder values have been added, this does not affect the size of the device tree and therefore the packing does not need to be performed again. Add a new SetCalculatedProperties method to handle this. Signed-off-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'tools/binman/README')
-rw-r--r--tools/binman/README29
1 files changed, 20 insertions, 9 deletions
diff --git a/tools/binman/README b/tools/binman/README
index 008d575052..8b598a75c8 100644
--- a/tools/binman/README
+++ b/tools/binman/README
@@ -462,14 +462,22 @@ Order of image creation
Image creation proceeds in the following order, for each entry in the image.
-1. ProcessFdt() - process the device tree information as required by the
+1. AddMissingProperties() - binman can add calculated values to the device
+tree as part of its processing, for example the position and size of each
+entry. This method adds any properties associated with this, expanding the
+device tree as needed. These properties can have placeholder values which are
+set later by SetCalculatedProperties(). By that stage the size of sections
+cannot be changed (since it would cause the images to need to be repacked),
+but the correct values can be inserted.
+
+2. ProcessFdt() - process the device tree information as required by the
particular entry. This may involve adding or deleting properties. If the
processing is complete, this method should return True. If the processing
cannot complete because it needs the ProcessFdt() method of another entry to
run first, this method should return False, in which case it will be called
again later.
-2. GetEntryContents() - the contents of each entry are obtained, normally by
+3. GetEntryContents() - the contents of each entry are obtained, normally by
reading from a file. This calls the Entry.ObtainContents() to read the
contents. The default version of Entry.ObtainContents() calls
Entry.GetDefaultFilename() and then reads that file. So a common mechanism
@@ -478,35 +486,38 @@ functions must return True when they have read the contents. Binman will
retry calling the functions a few times if False is returned, allowing
dependencies between the contents of different entries.
-3. GetEntryPositions() - calls Entry.GetPositions() for each entry. This can
+4. GetEntryPositions() - calls Entry.GetPositions() for each entry. This can
return a dict containing entries that need updating. The key should be the
entry name and the value is a tuple (pos, size). This allows an entry to
provide the position and size for other entries. The default implementation
of GetEntryPositions() returns {}.
-4. PackEntries() - calls Entry.Pack() which figures out the position and
+5. PackEntries() - calls Entry.Pack() which figures out the position and
size of an entry. The 'current' image position is passed in, and the function
returns the position immediately after the entry being packed. The default
implementation of Pack() is usually sufficient.
-5. CheckSize() - checks that the contents of all the entries fits within
+6. CheckSize() - checks that the contents of all the entries fits within
the image size. If the image does not have a defined size, the size is set
large enough to hold all the entries.
-6. CheckEntries() - checks that the entries do not overlap, nor extend
+7. CheckEntries() - checks that the entries do not overlap, nor extend
outside the image.
-7. ProcessEntryContents() - this calls Entry.ProcessContents() on each entry.
+8. SetCalculatedProperties() - update any calculated properties in the device
+tree. This sets the correct 'pos' and 'size' vaues, for example.
+
+9. ProcessEntryContents() - this calls Entry.ProcessContents() on each entry.
The default implementatoin does nothing. This can be overriden to adjust the
contents of an entry in some way. For example, it would be possible to create
an entry containing a hash of the contents of some other entries. At this
stage the position and size of entries should not be adjusted.
-8. WriteSymbols() - write the value of symbols into the U-Boot SPL binary.
+10. WriteSymbols() - write the value of symbols into the U-Boot SPL binary.
See 'Access to binman entry positions at run time' below for a description of
what happens in this stage.
-9. BuildImage() - builds the image and writes it to a file. This is the final
+11. BuildImage() - builds the image and writes it to a file. This is the final
step.