binman: Update documentation for image creation

There are a few more steps in the process now. Update the documentation to
reflect this.
Signed-off-by: NSimon Glass <sjg@chromium.org>

tools/binman/README

@@ -679,22 +679,35 @@ large enough to hold all the entries.
 7. CheckEntries() - checks that the entries do not overlap, nor extend
 outside the image.
 
-8. SetCalculatedProperties() - update any calculated properties in the device
+8. SetImagePos() - sets the image position of every entry. This is the absolute
+position 'image-pos', as opposed to 'offset' which is relative to the containing
+section. This must be done after all offsets are known, which is why it is quite
+late in the ordering.
+
+9. SetCalculatedProperties() - update any calculated properties in the device
 tree. This sets the correct 'offset' and 'size' vaues, for example.
 
-9. ProcessEntryContents() - this calls Entry.ProcessContents() on each entry.
+10. 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 offset and size of entries should not be adjusted unless absolutely
 necessary, since it requires a repack (going back to PackEntries()).
 
-10. WriteSymbols() - write the value of symbols into the U-Boot SPL binary.
+11. ResetForPack() - if the ProcessEntryContents() step failed, in that an entry
+has changed its size, then there is no alternative but to go back to step 5 and
+try again, repacking the entries with the updated size. ResetForPack() removes
+the fixed offset/size values added by binman, so that the packing can start from
+scratch.
+
+12. WriteSymbols() - write the value of symbols into the U-Boot SPL binary.
 See 'Access to binman entry offsets at run time' below for a description of
 what happens in this stage.
 
-11. BuildImage() - builds the image and writes it to a file. This is the final
-step.
+13. BuildImage() - builds the image and writes it to a file
+
+14. WriteMap() - writes a text file containing a map of the image. This is the
+final step.
 
 
 Automatic .dtsi inclusion