binman: Rename 'position' to 'offset'

After some thought, I believe there is an unfortunate naming flaw in
binman. Entries have a position and size, but now that we support
hierarchical sections it is unclear whether a position should be an
absolute position within the image, or a relative position within its
parent section.

At present 'position' actually means the relative position. This indicates
a need for an 'image position' for code that wants to find the location of
an entry without having to do calculations back through parents to
discover this image position.

A better name for the current 'position' or 'pos' is 'offset'. It is not
always an absolute position, but it is always an offset from its parent
offset.

It is unfortunate to rename this concept now, 18 months after binman was
introduced. However I believe it is the right thing to do. The impact is
mostly limited to binman itself and a few changes to in-tree users to
binman:

   tegra
   sunxi
   x86

The change makes old binman definitions (e.g. downstream or out-of-tree)
incompatible if they use the 'pos = <...>' property. Later work will
adjust binman to generate an error when it is used.

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

1 files changed, 18 insertions, 17 deletions

diff --git a/tools/binman/etype/u_boot_with_ucode_ptr.py b/tools/binman/etype/u_boot_with_ucode_ptr.py
index 8b1e41152e..97e58a0bfc 100644
--- a/tools/binman/etype/u_boot_with_ucode_ptr.py
+++ b/tools/binman/etype/u_boot_with_ucode_ptr.py
@@ -23,7 +23,7 @@ class Entry_u_boot_with_ucode_ptr(Entry_blob):
     def __init__(self, section, etype, node):
         Entry_blob.__init__(self, section, etype, node)
         self.elf_fname = 'u-boot'
-        self.target_pos = None
+        self.target_offset = None
 
     def GetDefaultFilename(self):
         return 'u-boot-nodtb.bin'
@@ -33,52 +33,53 @@ class Entry_u_boot_with_ucode_ptr(Entry_blob):
         fname = tools.GetInputFilename(self.elf_fname)
         sym = elf.GetSymbolAddress(fname, '_dt_ucode_base_size')
         if sym:
-           self.target_pos = sym
+           self.target_offset = sym
         elif not fdt_util.GetBool(self._node, 'optional-ucode'):
             self.Raise('Cannot locate _dt_ucode_base_size symbol in u-boot')
         return True
 
     def ProcessContents(self):
         # If the image does not need microcode, there is nothing to do
-        if not self.target_pos:
+        if not self.target_offset:
             return
 
-        # Get the position of the microcode
+        # Get the offset of the microcode
         ucode_entry = self.section.FindEntryType('u-boot-ucode')
         if not ucode_entry:
             self.Raise('Cannot find microcode region u-boot-ucode')
 
         # Check the target pos is in the section. If it is not, then U-Boot is
-        # being linked incorrectly, or is being placed at the wrong position
+        # being linked incorrectly, or is being placed at the wrong offset
         # in the section.
         #
         # The section must be set up so that U-Boot is placed at the
         # flash address to which it is linked. For example, if
         # CONFIG_SYS_TEXT_BASE is 0xfff00000, and the ROM is 8MB, then
-        # the U-Boot region must start at position 7MB in the section. In this
-        # case the ROM starts at 0xff800000, so the position of the first
+        # the U-Boot region must start at offset 7MB in the section. In this
+        # case the ROM starts at 0xff800000, so the offset of the first
         # entry in the section corresponds to that.
-        if (self.target_pos < self.pos or
-                self.target_pos >= self.pos + self.size):
+        if (self.target_offset < self.offset or
+                self.target_offset >= self.offset + self.size):
             self.Raise('Microcode pointer _dt_ucode_base_size at %08x is '
                 'outside the section ranging from %08x to %08x' %
-                (self.target_pos, self.pos, self.pos + self.size))
+                (self.target_offset, self.offset, self.offset + self.size))
 
         # Get the microcode, either from u-boot-ucode or u-boot-dtb-with-ucode.
         # If we have left the microcode in the device tree, then it will be
         # in the former. If we extracted the microcode from the device tree
         # and collated it in one place, it will be in the latter.
         if ucode_entry.size:
-            pos, size = ucode_entry.pos, ucode_entry.size
+            offset, size = ucode_entry.offset, ucode_entry.size
         else:
             dtb_entry = self.section.FindEntryType('u-boot-dtb-with-ucode')
             if not dtb_entry or not dtb_entry.ready:
                 self.Raise('Cannot find microcode region u-boot-dtb-with-ucode')
-            pos = dtb_entry.pos + dtb_entry.ucode_offset
+            offset = dtb_entry.offset + dtb_entry.ucode_offset
             size = dtb_entry.ucode_size
 
-        # Write the microcode position and size into the entry
-        pos_and_size = struct.pack('<2L', pos, size)
-        self.target_pos -= self.pos
-        self.ProcessContentsUpdate(self.data[:self.target_pos] + pos_and_size +
-                                   self.data[self.target_pos + 8:])
+        # Write the microcode offset and size into the entry
+        offset_and_size = struct.pack('<2L', offset, size)
+        self.target_offset -= self.offset
+        self.ProcessContentsUpdate(self.data[:self.target_offset] +
+                                   offset_and_size +
+                                   self.data[self.target_offset + 8:])