1 files changed, 129 insertions, 0 deletions
diff --git a/tools/binman/elf.py b/tools/binman/elf.py
new file mode 100644
index 00000000000..80ff2253f03
--- /dev/null
+++ b/tools/binman/elf.py
@@ -0,0 +1,129 @@
+# Copyright (c) 2016 Google, Inc
+# Written by Simon Glass <sjg@chromium.org>
+#
+# SPDX-License-Identifier:      GPL-2.0+
+#
+# Handle various things related to ELF images
+#
+
+from collections import namedtuple, OrderedDict
+import command
+import os
+import re
+import struct
+
+import tools
+
+# This is enabled from control.py
+debug = False
+
+Symbol = namedtuple('Symbol', ['section', 'address', 'size', 'weak'])
+
+
+def GetSymbols(fname, patterns):
+    """Get the symbols from an ELF file
+
+    Args:
+        fname: Filename of the ELF file to read
+        patterns: List of regex patterns to search for, each a string
+
+    Returns:
+        None, if the file does not exist, or Dict:
+          key: Name of symbol
+          value: Hex value of symbol
+    """
+    stdout = command.Output('objdump', '-t', fname, raise_on_error=False)
+    lines = stdout.splitlines()
+    if patterns:
+        re_syms = re.compile('|'.join(patterns))
+    else:
+        re_syms = None
+    syms = {}
+    syms_started = False
+    for line in lines:
+        if not line or not syms_started:
+            if 'SYMBOL TABLE' in line:
+                syms_started = True
+            line = None  # Otherwise code coverage complains about 'continue'
+            continue
+        if re_syms and not re_syms.search(line):
+            continue
+
+        space_pos = line.find(' ')
+        value, rest = line[:space_pos], line[space_pos + 1:]
+        flags = rest[:7]
+        parts = rest[7:].split()
+        section, size =  parts[:2]
+        if len(parts) > 2:
+            name = parts[2]
+            syms[name] = Symbol(section, int(value, 16), int(size,16),
+                                flags[1] == 'w')
+    return syms
+
+def GetSymbolAddress(fname, sym_name):
+    """Get a value of a symbol from an ELF file
+
+    Args:
+        fname: Filename of the ELF file to read
+        patterns: List of regex patterns to search for, each a string
+
+    Returns:
+        Symbol value (as an integer) or None if not found
+    """
+    syms = GetSymbols(fname, [sym_name])
+    sym = syms.get(sym_name)
+    if not sym:
+        return None
+    return sym.address
+
+def LookupAndWriteSymbols(elf_fname, entry, image):
+    """Replace all symbols in an entry with their correct values
+
+    The entry contents is updated so that values for referenced symbols will be
+    visible at run time. This is done by finding out the symbols positions in
+    the entry (using the ELF file) and replacing them with values from binman's
+    data structures.
+
+    Args:
+        elf_fname: Filename of ELF image containing the symbol information for
+            entry
+        entry: Entry to process
+        image: Image which can be used to lookup symbol values
+    """
+    fname = tools.GetInputFilename(elf_fname)
+    syms = GetSymbols(fname, ['image', 'binman'])
+    if not syms:
+        return
+    base = syms.get('__image_copy_start')
+    if not base:
+        return
+    for name, sym in syms.iteritems():
+        if name.startswith('_binman'):
+            msg = ("Image '%s': Symbol '%s'\n   in entry '%s'" %
+                   (image.GetPath(), name, entry.GetPath()))
+            offset = sym.address - base.address
+            if offset < 0 or offset + sym.size > entry.contents_size:
+                raise ValueError('%s has offset %x (size %x) but the contents '
+                                 'size is %x' % (entry.GetPath(), offset,
+                                                 sym.size, entry.contents_size))
+            if sym.size == 4:
+                pack_string = '<I'
+            elif sym.size == 8:
+                pack_string = '<Q'
+            else:
+                raise ValueError('%s has size %d: only 4 and 8 are supported' %
+                                 (msg, sym.size))
+
+            # Look up the symbol in our entry tables.
+            value = image.LookupSymbol(name, sym.weak, msg)
+            if value is not None:
+                value += base.address
+            else:
+                value = -1
+                pack_string = pack_string.lower()
+            value_bytes = struct.pack(pack_string, value)
+            if debug:
+                print('%s:\n   insert %s, offset %x, value %x, length %d' %
+                      (msg, name, offset, value, len(value_bytes)))
+            entry.data = (entry.data[:offset] + value_bytes +
+                        entry.data[offset + sym.size:])