Merge branch '2022-03-09-events-subsystem' into next

To quote the author:
It is a common need in U-Boot to have one subsystem notify another
when something happens. An example is reading a partition table when a
new block device is set up.

It is also common to add weak functions and 'hook' functions to modify
how U-Boot works. See for example ft_board_setup() and the like.

U-Boot would benefit from a generic mechanism to handle these cases,
with the ability to hook into various 'events' in a
subsystem-independent and transparent way.

This series provides a way to create and dispatch events, with a way of
registering a 'spy' which watches for events of different types. This
allows 'hook' functions to be created in a generic way.

It also includes a script to list the hooks in an image, which is a bit
easier to debug than weak functions, as well as an 'event' command to
do the same from within U-Boot.

These 'static' events can be used to replace hooks like misc_init_f(),
for example. Also included is basic support for 'dynamic' events, where
a spy can be registered at runtime. The need for this is still being
figured out.

1 files changed, 51 insertions, 7 deletions

diff --git a/tools/binman/elf.py b/tools/binman/elf.py
index 5e7d6ae7b97..35971731d05 100644
--- a/tools/binman/elf.py
+++ b/tools/binman/elf.py
@@ -85,6 +85,57 @@ def GetSymbols(fname, patterns):
     # Sort dict by address
     return OrderedDict(sorted(syms.items(), key=lambda x: x[1].address))
 
+def _GetFileOffset(elf, addr):
+    """Get the file offset for an address
+
+    Args:
+        elf (ELFFile): ELF file to check
+        addr (int): Address to search for
+
+    Returns
+        int: Offset of that address in the ELF file, or None if not valid
+    """
+    for seg in elf.iter_segments():
+        seg_end = seg['p_vaddr'] + seg['p_filesz']
+        if seg.header['p_type'] == 'PT_LOAD':
+            if addr >= seg['p_vaddr'] and addr < seg_end:
+                return addr - seg['p_vaddr'] + seg['p_offset']
+
+def GetFileOffset(fname, addr):
+    """Get the file offset for an address
+
+    Args:
+        fname (str): Filename of ELF file to check
+        addr (int): Address to search for
+
+    Returns
+        int: Offset of that address in the ELF file, or None if not valid
+    """
+    if not ELF_TOOLS:
+        raise ValueError('Python elftools package is not available')
+    with open(fname, 'rb') as fd:
+        elf = ELFFile(fd)
+        return _GetFileOffset(elf, addr)
+
+def GetSymbolFromAddress(fname, addr):
+    """Get the symbol at a particular address
+
+    Args:
+        fname (str): Filename of ELF file to check
+        addr (int): Address to search for
+
+    Returns:
+        str: Symbol name, or None if no symbol at that address
+    """
+    if not ELF_TOOLS:
+        raise ValueError('Python elftools package is not available')
+    with open(fname, 'rb') as fd:
+        elf = ELFFile(fd)
+        syms = GetSymbols(fname, None)
+    for name, sym in syms.items():
+        if sym.address == addr:
+            return name
+
 def GetSymbolFileOffset(fname, patterns):
     """Get the symbols from an ELF file
 
@@ -97,13 +148,6 @@ def GetSymbolFileOffset(fname, patterns):
           key: Name of symbol
           value: Hex value of symbol
     """
-    def _GetFileOffset(elf, addr):
-        for seg in elf.iter_segments():
-            seg_end = seg['p_vaddr'] + seg['p_filesz']
-            if seg.header['p_type'] == 'PT_LOAD':
-                if addr >= seg['p_vaddr'] and addr < seg_end:
-                    return addr - seg['p_vaddr'] + seg['p_offset']
-
     if not ELF_TOOLS:
         raise ValueError('Python elftools package is not available')