binman: Allow extracting a file in an alternative format

In some cases entries encapsulate other data and it is useful to access
the data within. An example is the fdtmap which consists of a 16-byte
header, followed by a devicetree.

Provide an option to specify an alternative format when extracting files.
In the case of fdtmap, this is 'fdt', which produces an FDT file which can
be viewed with fdtdump.

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

1 files changed, 24 insertions, 4 deletions

diff --git a/tools/binman/control.py b/tools/binman/control.py
index 7da69ba38d..dcf070da85 100644
--- a/tools/binman/control.py
+++ b/tools/binman/control.py
@@ -200,8 +200,24 @@ def ReadEntry(image_fname, entry_path, decomp=True):
     return entry.ReadData(decomp)
 
 
+def ShowAltFormats(image):
+    """Show alternative formats available for entries in the image
+
+    This shows a list of formats available.
+
+    Args:
+        image (Image): Image to check
+    """
+    alt_formats = {}
+    image.CheckAltFormats(alt_formats)
+    print('%-10s  %-20s  %s' % ('Flag (-F)', 'Entry type', 'Description'))
+    for name, val in alt_formats.items():
+        entry, helptext = val
+        print('%-10s  %-20s  %s' % (name, entry.etype, helptext))
+
+
 def ExtractEntries(image_fname, output_fname, outdir, entry_paths,
-                   decomp=True):
+                   decomp=True, alt_format=None):
     """Extract the data from one or more entries and write it to files
 
     Args:
@@ -217,6 +233,10 @@ def ExtractEntries(image_fname, output_fname, outdir, entry_paths,
     """
     image = Image.FromFile(image_fname)
 
+    if alt_format == 'list':
+        ShowAltFormats(image)
+        return
+
     # Output an entry to a single file, as a special case
     if output_fname:
         if not entry_paths:
@@ -224,7 +244,7 @@ def ExtractEntries(image_fname, output_fname, outdir, entry_paths,
         if len(entry_paths) != 1:
             raise ValueError('Must specify exactly one entry path to write with -f')
         entry = image.FindEntryPath(entry_paths[0])
-        data = entry.ReadData(decomp)
+        data = entry.ReadData(decomp, alt_format)
         tools.WriteFile(output_fname, data)
         tout.Notice("Wrote %#x bytes to file '%s'" % (len(data), output_fname))
         return
@@ -236,7 +256,7 @@ def ExtractEntries(image_fname, output_fname, outdir, entry_paths,
     tout.Notice('%d entries match and will be written' % len(einfos))
     for einfo in einfos:
         entry = einfo.entry
-        data = entry.ReadData(decomp)
+        data = entry.ReadData(decomp, alt_format)
         path = entry.GetPath()[1:]
         fname = os.path.join(outdir, path)
 
@@ -584,7 +604,7 @@ def Binman(args):
 
             if args.cmd == 'extract':
                 ExtractEntries(args.image, args.filename, args.outdir, args.paths,
-                               not args.uncompressed)
+                               not args.uncompressed, args.format)
 
             if args.cmd == 'replace':
                 ReplaceEntries(args.image, args.filename, args.indir, args.paths,