simg: Use 4KB alignment for CDB and boot log images

2 files changed, 30 insertions, 14 deletions

diff --git a/cxmanage/image.py b/cxmanage/image.py
index a91fde0..51f6816 100644
--- a/cxmanage/image.py
+++ b/cxmanage/image.py
@@ -35,7 +35,7 @@ import os
 import tempfile
 
 from cxmanage import CxmanageError
-from cxmanage.simg import create_simg, has_simg, valid_simg
+from cxmanage.simg import create_simg, has_simg, valid_simg, get_simg_contents
 
 class Image:
     """ An image consists of an image type, a filename, and any info needed
@@ -77,8 +77,9 @@ class Image:
                 daddr = self.daddr
 
             # Create simg
-            simg = create_simg(contents, version=version,
-                    daddr=daddr, skip_crc32=self.skip_crc32)
+            align = (self.type in ["CDB", "BOOT_LOG"])
+            simg = create_simg(contents, version=version, daddr=daddr,
+                    skip_crc32=self.skip_crc32, align=align)
             filename = tempfile.mkstemp(".simg", work_dir + "/")[1]
             open(filename, "w").write(simg)
 
@@ -97,17 +98,20 @@ class Image:
         if self.simg:
             return os.path.getsize(self.filename)
         else:
-            return os.path.getsize(self.filename) + 28
+            contents = open(self.filename).read()
+            align = (self.type in ["CDB", "BOOT_LOG"])
+            simg = create_simg(contents, skip_crc32=True, align=align)
+            return len(simg)
 
     def verify(self):
         """ Return true if the image is valid, false otherwise """
 
-        if self.type == "CDB":
+        if self.type in ["CDB", "BOOT_LOG"]:
             # Look for "CDBH"
             contents = open(self.filename).read()
             if self.simg:
-                return contents[28:32] == "CDBH"
-            else:
-                return contents[:4] == "CDBH"
+                contents = get_simg_contents(contents)
+
+            return contents[:4] == "CDBH"
 
         return True
diff --git a/cxmanage/simg.py b/cxmanage/simg.py
index 175e3c5..a6bfd0e 100644
--- a/cxmanage/simg.py
+++ b/cxmanage/simg.py
@@ -71,7 +71,7 @@ class SIMGHeader:
                 self.crc32)
 
 
-def create_simg(contents, version=0, daddr=0, skip_crc32=False):
+def create_simg(contents, version=0, daddr=0, skip_crc32=False, align=False):
     """Create an SIMG version of a file
 
     Assumes version and hdrfmt are 0.
@@ -82,6 +82,9 @@ def create_simg(contents, version=0, daddr=0, skip_crc32=False):
     header.imglen = len(contents)
     header.daddr = daddr
 
+    if align:
+        header.imgoff = 4096
+
     # Calculate crc value
     if skip_crc32:
         crc32 = 0
@@ -92,7 +95,7 @@ def create_simg(contents, version=0, daddr=0, skip_crc32=False):
     header.flags = 0xFFFFFFFF
     header.crc32 = crc32
 
-    return str(header) + contents
+    return str(header).ljust(header.imgoff, chr(0)) + contents
 
 
 def has_simg(simg):
@@ -112,16 +115,17 @@ def valid_simg(simg):
     if not has_simg(simg):
         return False
     header = SIMGHeader(simg[:28])
-    contents = simg[28:]
 
     # Check offset
-    if header.imgoff != 28:
+    if header.imgoff < 28:
         return False
 
     # Check length
+    start = header.imgoff
+    end = start + header.imglen
+    contents = simg[start:end]
     if len(contents) < header.imglen:
         return False
-    contents = contents[:header.imglen]
 
     # Check crc32
     crc32 = header.crc32
@@ -136,7 +140,15 @@ def valid_simg(simg):
 
 def get_simg_header(simg):
     """ Return the header of this SIMG """
-    if len(simg) < 28 or not has_simg(simg):
+    if not valid_simg(simg):
         raise ValueError("Failed to read invalid SIMG")
 
     return SIMGHeader(simg[:28])
+
+
+def get_simg_contents(simg):
+    """ Return the contents of this SIMG """
+    header = get_simg_header(simg)
+    start = header.imgoff
+    end = start + header.imglen
+    return simg[start:end]