diff options
Diffstat (limited to 'cxmanage/simg.py')
| -rw-r--r-- | cxmanage/simg.py | 24 |
1 files changed, 18 insertions, 6 deletions
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] |