def create_simg(contents,
priority=0,
daddr=0,
skip_crc32=False,
align=False,
version=None):
"""Create an SIMG version of a file.
>>> from cxmanage_api.simg import create_simg
>>> simg = create_simg(contents='foobarbaz')
>>> simg
'SIMG\\x02\\x00\\x00\\x00<\\x00\\x00\\x00\\t\\x00\\x00\\x00\\x00\\x00\\x00
\\x00\\xff\\xff\\xff\\xffK\\xf3\\xea\\x0c\\x00\\x00\\x00\\x00\\x00\\x00
\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00
\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00foobarbaz'
:param contents: Contents of the SIMG file.
:type contents: string
:param priority: SIMG Header priority value.
:type priority: integer
:param daddr: SIMG Header daddr value.
:type daddr: integer
:param skip_crc32: Flag to skip crc32 calculating.
:type skip_crc32: boolean
:param align: Flag used to turn on/off image offset of 4096.
:type align: boolean
:param version: Version string.
:type version: string
:returns: String representation of the SIMG file.
:rtype: string
"""
if (version == None):
version = ''
header = SIMGHeader()
header.priority = priority
header.imglen = len(contents)
header.daddr = daddr
header.version = version
if (align):
header.imgoff = 4096
# Calculate crc value
if (skip_crc32):
crc32 = 0
else:
crc32 = get_crc32(contents, get_crc32(str(header)[:MIN_HEADER_LENGTH]))
# Get SIMG header
header.flags = 0xFFFFFFFF
header.crc32 = crc32
return str(header).ljust(header.imgoff, chr(0)) + contents
def create_simg(contents, priority=0, daddr=0, skip_crc32=False, align=False,
version=None):
"""Create an SIMG version of a file.
>>> from cxmanage_api.simg import create_simg
>>> simg = create_simg(contents='foobarbaz')
>>> simg
'SIMG\\x02\\x00\\x00\\x00<\\x00\\x00\\x00\\t\\x00\\x00\\x00\\x00\\x00\\x00
\\x00\\xff\\xff\\xff\\xffK\\xf3\\xea\\x0c\\x00\\x00\\x00\\x00\\x00\\x00
\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00
\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00foobarbaz'
:param contents: Contents of the SIMG file.
:type contents: string
:param priority: SIMG Header priority value.
:type priority: integer
:param daddr: SIMG Header daddr value.
:type daddr: integer
:param skip_crc32: Flag to skip crc32 calculating.
:type skip_crc32: boolean
:param align: Flag used to turn on/off image offset of 4096.
:type align: boolean
:param version: Version string.
:type version: string
:returns: String representation of the SIMG file.
:rtype: string
"""
if (version == None):
version = ''
header = SIMGHeader()
header.priority = priority
header.imglen = len(contents)
header.daddr = daddr
header.version = version
if (align):
header.imgoff = 4096
# Calculate crc value
if (skip_crc32):
crc32 = 0
else:
crc32 = get_crc32(contents, get_crc32(str(header)[:MIN_HEADER_LENGTH]))
# Get SIMG header
header.flags = 0xFFFFFFFF
header.crc32 = crc32
return str(header).ljust(header.imgoff, chr(0)) + contents
def get_contents(self):
"""Returns a raw string representation of the uboot environment.
>>> uboot.get_contents()
'j4\x88\xb7bootcmd_default=run bootcmd_sata; run bootcmd_pxe ... '
>>> #
>>> # Output trimmed for brevity ...
>>> #
:returns: Raw string representation of the UBoot Environment.
:rtype: string
"""
contents = ""
# Add variables
for variable in self.variables:
contents += "%s=%s\0" % (variable, self.variables[variable])
contents += "\0"
# Add padding to end
contents += "".join(
[chr(255) for _ in range(ENVIRONMENT_SIZE - len(contents) - 4)])
# Add crc32 to beginning
crc32 = get_crc32(contents, 0xFFFFFFFF) ^ 0xFFFFFFFF
contents = struct.pack("<I", crc32) + contents
return contents
def get_contents(self):
"""Returns a raw string representation of the uboot environment.
>>> uboot.get_contents()
'j4\x88\xb7bootcmd_default=run bootcmd_sata; run bootcmd_pxe ... '
>>> #
>>> # Output trimmed for brevity ...
>>> #
:returns: Raw string representation of the UBoot Environment.
:rtype: string
"""
contents = ""
# Add variables
for variable in self.variables:
contents += "%s=%s\0" % (variable, self.variables[variable])
contents += "\0"
# Add padding to end
contents += "".join([chr(255)
for _ in range(ENVIRONMENT_SIZE - len(contents) - 4)])
# Add crc32 to beginning
crc32 = get_crc32(contents, 0xFFFFFFFF) ^ 0xFFFFFFFF
contents = struct.pack("<I", crc32) + contents
return contents
def valid_simg(simg):
"""Return true if this is a valid SIMG.
>>> from cxmanage_api.simg import create_simg
>>> simg=create_simg(contents='foobarbaz')
>>> from cxmanage_api.simg import valid_simg
>>> valid_simg(simg=simg)
True
:param simg: SIMG string (representation of a SIMG file).
:type simg: string
:returns: Whether or not the SIMG is valid.
:rtype: boolean
"""
if (not has_simg(simg)):
return False
header = SIMGHeader(simg[:HEADER_LENGTH])
# Check offset
if (header.imgoff < MIN_HEADER_LENGTH):
return False
# Check length
start = header.imgoff
end = start + header.imglen
contents = simg[start:end]
if (len(contents) < header.imglen):
return False
# Check crc32
crc32 = header.crc32
if (crc32 != 0):
header.flags = 0
header.crc32 = 0
if (crc32 != get_crc32(contents,
get_crc32(str(header)[:MIN_HEADER_LENGTH]))):
return False
return True
def valid_simg(simg):
"""Return true if this is a valid SIMG.
>>> from cxmanage_api.simg import create_simg
>>> simg=create_simg(contents='foobarbaz')
>>> from cxmanage_api.simg import valid_simg
>>> valid_simg(simg=simg)
True
:param simg: SIMG string (representation of a SIMG file).
:type simg: string
:returns: Whether or not the SIMG is valid.
:rtype: boolean
"""
if (not has_simg(simg)):
return False
header = SIMGHeader(simg[:HEADER_LENGTH])
# Check offset
if (header.imgoff < MIN_HEADER_LENGTH):
return False
# Check length
start = header.imgoff
end = start + header.imglen
contents = simg[start:end]
if (len(contents) < header.imglen):
return False
# Check crc32
crc32 = header.crc32
if (crc32 != 0):
header.flags = 0
header.crc32 = 0
if (crc32 != get_crc32(contents,
get_crc32(str(header)[:MIN_HEADER_LENGTH]))):
return False
return True
