jffs2.py
ofrak.core.jffs2
Jffs2Filesystem (GenericBinary, FilesystemRoot)
dataclass
Filesystem stored in a JFFS2 format.
Jffs2Packer (Packer)
Pack files into a compressed JFFS2 filesystem.
pack(self, resource, config=None)
async
Pack the given resource.
Users should not call this method directly; rather, they should run Resource.run or Resource.pack.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
resource |
Resource |
required | |
config |
Optional config for packing. If an implementation provides a default, this default will always be used when config would otherwise be None. Note that a copy of the default config will be passed, so the default config values cannot be modified persistently by a component run. |
None |
Source code in ofrak/core/jffs2.py
async def pack(self, resource: Resource, config=None):
jffs2_view: Jffs2Filesystem = await resource.view_as(Jffs2Filesystem)
temp_flush_dir = await jffs2_view.flush_to_disk()
with tempfile.NamedTemporaryFile(suffix=".sqsh", mode="rb", delete_on_close=False) as temp:
temp.close()
cmd = [
"mkfs.jffs2",
"-r",
temp_flush_dir,
"-o",
temp.name,
]
proc = await asyncio.create_subprocess_exec(
*cmd,
)
returncode = await proc.wait()
if proc.returncode:
raise CalledProcessError(returncode=returncode, cmd=cmd)
with open(temp.name, "rb") as new_fh:
new_data = new_fh.read()
# Passing in the original range effectively replaces the original data with the new data
resource.queue_patch(Range(0, await resource.get_data_length()), new_data)
Jffs2Unpacker (Unpacker)
Unpack a JFFS2 filesystem.
unpack(self, resource, config=None)
async
Unpack the given resource.
Users should not call this method directly; rather, they should run Resource.run or Resource.unpack.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
resource |
Resource |
The resource that is being unpacked |
required |
config |
Optional config for unpacking. If an implementation provides a default, this default will always be used when config would otherwise be None. Note that a copy of the default config will be passed, so the default config values cannot be modified persistently by a component run. |
None |
Source code in ofrak/core/jffs2.py
async def unpack(self, resource: Resource, config=None):
async with resource.temp_to_disk() as temp_path:
with tempfile.TemporaryDirectory() as temp_flush_dir:
cmd = [
"jefferson",
"--force",
"--dest",
temp_flush_dir,
temp_path,
]
proc = await asyncio.create_subprocess_exec(
*cmd,
)
returncode = await proc.wait()
if proc.returncode:
raise CalledProcessError(returncode=returncode, cmd=cmd)
jffs2_view = await resource.view_as(Jffs2Filesystem)
await jffs2_view.initialize_from_disk(temp_flush_dir)