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model.py

ofrak_patch_maker.model

These classes must only ever contain "immutable" data.

We never want to worry about the state of these objects at any point during a patch injection.

AssembledObject dataclass

The result of any compile or assemble step

Attributes:

Name Type Description
path str

.o file path

file_format BinFileType

.elf, .coff, etc.

segment_map Mapping[str, ofrak_patch_maker.toolchain.model.Segment]

e.g. {".text", Segment(...)}

BOM dataclass

"BOM" stands for Batched Objects and Metadata

Keeping this class frozen ensures we have a hash for every instance.

Instances of this class should never be declared outside of PatchMaker.

Attributes:

Name Type Description
name str

a name

object_map Mapping[str, ofrak_patch_maker.model.AssembledObject]

{source file path: AssembledObject}

bss_size_required int
entry_point_symbol Optional[str]

symbol of the patch entrypoint, when relevant

FEM dataclass

"FEM" stands for Final Executable and Metadata

Keeping this class frozen ensures we have a hash for every instance

Instances of this class should never be declared outside of PatchMaker.

Attributes:

Name Type Description
name str
executable LinkedExecutable

LinkedExecutable dataclass

The result of any link step.

Attributes:

Name Type Description
path str

executable file path

file_format BinFileType

.elf, .coff, etc.

segments Tuple[ofrak_patch_maker.toolchain.model.Segment, ...]

the segments contained in this executable

symbols Mapping[str, int]

the global function and data symbol mapping information for this executable

relocatable bool

TODO: whether or not the executable is relocatable

PatchRegionConfig dataclass

PatchRegionConfig is the dataclass required to generate an .ld script. That describes a set of code and data patches.

For every available object file, new code and data Segments are populated with the target VM addresses/sizes within the client firmware.

PatchMaker uses this information to generate memory regions and the sections that will go into those memory regions.

Attributes:

Name Type Description
patch_name str

a name

segments Mapping[str, Tuple[ofrak_patch_maker.toolchain.model.Segment, ...]]

{object file path: Tuple of Segments}