4.1 KiB
pelfy
Description
Pelfy is ELF (Executable and Linkable Format) parser written in python. It shows header fields, sections, symbols and relocation and gives access to all raw data as well as human readable names.
Key Features
- Provide names for fields and values as well as descriptions
- Relocation types for x86, mips, arm and risc-v all in 32 and 64 bit
- Compact syntax
- Outputs tables in HTML, markdown or text
- Jupyter notebook support
- Pure python and no dependencies
Usage Scenarios
- Reverse engineering tools
- Testing
- Documentation
Installation
The package has no additional decencies. It can be installed with pip:
pip install pelfy
Usage
Example code and its outputs:
import pelfy
elf = pelfy.open_elf_file('obj/test-c-riscv64-linux-gnu-gcc-12-O3.o')
elf.sections
| index | name | type | description |
|---|---|---|---|
| 0 | SHT_NULL | Section header table entry unused | |
| 1 | .text | SHT_PROGBITS | Program data |
| 2 | .rela.text | SHT_RELA | Relocation entries with addends |
| 3 | .data | SHT_PROGBITS | Program data |
| 4 | .bss | SHT_NOBITS | Program space with no data (bss) |
| 5 | .comment | SHT_PROGBITS | Program data |
| 6 | .note.GNU-stack | SHT_PROGBITS | Program data |
| 7 | .riscv.attributes | 0x70000003 | Application-specific |
| 8 | .symtab | SHT_SYMTAB | Symbol table |
| 9 | .strtab | SHT_STRTAB | String table |
| 10 | .shstrtab | SHT_STRTAB | String table |
elf.functions
| index | name | info | size | stb | description |
|---|---|---|---|---|---|
| 11 | result_float | STT_FUNC | 8 | STB_GLOBAL | Symbol is a code object |
| 12 | result_float_float | STT_FUNC | 12 | STB_GLOBAL | Symbol is a code object |
| 13 | add_float_float | STT_FUNC | 12 | STB_GLOBAL | Symbol is a code object |
| 14 | mul_float_float | STT_FUNC | 12 | STB_GLOBAL | Symbol is a code object |
| 15 | read_float | STT_FUNC | 16 | STB_GLOBAL | Symbol is a code object |
elf.symbols['read_float'].get_relocations()
| index | symbol name | type | calculation |
|---|---|---|---|
| 4 | .LANCHOR0 | R_RISCV_PCREL_HI20 | S + A - P |
| 5 | R_RISCV_RELAX | ||
| 6 | .L0 | R_RISCV_PCREL_LO12_I | S - P |
| 7 | R_RISCV_RELAX | ||
| 8 | result_float_float | R_RISCV_CALL_PLT | S + A - P |
| 9 | R_RISCV_RELAX |
Contributing
Contributions are welcome! Please open an issue or submit a pull request on GitHub.
Developer Guide
To get started with developing the pelfy package, follow these steps:
First, clone the repository to your local machine using Git:
git clone https://github.com/Nonannet/pelfy.git
cd pelfy
Install the package while keeping files in the current dev directory:
pip install -e .
Install pytest (unit testing), mypy (type checking) and flake8 (style guide checking):
pip install pytest mypy flake8
Ensure that everything is set up correctly by running the tests:
pytest
For creating additional test object files place the source c-files in the tests/src/ directory,
change the current directory to tests/src/ and run bash run_cross_compilation.sh. This
script uses a docker container to cross compile all c-files to object files and outputs
them in the tests/obj directory.
License
This project is licensed under the MIT License - see the LICENSE file for details.