https://github.com/ryanhaticus/legv8-disassembler
C++ disassembler for the LEGv8 subset of ARM.
https://github.com/ryanhaticus/legv8-disassembler
disassembler legv8 legv8-arm
Last synced: 7 months ago
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C++ disassembler for the LEGv8 subset of ARM.
- Host: GitHub
- URL: https://github.com/ryanhaticus/legv8-disassembler
- Owner: ryanhaticus
- Created: 2023-11-05T09:01:58.000Z (almost 2 years ago)
- Default Branch: main
- Last Pushed: 2023-11-06T18:06:49.000Z (almost 2 years ago)
- Last Synced: 2025-03-01T02:16:02.508Z (8 months ago)
- Topics: disassembler, legv8, legv8-arm
- Language: C++
- Homepage:
- Size: 9.77 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Authors: authors.txt
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README
# LEGv8 Disassembler
Enclosed in this repository is a disassembler (binary to assembly) for 32-bit LEGv8 (a subset of ARM first described by David A. Patterson and John L. Hennessy) instructions written in C++.
## Coursework
This project was developed as part of COM S 321 (Computer Architecture) at Iowa State University, instructed by Dr. Jeremy Sheaffer.
## What's included?
The disassembler can handle the following instruction types:
- B
- CB
- D
- I
- IW
- R
Specifically, supporting the following instructions:
- ADD
- ADDI
- AND
- ANDI
- B
- B.cond (EQ, NE, HS, LO, MI, PL, VS, VC, HI, LS, GE, LT, GT, LE)
- BL
- BR
- CBNZ
- CBZ
- EOR
- EORI
- LDUR
- LSL
- LSR
- ORR
- ORRI
- STUR
- SUB
- SUBI
- SUBIS
- SUBS
- MUL
Along with these special instructions, implemented by some emulators:
- PRNT
- PRNL
- DUMP
- HALT
## Endianness
As most modern systems are little-endian, we assume that the input binary is little-endian.
## Usage
Per course guidelines, the project ships with a `build.sh` and `run.sh` - these do what you expect.
To build the project, simply run `./build.sh`. You must have `make` and `g++` installed ahead of time. You will see the executable `disasm` generated. You may execute this binary directly, or use the provided `run.sh` script.
Next, to disassemble a binary, run `./run.sh `. The disassembled output will be written to `.legv8asm`. For example, if you run `./run.sh test.bin`, the output will be written to `test.bin.legv8asm`.
## Considerations
When originally approaching this project, I had wanted to use a more object-oriented approach. However, I quickly realized it'd be rather burdensome to ensure I was shifting out values and storing them in class members correctly.
Instead, I opted to create classic C `struct`s to represent the various instruction types. Once I dynamically identify an instruction's opcode, I can then cast the `uint32_t` bitfield to the appropriate `struct` and access the fields directly without headache. For those interested in creating a disassembler, I highly recommend this approach.