https://github.com/bgourlie/asm6502

A simple 6502 assembler written in Rust
https://github.com/bgourlie/asm6502

assembler retrocomputing rust

Last synced: 3 months ago
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A simple 6502 assembler written in Rust

• Host: GitHub
• URL: https://github.com/bgourlie/asm6502
• Owner: bgourlie
• License: mit
• Created: 2017-01-12T05:14:49.000Z (almost 8 years ago)
• Default Branch: master
• Last Pushed: 2022-08-26T01:32:42.000Z (over 2 years ago)
• Last Synced: 2024-09-06T03:38:14.501Z (4 months ago)
• Topics: assembler, retrocomputing, rust
• Language: Rust
• Homepage:
• Size: 73.2 KB
• Stars: 19
• Watchers: 4
• Forks: 3
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# asm6502

[![Build Status](https://travis-ci.org/bgourlie/asm6502.svg?branch=master)](https://travis-ci.org/bgourlie/asm6502)

[![Crates.io](https://img.shields.io/crates/v/asm6502.svg)](https://crates.io/crates/asm6502)

A work-in-progress 6502 assembler.

This assembler currently serves the immediate needs of my [NES emulator](https://github.com/bgourlie/rs-nes). As such,

it doesn't do anything except translate literal 6502 assembly into machine code. Not even labels are supported, and

relative addresses must specify a numeric offset. Any contributions are welcome, however. I'd love for this to 

become a more fully-featured assembler.

### Usage

```rust

use asm6502::assemble;

let asm = "LDA #1\nADC #1\nCMP #2".as_bytes();

let mut buf = Vec::::new();

if let Err(msg) = assemble(asm, &mut buf) {

     panic!("Failed to assemble: {}", msg);

}

 

assert_eq!(&[0xa9, 0x1, 0x69, 0x1, 0xc9, 0x2], &buf[..]);

```

The input and output parameters of the `assemble` function are generic over the 

[`Read`](https://doc.rust-lang.org/stable/std/io/trait.Read.html) and 

[`Write`](https://doc.rust-lang.org/stable/std/io/trait.Write.html) traits, 

respectively. A more typical usage of this function would accept an input file and an output file.

### Known Issues

If the assembly ends with an implied instruction, it will need to be followed by a newline in order to be parsed

correctly, and will fail to parse otherwise. See my StackOverflow question 

[here](http://stackoverflow.com/q/41658386/547365) documenting the issue and the work-in-progress nom

[pull request](https://github.com/Geal/nom/pull/413) addressing the underlying issue.