QEMU-DMLC

A DML 1.4 compiler for QEMU device models, written in Rust.

Overview

qemu-dmlc parses DML (Device Modeling Language) 1.4 source files and generates QEMU device model code. It currently supports:

• C backend generation (.h + .c)
• Rust backend skeleton generation (.rs)
• optional Rust integration artifact snippets (Cargo.toml, meson.build, Kconfig)

Features

Supported DML Features

• Device, bank, register, field, and group hierarchy
• Parameters (param) with types and default values
• Methods with C-like syntax
• Session and saved state declarations
• Templates with is inheritance
• C-like expressions and control flow
• Log statements
• Conditional compilation (#if/#else)

Excluded (Simics-Specific)

• Full Simics runtime semantics (interfaces, hooks, ports, subdevices)
• Complete behavior lowering for complex Simics constructs

Notes:

• Rust skeleton generation includes compatibility parsing for several Simics-style declarations (connect, attribute, implement, event) to reduce parser failures, but these are not yet fully semantics-complete in the backend.

Building

cargo build --release

The binary will be at target/release/qemu-dmlc.

Usage

# Parse and validate a DML file
./target/release/qemu-dmlc --parse-only device.dml

# Generate C output (default language)
./target/release/qemu-dmlc --lang c device.dml -o output
# -> output.h + output.c

# Generate Rust skeleton output
./target/release/qemu-dmlc --lang rust device.dml -o output
# -> output.rs

# Generate Rust skeleton + optional integration artifact snippets
./target/release/qemu-dmlc --lang rust --rust-artifacts device.dml -o output
# -> output.rs + output.Cargo.toml + output.meson.build.snippet + output.Kconfig.snippet

Project Structure

qemu-dmlc/
├── src/
│   ├── lib.rs           # Crate root
│   ├── main.rs          # CLI entry point
│   ├── parser/
│   │   ├── grammar.pest # PEG grammar
│   │   └── mod.rs       # Parser implementation
│   ├── ast/
│   │   └── mod.rs       # AST type definitions
│   └── codegen/
│       ├── mod.rs       # Public codegen API + dispatch
│       ├── ir.rs        # Shared AST lowering/model
│       ├── c_backend.rs # C backend emitter
│       └── rust_backend.rs # Rust backend emitter
├── scripts/
│   └── test_dml.sh      # Regression test script
├── test/
│   └── dml_sample/      # Test DML files
├── dml_qemu.ebnf        # QEMU subset grammar (EBNF)
└── doc/
    └── dml_formal_grammar.ebnf  # Full DML 1.4 grammar

Testing

Run unit tests:

cargo test

Run regression script (multi-mode):

# Parse-only regression
./scripts/test_dml.sh --modes parse -f feat/bank

# Parse + Rust generation regression
./scripts/test_dml.sh --modes parse,rust -f feat/bank -b ./target/debug/qemu-dmlc

# Rust generation + artifact emission regression
./scripts/test_dml.sh --modes rust-artifacts -f feat/bank/register_size_param -b ./target/debug/qemu-dmlc

# Rust regression excluding qemu_model samples
./scripts/test_dml.sh --modes rust --exclude-qemu-model -b ./target/debug/qemu-dmlc

# Rust regression excluding any path by regex
./scripts/test_dml.sh --modes rust --exclude 'device/qemu_model|feat/port' -b ./target/debug/qemu-dmlc

Dependencies

• pest 2.7 — PEG parser generator
• clap 4 — CLI argument parsing
• miette 7 — Error reporting
• thiserror 2 — Error types
• tracing — Logging

References

• DML 1.4 Language Specification
• QEMU Device Models