UDB VSCode Extension

A Visual Studio Code extension for working with UDB (Unified Database) specification files used in the RISC-V Unified Database project. This extension works with the .udb file extension.

Features

Syntax Highlighting

Full syntax highlighting for UDB schema files, making it easier to read and navigate complex database definitions at a glance.

Autocomplete

Context-aware autocomplete suggestions as you type, helping you write valid UDB schemas faster and with fewer errors.

Schema Support

Dedicated support for the following UDB schema types:

• CSR schemas — author Control and Status Register definitions
• Instruction schemas — define and edit RISC-V instruction definitions
• Extension schemas — work with RISC-V extension definitions
• Exception code schemas — define exception codes
• Instruction opcode schemas — define instruction opcodes
• Instruction variable type schemas — define instruction variable types
• Interrupt code schemas — define interrupt codes
• Manual schemas — define manual metadata
• Manual version schemas — define manual version metadata
• Non-ISA schemas — define non-ISA specifications
• Profile family schemas — define profile families
• Profile schemas — define RISC-V profiles
• Register file schemas — define register files

Some schemas have partial support:

• Config schemas — define architecture configurations

Cross-Referencing

Navigate across related schema definitions with cross-referencing support — jump to referenced definitions directly from within your editor.

Workflows

There are two different ways to use this extension: Creating new RISC-V specifications and modifying existing RISC-V specifications (in the form of .yaml files),.

Creating New Specifications

To create new specifications, simply create a file with the .udb file extension and enjoy the features! Once you're done, use the convertudb.py Python script to convert the .udb file into a .yaml file as follows:

python convertudb.py [specification].udb

This generates an equivalent .yaml file so that you can then push the new specification into the RISC-V Unified Database repository.

Modifying Existing Specifications

To modify existing specification files, use same the convertudb.py Python script to first convert the existing .yaml file into its .udb equivalent as follows:

python convertudb.py [specification].yaml

This generates a .udb file you can then use to make changes while taking advantage of this extension's features. After making your changes, you can use the same script to convert the .udb file back into a .yaml file before pushing it to the RISC-V Unified Database repository.

Requirements

• Visual Studio Code v1.109.0 or higher
• Java 21 or later — required to run the language server
• Python — required to convert between .yaml and .udb files

Installing Java

If you don't have Java 21+ installed, the extension will show an error with installation instructions. Here's a quick setup guide:

macOS

brew install openjdk@21

Windows

Download and install from Adoptium or Oracle JDK

Linux (Ubuntu/Debian)

sudo apt update
sudo apt install openjdk-21-jdk

Linux (Fedora/RHEL)

sudo dnf install java-21-openjdk

Verify installation:

java -version

You should see output like:

openjdk version "21.0.x" ...

Getting Started

1. Install Java 21+ (see above)
2. Install the extension from the VS Code Marketplace
3. Open a folder containing your UDB schema files
4. Start editing — syntax highlighting, autocomplete, and cross-referencing will activate automatically on .udb files

Troubleshooting

Language server doesn't start

1. Check the Output panel: View → Output and select UDB Language Server from the dropdown
2. Verify Java is installed: run java -version in your terminal
3. If Java is installed but the extension doesn't find it, configure the path in VS Code settings:

"udb.javaPath": "/path/to/java"

For example on macOS with Homebrew:

"udb.javaPath": "/opt/homebrew/opt/openjdk@21/bin/java"

Version mismatch error

If you see an error about Java version, ensure you have Java 21 or later installed:

java -version

If you have multiple Java versions installed, use the udb.javaPath setting to point to Java 21+.

Feedback & Contributions

This extension was developed by the Harvey Mudd Clinic Team for Qualcomm and is currently maintained by Qualcomm. For bugs or feature requests, please open an issue on the project repository.