Example SVSM loadable module

This project contains a very simple example of a loadable module that can be added to the coconut-SVSM ramfs initial filesystem. On startup, coconut-SVSM will enumerate modules and call the entry point at CPL-3. See the coconut-SVSM project here: https://github.com/coconut-svsm/svsm

This project has been created to support the PR titled "Draft: Add support for loadable modules at CPL-3" as an example module.

Building

Build the example module with:

cargo build

Packaging for coconut-SVSM

The module is built into the file target/debug/svsm-module. This needs to be added to the filesystem image that is included in your SVSM build.

To build the image you need to use the coconut packit tool. Clone and build it from here: https://github.com/coconut-svsm/packit

Once you have packit installed, create the directory structure expected by the loadable module support on coconut-SVSM:

mkdir -p image/modules/
cp target/debug/svsm-module image/modules
strip image/modules/svsm-module
packit --output fs.bin --dir image/

Once you have built the image you can bundle it in the coconut-SVSM initial ramfs image:

cd coco-svsm/
FS_FILE = /path/to/fs.bin make