Getting started

Prerequisites

  • .NET SDK 10.0 or later (dotnet --version). The Cosmos gen3 tool and SDK target net10.0.
  • A host that QEMU runs on. On macOS/Linux the Cosmos installer bundles QEMU, clang/lld, xorriso and GDB; on Windows use the installer from the Cosmos gen3 releases.

Install the toolchain 

dotnet tool install -g Cosmos.Tools     # the `cosmos` CLI
cosmos install                          # patcher, templates, VS Code ext, native tools
cosmos check                            # verify everything resolved

cosmos check should report .NET SDK, clang/lld, xorriso, QEMU (x64 + arm64) and GDB all present.

If cosmos isn’t found afterwards, add the global tools dir to your PATH (~/.dotnet/tools) and restart your shell.

Build

The kernel project lives in Medli3/ (the predecessor trees Medli-Legacy/ and Medli-Classic/ are reference only). Build it with -p from the repo root, or cd into it first:

cosmos build -p Medli3              # host architecture (auto-detected)
cosmos build -p Medli3 -a x64       # force x86-64
cosmos build -p Medli3 -a arm64     # force ARM64
# or:  cd Medli3 && cosmos build

The bootable ISO lands in Medli3/output-<arch>/Medli3.iso. (./run.sh does the build + boot for you.)

Run 

./run.sh                  # build + boot x64 in QEMU
./run.sh arm64            # ARM64 (also: amd64 / x86_64 / aarch64 aliases)

You should see the white-on-blue boot screen (logo, welcome banner, colour spectrum) and a medli~> prompt. Type help. Type shutdown to power off.

See Building & running for QEMU specifics (especially ARM64 input) and the cosmos run vs run.sh difference.