From 1e6e7fb0b6c51999d2295c1c104bcfb1a79d7aab Mon Sep 17 00:00:00 2001
From: Moritz Sanft <58110325+msanft@users.noreply.github.com>
Date: Tue, 19 Nov 2024 16:15:57 +0100
Subject: [PATCH] packages/boot-microvm: init

This adds a little helper script to boot a Micro VM, as we build them for Kata bare-metal, via QEMU.
---
 packages/by-name/boot-microvm/package.nix | 36 +++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 packages/by-name/boot-microvm/package.nix

diff --git a/packages/by-name/boot-microvm/package.nix b/packages/by-name/boot-microvm/package.nix
new file mode 100644
index 000000000..416f82a26
--- /dev/null
+++ b/packages/by-name/boot-microvm/package.nix
@@ -0,0 +1,36 @@
+# Copyright 2024 Edgeless Systems GmbH
+# SPDX-License-Identifier: AGPL-3.0-only
+
+{
+  writeShellApplication,
+  qemu,
+  OVMF,
+}:
+
+# Usage example:
+# outPath=$(nix build .#kata.kata-image --print-out-paths); nix run .#boot-microvm -- "${outPath}/bzImage" "${outPath}/initrd" "${outPath}/image-podvm-gpu_1-rc1.raw" "$(nix eval --raw .#kata.kata-image.cmdline)"
+
+writeShellApplication {
+  name = "boot-microvm";
+  runtimeInputs = [ qemu ];
+  text = ''
+    if [ $# -ne 4 ]; then
+      echo "Usage: $0 <kernel> <initrd> <rootfs> <cmdline>";
+      exit 1;
+    fi
+
+    tmpFile=$(mktemp)
+    cp "$3" "$tmpFile"
+
+    qemu-system-x86_64 \
+      -enable-kvm \
+      -m 3G \
+      -nographic \
+      -drive if=pflash,format=raw,readonly=on,file=${OVMF.firmware} \
+      -drive if=pflash,format=raw,readonly=on,file=${OVMF.variables} \
+      -kernel "$1" \
+      -initrd "$2" \
+      -append "$4" \
+      -drive "if=virtio,format=raw,file=$tmpFile" 
+  '';
+}