1 files changed, 25 insertions, 0 deletions
diff --git a/nixpkgs/nixos/lib/qemu-flags.nix b/nixpkgs/nixos/lib/qemu-flags.nix
new file mode 100644
index 00000000000..774f66b4804
--- /dev/null
+++ b/nixpkgs/nixos/lib/qemu-flags.nix
@@ -0,0 +1,25 @@
+# QEMU flags shared between various Nix expressions.
+{ pkgs }:
+
+let
+  zeroPad = n: if n < 10 then "0${toString n}" else toString n;
+in
+
+{
+
+  qemuNICFlags = nic: net: machine:
+    [ "-device virtio-net-pci,netdev=vlan${toString nic},mac=52:54:00:12:${zeroPad net}:${zeroPad machine}"
+      "-netdev vde,id=vlan${toString nic},sock=$QEMU_VDE_SOCKET_${toString net}"
+    ];
+
+  qemuSerialDevice = if pkgs.stdenv.isi686 || pkgs.stdenv.isx86_64 then "ttyS0"
+        else if pkgs.stdenv.isAarch32 || pkgs.stdenv.isAarch64 then "ttyAMA0"
+        else throw "Unknown QEMU serial device for system '${pkgs.stdenv.hostPlatform.system}'";
+
+  qemuBinary = qemuPkg: {
+    x86_64-linux = "${qemuPkg}/bin/qemu-kvm -cpu kvm64";
+    armv7l-linux = "${qemuPkg}/bin/qemu-system-arm -enable-kvm -machine virt -cpu host";
+    aarch64-linux = "${qemuPkg}/bin/qemu-system-aarch64 -enable-kvm -machine virt,gic-version=host -cpu host";
+    x86_64-darwin = "${qemuPkg}/bin/qemu-kvm -cpu kvm64";
+  }.${pkgs.stdenv.hostPlatform.system} or "${qemuPkg}/bin/qemu-kvm";
+}