xen: rewrite build expression to be more modular, support upstream qemu and seabios

Also:

* provides a bunch of build options
* documents build options config in longDescription
* provides a bunch of predefined packages and documents them some more
* sources' hashes stay the same

1 files changed, 64 insertions, 0 deletions

diff --git a/pkgs/applications/virtualization/xen/packages.nix b/pkgs/applications/virtualization/xen/packages.nix
new file mode 100644
index 00000000000..633ec4f3d12
--- /dev/null
+++ b/pkgs/applications/virtualization/xen/packages.nix
@@ -0,0 +1,64 @@
+{ callPackage
+, stdenv, overrideCC, gcc49
+}:
+
+# TODO on new Xen version: generalize this to generate [vanilla slim
+# light] for each ./<version>.nix.
+
+rec {
+
+  xen_4_5-vanilla = callPackage ./4.5.nix {
+    # At the very least included seabios and etherboot need gcc49,
+    # so we have to build all of it with gcc49.
+    stdenv = overrideCC stdenv gcc49;
+
+    meta = {
+      description = "vanilla";
+      longDescription = ''
+        Vanilla version of Xen. Uses forks of Qemu and Seabios bundled
+        with Xen. This gives vanilla experince, but wastes space and
+        build time: typical NixOS setup that runs lots of VMs will
+        build three different versions of Qemu when using this (two
+        forks and upstream).
+      '';
+    };
+  };
+
+  xen_4_5-slim = xen_4_5-vanilla.override {
+    withInternalQemu = false;
+    withInternalTraditionalQemu = true;
+    withInternalSeabios = false;
+    withSeabios = true;
+
+    meta = {
+      description = "slim";
+      longDescription = ''
+        Slimmed-down version of Xen that reuses nixpkgs packages as
+        much as possible. Different parts may get out of sync, but
+        this builds faster and uses less space than vanilla. Use with
+        `qemu_xen` from nixpkgs.
+      '';
+    };
+  };
+
+  xen_4_5-light = xen_4_5-vanilla.override {
+    withInternalQemu = false;
+    withInternalTraditionalQemu = false;
+    withInternalSeabios = false;
+    withSeabios = true;
+
+    meta = {
+      description = "light";
+      longDescription = ''
+        Slimmed-down version of Xen without `qemu-traditional` (you
+        don't need it if you don't know what it is). Use with
+        `qemu_xen-light` from nixpkgs.
+      '';
+    };
+  };
+
+  xen-vanilla = xen_4_5-vanilla;
+  xen-slim = xen_4_5-slim;
+  xen-light = xen_4_5-light;
+
+}