move userspace to top level to facilitate overriding

src/default.nix

@@ -18,10 +18,11 @@ let
         initramfs_image = self.initramfs;
       };
       kernel        = self.callPackage ./kernel { };
+      userspace = self.callPackage ./userspace {
+        kernelname = "${self.kernel.version}-${self.platform_name}";
+      };
       initramfs     = self.callPackage ./initramfs {
-        userspace = self.callPackage ./userspace {
-          kernelname = "${self.kernel.version}-${self.platform_name}";
-        };
+        inherit (self) userspace;
       };
     }))
   .overrideScope' overlay;

src/initramfs/default.nix

@@ -28,5 +28,4 @@ nixpkgsOnBuildForHost.stdenv.mkDerivation {
     popd
   '';
   dontInstall = true;
-  passthru = { inherit userspace kernel; };
 }

src/platform/kevin/default.nix

@@ -24,40 +24,38 @@
         '';
       });
 
-    initramfs = prev.initramfs.override {
-      userspace = prev.initramfs.passthru.userspace.override {
-        # order matters!  this is also the order in which the modules are insmoded
-        modules_insmod = [
-          "drivers/video/backlight/pwm_bl.ko"
-          "drivers/gpu/drm/panel/panel-simple.ko"
-          "drivers/gpu/drm/bridge/analogix/analogix_dp.ko"
-          "drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.ko"
-          "drivers/gpu/drm/bridge/synopsys/dw-hdmi.ko"
-          "drivers/gpu/drm/rockchip/rockchipdrm.ko"
-          "drivers/usb/dwc3/dwc3-of-simple.ko"
-          "drivers/usb/dwc3/dwc3.ko"
-          "drivers/usb/host/ehci-hcd.ko"
-          "drivers/usb/host/ehci-platform.ko"
-          "drivers/usb/host/ohci-hcd.ko"
-          "drivers/usb/host/ohci-platform.ko"
-          "drivers/usb/storage/usb-storage.ko"
-          "drivers/usb/storage/uas.ko"
-          "drivers/usb/host/xhci-hcd.ko"
-          "drivers/usb/host/xhci-plat-hcd.ko"
-        ];
-        # FIXME: need firmware for mwifiex and ath9k as well.
-        modules_noinsmod = [
-          "lib/crypto/libarc4.ko"
-          "net/mac80211/mac80211.ko"
-          "drivers/net/wireless/ath/ath9k/ath9k.ko"
-          "drivers/net/wireless/ath/ath9k/ath9k_common.ko"
-          "drivers/net/wireless/ath/ath9k/ath9k_htc.ko"
-          "drivers/net/wireless/ath/ath9k/ath9k_hw.ko"
-          "drivers/net/wireless/ath/ath.ko"
-          "drivers/net/wireless/marvell/mwifiex/mwifiex_pcie.ko"
-          "drivers/net/wireless/marvell/mwifiex/mwifiex.ko"
-        ];
-      };
+    userspace = prev.userspace.override {
+      # order matters!  this is also the order in which the modules are insmoded
+      modules_insmod = [
+        "drivers/video/backlight/pwm_bl.ko"
+        "drivers/gpu/drm/panel/panel-simple.ko"
+        "drivers/gpu/drm/bridge/analogix/analogix_dp.ko"
+        "drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.ko"
+        "drivers/gpu/drm/bridge/synopsys/dw-hdmi.ko"
+        "drivers/gpu/drm/rockchip/rockchipdrm.ko"
+        "drivers/usb/dwc3/dwc3-of-simple.ko"
+        "drivers/usb/dwc3/dwc3.ko"
+        "drivers/usb/host/ehci-hcd.ko"
+        "drivers/usb/host/ehci-platform.ko"
+        "drivers/usb/host/ohci-hcd.ko"
+        "drivers/usb/host/ohci-platform.ko"
+        "drivers/usb/storage/usb-storage.ko"
+        "drivers/usb/storage/uas.ko"
+        "drivers/usb/host/xhci-hcd.ko"
+        "drivers/usb/host/xhci-plat-hcd.ko"
+      ];
+      # FIXME: need firmware for mwifiex and ath9k as well.
+      modules_noinsmod = [
+        "lib/crypto/libarc4.ko"
+        "net/mac80211/mac80211.ko"
+        "drivers/net/wireless/ath/ath9k/ath9k.ko"
+        "drivers/net/wireless/ath/ath9k/ath9k_common.ko"
+        "drivers/net/wireless/ath/ath9k/ath9k_htc.ko"
+        "drivers/net/wireless/ath/ath9k/ath9k_hw.ko"
+        "drivers/net/wireless/ath/ath.ko"
+        "drivers/net/wireless/marvell/mwifiex/mwifiex_pcie.ko"
+        "drivers/net/wireless/marvell/mwifiex/mwifiex.ko"
+      ];
     };
 
     coreboot =