extract common config for qemu devices into module

devices/families/qemu.nix

@@ -0,0 +1,54 @@
+{ config, pkgs, ... }:
+{
+  config = {
+    kernel = {
+      src = pkgs.pkgsBuildBuild.fetchurl {
+        name = "linux.tar.gz";
+        url = "https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.15.71.tar.gz";
+        hash = "sha256-yhO2cXIeIgUxkSZf/4aAsF11uxyh+UUZu6D1h92vCD8=";
+      };
+      config = {
+        MTD = "y";
+        MTD_BLOCK = "y";
+        MTD_CMDLINE_PARTS = "y";
+        MTD_PHRAM = "y";
+
+        VIRTIO_MENU = "y";
+        PCI = "y";
+        VIRTIO_PCI = "y";
+        BLOCK = "y";
+        VIRTIO_BLK = "y";
+        VIRTIO_NET = "y";
+      };
+    };
+    hardware =
+      let
+        mac80211 =  pkgs.mac80211.override {
+          drivers = ["mac80211_hwsim"];
+          klibBuild = config.system.outputs.kernel.modulesupport;
+        };
+      in {
+        defaultOutput = "vmroot";
+        rootDevice = "/dev/mtdblock0";
+        dts.src = null;
+        flash.eraseBlockSize = 65536;
+        networkInterfaces =
+          let inherit (config.system.service.network) link;
+          in {
+            wan = link.build {
+              devpath = "/devices/pci0000:00/0000:00:13.0/virtio0";
+              ifname = "wan";
+            };
+            lan = link.build {
+              devpath = "/devices/pci0000:00/0000:00:14.0/virtio1";
+              ifname = "lan";
+            };
+
+            wlan_24 = link.build {
+              ifname = "wlan0";
+              dependencies = [ mac80211 ];
+            };
+          };
+      };
+  };
+}

devices/qemu-aarch64/default.nix

@@ -27,29 +27,15 @@
   installer = "vmroot";
 
   module = {pkgs, config, lim, ... }: {
-    imports = [ ../../modules/arch/aarch64.nix ];
+    imports = [
+      ../../modules/arch/aarch64.nix
+      ../families/qemu.nix
+    ];
     kernel = {
-      src = pkgs.pkgsBuildBuild.fetchurl {
-        name = "linux.tar.gz";
-        url = "https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.15.71.tar.gz";
-        hash = "sha256-yhO2cXIeIgUxkSZf/4aAsF11uxyh+UUZu6D1h92vCD8=";
-      };
       config = {
         VIRTUALIZATION = "y";
         PCI_HOST_GENERIC="y";
 
-        MTD = "y";
-        MTD_BLOCK = "y";
-        MTD_CMDLINE_PARTS = "y";
-        MTD_PHRAM = "y";
-
-        VIRTIO_MENU = "y";
-        PCI = "y";
-        VIRTIO_PCI = "y";
-        BLOCK = "y";
-        VIRTIO_BLK = "y";
-        VIRTIO_NET = "y";
-
         SERIAL_AMBA_PL011 = "y";
         SERIAL_AMBA_PL011_CONSOLE = "y";
       };
@@ -57,31 +43,5 @@
     boot.commandLine = [
       "console=ttyAMA0,38400"
     ];
-    hardware =
-      let
-        mac80211 =  pkgs.mac80211.override {
-          drivers = ["mac80211_hwsim"];
-          klibBuild = config.system.outputs.kernel.modulesupport;
-        };
-      in {
-        defaultOutput = "vmroot";
-        loadAddress = lim.parseInt "0x0";
-        entryPoint = lim.parseInt "0x0";
-        rootDevice = "/dev/mtdblock0";
-
-        flash.eraseBlockSize = 65536; # c.f. pkgs/mips-vm/mips-vm.sh
-        networkInterfaces =
-          let inherit (config.system.service.network) link;
-          in {
-            wan = link.build { ifname = "eth0"; };
-            lan = link.build { ifname = "eth1"; };
-
-            wlan_24 = link.build {
-              ifname = "wlan0";
-              dependencies = [ mac80211 ];
-            };
-          };
-      };
-
   };
 }

devices/qemu-armv7l/default.nix

@@ -25,33 +25,19 @@
   installer = "vmroot";
 
   module = {pkgs, config, lim, ... }: {
-    imports = [ ../../modules/arch/arm.nix ];
+    imports = [
+      ../../modules/arch/arm.nix
+      ../families/qemu.nix
+    ];
     kernel = {
-      src = pkgs.pkgsBuildBuild.fetchurl {
-        name = "linux.tar.gz";
-        url = "https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.15.71.tar.gz";
-        hash = "sha256-yhO2cXIeIgUxkSZf/4aAsF11uxyh+UUZu6D1h92vCD8=";
-      };
       config = {
         PCI_HOST_GENERIC = "y";
-        PCI = "y";
         ARCH_VIRT = "y";
 
         VFP = "y";
         NEON = "y";
         AEABI = "y";
 
-        MTD = "y";
-        MTD_BLOCK = "y";
-        MTD_CMDLINE_PARTS = "y";
-        MTD_PHRAM = "y";
-
-        VIRTIO_MENU = "y";
-        VIRTIO_PCI = "y";
-        BLOCK = "y";
-        VIRTIO_BLK = "y";
-        VIRTIO_NET = "y";
-
         SERIAL_AMBA_PL011 = "y";
         SERIAL_AMBA_PL011_CONSOLE = "y";
       };
@@ -59,31 +45,9 @@
     boot.commandLine = [
       "console=ttyAMA0"
     ];
-    hardware =
+    hardware = {
-      let
-        mac80211 =  pkgs.mac80211.override {
-          drivers = ["mac80211_hwsim"];
-          klibBuild = config.system.outputs.kernel.modulesupport;
-        };
-      in {
-        defaultOutput = "vmroot";
       loadAddress = lim.parseInt "0x00010000";
       entryPoint = lim.parseInt "0x00010000";
-        rootDevice = "/dev/mtdblock0";
-
-        flash.eraseBlockSize = 65536; # c.f. pkgs/mips-vm/mips-vm.sh
-        networkInterfaces =
-          let inherit (config.system.service.network) link;
-          in {
-            wan = link.build { ifname = "eth0"; };
-            lan = link.build { ifname = "eth1"; };
-
-            wlan_24 = link.build {
-              ifname = "wlan0";
-              dependencies = [ mac80211 ];
     };
   };
-      };
-
-  };
 }

devices/qemu/default.nix

@@ -37,61 +37,18 @@
 
   '';
   module = {pkgs, config, lim, ... }: {
-    imports = [ ../../modules/arch/mipseb.nix ];
+    imports = [
+      ../../modules/arch/mipseb.nix
+      ../families/qemu.nix
+    ];
     kernel = {
-      src = pkgs.pkgsBuildBuild.fetchurl {
-        name = "linux.tar.gz";
-        url = "https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.15.71.tar.gz";
-        hash = "sha256-yhO2cXIeIgUxkSZf/4aAsF11uxyh+UUZu6D1h92vCD8=";
-      };
       config = {
         MIPS_MALTA= "y";
         CPU_MIPS32_R2= "y";
 
-        MTD = "y";
-        MTD_BLOCK = "y";
-        MTD_CMDLINE_PARTS = "y";
-        MTD_PHRAM = "y";
-
-        VIRTIO_MENU = "y";
-        PCI = "y";
-        VIRTIO_PCI = "y";
-        BLOCK = "y";
-        VIRTIO_BLK = "y";
-        VIRTIO_NET = "y";
-
         SERIAL_8250= "y";
         SERIAL_8250_CONSOLE= "y";
       };
     };
-    hardware =
-      let
-        mac80211 =  pkgs.mac80211.override {
-          drivers = ["mac80211_hwsim"];
-          klibBuild = config.system.outputs.kernel.modulesupport;
-        };
-      in {
-        defaultOutput = "vmroot";
-        rootDevice = "/dev/mtdblock0";
-        flash.eraseBlockSize = 65536;
-        networkInterfaces =
-          let inherit (config.system.service.network) link;
-          in {
-            wan = link.build {
-              devpath = "/devices/pci0000:00/0000:00:13.0/virtio0";
-              ifname = "wan";
-            };
-            lan = link.build {
-              devpath = "/devices/pci0000:00/0000:00:14.0/virtio1";
-              ifname = "lan";
-            };
-
-            wlan_24 = link.build {
-              ifname = "wlan0";
-              dependencies = [ mac80211 ];
-            };
-          };
-      };
-
   };
 }