nixos/tests/boot: inline + fix UEFI start command generation

nixos/tests/boot.nix

@@ -4,10 +4,41 @@
 }:
 
 with import ../lib/testing-python.nix { inherit system pkgs; };
-with pkgs.lib;
 
 let
-  qemu-common = import ../lib/qemu-common.nix { inherit (pkgs) lib pkgs; };
+  lib = pkgs.lib;
+  qemu-common = import ../lib/qemu-common.nix { inherit lib pkgs; };
+
+  mkStartCommand = {
+    memory ? 2048,
+    cdrom ? null,
+    usb ? null,
+    pxe ? null,
+    uboot ? false,
+    uefi ? false,
+    extraFlags ? [],
+  }: let
+    qemu = qemu-common.qemuBinary pkgs.qemu_test;
+
+    flags = [
+      "-m" (toString memory)
+      "-netdev" ("user,id=net0" + (lib.optionalString (pxe != null) ",tftp=${pxe},bootfile=netboot.ipxe"))
+      "-device" ("virtio-net-pci,netdev=net0" + (lib.optionalString (pxe != null && uefi) ",romfile=${pkgs.ipxe}/ipxe.efirom"))
+    ] ++ lib.optionals (cdrom != null) [
+      "-cdrom" cdrom
+    ] ++ lib.optionals (usb != null) [
+      "-device" "usb-ehci"
+      "-drive" "id=usbdisk,file=${usb},if=none,readonly"
+      "-device" "usb-storage,drive=usbdisk"
+    ] ++ lib.optionals (pxe != null) [
+      "-boot" "order=n"
+    ] ++ lib.optionals uefi [
+      "-drive" "if=pflash,format=raw,unit=0,readonly=on,file=${pkgs.OVMF.firmware}"
+      "-drive" "if=pflash,format=raw,unit=1,readonly=on,file=${pkgs.OVMF.variables}"
+    ] ++ extraFlags;
+
+    flagsStr = lib.concatStringsSep " " flags;
+  in "${qemu} ${flagsStr}";
 
   iso =
     (import ../lib/eval-config.nix {
@@ -28,21 +59,16 @@ let
       ];
     }).config.system.build.sdImage;
 
-  pythonDict = params: "\n    {\n        ${concatStringsSep ",\n        " (mapAttrsToList (name: param: "\"${name}\": \"${param}\"") params)},\n    }\n";
-
-  makeBootTest = name: extraConfig:
+  makeBootTest = name: config:
     let
-      machineConfig = pythonDict ({
-        qemuBinary = qemu-common.qemuBinary pkgs.qemu_test;
-        qemuFlags = "-m 768";
-      } // extraConfig);
+      startCommand = mkStartCommand config;
     in
       makeTest {
         name = "boot-" + name;
         nodes = { };
         testScript =
           ''
-            machine = create_machine(${machineConfig})
+            machine = create_machine({"startCommand": "${startCommand}"})
             machine.start()
             machine.wait_for_unit("multi-user.target")
             machine.succeed("nix store verify --no-trust -r --option experimental-features nix-command /run/current-system")
@@ -73,43 +99,35 @@ let
           config.system.build.netbootIpxeScript
         ];
       };
-      machineConfig = pythonDict ({
-        qemuBinary = qemu-common.qemuBinary pkgs.qemu_test;
-        qemuFlags = "-boot order=n -m 2000";
-        netBackendArgs = "tftp=${ipxeBootDir},bootfile=netboot.ipxe";
+      startCommand = mkStartCommand ({
+        pxe = ipxeBootDir;
       } // extraConfig);
     in
       makeTest {
         name = "boot-netboot-" + name;
         nodes = { };
         testScript = ''
-            machine = create_machine(${machineConfig})
+            machine = create_machine({"startCommand": "${startCommand}"})
             machine.start()
             machine.wait_for_unit("multi-user.target")
             machine.shutdown()
           '';
       };
-  uefiBinary = {
-    x86_64-linux = "${pkgs.OVMF.fd}/FV/OVMF.fd";
-    aarch64-linux = "${pkgs.OVMF.fd}/FV/QEMU_EFI.fd";
-  }.${pkgs.stdenv.hostPlatform.system};
 in {
     uefiCdrom = makeBootTest "uefi-cdrom" {
+      uefi = true;
       cdrom = "${iso}/iso/${iso.isoName}";
-      bios = uefiBinary;
     };
 
     uefiUsb = makeBootTest "uefi-usb" {
+      uefi = true;
       usb = "${iso}/iso/${iso.isoName}";
-      bios = uefiBinary;
     };
 
     uefiNetboot = makeNetbootTest "uefi" {
-      bios = uefiBinary;
-      # Custom ROM is needed for EFI PXE boot. I failed to understand exactly why, because QEMU should still use iPXE for EFI.
-      netFrontendArgs = "romfile=${pkgs.ipxe}/ipxe.efirom";
+      uefi = true;
     };
-} // optionalAttrs (pkgs.stdenv.hostPlatform.system == "x86_64-linux") {
+} // lib.optionalAttrs (pkgs.stdenv.hostPlatform.system == "x86_64-linux") {
     biosCdrom = makeBootTest "bios-cdrom" {
       cdrom = "${iso}/iso/${iso.isoName}";
     };
@@ -124,9 +142,12 @@ in {
       sdImage = "${sd}/sd-image/${sd.imageName}";
       mutableImage = "/tmp/linked-image.qcow2";
 
-      machineConfig = pythonDict {
-        bios = "${pkgs.ubootQemuX86}/u-boot.rom";
-        qemuFlags = "-m 768 -machine type=pc,accel=tcg -drive file=${mutableImage},if=ide,format=qcow2";
+      startCommand = mkStartCommand {
+        extraFlags = [
+          "-bios" "${pkgs.ubootQemuX86}/u-boot.rom"
+          "-machine" "type=pc,accel=tcg"
+          "-drive" "file=${mutableImage},if=virtio"
+        ];
       };
     in makeTest {
       name = "boot-uboot-extlinux";
@@ -138,7 +159,7 @@ in {
         if os.system("qemu-img create -f qcow2 -F raw -b ${sdImage} ${mutableImage}") != 0:
             raise RuntimeError("Could not create mutable linked image")
 
-        machine = create_machine(${machineConfig})
+        machine = create_machine({"startCommand": "${startCommand}"})
         machine.start()
         machine.wait_for_unit("multi-user.target")
         machine.succeed("nix store verify -r --no-trust --option experimental-features nix-command /run/current-system")