diff options
| -rw-r--r-- | nixos/modules/virtualisation/qemu-vm.nix | 58 |
1 files changed, 55 insertions, 3 deletions
diff --git a/nixos/modules/virtualisation/qemu-vm.nix b/nixos/modules/virtualisation/qemu-vm.nix index 7d8c83ed78db..5cbc648b7a9c 100644 --- a/nixos/modules/virtualisation/qemu-vm.nix +++ b/nixos/modules/virtualisation/qemu-vm.nix @@ -263,7 +263,8 @@ let if cfg.useEFIBoot then "efi_bootloading_with_default_fs" else "legacy_bootloading_with_default_fs" else - "direct_boot_with_default_fs" + if cfg.directBoot.enable then "direct_boot_with_default_fs" + else "custom" else "custom"; suggestedRootDevice = { @@ -769,6 +770,40 @@ in ''; }; + virtualisation.directBoot = { + enable = + mkOption { + type = types.bool; + default = !cfg.useBootLoader; + defaultText = "!cfg.useBootLoader"; + description = + lib.mdDoc '' + If enabled, the virtual machine will boot directly into the kernel instead of through a bootloader. Other relevant parameters such as the initrd are also passed to QEMU. + + If you want to test netboot, consider disabling this option. + + This will not boot / reboot correctly into a system that has switched to a different configuration on disk. + + This is enabled by default if you don't enable bootloaders, but you can still enable a bootloader if you need. + Read more about this feature: <https://qemu-project.gitlab.io/qemu/system/linuxboot.html>. + ''; + }; + initrd = + mkOption { + type = types.str; + default = "${config.system.build.initialRamdisk}/${config.system.boot.loader.initrdFile}"; + defaultText = "\${config.system.build.initialRamdisk}/\${config.system.boot.loader.initrdFile}"; + description = + lib.mdDoc '' + In direct boot situations, you may want to influence the initrd to load + to use your own customized payload. + + This is useful if you want to test the netboot image without + testing the firmware or the loading part. + ''; + }; + }; + virtualisation.useBootLoader = mkOption { type = types.bool; @@ -895,6 +930,18 @@ in virtualisation.memorySize is above 2047, but qemu is only able to allocate 2047MB RAM on 32bit max. ''; } + { assertion = cfg.directBoot.initrd != options.virtualisation.directBoot.initrd.default -> cfg.directBoot.enable; + message = + '' + You changed the default of `virtualisation.directBoot.initrd` but you are not + using QEMU direct boot. This initrd will not be used in your current + boot configuration. + + Either do not mutate `virtualisation.directBoot.initrd` or enable direct boot. + + If you have a more advanced usecase, please open an issue or a pull request. + ''; + } ]; warnings = @@ -915,6 +962,11 @@ in Otherwise, we recommend ${opt.writableStore} = false; + '' + ++ optional (cfg.directBoot.enable && cfg.useBootLoader) + '' + You enabled direct boot and a bootloader, QEMU will not boot your bootloader, rendering + `useBootLoader` useless. You might want to disable one of those options. ''; # In UEFI boot, we use a EFI-only partition table layout, thus GRUB will fail when trying to install @@ -1036,9 +1088,9 @@ in alphaNumericChars = lowerChars ++ upperChars ++ (map toString (range 0 9)); # Replace all non-alphanumeric characters with underscores sanitizeShellIdent = s: concatMapStrings (c: if builtins.elem c alphaNumericChars then c else "_") (stringToCharacters s); - in mkIf (!cfg.useBootLoader) [ + in mkIf cfg.directBoot.enable [ "-kernel \${NIXPKGS_QEMU_KERNEL_${sanitizeShellIdent config.system.name}:-${config.system.build.toplevel}/kernel}" - "-initrd ${config.system.build.toplevel}/initrd" + "-initrd ${cfg.directBoot.initrd}" ''-append "$(cat ${config.system.build.toplevel}/kernel-params) init=${config.system.build.toplevel}/init regInfo=${regInfo}/registration ${consoles} $QEMU_KERNEL_PARAMS"'' ]) (mkIf cfg.useEFIBoot [ |