pillar: Add support for predefined OVMF settings based on resolution.

Implemented logic to select predefined OVMF_VARS.fd files for specific
screen resolutions. Added pre-saved OVMF settings for 800x600, 1024x768,
1280x800, and 1920x1080 resolutions, ensuring clean boot entries.

Signed-off-by: Nikolay Martyanov <nikolay@zededa.com>

pkg/pillar/hypervisor/kvm.go

@@ -738,19 +738,36 @@ func getOVMFSettingsFilename(domainName string) (string, error) {
 	return types.OVMFSettingsDir + "/" + domainUUID.String() + "_OVMF_VARS.fd", nil
 }
 
-func prepareOVMFSettings(domainName string) error {
+func prepareOVMFSettings(config types.DomainConfig, status types.DomainStatus, globalConfig *types.ConfigItemValueMap) error {
 	// Create the OVMF settings directory if it does not exist
 	if err := os.MkdirAll(types.OVMFSettingsDir, 0755); err != nil {
 		return logError("failed to create OVMF settings directory: %v", err)
 	}
 	// Create a copy of the ovmf_vars.bin file in <domainName>_ovmf_vars.bin
-	ovmfSettingsFile, err := getOVMFSettingsFilename(domainName)
+	ovmfSettingsFile, err := getOVMFSettingsFilename(status.DomainName)
 	if err != nil {
 		return logError("failed to get OVMF settings file: %v", err)
 	}
+	// Check if we need custom OVMF settings for the domain (the resolution)
+	fmlResolution := types.FmlResolutionUnset
+	if config.VirtualizationMode == types.FML {
+		// if we are not getting the resolution from the cloud-init, check the
+		// global config.
+		fmlResolution = status.FmlCustomResolution
+		if fmlResolution == types.FmlResolutionUnset {
+			if fmlResolution, err = getFmlCustomResolution(&status, globalConfig); err != nil {
+				return logError("failed to get custom resolution for domain %s: %v", status.DomainName, err)
+			}
+		}
+	}
+	// Find the necessary OVMF settings file
+	ovmfSettingsFileSrc := types.OVMFSettingsTemplate
+	if fmlResolution != types.FmlResolutionUnset {
+		ovmfSettingsFileSrc = types.CustomOVMFSettingsDir + "/OVMF_VARS_" + fmlResolution + ".fd"
+	}
 	if _, err := os.Stat(ovmfSettingsFile); os.IsNotExist(err) {
-		if err := fileutils.CopyFile(types.OVMFSettingsTemplate, ovmfSettingsFile); err != nil {
-			return logError("failed to copy ovmf_vars.bin file: %v", err)
+		if err := fileutils.CopyFile(ovmfSettingsFileSrc, ovmfSettingsFile); err != nil {
+			return logError("failed to copy OVMF_VARS file: %v", err)
 		}
 	}
 	// Set the RW permissions for the OVMF settings file
@@ -779,14 +796,6 @@ func (ctx KvmContext) Setup(status types.DomainStatus, config types.DomainConfig
 	domainName := status.DomainName
 	domainUUID := status.UUIDandVersion.UUID
 
-	// this needs to be reworked to fit into the OVMF_VAR changes.
-	res, err := getFmlCustomResolution(&status, globalConfig)
-	if err != nil {
-		logError("failed to get fml custom resolution: %v", err)
-	} else {
-		logError("fml custom resolution is set to: %s", res)
-	}
-
 	// check if vTPM is enabled
 	swtpmCtrlSock := ""
 	if status.VirtualTPM {
@@ -800,7 +809,7 @@ func (ctx KvmContext) Setup(status types.DomainStatus, config types.DomainConfig
 	// for ARM produces a single QEMU_EFI.fd file that contains both OVMF_VARS.fd
 	// and OVMF_CODE.fd.
 	if config.VirtualizationMode == types.FML && runtime.GOARCH == "amd64" {
-		if err := prepareOVMFSettings(domainName); err != nil {
+		if err := prepareOVMFSettings(config, status, globalConfig); err != nil {
 			return logError("failed to setup OVMF settings for domain %s: %v", status.DomainName, err)
 		}
 	}

pkg/pillar/types/locationconsts.go

@@ -137,6 +137,8 @@ const (
 	OVMFSettingsDir = SealedDirName + "/ovmf"
 	// OVMFSettingsTemplate - template file for OVMF settings
 	OVMFSettingsTemplate = "/usr/lib/xen/boot/OVMF_VARS.fd"
+	// CustomOVMFSettingsDir - directory for custom OVMF settings (for different resolutions)
+	CustomOVMFSettingsDir = "/hostfs/etc/ovmf"
 )
 
 var (