fix: make Talos work on Rockpi 4c boards again

Suppress `efivars` `ENODEV` errors: skip mount and proceed with boot
sequence.

Signed-off-by: Artem Chernyshev <artem.chernyshev@talos-systems.com>
(cherry picked from commit ffa5e05)

internal/pkg/mount/mount.go

@@ -7,6 +7,7 @@ package mount
 import (
 	"bufio"
 	"context"
+	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -67,6 +68,14 @@ func mountMountpoint(mountpoint *Point) (skipMount bool, err error) {
 
 	if !skipMount {
 		if err = mountpoint.Mount(); err != nil {
+			if mountpoint.MountFlags.Check(SkipIfNoDevice) && errors.Is(err, unix.ENODEV) {
+				if mountpoint.Logger != nil {
+					mountpoint.Logger.Printf("error mounting: %q: %s", mountpoint.Source(), err)
+				}
+
+				return true, nil
+			}
+
 			return false, fmt.Errorf("error mounting: %w", err)
 		}
 	}

internal/pkg/mount/options.go

@@ -33,6 +33,8 @@ const (
 	SkipIfMounted
 	// SkipIfNoFilesystem is a flag for skipping formatting and mounting if the mountpoint has not filesystem.
 	SkipIfNoFilesystem
+	// SkipIfNoDevice is a flag for skipping errors when the device is not found.
+	SkipIfNoDevice
 )
 
 // Flags is the mount flags.

internal/pkg/mount/pseudo.go

@@ -35,7 +35,9 @@ func PseudoSubMountPoints() (mountpoints *Points, err error) {
 
 	if _, err := os.Stat(constants.EFIVarsMountPoint); err == nil {
 		// mount EFI vars if they exist
-		pseudo.Set("efivars", NewMountPoint("efivarfs", constants.EFIVarsMountPoint, "efivarfs", unix.MS_NOSUID|unix.MS_NOEXEC|unix.MS_NODEV|unix.MS_RELATIME|unix.MS_RDONLY, ""))
+		pseudo.Set("efivars", NewMountPoint("efivarfs", constants.EFIVarsMountPoint, "efivarfs", unix.MS_NOSUID|unix.MS_NOEXEC|unix.MS_NODEV|unix.MS_RELATIME|unix.MS_RDONLY, "",
+			WithFlags(SkipIfNoDevice),
+		))
 	}
 
 	return pseudo, nil