copyUbootFiles: don't continue if deviceinfo_ubootboardname is unset (MR 18)

If this isn't set in the deviceinfo file, then the device probably
doesn't support the post-processing-with-uboot-files stuff that c07eafd0
set out to address.

main.go

@@ -71,6 +71,14 @@ func main() {
 		log.Fatal("generateInitfsExtra: ", err)
 	}
 
+	if err := copyUbootFiles(workDir, devinfo); errors.Is(err, os.ErrNotExist) {
+		log.Println("u-boot files copying skipped: ", err)
+	} else {
+		if err != nil {
+			log.Fatal("copyUbootFiles: ", err)
+		}
+	}
+
 	// Final processing of initramfs / kernel is done by boot-deploy
 	if err := bootDeploy(workDir, *outDir); err != nil {
 		log.Fatal("bootDeploy: ", err)
@@ -409,6 +417,7 @@ func getInitfsExtraFiles(files misc.StringSet, devinfo deviceinfo.DeviceInfo) er
 	log.Println("== Generating initramfs extra ==")
 	binariesExtra := misc.StringSet{
 		"/lib/libz.so.1":        false,
+		"/sbin/btrfs":           false,
 		"/sbin/dmsetup":         false,
 		"/sbin/e2fsck":          false,
 		"/usr/sbin/parted":      false,
@@ -566,6 +575,50 @@ func getKernelVersion() (string, error) {
 	return strings.TrimSpace(string(contents)), nil
 }
 
+func Copy(srcFile, dstFile string) error {
+	out, err := os.Create(dstFile)
+	if err != nil {
+		return err
+	}
+
+	defer out.Close()
+
+	in, err := os.Open(srcFile)
+	if err != nil {
+		return err
+	}
+	defer in.Close()
+
+	_, err = io.Copy(out, in)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func copyUbootFiles(path string, devinfo deviceinfo.DeviceInfo) error {
+	if devinfo.UbootBoardname == "" {
+		return nil
+	}
+
+	srcDir := filepath.Join("/usr/share/u-boot", devinfo.UbootBoardname)
+	entries, err := ioutil.ReadDir(srcDir)
+	if err != nil {
+		return err
+	}
+	for _, entry := range entries {
+		sourcePath := filepath.Join(srcDir, entry.Name())
+		destPath := filepath.Join(path, entry.Name())
+
+		if err := Copy(sourcePath, destPath); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 func generateInitfs(name string, path string, kernVer string, devinfo deviceinfo.DeviceInfo) error {
 	initfsArchive, err := archive.New()
 	if err != nil {

pkgs/deviceinfo/deviceinfo.go

@@ -16,6 +16,7 @@ import (
 type DeviceInfo struct {
 	AppendDtb                     string
 	Arch                          string
+	UbootBoardname                string
 	BootimgAppendSEAndroidEnforce string
 	BootimgBlobpack               string
 	BootimgDtbSecond              string