# Pastebin bS2PX05E
// envFile returns a filepath for the lkenv bootloader environment file. For
// prepare-image time operations, it will be a normal config file, for runtime
// operations it will be a device file from a udev-created symlink in /dev/disk.
// If backup is true then the filename is suffixed with "bak" or at runtime the
// partition label is suffixed with "bak".
func (l *lk) envFile(backup bool) (string, error) {
	partitionLabelOrConfFile := l.partLabelForRole()
	if backup {
		partitionLabelOrConfFile += "bak"
	}
	if l.prepareImageTime {
		// at prepare-image time, we just use the env file, but append .bin
		// since it is a file from the gadget we will evenutally install into
		// a partition when flashing the image
		return filepath.Join(l.dir(), partitionLabelOrConfFile+".bin"), nil
	}

	if l.role == RoleSole {
		// for V1, we just use the partition label directly, dir() here will be
		// the udev by-partlabel symlink dir.
		// see TODO: in l.dir(), this should eventually also be using
		// envFileForPartName() too
		return filepath.Join(l.dir(), partitionLabelOrConfFile), nil
	}

	// for RoleRun or RoleRecovery, we need to find the partition securely
	envFile, _, err := l.envFileForPartName(partitionLabelOrConfFile)
	if err != nil {
		return "", err
	}
	return envFile, nil
}