def systemd_populate_packages(d):
    import re
    import shlex

    if not bb.utils.contains('DISTRO_FEATURES', 'systemd', True, False, d):
        return

    def get_package_var(d, var, pkg):
        val = (d.getVar('%s_%s' % (var, pkg)) or "").strip()
        if val == "":
            val = (d.getVar(var) or "").strip()
        return val

    # Check if systemd-packages already included in PACKAGES
    def systemd_check_package(pkg_systemd):
        packages = d.getVar('PACKAGES')
        if not pkg_systemd in packages.split():
            bb.error('%s does not appear in package list, please add it' % pkg_systemd)


    def systemd_generate_package_scripts(pkg):
        bb.debug(1, 'adding systemd calls to postinst/postrm for %s' % pkg)

        paths_escaped = ' '.join(shlex.quote(s) for s in d.getVar('SYSTEMD_SERVICE_' + pkg).split())
        d.setVar('SYSTEMD_SERVICE_ESCAPED_' + pkg, paths_escaped)

        # Add pkg to the overrides so that it finds the SYSTEMD_SERVICE_pkg
        # variable.
        localdata = d.createCopy()
        localdata.prependVar("OVERRIDES", pkg + ":")

        postinst = d.getVar('pkg_postinst_%s' % pkg)
        if not postinst:
            postinst = '#!/bin/sh\n'
        postinst += localdata.getVar('systemd_postinst')
        d.setVar('pkg_postinst_%s' % pkg, postinst)

        prerm = d.getVar('pkg_prerm_%s' % pkg)
        if not prerm:
            prerm = '#!/bin/sh\n'
        prerm += localdata.getVar('systemd_prerm')
        d.setVar('pkg_prerm_%s' % pkg, prerm)


    # Add files to FILES_*-systemd if existent and not already done
    def systemd_append_file(pkg_systemd, file_append):
        appended = False
        if os.path.exists(oe.path.join(d.getVar("D"), file_append)):
            var_name = "FILES_" + pkg_systemd
            files = d.getVar(var_name, False) or ""
            if file_append not in files.split():
                d.appendVar(var_name, " " + file_append)
                appended = True
        return appended

    # Add systemd files to FILES_*-systemd, parse for Also= and follow recursive
    def systemd_add_files_and_parse(pkg_systemd, path, service, keys):
        # avoid infinite recursion
        if systemd_append_file(pkg_systemd, oe.path.join(path, service)):
            fullpath = oe.path.join(d.getVar("D"), path, service)
            if service.find('.service') != -1:
                # for *.service add *@.service
                service_base = service.replace('.service', '')
                systemd_add_files_and_parse(pkg_systemd, path, service_base + '@.service', keys)
            if service.find('.socket') != -1:
                # for *.socket add *.service and *@.service
                service_base = service.replace('.socket', '')
                systemd_add_files_and_parse(pkg_systemd, path, service_base + '.service', keys)
                systemd_add_files_and_parse(pkg_systemd, path, service_base + '@.service', keys)
            for key in keys.split():
                # recurse all dependencies found in keys ('Also';'Conflicts';..) and add to files
                cmd = "grep %s %s | sed 's,%s=,,g' | tr ',' '\\n'" % (key, shlex.quote(fullpath), key)
                pipe = os.popen(cmd, 'r')
                line = pipe.readline()
                while line:
                    line = line.replace('\n', '')
                    systemd_add_files_and_parse(pkg_systemd, path, line, keys)
                    line = pipe.readline()
                pipe.close()

    # Check service-files and call systemd_add_files_and_parse for each entry
    def systemd_check_services():
        searchpaths = [oe.path.join(d.getVar("sysconfdir"), "systemd", "system"),]
        searchpaths.append(d.getVar("systemd_system_unitdir"))
        systemd_packages = d.getVar('SYSTEMD_PACKAGES')

        keys = 'Also'
        # scan for all in SYSTEMD_SERVICE[]
        for pkg_systemd in systemd_packages.split():
            for service in get_package_var(d, 'SYSTEMD_SERVICE', pkg_systemd).split():
                path_found = ''

                # Deal with adding, for example, 'ifplugd@eth0.service' from
                # 'ifplugd@.service'
                base = None
                at = service.find('@')
                if at != -1:
                    ext = service.rfind('.')
                    base = service[:at] + '@' + service[ext:]

                for path in searchpaths:
                    if os.path.exists(oe.path.join(d.getVar("D"), path, service)):
                        path_found = path
                        break
                    elif base is not None:
                        if os.path.exists(oe.path.join(d.getVar("D"), path, base)):
                            path_found = path
                            break

                if path_found != '':
                    systemd_add_files_and_parse(pkg_systemd, path_found, service, keys)
                else:
                    bb.fatal("Didn't find service unit '{0}', specified in SYSTEMD_SERVICE_{1}. {2}".format(
                        service, pkg_systemd, "Also looked for service unit '{0}'.".format(base) if base is not None else ""))

    def systemd_create_presets(pkg, action):
        presetf = oe.path.join(d.getVar("PKGD"), d.getVar("systemd_unitdir"), "system-preset/98-%s.preset" % pkg)
        bb.utils.mkdirhier(os.path.dirname(presetf))
        with open(presetf, 'a') as fd:
            for service in d.getVar('SYSTEMD_SERVICE_%s' % pkg).split():
                fd.write("%s %s\n" % (action,service))
        d.appendVar("FILES_%s" % pkg, ' ' + oe.path.join(d.getVar("systemd_unitdir"), "system-preset/98-%s.preset" % pkg))

    # Run all modifications once when creating package
    if os.path.exists(d.getVar("D")):
        for pkg in d.getVar('SYSTEMD_PACKAGES').split():
            systemd_check_package(pkg)
            if d.getVar('SYSTEMD_SERVICE_' + pkg):
                systemd_generate_package_scripts(pkg)
                action = get_package_var(d, 'SYSTEMD_AUTO_ENABLE', pkg)
                if action in ("enable", "disable"):
                    systemd_create_presets(pkg, action)
                elif action not in ("mask", "preset"):
                    bb.fatal("SYSTEMD_AUTO_ENABLE_%s '%s' is not 'enable', 'disable', 'mask' or 'preset'" % (pkg, action))
        systemd_check_services()

systemd_populate_packages(d)