diff --git a/pym/cl_utils.py b/pym/cl_utils.py
index 5c6a199..da5ef2e 100644
--- a/pym/cl_utils.py
+++ b/pym/cl_utils.py
@@ -1479,3 +1479,36 @@ def countFiles(dirpath,onefilesystem=True):
             for dirname in mountDirs:
                 dirnames.remove(dirname)
     return num
+
+class InitrdFile(object):
+    re_kver_path = re.compile("/modules/([^/]+)/kernel")
+    def __init__(self, _file):
+        self._file = _file
+
+    def get_kernel_version(self):
+        for fn in self.get_names():
+            if "/modules/" in fn and "/kernel" in fn:
+                m = self.re_kver_path.search(fn)
+                if m:
+                    return m.group(1)
+                else:
+                    break
+        return ""
+
+    def get_names(self):
+        if not path.exists(self._file):
+            # raise IOError
+            open(self._file)
+        gz = Popen(['/bin/gzip', "-dc", self._file], stdout=PIPE, stderr=PIPE,
+            close_fds=True)
+        cpio = Popen(["/bin/cpio","-tf"], stdout=PIPE, stdin=gz.stdout,
+            stderr=PIPE, close_fds=True)
+        try:
+            for fn in cpio.stdout.xreadlines():
+                yield fn.rstrip()
+        finally:
+            cpio.terminate()
+            gz.terminate()
+
+    def __iter__(self):
+        return iter(self.get_names())
diff --git a/pym/cl_vars_share.py b/pym/cl_vars_share.py
index 52a114e..ec4981a 100644
--- a/pym/cl_vars_share.py
+++ b/pym/cl_vars_share.py
@@ -16,9 +16,11 @@
 
 import os
 import sys
-from cl_utils import getpathenv, runOsCommand, typeFile,process
+from cl_utils import (getpathenv, runOsCommand, typeFile,process,
+                      listDirectory, InitrdFile)
 import re
 from os import path, R_OK
+
 try:
     from cl_ldap import ldapUser
 except ImportError:
@@ -276,10 +278,13 @@ class varsShare:
 
     def getFilesByType(self,pathname,descr):
         """Get files from "pathname" has "descr" in descriptions"""
-        filelist = map(lambda x:path.join(pathname,x),os.listdir(pathname))
+        return list(self.get_files_by_type(pathname, descr))
+
+    def get_files_by_type(self, pathname, descr):
         ftype = typeFile(magic=0x4).getMType
-        filesWithType = map(lambda x:(x,ftype(x)), filelist)
-        return filter(lambda x:descr in x[1],filesWithType)
+        for x in listDirectory(pathname, fullPath=True):
+            if descr in ftype(x):
+                yield x
 
     def getInitrd(self,arch,shortname,chroot,kernel,suffix="",notsuffix=""):
         """Get initrd for kernel"""
@@ -629,3 +634,96 @@ class varsShare:
             return res[:8]
         else:
             return "no_uid"
+
+    def get_current_kernel_src(self, prefix='/'):
+        """
+        Get current kernel source directory
+        """
+        src_path = "usr/src"
+        current_linux_src = path.join(src_path,"linux")
+        symlink_kernel = path.join(prefix,current_linux_src)
+        if not path.exists(symlink_kernel) or not path.islink(symlink_kernel):
+            raise ValueError("Failed to determine current kernel version")
+        return path.join(src_path,os.readlink(symlink_kernel))
+
+    def get_config_version(self, configfile):
+        re_config = re.compile("Automatically generated file;.*\n"
+                               ".*?Linux/\S+\s+(\S+)\s", re.M)
+        if path.exists(configfile):
+            with open(configfile) as f:
+                match = re_config.search(f.read(200))
+                if match:
+                    return match.group(1)
+
+    def get_src_kernel_version(self, kernel_src):
+        """
+        Get version of kernel from .config
+        """
+        config_path = path.join(kernel_src, ".config")
+        makefile_path = path.join(kernel_src, "Makefile")
+
+        # get version from config
+        version = self.get_config_version(config_path)
+        if version:
+            return version
+
+        # get version from Makefile
+        re_makefile = re.compile("^VERSION = (\S+)\n"
+            "PATCHLEVEL = (\S+)\n"
+            "SUBLEVEL = (\S+)\n"
+            "EXTRAVERSION = (\S*)\n", re.M)
+        if path.exists(makefile_path):
+            with open(makefile_path) as f:
+                match = re_makefile.search(f.read(200))
+                if match:
+                    return "{0}.{1}.{2}{3}".format(*match.groups())
+        return ""
+
+    def list_initramfs(self, prefix='/', bootdir='boot'):
+        boot_dir = path.join(prefix, bootdir)
+        return self.get_files_by_type(boot_dir,"ASCII cpio archive")
+
+    def filter_initramfs(self, iterable, version=None):
+        for fn in iterable:
+            if InitrdFile(fn).get_kernel_version() == version:
+                yield fn
+
+    def list_kernel(self, prefix='/', bootdir='boot'):
+        boot_dir = path.join(prefix, bootdir)
+        return self.get_files_by_type(boot_dir, "boot executable bzImage")
+
+    def filter_kernel(self, iterable, version=None):
+        ftype = typeFile(magic=0x4).getMType
+        re_kver = re.compile("bzImage, version (\S+)\s")
+        for fn in iterable:
+            m = re_kver.search(ftype(fn))
+            if m.group(1) == version:
+                yield fn
+
+    def list_config(self, prefix='/', bootdir='boot'):
+        boot_dir = path.join(prefix, bootdir)
+        return self.get_files_by_type(boot_dir, "Linux make config build file")
+
+    def filter_config(self, iterable, version=None):
+        for fn in iterable:
+            if self.get_config_version(fn) == version:
+                yield fn
+
+    def list_system_map(self, prefix='/', bootdir='boot'):
+        boot_dir = path.join(prefix, bootdir)
+        for fn in listDirectory(boot_dir):
+            if fn.startswith("System.map"):
+                yield path.join(boot_dir, fn)
+
+    def filter_system_map(self, iterable, version=None):
+        re_kver = re.compile("System.map-(\S+)$")
+        for fn in iterable:
+            m = re_kver.search(fn)
+            if m and m.group(1) == version:
+                yield fn
+
+    def max_default(self, iterable, key=lambda x:x, default=None):
+        try:
+            return max(iterable, key=key)
+        except ValueError:
+            return default