Is the term Achala the same as Equanimity?

In some Traditions - possibly Mahayana and/or Tibetan - Achala is translated as the immovable, which is sometimes depicted as a diety. This seems quite similar to, or the same as, equanimity (Upekkha), which is a term found in generous amounts throughout the Pali Cannon. In my personal understanding, a mind imbued with equanimity is a mind free from conditionality. Although karmic imprints still appear, one sees very quickly the nature of their deceptions. When they surface, they cannot get a foothold on anything. In Theravada, there are some references that indicate this: the Buddha and his chief disciples would sometimes call out, 'I see you Mara'. They were simply recognizing their own karmic imprints, (desires to think, say or do things that were unwholesome). Equanimity is when you are not moved by these inner sensations. They don't become actions (karmas). So, does Achala mean the same thing as equanimity (Upekkha)? If not, how are the two terms different?