Until can be used as a subordinate conjunction (subordinate clauses follow until) and a preposition (noun/noun phrase/gerund/to infinite follows it.)

What is the grammar of these sentences?

Example 1: We will wait here until called. (called is a past participle) (until calling is okay as 'calling' is a gerund. 'until the call' is okay as well.)

Example 2: You are innocent until proven guilty. (guilty is an adjective. Proven is an adjective/past participle)