What does 할꼬 mean?

Here is a poem from the Korean Lab Web site:

형제 노래--------------<전래 동요>

우물가엔 나무 兄弟
하늘에는 별이 형제
우리 집엔 나와 언니

나무 형젠 열매 맺고
별 형제는 빛을 내니
우리 형제 무얼 할꼬.

The Sibling Song---------Unknown Author

Down by the well are sibling trees
Up in the sky are sibling stars
Inside our house are sis and me

Since fruit's given by sibling trees
And light's given by sibling stars
Wonder what's given by sis and me.

-을꼬 is an archaic verb ending that is similar to -을까.