How to build up this floor?

[farmerjohn1324]

I guess the wood didn't go all the way to the wall. Noticed a hole in the corner today, so ripped the carpet back. I need to put some wood to the edge, then put new Tackstrips, but I don't know how to patch a floor on the edge right against a wall like this.

 

[slownsteady]

Do you have access from underneath? (i.e. basement)