Is there an existing ticket or wiki page describing the work required for adding an ARM backend to the NCG?

I tried the following search with no luck:

https://ghc.haskell.org/trac/ghc/query?status=infoneeded&status=merge&status=new&status=patch&component=Compiler+(NCG)&col=id&col=summary&col=status&col=type&col=priority&col=milestone&col=component&order=priority