  The transport of heat and particles in the relatively collisional edge
regions of magnetically confined plasmas is a scientifically challenging and
technologically important problem. Understanding and predicting this transport
requires the self-consistent evolution of plasma fluctuations, global profiles
and flows, but the numerical tools capable of doing this in realistic
(diverted) geometry are only now being developed. Here a 5-field reduced
2-fluid plasma model for the study of instabilities and turbulence in
magnetised plasmas is presented, built on the BOUT++ framework. This cold ion
model allows the evolution of global profiles, electric fields and flows on
transport timescales, with flux-driven cross-field transport determined
self-consistently by electromagnetic turbulence. Developments in the model
formulation and numerical implementation are described, and simulations are
performed in poloidally limited and diverted tokamak configurations.
