Writing your own runtime, runtime hooks, etc.

[solidstate1991 via Digitalmars-d-learn]

I'm thinking about writing, or well, rather modifying the 
existing default runtime of D, mainly by stripping out the GC and 
moving memory management to a primarily manual one. Option for 
refcounting etc. will be added (especially as it exists in 
Phobos, I just need to modify it), reworking D arrays for manual 
management will be a wild ride though.

I will try to catalogue the runtime hooks too during my process, 
however I don't really see any info about how to use a custom 
made runtime. Is it enough to just use betterC, then include the 
newly created runtime as a dependency? Do I need to mess with 
compiler configurations?