[uml-user] Fixmap not implemented - why?

[Carl S. <csp...@ya...>]

comment from include/asm-um/fixmap.h:
/*
 * on UP currently we will have no trace of the fixmap mechanizm,
 * no page table allocations, etc. This might change in the
 * future, say framebuffers for the console driver(s) could be
 * fix-mapped?
 */

I was wondering why the fixmap stuff is unimplemented, in as much
as I would like to testout the vsyscall stuff ?  It doesn't seem
as if it would be hard to implement..