[elysium-cvs] Pmap routines added

[Kasper V. L. <ve...@da...>]

I've added some pmap (physical map) routines to the kernel. These are:

pmalloc() - allocate a page
pfree() - free a page
pmap_init() - initialise the pmap

The pmap support is by no means done yet, since the pages cannot be
protected. Furthermore it might be useful to have several free lists -
e.g. one for memory below 16mb (for DMA), one for memory between 16mb
and 256mb (for kernel/application use), and one for memory above 256mb
(for application use).

/Kasper