How to get the kernel memory range on OpenSolaris

# echo "p0::pmap" | mdb -k

or

# echo "kas::walk seg | ::seg" |  mdb -k

will give you base virtual address and virtual sizes for the kernel's
memory segments.

Walking the list of kernel pages to get physical page numbers:

# echo "kvp::walk page | ::print page_t p_pagenum" | mdb -k

should work (but may not be complete).  In general, if you have a kernel
virtual address,
 # echo "virtual_address::vtop" | mdb -k

will give you the physical address.