rsnix: memory management — free-list heap, bitmap pages, paging adoption

- uefi.rs: full EfiMemoryType constants (0-14) + memory_type_name(); fix
  MEMORY_TYPE_LOADER_DATA from 6 to 2 per the UEFI spec
- memory.rs: replace the bump allocator with a first-fit free-list heap
  (splitting, coalescing, 8-byte back-pointer for alignment-safe free);
  add a bitmap physical page allocator (heap region reserved, page-0
  guard, aligned runs); grow the heap from the page allocator on demand
- paging.rs: identity page-table helpers — adopt_tables() rebuilds the
  firmware map into our own tables (OVMF maps its tables read-only, so
  the firmware tree can't be modified in place) and switches CR3;
  map_page/unmap_page/is_mapped with 2 MB/1 GB large-page splitting
- main.rs: boot self-tests for heap, pages, and paging

1 files changed, 1 insertions, 0 deletions

diff --git a/rsnix/src/lib.rs b/rsnix/src/lib.rs
index 0bc0cb9..d2dacf0 100644
--- a/rsnix/src/lib.rs
+++ b/rsnix/src/lib.rs
@@ -6,6 +6,7 @@ pub mod font;
 pub mod gop;
 pub mod interrupts;
 pub mod memory;
+pub mod paging;
 pub mod ps2;
 pub mod serial;
 pub mod uefi;