Kernel: Move kernel above the 3GB virtual address mark

The kernel and its static data structures are no longer identity-mapped
in the bottom 8MB of the address space, but instead move above 3GB.

The first 8MB above 3GB are pseudo-identity-mapped to the bottom 8MB of
the physical address space. But things don't have to stay this way!

Thanks to Jesse who made an earlier attempt at this, it was really easy
to get device drivers working once the page tables were in place! :^)

Fixes #734.

1 files changed, 2 insertions, 2 deletions

diff --git a/Kernel/Heap/kmalloc.cpp b/Kernel/Heap/kmalloc.cpp
index c54ab38a00..6d5b6fec75 100644
--- a/Kernel/Heap/kmalloc.cpp
+++ b/Kernel/Heap/kmalloc.cpp
@@ -20,11 +20,11 @@ struct [[gnu::packed]] allocation_t
     size_t nchunk;
 };
 
-#define BASE_PHYSICAL (4 * MB)
+#define BASE_PHYSICAL (0xc0000000 + (4 * MB))
 #define CHUNK_SIZE 8
 #define POOL_SIZE (3 * MB)
 
-#define ETERNAL_BASE_PHYSICAL (2 * MB)
+#define ETERNAL_BASE_PHYSICAL (0xc0000000 + (2 * MB))
 #define ETERNAL_RANGE_SIZE (2 * MB)
 
 static u8 alloc_map[POOL_SIZE / CHUNK_SIZE / 8];