[Kernel] PMM excludes contiguous chunk pool from general allocator

docs/todo.md

@@ -320,3 +320,4 @@ Auto install LLD link? Or llvm with brew? Need lld-link for the UEFI build
 // different on each OS), we could have an enum to model the possible font options, with an escape hatch 
 // 'get from this path' variant, which could perhaps hold different values depending on the OS. 
 
+Better errors when you try to use (ex.) printf before the VMM has initialized

rust_kernel_libs/pmm/src/lib.rs

@@ -171,7 +171,7 @@ pub unsafe fn pmm_init() {
         }
         // Floor each region to a frame boundary
         // This will cut off a bit of usable memory, but we'll only lose a few frames at most
-        let base = page_ceil(region.addr);
+        let mut base = page_ceil(region.addr);
         // Subtract whatever extra we got by aligning to a frame boundary above
         let mut region_size = page_floor(region.len - (base - region.addr));
 
@@ -182,6 +182,7 @@ pub unsafe fn pmm_init() {
             // Trim the contiguous chunk pool from the region and allow the rest of the frames to
             // be given to the general-purpose allocator
             region_size -= CONTIGUOUS_CHUNK_POOL_SIZE;
+            base += CONTIGUOUS_CHUNK_POOL_SIZE;
         }
 
         let page_count = (region_size + (PAGE_SIZE - 1)) / PAGE_SIZE;