Remove high memory kernel and needless prints

1 files changed, 3 insertions, 21 deletions

diff --git a/arch/x86_64/src/boot/boot.s b/arch/x86_64/src/boot/boot.s
index 7b4e193..0c21c66 100644
--- a/arch/x86_64/src/boot/boot.s
+++ b/arch/x86_64/src/boot/boot.s
@@ -17,8 +17,8 @@
  *
  * We need:
  *   - A single PML 4 (since we will only use 4-level paging)
- *   - 2 PML 3s (since we need to map high (-2GiB) and low (1+MiB) memory)
- *   - 2 PML 2s (since we need to map high (-2GiB) and low (1+MiB) memory)
+ *   - 2 PML 3s (since we need to map low (1+MiB) memory)
+ *   - 2 PML 2s (since we need to map low (1+MiB) memory)
  */
 
 .global page_map_level_4
@@ -26,13 +26,9 @@ page_map_level_4: .skip 512 * 8
 
 .global page_map_level_3_low
 page_map_level_3_low: .skip 512 * 8
-.global page_map_level_3_high
-page_map_level_3_high: .skip 512 * 8
 
 .global page_map_level_2_low
 page_map_level_2_low: .skip 512 * 8
-.global page_map_level_2_high
-page_map_level_2_high: .skip 512 * 8
 
 /**
  * Reserve some space for the Multiboot 2 information pointer.
@@ -306,10 +302,7 @@ enable_sse:
  *
  * We map all physical memory we were loaded in plus one additional page. The
  * mapping is done in terms of huge pages (2 MiB per page) to save on required
- * page map entries. Note that we also map memory both in the low and high
- * virtual address ranges, giving us two ways of accessing it. We need to do
- * this, because the bootstrapping code lives in low memory, while the rest of
- * the kernel will reside on the high end.
+ * page map entries.
  */
 prepare_page_maps:
     /* Add an entry to the PML4, pointing to the low PML3 */
@@ -317,21 +310,11 @@ prepare_page_maps:
     or $0x3, %eax
     mov %eax, (page_map_level_4 + ((0x0000000000100000 >> 39) & 0x1ff) * 8)
 
-    /* Add an entry to the PML4, pointing to the high PML3 */
-    mov $page_map_level_3_high, %eax
-    or $0x3, %eax
-    mov %eax, (page_map_level_4 + ((0xffffffff80100000 >> 39) & 0x1ff) * 8)
-
     /* Add an entry to the low PML3, pointing to the low PML2 */
     mov $page_map_level_2_low, %eax
     or $0x3, %eax
     mov %eax, (page_map_level_3_low + ((0x0000000000100000 >> 30) & 0x1ff) * 8)
 
-    /* Add an entry to the high PML3, pointing to the high PML2 */
-    mov $page_map_level_2_high, %eax
-    or $0x3, %eax
-    mov %eax, (page_map_level_3_high + ((0xffffffff80100000 >> 30) & 0x1ff) * 8)
-
     xor %ecx, %ecx
 
     mov $_end_linear, %esi
@@ -343,7 +326,6 @@ prepare_page_maps:
     mul %ecx
     or $((1 << 0) | (1 << 1) | (1 << 7)), %eax
     mov %eax, page_map_level_2_low(,%ecx,8)
-    mov %eax, page_map_level_2_high(,%ecx,8)
 
     inc %ecx
     cmp %esi, %ecx