diff options
| -rw-r--r-- | boot/startup-x86_64.s | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/boot/startup-x86_64.s b/boot/startup-x86_64.s index 4f115e9..448576a 100644 --- a/boot/startup-x86_64.s +++ b/boot/startup-x86_64.s @@ -12,7 +12,7 @@ MAX_MEM: equ 512 [GLOBAL pml4] [GLOBAL pdp] -; functions from the other parts +; functions from other parts of rustubs [EXTERN vectors_start] [EXTERN idt] [EXTERN idt_descr] @@ -49,9 +49,9 @@ init_longmode: mov cr4, eax setup_paging: - ; Provisional identical page mapping, using 1G huge page (therefore only 2 table - ; levels needed) - ; + ; Provisional identical page mapping, using 1G huge page, therefore only 2 + ; table levels needed. see docs/x86_paging.txt + ; PML4 (Page Map Level 4 / 1st level) mov eax, pdp or eax, 0xf @@ -77,7 +77,8 @@ fill_tables2_done: mov cr3, eax activate_long_mode: ; activate Long Mode (for now in compatibility mode) - mov ecx, 0x0C0000080 ; select EFER (Extended Feature Enable Register) + ; select EFER (Extended Feature Enable Register) + mov ecx, 0x0C0000080 rdmsr or eax, 1 << 8 ; LME (Long Mode Enable) wrmsr @@ -158,7 +159,7 @@ gdt_80: [SECTION .bss] - global init_stack:data (init_stack.end - init_stack) +global init_stack:data (init_stack.end - init_stack) init_stack: resb STACKSIZE .end: |