Enable A20.

2022-11-19 22:02:37 +03:00 · 2022-11-19 22:02:37 +03:00 · e40bde036d
commit e40bde036d
parent 7e678618d1
1 changed files with 4 additions and 1 deletions
--- a/mbr.S
+++ b/mbr.S
@ -54,6 +54,9 @@ bios_disk_read:


 switch_to_32bit:
+    mov	$2, %al
+    out	%al, $0x92          // enable A20
+
    cli                     // 1. disable interrupts
    lgdt gdt_descriptor     // 2. load GDT descriptor
    mov %cr0, %eax