Arm!

bootloader/x86/unreal.asm

@@ -1,54 +0,0 @@
-SECTION .text
-USE16
-
-; switch to unreal mode; ds and es can address up to 4GiB
-unreal:
-    cli
-
-    lgdt [unreal_gdtr]
-
-    push es
-    push ds
-
-    mov  eax, cr0          ; switch to pmode by
-    or al,1                ; set pmode bit
-    mov  cr0, eax
-
-    jmp $+2
-
-; http://wiki.osdev.org/Babystep7
-; When this register given a "selector", a "segment descriptor cache register"
-; is filled with the descriptor values, including the size (or limit). After
-; the switch back to real mode, these values are not modified, regardless of
-; what value is in the 16-bit segment register. So the 64k limit is no longer
-; valid and 32-bit offsets can be used with the real-mode addressing rules
-    mov bx, unreal_gdt.data
-    mov es, bx
-    mov ds, bx
-
-    and al,0xFE            ; back to realmode
-    mov  cr0, eax          ; by toggling bit again
-
-    pop ds
-    pop es
-    sti
-    ret
-
-
-unreal_gdtr:
-    dw unreal_gdt.end + 1  ; size
-    dd unreal_gdt          ; offset
-
-unreal_gdt:
-.null equ $ - unreal_gdt
-    dq 0
-.data equ $ - unreal_gdt
-    istruc GDTEntry
-        at GDTEntry.limitl,        dw 0xFFFF
-        at GDTEntry.basel,         dw 0x0
-        at GDTEntry.basem,         db 0x0
-        at GDTEntry.attribute,        db attrib.present | attrib.user | attrib.writable
-        at GDTEntry.flags__limith, db 0xFF | flags.granularity | flags.default_operand_size
-        at GDTEntry.baseh,         db 0x0
-    iend
-.end equ $ - unreal_gdt