.

bootloader-legacy/boot.asm

@@ -100,13 +100,42 @@ _prot_begin:
     mov ebx, _motd_32
     call println_vga
 
+    ; Test if 64bit available
+    call test_support_long_mode
+    cmp eax, 0
+    je _test_passed
+    mov ebx, _motd_no_long_mode
+    call println_vga
+    jmp _stall ; debug, tmp
+    jmp _call_kern_32
+_test_passed:
+
+    jmp inline_enter_long_mode
+%include "./inline_x64lib.inc"
+    jmp _call_kern_64
+
+[bits 32]
+_call_kern_32:
     ; Enter the kernel. This should never return.
     call KERN_ADDR
 
     ; Kernel returns.
     mov ebx, _motd_endk
     call println_vga
+    jmp _stall
+
+[bits 64]
+_call_kern_64:
+    ; Enter the kernel. This should never return.
+    call KERN_ADDR
 
+    ; Kernel returns.
+    mov ebx, _motd_endk
+    call println_vga
+    jmp _stall
+
+
+[bits 32]
 _stall:
     jmp $
 
@@ -118,6 +147,8 @@ _motd_kern_ok:
     db '[LOAD KERN SUCC]', 0x0
 _motd_endk:
     db '[LOAD KERN SUCC] [ENTER X86 MODE SUCC] [KERN EXITED]', 0x0
+_motd_no_long_mode:
+    db '[ENTER LONG MODE ERR] NOT_SUPPORTED', 0x0
 _boot_drive_id:
     db 0x0
     

bootloader-legacy/x64lib.inc → bootloader-legacy/inline_x64lib.inc

@@ -66,7 +66,33 @@ _fail_no_long_mode_3:
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
-enter_long_mode:
+GDT64:                           ; Global Descriptor Table (64-bit).
+    .Null: equ $ - GDT64         ; The null descriptor.
+    dw 0xFFFF                    ; Limit (low).
+    dw 0                         ; Base (low).
+    db 0                         ; Base (middle)
+    db 0                         ; Access.
+    db 1                         ; Granularity.
+    db 0                         ; Base (high).
+    .Code: equ $ - GDT64         ; The code descriptor.
+    dw 0                         ; Limit (low).
+    dw 0                         ; Base (low).
+    db 0                         ; Base (middle)
+    db 10011010b                 ; Access (exec/read).
+    db 10101111b                 ; Granularity, 64 bits flag, limit19:16.
+    db 0                         ; Base (high).
+    .Data: equ $ - GDT64         ; The data descriptor.
+    dw 0                         ; Limit (low).
+    dw 0                         ; Base (low).
+    db 0                         ; Base (middle)
+    db 10010010b                 ; Access (read/write).
+    db 00000000b                 ; Granularity.
+    db 0                         ; Base (high).
+    .Pointer:                    ; The GDT-pointer.
+    dw $ - GDT64 - 1             ; Limit.
+    dq GDT64                     ; Base.
+
+inline_enter_long_mode:
     ;;;;;;;;;;;;; section 1: paging
     ; disable paging in 32bit protected mode (if any)
     mov eax, cr0
@@ -116,6 +142,22 @@ _set_one_entry:
     or eax, 1 << 31              ; Set the PG-bit, which is the 32nd bit (bit 31).
     mov cr0, eax                 ; Set control register 0 to the A-register.
 
+    ;;;;;;;;;;;;;;;;; Section 3: enter 64bit long mode
+    lgdt [GDT64.Pointer]         ; Load the 64-bit global descriptor table.
+    jmp GDT64.Code:Realm64       ; Set the code segment and enter 64-bit long mode.
+
+[BITS 64]
+ 
+Realm64:
+    cli                           ; Clear the interrupt flag.
+    mov ax, GDT64.Data            ; Set the A-register to the data descriptor.
+    mov ds, ax                    ; Set the data segment to the A-register.
+    mov es, ax                    ; Set the extra segment to the A-register.
+    mov fs, ax                    ; Set the F-segment to the A-register.
+    mov gs, ax                    ; Set the G-segment to the A-register.
+    mov ss, ax                    ; Set the stack segment to the A-register.
+    ; done
+