;=----------------------------------------------------------------------------=;
;                            GNU GPL OS/K                                      ;
;                                                                              ;
;   Authors: spectral`                                                         ;
;            NeoX                                                              ;
;                                                                              ;
;   Desc:   Kernel (second stage) Loader for OS/K INCLUDED FUNCTIONS           ;
;                   (x86_64 architecture only)                                 ;
;=----------------------------------------------------------------------------=;

[BITS 16]

disable_cursor:
    pushf
    push eax
    push edx
    mov dx, 0x3D4
    mov al, 0xA                             ; low cursor shape register
    out dx, al
    inc dx
    mov al, 0x20                            ; bits 6-7 unused, bit 5 disables the cursor, bits 0-4 control the cursor shape
    out dx, al
    pop edx
    pop eax
    popf
    ret

get_dimensions:
    push eax
    push ebx
    mov ah, 0x0F
    int 0x10
    mov [VGA_HEIGHT], ah
    mov [VIDEO_MODE], al
    pop ebx
    pop eax
    ret

Is64bits:
;-----------------------------------------------------------------------;
; Checks if the CPU is compatible with 64-bits operating systems        ;
; If the 21th bit of the eax register is set, then CPUID is supported   ;
; We then test CPUID's result to see if long mode is supported          ;
;-----------------------------------------------------------------------;
    pushfd                                  ; recovering the flags in eax
    pop eax
    mov ecx, eax
    xor eax, 0x200000
    push eax
    popfd
    pushfd
    pop eax
    xor eax, ecx
    shr eax, 21
    and eax, 1                              ; magical spell of murta
    push ecx
    popfd
    test eax, eax
    jz .NonCompat                           ; if (CPUID non supporté) goto NonCompat
    mov eax, 0x80000000
    cpuid
    cmp eax, 0x80000001
    jb .NonCompat                           ; if (eax <= 0x80000001) goto NonCompat
    mov eax, 0x80000001
    cpuid
    test edx, 1 << 29
    jz .NonCompat                           ; if (edx != 1 << 29) goto NonCompat
    ret                                     ; back to mbr.s
.NonCompat:
    stc
    ret

PrintB:
;---------------------------------------------------;
; Print out a simple string.                        ;
;                                                   ;
; Expects: DS:SI = String to print                  ;
;                                                   ;
; Returns: None                                     ;
;                                                   ;
;---------------------------------------------------;
    lodsb                                       ; Load byte from ds:si to al
    or al, al                                   ; If al is empty stop looping
    jz .done                                    ; Done looping and return
    mov ah, 0x0e                                ; Teletype output
    int 0x10                                    ; Video interupt
    jmp PrintB                                  ; Loop untill string is null
    .done:
    ret