VesaSetup:
    
    pusha

    ;VESA: get all available vesa modes!
    mov ax,0	; set target address in es:di (0:offset)
    mov es,ax
    mov di,VESA_MODES
    mov ax,0x4f00   ;vesa function: Get Controller Info
    int 0x10	; call the interrupt to get the data from the bios!
    vesa_err:
    mov bx, VESA_CHECK1
    call print_string
    cmp ax,0x004f
    je vesa_ok
    jmp vesa_err
    vesa_ok:
    ;


    ;VESA: get vesa info on mode of interest
    mov ax,0	; set target address in es:di (0:offset)
    mov es,ax
    mov di,VESA_MODE_INFO
    mov ax,0x4f01   ;vesa function: Get Mode Info
    mov cx,VESA_MODE_SELECT   
    int 0x10	; call the interrupt to get the data from the bios!
    vesa_err2:
    mov bx, VESA_CHECK2
    call print_string
    cmp ax,0x004f
    je vesa_ok2
    jmp vesa_err2
    vesa_ok2:


    ;VESA: finally switch to the mode of choice!
    mov ax,0x4f02   ;vesa function: Set Mode
    mov bx,VESA_MODE_SELECT 
    int 0x10
    vesa_err3:
    mov bx, VESA_CHECK3
    call print_string
    cmp ax,0x004f
    je vesa_ok3
    jmp vesa_err3
    vesa_ok3:
    popa
    ret