source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Boot/BootMenuEvent.asm@ 242

; Project name  :   XTIDE Universal BIOS
; Description   :   Boot Menu event handler for menu library callbacks.

; Section containing code
SECTION .text

;--------------------------------------------------------------------
; BootMenuEvent_Handler
;   Common parameters for all events:
;       BX:         Menu event (anything from MENUEVENT struct)
;       SS:BP:      Menu library handle
;   Common return values for all events:
;       CF:         Set if event processed
;                   Cleared if event not processed
;   Corrupts registers:
;       All
;--------------------------------------------------------------------
ALIGN JUMP_ALIGN
BootMenuEvent_Handler:

%ifdef MENUEVENT_INLINE_OFFSETS

    add     bx, BootMenuEvent_Handler
    jmp     bx

MENUEVENT_InitializeMenuinitFromDSSI equ  (BootMenuEvent_Handler.InitializeMenuinitFromDSSI - BootMenuEvent_Handler)
MENUEVENT_ExitMenu equ  (BootMenuEvent_EventCompleted - BootMenuEvent_Handler)
MENUEVENT_ItemHighlightedFromCX equ (BootMenuEvent_Handler.ItemHighlightedFromCX - BootMenuEvent_Handler)
MENUEVENT_ItemSelectedFromCX equ (BootMenuEvent_Handler.ItemSelectedFromCX - BootMenuEvent_Handler)
MENUEVENT_KeyStrokeInAX equ (BootMenuEvent_Handler.KeyStrokeInAX - BootMenuEvent_Handler)
MENUEVENT_RefreshTitle equ (BootMenuPrint_TitleStrings - BootMenuEvent_Handler)
MENUEVENT_RefreshInformation equ (BootMenuPrint_RefreshInformation - BootMenuEvent_Handler)
MENUEVENT_RefreshItemFromCX equ (BootMenuPrint_RefreshItem - BootMenuEvent_Handler)
;
; Note that there is no entry for MENUEVENT_IdleProcessing.  If MENUEVENT_IDLEPROCESSING_ENABLE is not %defined,
; then the entry point will not be called (saving memory on this end and at the CALL point).
;

%else

    cmp     bx, BYTE MENUEVENT.RefreshItemFromCX    ; Above last supported item?
    ja      SHORT .EventNotHandled
    jmp     [cs:bx+.rgfnEventSpecificHandlers]

.EventNotHandled:
    clc
    ret

ALIGN WORD_ALIGN
.rgfnEventSpecificHandlers:
    dw      .InitializeMenuinitFromDSSI         ; MENUEVENT.InitializeMenuinitFromDSSI
    dw      BootMenuEvent_EventCompleted        ; MENUEVENT.ExitMenu
    dw      .EventNotHandled                    ; MENUEVENT.IdleProcessing
    dw      .ItemHighlightedFromCX              ; MENUEVENT.ItemHighlightedFromCX
    dw      .ItemSelectedFromCX                 ; MENUEVENT.ItemSelectedFromCX
    dw      .KeyStrokeInAX                      ; MENUEVENT.KeyStrokeInAX
    dw      BootMenuPrint_TitleStrings          ; MENUEVENT.RefreshTitle
    dw      BootMenuPrint_RefreshInformation    ; MENUEVENT.RefreshInformation
    dw      BootMenuPrint_RefreshItem           ; MENUEVENT.RefreshItemFromCX

%endif


; Parameters:
;   DS:SI:      Ptr to MENUINIT struct to initialize
; Returns:
;   DS:SI:      Ptr to initialized MENUINIT struct
ALIGN JUMP_ALIGN
.InitializeMenuinitFromDSSI:
    push    ds
    call    RamVars_GetSegmentToDS
    call    .GetDefaultMenuitemToDX
    call    BootMenu_GetMenuitemCountToAX
    pop     ds
    mov     [si+MENUINIT.wItems], ax
    mov     [si+MENUINIT.wHighlightedItem], dx
    mov     WORD [si+MENUINIT.wTitleAndInfoLines], BOOT_MENU_TITLE_AND_INFO_LINES
    mov     BYTE [si+MENUINIT.bWidth], BOOT_MENU_WIDTH
    call    BootMenu_GetHeightToAHwithItemCountInAL
    mov     [si+MENUINIT.bHeight], ah
    mov     ax, [cs:ROMVARS.wBootTimeout]
    CALL_MENU_LIBRARY StartSelectionTimeoutWithTicksInAX
    stc
    ret

ALIGN JUMP_ALIGN
.GetDefaultMenuitemToDX:
    mov     dl, [cs:ROMVARS.bBootDrv]   ; Default boot drive
    call    BootMenu_IsDriveInSystem
    jnc     SHORT .DoNotSetDefaultMenuitem
    call    DriveXlate_SetDriveToSwap
    jmp     BootMenu_GetMenuitemToDXforDriveInDL
ALIGN JUMP_ALIGN
.DoNotSetDefaultMenuitem:
    xor     dx, dx                      ; Whatever appears first on boot menu
    ret


; Parameters:
;   CX:         Index of new highlighted item
;   DX:         Index of previously highlighted item or NO_ITEM_HIGHLIGHTED
ALIGN JUMP_ALIGN
.ItemHighlightedFromCX:
    push    cx
    call    BootMenu_GetDriveToDXforMenuitemInCX_And_RamVars_GetSegmentToDS     
    call    DriveXlate_Reset
    call    DriveXlate_SetDriveToSwap

    xor     ax, ax  ; Update first floppy drive (for translated drive number)
    CALL_MENU_LIBRARY RefreshItemFromAX
    mov     dl, 80h
    call    BootMenu_GetMenuitemToDXforDriveInDL
    xchg    ax, dx  ; Update first hard disk (for translated drive number)
    CALL_MENU_LIBRARY RefreshItemFromAX
    pop     ax      ; Update new item (for translated drive number)
    CALL_MENU_LIBRARY RefreshItemFromAX
    CALL_MENU_LIBRARY RefreshInformation
    stc
    ret


; Parameters:
;   AL:         ASCII character for the key
;   AH:         Keyboard library scan code for the key
ALIGN JUMP_ALIGN
.KeyStrokeInAX:
    cmp     ah, ROM_BOOT_HOTKEY_SCANCODE
    jne     SHORT .CheckDriveHotkeys
    ;; NOTE: carry flag will be clear after compare above that resulted in zero
    jmp     Int19hMenu_JumpToBootSector_or_RomBoot      
ALIGN JUMP_ALIGN
.CheckDriveHotkeys:
    call    BootMenu_GetMenuitemToAXforAsciiHotkeyInAL
    cmp     ax, [bp+MENUINIT.wItems]
    jae     SHORT BootMenuEvent_EventCompleted  ; Invalid key
    CALL_MENU_LIBRARY HighlightItemFromAX
    ; Fall to .ItemSelectedFromCX


; Parameters:
;   CX:         Index of selected item
ALIGN JUMP_ALIGN
.ItemSelectedFromCX:
    CALL_MENU_LIBRARY Close
        
BootMenuEvent_EventCompleted:
    stc
    ret