; Project name : XTIDE Universal BIOS ; Description : Displays Boot Menu. ; Section containing code SECTION .text ;-------------------------------------------------------------------- ; Displays Boot Menu and returns Drive or Function number. ; ; BootMenu_DisplayAndReturnSelection ; Parameters: ; DS: RAMVARS segment ; Returns: ; DX: Untranslated drive number to be used for booting ; Corrupts registers: ; All General Purpose Registers ;-------------------------------------------------------------------- ALIGN JUMP_ALIGN BootMenu_DisplayAndReturnSelection: call DriveXlate_Reset call BootMenuPrint_TheBottomOfScreen call BootMenu_Enter ; Get selected menuitem index to CX call BootMenuPrint_ClearScreen call BootMenu_GetDriveToDXforMenuitemInCX jnc BootMenu_DisplayAndReturnSelection ret ;-------------------------------------------------------------------- ; BootMenu_GetDriveToDXforMenuitemInCX ; Parameters: ; CX: Index of menuitem selected from Boot Menu ; Returns: ; DX: Drive number to be used for booting ; DS: RAMVARS segment ; CF: Set: There is a selected menu item, DL is valid ; Clear: There is no selected menu item, DL is not valid ; Corrupts registers: ; CX, DI ;-------------------------------------------------------------------- ALIGN JUMP_ALIGN BootMenu_GetDriveToDXforMenuitemInCX_And_RamVars_GetSegmentToDS: call RamVars_GetSegmentToDS ;;; fall-through ALIGN JUMP_ALIGN BootMenu_GetDriveToDXforMenuitemInCX: cmp cl, NO_ITEM_HIGHLIGHTED je SHORT .ReturnFloppyDriveInDX ; Clear CF if branch taken mov dl, cl ; Copy menuitem index to DX call FloppyDrive_GetCountToCX cmp dl, cl ; Floppy drive? jb SHORT .ReturnFloppyDriveInDX ; Set CF if branch taken or cl, 80h ; Or 80h into CL before the sub ; to cause CF to be set after ; and result has high order bit set sub dl, cl ; Remove floppy drives from index .ReturnFloppyDriveInDX: ret ;-------------------------------------------------------------------- ; Enters Boot Menu or submenu. ; ; BootMenu_Enter ; Parameters: ; Nothing ; Returns: ; CX: Index of selected item or NO_ITEM_SELECTED ; Corrupts registers: ; AX, BX, DI ;-------------------------------------------------------------------- ALIGN JUMP_ALIGN BootMenu_Enter: mov bx, BootMenuEvent_Handler CALL_MENU_LIBRARY DisplayWithHandlerInBXandUserDataInDXAX xchg cx, ax ret ;-------------------------------------------------------------------- ; Returns number of menuitems in Boot Menu. ; ; BootMenu_GetMenuitemCountToAX ; Parameters: ; DS: RAMVARS segment ; Returns: ; AX: Number of boot menu items ; Corrupts registers: ; CX ;-------------------------------------------------------------------- ALIGN JUMP_ALIGN BootMenu_GetMenuitemCountToAX: call RamVars_GetHardDiskCountFromBDAtoCX xchg ax, cx call FloppyDrive_GetCountToCX add ax, cx ret ;-------------------------------------------------------------------- ; BootMenu_GetHeightToAHwithItemCountInAL ; Parameters: ; AL: Number of menuitems ; Returns: ; AH: Boot menu height ; Corrupts registers: ; AL, CX, DI ;-------------------------------------------------------------------- ALIGN JUMP_ALIGN BootMenu_GetHeightToAHwithItemCountInAL: add al, BOOT_MENU_HEIGHT_WITHOUT_ITEMS xchg cx, ax CALL_DISPLAY_LIBRARY GetColumnsToALandRowsToAH sub ah, MENU_SCREEN_BOTTOM_LINES*2 ; Leave space for bottom info cmp ah, cl jb SHORT .Return mov ah, cl ALIGN JUMP_ALIGN, ret .Return: ret ;-------------------------------------------------------------------- ; BootMenu_GetMenuitemToAXforAsciiHotkeyInAL ; Parameters: ; AL: ASCII hotkey ; Returns: ; AX: Menuitem index ; Corrupts registers: ; CX ;-------------------------------------------------------------------- ALIGN JUMP_ALIGN BootMenu_GetMenuitemToAXforAsciiHotkeyInAL: call Char_ALtoUpperCaseLetter call BootMenu_GetLetterForFirstHardDiskToCL xor ah, ah cmp al, cl ; Letter is for Hard Disk? jae SHORT .StartFromHardDiskLetter sub al, 'A' ; Letter to Floppy Drive menuitem ret ALIGN JUMP_ALIGN .StartFromHardDiskLetter: sub al, cl ; Hard Disk index call FloppyDrive_GetCountToCX add ax, cx ; Menuitem index ret ;-------------------------------------------------------------------- ; Returns letter for first hard disk. Usually it will be 'c' but it ; can be higher if more than two floppy drives are found. ; ; BootMenu_GetLetterForFirstHardDiskToCL ; Parameters: ; Nothing ; Returns: ; CL: Upper case letter for first hard disk ; Corrupts registers: ; CH ;-------------------------------------------------------------------- ALIGN JUMP_ALIGN BootMenu_GetLetterForFirstHardDiskToCL: call FloppyDrive_GetCountToCX add cl, 'A' cmp cl, 'C' ja .Return mov cl, 'C' ALIGN JUMP_ALIGN, ret .Return: ret ;-------------------------------------------------------------------- ; BootMenu_GetMenuitemToDXforDriveInDL ; Parameters: ; DL: Drive number ; Returns: ; DX: Menuitem index (assuming drive is available) ; Corrupts registers: ; Nothing ;-------------------------------------------------------------------- ALIGN JUMP_ALIGN BootMenu_GetMenuitemToDXforDriveInDL: xor dh, dh ; Drive number now in DX test dl, dl jns SHORT .ReturnItemIndexInDX ; Return if floppy drive (HD bit not set) call FloppyDrive_GetCountToCX and dl, ~80h ; Clear HD bit add dx, cx .ReturnItemIndexInDX: ret ;-------------------------------------------------------------------- ; Checks is drive number valid for this system. ; ; BootMenu_IsDriveInSystem ; Parameters: ; DL: Drive number ; DS: RAMVARS segment ; Returns: ; CF: Set if drive number is valid ; Clear if drive is not present in system ; Corrupts registers: ; AX, CX ;-------------------------------------------------------------------- ALIGN JUMP_ALIGN BootMenu_IsDriveInSystem: test dl, dl ; Floppy drive? jns SHORT .IsFloppyDriveInSystem call RamVars_GetHardDiskCountFromBDAtoCX ; Hard Disk count to CX or cl, 80h ; Set Hard Disk bit to CX jmp SHORT .CompareDriveNumberToDriveCount .IsFloppyDriveInSystem: call FloppyDrive_GetCountToCX .CompareDriveNumberToDriveCount: cmp dl, cl ; Set CF when DL is smaller ret