;-----------------------------------------------------------------------------
; Az FS regisztert tilos atirni kimenteni/visszatolteni stb.!!!!!
;	(ekkor visszater real modba)!!!!!!!
;-----------------------------------------------------------------------------


				; Tabla de descriptores
LABEL DescTabl
        DB 8 DUP (?)            ; Descriptor 0 no utilizado

        DW 0FFFFh               ; 4 Gigabyte (64K pag) de tama$o
        DW 0                    ; b15..0  del origen
        DB 0                    ; b23..16 del origen
        DB 10010010b            ; b7:  presente (s! = 1)
                                ; b65: privilege level (00)
                                ; b4:  segmento de sistema:  (no=1)
                                ; b3:  no ejecutable (0)
                                ; b2:  no hacia abajo (0)
                                ; b1:  escribible (1)
                                ; b0:  acceso (no a#n)
        DB 11001111b            ; b7:  granularidad (p ginas = 1)
                                ; b6:  grande (?) (s! = 1)
                                ; b5:  (?)    (0)
                                ; b4:  no utilizado (0)
                                ; b30: 19..16 del l!mite (1111)
        DB 0                    ; b31..24 del origen del segmento

NemJo		db "Csak real modban fut helyesen!",13,10,"$"
Xinst		db "Nincs XMS memoria kezelo!",13,10,"$"
nomem		db "A memoria lefoglalas nem sikerult",13,10,"$"


XMSHandle	dw	0
XMSBase		dd	0

StartMem	dd	0		;lefoglalt memoria elso byte-ja
EndMem		dd	0		;lefoglalt memoria utolso byte-ja+1





gdtref:  DW      0Fh             ; limite de la gdt: 2 descriptores
l_ref:   DW      OFFSET DescTabl, 0

XMSDrv:		db	9ah	;call	far xxxx:xxxx
XMSEntry:	dd	?	
		ret
;-------------------------------------------------------------------------------
;XMSInstalled	,XMS meghajto program instalalva van-e
;	be: -
;	ki: ax= False  XMS Drv. nincs
;	    ax= True   XMS Drv. van
;	    cx= XMS verzio kod (pl. 3.00 -> 0300h)
;	    bx= XMS driver verzio kod (pl. 3.10 -> 0310h)
;	    dx= 1, ha HMA elerheto, egyebkent dx=0
;		XMSEntry valtozo balaltodik
;------------------------------------------------------------------------------
XMSInstalled:	mov	ax,4300h
		int	2fh
		cmp	al,80H
		mov	ax,False
		jne	short XMSIExit
					;XMS belepesi pont beallitasa
					;az 'XMSEntry' valtozoban a belepesi pont cime
		mov	ax,4310h
		int	2fh
		mov	word ptr cs:XMSEntry[0],bx
		mov	word ptr cs:XMSEntry[2],es
		xor	ax,ax
		call	cs:[XMSdrv]
		mov	cx,ax
					;driver legalabb 2.0-as legyen
		

		mov	ax,true
XMSIExit:	ret
;
;-----------------------------------------------------------------------------
;XMSAvail	, elerheto XMS memoria lekerdezes
;	be: -
;	ki: ax - elerheto legnagyobb XMS memoria merete
;	    dx - teljes szabad XMS memoria merete
;	    bx - hibakod 80,81,A1-es lehet
;-----------------------------------------------------------------------------
XMSAvail	macro
		mov	ax,0801h
		call	cs:[XMSdrv]
		endm
;
;-----------------------------------------------------------------------------
;AllocateXMS ,XMS memoria lefoglalasa
;	be: dx - lefoglalando memoria kbyte-ban
;	ki: ax - vegrehajtas kodja 0= nincs hiba
;	    dx - XMS handle
;	    bl - lehetseges hibakodok 80,81,A0,A1
;-----------------------------------------------------------------------------
AllocateXMS	macro	memory
		mov	dx,memory
		mov	ah,9
		call	cs:[XMSdrv]
		endm
;
;------------------------------------------------------------------------------
;FreeXMS	,XMS memoria felszabaditasa
;	be: dx - felszabaditando XMS handle
;	ki: ax - vegrehajtas hiba kodjai
;	    bl - lehetseges hiakodok 80,81,A2,A3
;------------------------------------------------------------------------------
FreeXMS		macro	handle
		mov	ah,0ah
		mov	dx,handle
		call	cs:[XMSdrv]
		endm
;
;------------------------------------------------------------------------------
;XMSLock	,XMS memoriacim rogzites
;	be: dx - handle
;	ki: ax =1
;	    dx:bx - a rogzitett cim 
;	    ax = 0, akkor hibakod bl=80,81,A2,AC,AD
;------------------------------------------------------------------------------
XMSLock		macro	handle
		mov ah,0ch
		mov	dx,handle
		call	cs:[XMSdrv]
		endm
;
;------------------------------------------------------------------------------
;XMSUnlock	,rogzitett XMS cim felszabaditasa
;	be: dx - handle
;	ki: ax - 1 ok, az=0 hiba bl=80,81,A2,AA
;------------------------------------------------------------------------------
XMSUnlock	macro	handle
		mov	dx,handle
		mov ah,0dh
		call	cs:[XMSdrv]
		endm
;
;------------------------------------------------------------------------------
;LocalA20En	- A20 vonal helyi engedelyezese a direkt XMS elereshez
;	be: -
;	ki: ax=1 Enabled ,egyebkent hiba
;	    bl=hibakod 80,81,81
;------------------------------------------------------------------------------
LocalA20En	macro
		mov	ah,05h
		call	cs:[XMSdrv]
		endm
;------------------------------------------------------------------------------
;LocalA20Dis	- A20 vonal helyi tiltasa
;	be: -
;	ki: ax=1 disabled ,egyebkent hiba
;	    bl=hibakod 80,81,82,94
;------------------------------------------------------------------------------
LocalA20En	macro
		mov	ah,06h
		call	cs:[XMSdrv]
		endm
;------------------------------------------------------------------------------
;A20Info	- A20 vonalrol info szerzes
;	be: -
;	ki: ax=1 fizikailag engedelyezett ,egyebkent hiba
;	    bl=hibakod 80,81
;------------------------------------------------------------------------------
LocalA20En	macro
		mov	ah,07h
		call	cs:[XMSdrv]
		endm
;
;------------------------------------------------------------------------------
;Az FS 4 Gb szegmens beallitasa 
;
;------------------------------------------------------------------------------
Set4GB:	mov     ax,seg adataim
        mov     ds,ax
       				 ; Have to fix up the gdt reference
        mov     eax,seg adataim
        shl     eax,4
        add     [DWORD PTR l_ref],eax
        lgdt    [FWORD PTR cs:gdtref]



        mov     eax,cr0
        or      al,1
        mov     cr0,eax
	jmp	far ptr @@n
@@n:	        		; YA ESTAMOS EN PMODE!!!!!!!!!!!
        mov     ax,8
        mov     fs,ax           ; Selector del segmento plano de 4 gigas
        mov     eax,cr0
        and     eax,0FEh
        mov     cr0,eax
       				; ya estamos en rmode :_(((((((((
        			; PERO CON UN SEGMENTO DE 4 GIGAS!!!!
	jmp	far ptr realm
realm:	ret

;---------------------------------------------------------------------------
;---------------------------------------------------------------------------
XMSmain		proc
		push	dx
		mov	ax,seg adataim
		mov	ds,ax
		SMSW	ax
		test	ax,1
		jz	short Okjo
		Print_str Nemjo
		end_process 1

OkJO:		call	XMSInstalled
		and	ax,ax
		jnz	short XMSyes
		print_str xinst
		end_process 2

XMSyes:		pop	dx
		AllocateXMS dx		;1.9 Mb 
		cmp	ax,1
		jz	short Memok
		print_str nomem
		end_process 3

memok:		mov	ax,seg adataim
		mov	ds,ax
		mov	ds:XMSHandle,dx
		XMSLock	XMShandle
		movzx	edx,dx
		shl	edx,16
		mov	dx,bx		;dx 32 bites fizikai cimet adja
		mov	XMSBase,edx
		call	set4GB
		retf
		endp

XMSDone		proc
		mov	ax,seg adataim
		mov	ds,ax
		mov	bx,XMShandle		
		XMSUnlock bx
		mov	bx,XMShandle
		push	bx		
		FreeXMS	bx
		pop	ax
		xor	ax,ax
		mov	fs,ax
		retf
		endp

DosVerOk	proc
		mov	ah,30h	;dos verzio ellenorzese min 5.00 kell
		int	21h
		xchg	al,ah
		cmp	ax,0500h
		jnc	dosvok
		print_str dverr
		end_process 4
DosVok:		retf
		endp