[z180-stamp-cpm3.git] / cbios / mm.180

	page	255
	.z80


	global mmuinit
	global bnk2log,bnk2phy,hwl2phy,phy2log

	include config.inc
	include	z180reg.inc


;----------------------------------------------------------------------
; Memory Map 1:
;
;	Common	CAStart ..     0FFFF
;	Bank 0	  00000 .. CAStart-1
;	Bank 1    10000 ..
;	Bank 2
;
; Memory Map 2:
;
;	Common	  18000 .. 1BFFF	BANK1
;
;	Bank 0	  00000 .. 0BFFF	0
;	Bank 1    0C000 .. 17FFF	1*BNK_SIZE
;	Bank 2    1C000 .. 27FFF	2*BNK_SIZE + CMN_SIZE
;	Bank 3    28000 .. 33FFF	3*BNK_SIZE + CMN_SIZE
;	Bank n				n*BNK_SIZE + (n < 2) ? 0 : CMN_SIZE
;
;----------------------------------------------------------------------

	cseg

mmuinit:
	ld	a,USR$CBAR
	out0	(cbar),a
	ret

;--------------------------------------------------------------------
; Return the BBR value for the given bank number
;
; in  a: Bank number
; out a: bbr value

   if 0	; Memory Map 1

bnk2log:
	or	a		;
	ret	z		; Bank 0 is at physical address 0

	dec	a		;
	push	bc		;
	ld	c,a		;
	ld	b,BNK_SIZE	;
	mlt	bc		; bank size * bank number
	ld	a,c		;
	add	a,10h		; add bank0 + common
	pop	bc		;
	ret			;

   else ; Memory Map 2

bnk2log:
	or	a
	ret	z		; Bank 0 is at physical address 0

	push	bc
	ld	c,a		;
	ld	b,BNK_SIZE	;
	mlt	bc		; bank size * bank number
	cp	2		;
	ld	a,c		;
	pop	bc
	ret	c
	add	a,CMN_SIZE
	ret

    endif

    if 0 ; table version

	push	hl
	ld	hl,bnk_table	;
	add	a,l		;
	ld	l,a		;
	jr	nc,$+3		;
	inc	h		;
	ld	a,(hl)		;
	pop	hl
	ret

    endif

;--------------------------------------------------------------

;in  hl: Log. Address
;     a: Bank number
;
;out ahl: Phys. (linear) Address


bnk2phy:
	push	bc
	ld	c,a
	ld	a,h
	and	a,0f0h
	cp	CA*16
	ld	a,c
	pop	bc
	jr	c,b2p_banked
				; address is in common
    if 0 ; Memory Map 1
	ld	a,0		; base is 0
    else ; Memory Map 2
	ld	a,1		; same as bank1
    endif

b2p_banked:
	call	bnk2log		; get address base

	; fall thru

;--------------------------------------------------------------
;
; hl: Log. Address
;  a: Bank base (bbr)
;
;	     2           0       0
;	     0   6       8       0
; hl	          hhhhhhhhllllllll
;  a	+     bbbbbbbb
;
; OP: ahl = (a<<12) + (h<<8) + l
;
;out ahl: Phys. (linear) Address

log2phy:
	push	bc		;
l2p_i:
	ld	c,a		;
	ld	b,16		;
	mlt	bc		; bc = a<<4
	ld	a,c		;
	add	a,h		;
	ld	h,a		;
	ld	a,b		;
	adc	a,0		;
	pop	bc		;
	ret			;

;--------------------------------------------------------------
;
; hl: Log. Address
;
;
; OP: ahl = (bankbase<<12) + (h<<8) + l
;
;out ahl: Phys. (linear) Address


hwl2phy:
	push	bc		;
	in0	c,(cbar)	;
	ld	a,h		;
	or	00fh		; log. addr in common1?
	cp	c
	jr	c,hlp_1

	in0	a,(cbr)		; yes, cbr is address base
	jr	hl2p_x
hlp_1:
	ld	b,16		; log. address in baked area?
	mlt	bc
	ld	a,h
	cp	c
	jr	c,hlp_2
	in0	a,(bbr)		; yes, bbr is address base
	jr	hl2p_x
hlp_2:
	xor	a		; common1
hl2p_x:
	jr	nz,l2p_i

	pop	bc		; bank part is 0, no translation
	ret			;


;--------------------------------------------------------------
; return logical bank 0 address for given physical address.
;
; in: ahl: pyhsical addres (20 bit)
; out  hl: logical address.
;	   logical address is in bank 0 or common, no bank number returned
;

phy2log:
	or	a
	ret	z

	push	bc
	push	hl
	ld	l,h
	ld	h,0
	ld	bc,-16*SYS$CBR
	add	hl,bc
	ld	h,l
	pop	bc
	ld	l,c
	pop	bc
	ret

;--------------------------------------------------------------
; Trampoline for routines in banked ram.
; Switch stack pointer to "system" stack in top ram
; Save cbar
;
	extrn	bs$stack

	cseg	; common!

	public	_b0call
_b0call:
	push	af
	in0	a,(bbr)
	jr	nz,b0c_doit
	pop	af

	ex	(sp),hl			;16
	push	de
	ld	e,(hl)
	inc	hl
	ld	d,(hl)
	inc	hl
	ld	(b0c_fast_go),de
	pop	de
	ex	(sp),hl			;16
b0c_fast_go equ	$+1
	jp	0

b0c_doit:
	ld	(b0_save_hl),hl
	ld	(b0_save_de),de
	pop	hl
	ld	(b0_save_af),hl

	pop	de			;get ptr to 'function address' in de
	ld	hl,2
	add	hl,de
	push	hl			;put return address on stack

   if 0 ; link80

	ld	hl,0
	add	hl,sp			;
	ld	a,h
	cp	high (bs$stack-bs$stack$size) ;link80 can't process this
	jr	nc,$ + 5		;skip if stack allready in common bios ram

   else

	ld	hl,bs$stack-bs$stack$size
	ld	a,h
	dec	a
	ld	hl,0
	add	hl,sp			;
	cp	h
	jr	c,$ + 5			;skip if stack allready in common bios ram
   endif
	ld	sp,bs$stack		;

	push	hl			;save	user stack pointer

	in0	h,(bbr)			;
	push	hl			;
	ld	hl,b0c_ret
	push	hl
	xor	a
	out0	(bbr),a			;
	ex	de,hl			;ptr
	ld	e,(hl)			;get 'function address'
	inc	hl			;
	ld	d,(hl)			;
	push	de			;put on (switched) stack

	ld	hl,(b0_save_af)		;get back users registers
	push	hl
	pop	af
	ld	de,(b0_save_de)
	ld	hl,(b0_save_hl)
	ret				;go to function
b0c_ret:
	ld	(b0_save_hl),hl

	pop	hl			;
	out0	(bbr),h			;
	pop	hl			;
	ld	sp,hl			;
	ld	hl,(b0_save_hl)
	ret				;


b0_save_hl: dw	0
b0_save_de: dw	0
b0_save_af: dw	0


;====================================================================

  if 0

;--------------------------------------------------------------------
; Return the BBR value for the given bank number

bnk2bbr:
	or	a		; 4
	ret	z		; 5/10 | 11		14

	push	bc		;11 | 11
	ld	b,a		; 4
	ld	c,CA		; 6
	mlt	bc		;17			    >45
	ld	a,c		; 4
	add	a,10h		; 6
	pop	bc		; 9 | 10
	ret			; 9 | 10		76

	push	ix		;2 / 14 | 15
	ld	ix,bnktbl	;4 / 12 | 14
	ld	($+3+2),a	;3 / 15 | 19
	ld	a,(ix+0)	;3 / 14 | 19
	pop	ix		;2 / 12 | 14
	ret			;1 /  9 | 10		15 / 76|91

	push	hl		;1 / 11 | 11
	ld	hl,bnktbl	;3 /  9 | 10
	add	a,l		;1 /  4 | 4
	ld	l,a		;1 /  4 | 4
	ld	a,0		;1 /  6 | 7
	adc	a,h		;1 /  4 | 4
	ld	h,a		;1 /  4 | 4
	ld	a,(hl)		;1 /  6 | 7
	pop	hl		;1 /  9 | 10
	ret			;1 /  9 | 10		12 / 66|71

	push	hl		;1 / 11 | 11
	add	a,low bnktbl	;2 /  6 | 7
	ld	l,a		;1 /  4 | 4
	ld	a,0		;1 /  6 | 7
	adc	a,high bnktbl	;2 /  6 | 7
	ld	h,a		;1 /  4 | 4
	ld	a,(hl)		;1 /  6 | 7
	pop	hl		;1 /  9 | 10
	ret			;1 /  9 | 10		11 / 61|67

  endif


	end
Commit	Line	Data
ea5293bb L	1	page 255
	2	.z80
	3
	4
	5	global mmuinit
1e1c17d3	6	global bnk2log,bnk2phy,hwl2phy,phy2log
ea5293bb L	7
	8	include config.inc
	9	include z180reg.inc
	10
	11
	12	;----------------------------------------------------------------------
1e1c17d3	13	; Memory Map 1:
ea5293bb	14	;
1e1c17d3 L	15	; Common CAStart .. 0FFFF
	16	; Bank 0 00000 .. CAStart-1
	17	; Bank 1 10000 ..
ea5293bb L	18	; Bank 2
ea5293bb L	19	;
1e1c17d3 L	20	; Memory Map 2:
	21	;
	22	; Common 18000 .. 1BFFF BANK1
	23	;
	24	; Bank 0 00000 .. 0BFFF 0
	25	; Bank 1 0C000 .. 17FFF 1*BNK_SIZE
	26	; Bank 2 1C000 .. 27FFF 2*BNK_SIZE + CMN_SIZE
	27	; Bank 3 28000 .. 33FFF 3*BNK_SIZE + CMN_SIZE
	28	; Bank n n*BNK_SIZE + (n < 2) ? 0 : CMN_SIZE
	29	;
ea5293bb L	30	;----------------------------------------------------------------------
	31
	32	cseg
	33
	34	mmuinit:
	35	ld a,USR$CBAR
	36	out0 (cbar),a
	37	ret
	38
	39	;--------------------------------------------------------------------
	40	; Return the BBR value for the given bank number
	41	;
	42	; in a: Bank number
	43	; out a: bbr value
	44
1e1c17d3 L	45	if 0 ; Memory Map 1
1e1c17d3 L	46
ea5293bb L	47	bnk2log:
	48	or a ;
	49	ret z ; Bank 0 is at physical address 0
	50
1e1c17d3	51	dec a ;
ea5293bb	52	push bc ;
1e1c17d3 L	53	ld c,a ;
1e1c17d3 L	54	ld b,BNK_SIZE ;
ea5293bb L	55	mlt bc ; bank size * bank number
	56	ld a,c ;
	57	add a,10h ; add bank0 + common
	58	pop bc ;
	59	ret ;
	60
1e1c17d3 L	61	else ; Memory Map 2
	62
	63	bnk2log:
	64	or a
	65	ret z ; Bank 0 is at physical address 0
	66
	67	push bc
	68	ld c,a ;
	69	ld b,BNK_SIZE ;
	70	mlt bc ; bank size * bank number
	71	cp 2 ;
	72	ld a,c ;
	73	pop bc
	74	ret c
	75	add a,CMN_SIZE
	76	ret
	77
	78	endif
	79
	80	if 0 ; table version
	81
	82	push hl
	83	ld hl,bnk_table ;
	84	add a,l ;
	85	ld l,a ;
	86	jr nc,$+3 ;
	87	inc h ;
	88	ld a,(hl) ;
	89	pop hl
	90	ret
	91
	92	endif
	93
ea5293bb L	94	;--------------------------------------------------------------
	95
	96	;in hl: Log. Address
	97	; a: Bank number
	98	;
	99	;out ahl: Phys. (linear) Address
	100
	101
	102	bnk2phy:
1d26b866 L	103	push bc
	104	ld c,a
	105	ld a,h
	106	and a,0f0h
	107	cp CA*16
	108	ld a,c
	109	pop bc
1d26b866	110	jr c,b2p_banked
1e1c17d3 L	111	; address is in common
	112	if 0 ; Memory Map 1
	113	ld a,0 ; base is 0
	114	else ; Memory Map 2
	115	ld a,1 ; same as bank1
	116	endif
	117
1d26b866 L	118	b2p_banked:
1d26b866 L	119	call bnk2log ; get address base
1d26b866	120
ea5293bb L	121	; fall thru
	122
	123	;--------------------------------------------------------------
	124	;
	125	; hl: Log. Address
	126	; a: Bank base (bbr)
	127	;
	128	; 2 0 0
	129	; 0 6 8 0
	130	; hl hhhhhhhhllllllll
	131	; a + bbbbbbbb
	132	;
	133	; OP: ahl = (a<<12) + (h<<8) + l
	134	;
	135	;out ahl: Phys. (linear) Address
	136
	137	log2phy:
	138	push bc ;
	139	l2p_i:
	140	ld c,a ;
	141	ld b,16 ;
	142	mlt bc ; bc = a<<4
	143	ld a,c ;
	144	add a,h ;
	145	ld h,a ;
	146	ld a,b ;
	147	adc a,0 ;
	148	pop bc ;
	149	ret ;
	150
	151	;--------------------------------------------------------------
	152	;
1e1c17d3	153	; hl: Log. Address
ea5293bb L	154	;
ea5293bb L	155	;
1e1c17d3	156	; OP: ahl = (bankbase<<12) + (h<<8) + l
ea5293bb L	157	;
	158	;out ahl: Phys. (linear) Address
	159
	160
	161	hwl2phy:
	162	push bc ;
	163	in0 c,(cbar) ;
	164	ld a,h ;
	165	or 00fh ; log. addr in common1?
	166	cp c
	167	jr c,hlp_1
	168
	169	in0 a,(cbr) ; yes, cbr is address base
	170	jr hl2p_x
	171	hlp_1:
	172	ld b,16 ; log. address in baked area?
	173	mlt bc
	174	ld a,h
	175	cp c
	176	jr c,hlp_2
	177	in0 a,(bbr) ; yes, bbr is address base
	178	jr hl2p_x
	179	hlp_2:
	180	xor a ; common1
	181	hl2p_x:
	182	jr nz,l2p_i
	183
	184	pop bc ; bank part is 0, no translation
	185	ret ;
	186
	187
1e1c17d3 L	188	;--------------------------------------------------------------
	189	; return logical bank 0 address for given physical address.
	190	;
	191	; in: ahl: pyhsical addres (20 bit)
	192	; out hl: logical address.
	193	; logical address is in bank 0 or common, no bank number returned
	194	;
	195
	196	phy2log:
	197	or a
	198	ret z
	199
	200	push bc
	201	push hl
	202	ld l,h
	203	ld h,0
	204	ld bc,-16*SYS$CBR
	205	add hl,bc
	206	ld h,l
	207	pop bc
	208	ld l,c
	209	pop bc
	210	ret
	211
b43b4662 L	212	;--------------------------------------------------------------
	213	; Trampoline for routines in banked ram.
	214	; Switch stack pointer to "system" stack in top ram
	215	; Save cbar
	216	;
	217	extrn bs$stack
	218
	219	cseg ; common!
	220
	221	public _b0call
	222	_b0call:
40df51ae L	223	push af
	224	in0 a,(bbr)
	225	jr nz,b0c_doit
	226	pop af
b43b4662	227
40df51ae L	228	ex (sp),hl ;16
	229	push de
	230	ld e,(hl)
	231	inc hl
	232	ld d,(hl)
	233	inc hl
	234	ld (b0c_fast_go),de
	235	pop de
	236	ex (sp),hl ;16
	237	b0c_fast_go equ $+1
	238	jp 0
	239
	240	b0c_doit:
b43b4662 L	241	ld (b0_save_hl),hl
b43b4662 L	242	ld (b0_save_de),de
b43b4662 L	243	pop hl
	244	ld (b0_save_af),hl
	245
	246	pop de ;get ptr to 'function address' in de
	247	ld hl,2
	248	add hl,de
	249	push hl ;put return address on stack
	250
	251	if 0 ; link80
	252
	253	ld hl,0
	254	add hl,sp ;
	255	ld a,h
	256	cp high (bs$stack-bs$stack$size) ;link80 can't process this
	257	jr nc,$ + 5 ;skip if stack allready in common bios ram
	258
	259	else
	260
	261	ld hl,bs$stack-bs$stack$size
	262	ld a,h
	263	dec a
	264	ld hl,0
	265	add hl,sp ;
	266	cp h
	267	jr c,$ + 5 ;skip if stack allready in common bios ram
	268	endif
	269	ld sp,bs$stack ;
	270
	271	push hl ;save user stack pointer
40df51ae L	272
40df51ae L	273	in0 h,(bbr) ;
b43b4662 L	274	push hl ;
	275	ld hl,b0c_ret
	276	push hl
40df51ae L	277	xor a
40df51ae L	278	out0 (bbr),a ;
b43b4662 L	279	ex de,hl ;ptr
	280	ld e,(hl) ;get 'function address'
	281	inc hl ;
	282	ld d,(hl) ;
	283	push de ;put on (switched) stack
	284
	285	ld hl,(b0_save_af) ;get back users registers
	286	push hl
	287	pop af
	288	ld de,(b0_save_de)
	289	ld hl,(b0_save_hl)
	290	ret ;go to function
	291	b0c_ret:
	292	ld (b0_save_hl),hl
	293
	294	pop hl ;
40df51ae	295	out0 (bbr),h ;
b43b4662 L	296	pop hl ;
	297	ld sp,hl ;
	298	ld hl,(b0_save_hl)
	299	ret ;
	300
	301
	302	b0_save_hl: dw 0
	303	b0_save_de: dw 0
	304	b0_save_af: dw 0
	305
	306
	307
ea5293bb L	308	;====================================================================
	309
	310	if 0
	311
	312	;--------------------------------------------------------------------
	313	; Return the BBR value for the given bank number
	314
	315	bnk2bbr:
	316	or a ; 4
	317	ret z ; 5/10 \| 11 14
	318
	319	push bc ;11 \| 11
	320	ld b,a ; 4
	321	ld c,CA ; 6
	322	mlt bc ;17 >45
	323	ld a,c ; 4
	324	add a,10h ; 6
	325	pop bc ; 9 \| 10
	326	ret ; 9 \| 10 76
	327
	328	push ix ;2 / 14 \| 15
	329	ld ix,bnktbl ;4 / 12 \| 14
	330	ld ($+3+2),a ;3 / 15 \| 19
	331	ld a,(ix+0) ;3 / 14 \| 19
	332	pop ix ;2 / 12 \| 14
	333	ret ;1 / 9 \| 10 15 / 76\|91
	334
	335	push hl ;1 / 11 \| 11
	336	ld hl,bnktbl ;3 / 9 \| 10
	337	add a,l ;1 / 4 \| 4
	338	ld l,a ;1 / 4 \| 4
	339	ld a,0 ;1 / 6 \| 7
	340	adc a,h ;1 / 4 \| 4
	341	ld h,a ;1 / 4 \| 4
	342	ld a,(hl) ;1 / 6 \| 7
	343	pop hl ;1 / 9 \| 10
	344	ret ;1 / 9 \| 10 12 / 66\|71
	345
	346	push hl ;1 / 11 \| 11
	347	add a,low bnktbl ;2 / 6 \| 7
	348	ld l,a ;1 / 4 \| 4
	349	ld a,0 ;1 / 6 \| 7
	350	adc a,high bnktbl ;2 / 6 \| 7
	351	ld h,a ;1 / 4 \| 4
	352	ld a,(hl) ;1 / 6 \| 7
	353	pop hl ;1 / 9 \| 10
	354	ret ;1 / 9 \| 10 11 / 61\|67
	355
	356	endif
	357
	358
	359	end