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

	page	255
	.z80


	public mmuinit
	public bnk2log,bnk2phy,hwl2phy,phy2log
	public isv_sw

	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


;--------------------------------------------------------------------
; Trampoline for interrupt routines in banked ram.
; Switch stack pointer to "system" stack in top ram
; Save bbr

	cseg
isv_sw:					;
	ex	(sp),hl			;save hl, 'return adr' in hl
	push	de			;
	push	af			;
	ex	de,hl			;'return address' in de

  if 0
   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		;
  else
	ld	hl,0
	add	hl,sp
	ld	sp,istack
  endif
	push	hl			;save user stack pointer
	in0	h,(bbr)			;
	push	hl			;
	xor	a			;
	out0	(bbr),a			;
	ex	de,hl			;
	ld	e,(hl)			;
	inc	hl			;
	ld	d,(hl)			;
	ex	de,hl			;
	push	bc			;
	call	jphl			;

	pop	bc			;
	pop	hl			;
	out0	(bbr),h			;
	pop	hl			;
	ld	sp,hl			;
	pop	af			;
	pop	de			;
	pop	hl			;
	ei				;
	ret				;
jphl:
	jp	(hl)			;


	ds	24
istack:

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

  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
d6829fd3 L	1	page 255
	2	.z80
	3
	4
	5	public mmuinit
	6	public bnk2log,bnk2phy,hwl2phy,phy2log
	7	public isv_sw
	8
	9	include config.inc
	10	include z180reg.inc
	11
	12
	13	;----------------------------------------------------------------------
	14	; Memory Map 1:
	15	;
	16	; Common CAStart .. 0FFFF
	17	; Bank 0 00000 .. CAStart-1
	18	; Bank 1 10000 ..
	19	; Bank 2
	20	;
	21	; Memory Map 2:
	22	;
	23	; Common 18000 .. 1BFFF BANK1
	24	;
	25	; Bank 0 00000 .. 0BFFF 0
	26	; Bank 1 0C000 .. 17FFF 1*BNK_SIZE
	27	; Bank 2 1C000 .. 27FFF 2*BNK_SIZE + CMN_SIZE
	28	; Bank 3 28000 .. 33FFF 3*BNK_SIZE + CMN_SIZE
	29	; Bank n n*BNK_SIZE + (n < 2) ? 0 : CMN_SIZE
	30	;
	31	;----------------------------------------------------------------------
	32
	33	cseg
	34
	35	mmuinit:
	36	ld a,USR$CBAR
	37	out0 (cbar),a
	38	ret
	39
	40	;--------------------------------------------------------------------
	41	; Return the BBR value for the given bank number
	42	;
	43	; in a: Bank number
	44	; out a: bbr value
	45
	46	if 0 ; Memory Map 1
	47
	48	bnk2log:
	49	or a ;
	50	ret z ; Bank 0 is at physical address 0
	51
	52	dec a ;
	53	push bc ;
	54	ld c,a ;
	55	ld b,BNK_SIZE ;
	56	mlt bc ; bank size * bank number
	57	ld a,c ;
	58	add a,10h ; add bank0 + common
	59	pop bc ;
	60	ret ;
	61
	62	else ; Memory Map 2
	63
	64	bnk2log:
65	or a
66	ret z ; Bank 0 is at physical address 0
67
68	push bc
69	ld c,a ;
70	ld b,BNK_SIZE ;
71	mlt bc ; bank size * bank number
72	cp 2 ;
73	ld a,c ;
74	pop bc
75	ret c
76	add a,CMN_SIZE
77	ret
78
79	endif
80
81	if 0 ; table version
82
83	push hl
84	ld hl,bnk_table ;
85	add a,l ;
86	ld l,a ;
87	jr nc,$+3 ;
88	inc h ;
89	ld a,(hl) ;
90	pop hl
91	ret
92
93	endif
94
95	;--------------------------------------------------------------
96
97	;in hl: Log. Address
98	; a: Bank number
99	;
100	;out ahl: Phys. (linear) Address
101
102
103	bnk2phy:
104	push bc
105	ld c,a
106	ld a,h
107	and a,0f0h
108	cp CA*16
109	ld a,c
110	pop bc
111	jr c,b2p_banked
112	; address is in common
113	if 0 ; Memory Map 1
114	ld a,0 ; base is 0
115	else ; Memory Map 2
116	ld a,1 ; same as bank1
117	endif
118
119	b2p_banked:
120	call bnk2log ; get address base
121
122	; fall thru
123
124	;--------------------------------------------------------------
125	;
126	; hl: Log. Address
127	; a: Bank base (bbr)
128	;
129	; 2 0 0
130	; 0 6 8 0
131	; hl hhhhhhhhllllllll
132	; a + bbbbbbbb
133	;
134	; OP: ahl = (a<<12) + (h<<8) + l
135	;
136	;out ahl: Phys. (linear) Address
137
138	log2phy:
139	push bc ;
140	l2p_i:
141	ld c,a ;
142	ld b,16 ;
143	mlt bc ; bc = a<<4
144	ld a,c ;
145	add a,h ;
146	ld h,a ;
147	ld a,b ;
148	adc a,0 ;
149	pop bc ;
150	ret ;
151
152	;--------------------------------------------------------------
153	;
154	; hl: Log. Address
155	;
156	;
157	; OP: ahl = (bankbase<<12) + (h<<8) + l
158	;
159	;out ahl: Phys. (linear) Address
160
161
162	hwl2phy:
163	push bc ;
164	in0 c,(cbar) ;
165	ld a,h ;
166	or 00fh ; log. addr in common1?
167	cp c
168	jr c,hlp_1
169
170	in0 a,(cbr) ; yes, cbr is address base
171	jr hl2p_x
172	hlp_1:
173	ld b,16 ; log. address in baked area?
174	mlt bc
175	ld a,h
176	cp c
177	jr c,hlp_2
178	in0 a,(bbr) ; yes, bbr is address base
179	jr hl2p_x
180	hlp_2:
181	xor a ; common1
182	hl2p_x:
183	jr nz,l2p_i
184
185	pop bc ; bank part is 0, no translation
186	ret ;
187
188
189	;--------------------------------------------------------------
190	; return logical bank 0 address for given physical address.
191	;
192	; in: ahl: pyhsical addres (20 bit)
193	; out hl: logical address.
194	; logical address is in bank 0 or common, no bank number returned
195	;
196
197	phy2log:
198	or a
199	ret z
200
201	push bc
202	push hl
203	ld l,h
204	ld h,0
205	ld bc,-16*SYS$CBR
206	add hl,bc
207	ld h,l
208	pop bc
209	ld l,c
210	pop bc
211	ret
212
213	;--------------------------------------------------------------
214	; Trampoline for routines in banked ram.
215	; Switch stack pointer to "system" stack in top ram
216	; Save cbar
217	;
218	extrn bs$stack
219
220	cseg ; common!
221
222	public _b0call
223	_b0call:
224	push af
225	in0 a,(bbr)
226	jr nz,b0c_doit
227	pop af
228
229	ex (sp),hl ;16
230	push de
231	ld e,(hl)
232	inc hl
233	ld d,(hl)
234	inc hl
235	ld (b0c_fast_go),de
236	pop de
237	ex (sp),hl ;16
238	b0c_fast_go equ $+1
239	jp 0
240
241	b0c_doit:
242	ld (b0_save_hl),hl
243	ld (b0_save_de),de
244	pop hl
245	ld (b0_save_af),hl
246
247	pop de ;get ptr to 'function address' in de
248	ld hl,2
249	add hl,de
250	push hl ;put return address on stack
251
252	if 0 ; link80
253
254	ld hl,0
255	add hl,sp ;
256	ld a,h
257	cp high (bs$stack-bs$stack$size) ;link80 can't process this
258	jr nc,$ + 5 ;skip if stack allready in common bios ram
259
260	else
261
262	ld hl,bs$stack-bs$stack$size
263	ld a,h
264	dec a
265	ld hl,0
266	add hl,sp ;
267	cp h
268	jr c,$ + 5 ;skip if stack allready in common bios ram
269	endif
270	ld sp,bs$stack ;
271
272	push hl ;save user stack pointer
273
274	in0 h,(bbr) ;
275	push hl ;
276	ld hl,b0c_ret
277	push hl
278	xor a
279	out0 (bbr),a ;
280	ex de,hl ;ptr
281	ld e,(hl) ;get 'function address'
282	inc hl ;
283	ld d,(hl) ;
284	push de ;put on (switched) stack
285
286	ld hl,(b0_save_af) ;get back users registers
287	push hl
288	pop af
289	ld de,(b0_save_de)
290	ld hl,(b0_save_hl)
291	ret ;go to function
292	b0c_ret:
293	ld (b0_save_hl),hl
294
295	pop hl ;
296	out0 (bbr),h ;
297	pop hl ;
298	ld sp,hl ;
299	ld hl,(b0_save_hl)
300	ret ;
301
302
303	b0_save_hl: dw 0
304	b0_save_de: dw 0
305	b0_save_af: dw 0
306
307
308	;--------------------------------------------------------------------
309	; Trampoline for interrupt routines in banked ram.
310	; Switch stack pointer to "system" stack in top ram
311	; Save bbr
312
313	cseg
314	isv_sw: ;
315	ex (sp),hl ;save hl, 'return adr' in hl
316	push de ;
317	push af ;
318	ex de,hl ;'return address' in de
319
320	if 0
321	if 0 ; link80
322
323	ld hl,0
324	add hl,sp ;
325	ld a,h
326	cp high (bs$stack-bs$stack$size) ;link80 can't process this
327	jr nc,$ + 5 ;skip if stack allready in common bios ram
328
329	else
330
331	ld hl,bs$stack-bs$stack$size
332	ld a,h
333	dec a
334	ld hl,0
335	add hl,sp ;
336	cp h
337	jr c,$ + 5 ;skip if stack allready in common bios ram
338	endif
339	ld sp,bs$stack ;
340	else
341	ld hl,0
342	add hl,sp
343	ld sp,istack
344	endif
345	push hl ;save user stack pointer
346	in0 h,(bbr) ;
347	push hl ;
348	xor a ;
349	out0 (bbr),a ;
350	ex de,hl ;
351	ld e,(hl) ;
352	inc hl ;
353	ld d,(hl) ;
354	ex de,hl ;
355	push bc ;
356	call jphl ;
357
358	pop bc ;
359	pop hl ;
360	out0 (bbr),h ;
361	pop hl ;
362	ld sp,hl ;
363	pop af ;
364	pop de ;
365	pop hl ;
366	ei ;
367	ret ;
368	jphl:
369	jp (hl) ;
370
371
372	ds 24
373	istack:
374
375	;====================================================================
376
377	if 0
378
379	;--------------------------------------------------------------------
380	; Return the BBR value for the given bank number
381
382	bnk2bbr:
383	or a ; 4
384	ret z ; 5/10 \| 11 14
385
386	push bc ;11 \| 11
387	ld b,a ; 4
388	ld c,CA ; 6
389	mlt bc ;17 >45
390	ld a,c ; 4
391	add a,10h ; 6
392	pop bc ; 9 \| 10
393	ret ; 9 \| 10 76
394
395	push ix ;2 / 14 \| 15
396	ld ix,bnktbl ;4 / 12 \| 14
397	ld ($+3+2),a ;3 / 15 \| 19
398	ld a,(ix+0) ;3 / 14 \| 19
399	pop ix ;2 / 12 \| 14
400	ret ;1 / 9 \| 10 15 / 76\|91
401
402	push hl ;1 / 11 \| 11
403	ld hl,bnktbl ;3 / 9 \| 10
404	add a,l ;1 / 4 \| 4
405	ld l,a ;1 / 4 \| 4
406	ld a,0 ;1 / 6 \| 7
407	adc a,h ;1 / 4 \| 4
408	ld h,a ;1 / 4 \| 4
409	ld a,(hl) ;1 / 6 \| 7
410	pop hl ;1 / 9 \| 10
411	ret ;1 / 9 \| 10 12 / 66\|71
412
413	push hl ;1 / 11 \| 11
414	add a,low bnktbl ;2 / 6 \| 7
415	ld l,a ;1 / 4 \| 4
416	ld a,0 ;1 / 6 \| 7
417	adc a,high bnktbl ;2 / 6 \| 7
418	ld h,a ;1 / 4 \| 4
419	ld a,(hl) ;1 / 6 \| 7
420	pop hl ;1 / 9 \| 10
421	ret ;1 / 9 \| 10 11 / 61\|67
422
423	endif
424
425
426	end