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

	title	'LDRBIOS for CP/M 3.0'\r
\r
    ; Port Address Equates\r
\r
	include config.inc\r
	include z180reg.inc\r
\r
\r
    ; IDE Task File Register Definitions\r
\r
IDEDat	equ	IDEBASE+0	; Data Register\r
IDEErr	equ	IDEBASE+1	; Error Register\r
IDEFeat	equ	IDEBASE+1	; Feature Register\r
IDESCnt	equ	IDEBASE+2	; Sector Count\r
IDESNum	equ	IDEBASE+3	; Sector Number\r
IDECLo	equ	IDEBASE+4	; Cylinder Low\r
IDECHi	equ	IDEBASE+5	; Cylinder High\r
IDESDH	equ	IDEBASE+6	; Drive and Head\r
IDECmd	equ	IDEBASE+7	; Command / Status\r
\r
    ; IDE Hard disk commands:\r
\r
CmdHome	equ	10h		; Recalibrate\r
CmdRd	equ	20h		; Read Sector\r
CmdWr	equ	30h		; Write Sector\r
CmdInit	equ	91h		; Initialize Drive Params\r
CmdId	equ	0ECh		; Read ID\r
CmdSF	equ	0EFh		; Set Feature\r
\r
    ; Partition Table Structures\r
\r
PART_TYPE	equ	4\r
PART_START	equ	8\r
PART_SIZE	equ	12\r
\r
    ; Partition table id\r
    ; (see http://www.win.tue.nl/~aeb/partitions/partition_types-1.html)\r
\r
PARTID1_FAT16	equ	00EH\r
PARTID2_FAT16	equ	006H\r
PARTID_CPM	equ	052H\r
\r
\r
TIMEOUT	equ	1000\r
\r
cr	equ 13\r
lf	equ 10\r
\r
\r
	.z80\r
	cseg\r
\r
    ; BIOS Jump vector.\r
\r
?boot:	jp boot         ; initial entry on cold start\r
?wboot:	jp wboot	; reentry on program exit, warm start\r
\r
?const:	jp const	; return console input status\r
?conin:	jp conin	; return console input character\r
?cono:	jp conout	; send console output character\r
?list:	jp list 	; send list output character\r
?auxo:	jp auxout	; send auxilliary output character\r
?auxi:	jp auxin	; return auxilliary input character\r
\r
?home:	jp home 	; set disks to logical home\r
?sldsk:	jp seldsk	; select disk drive, return disk parameter info\r
?sttrk:	jp settrk	; set disk track\r
?stsec:	jp setsec	; set disk sector\r
?stdma:	jp setdma	; set disk I/O memory address\r
?read:	jp read 	; read physical block(s)\r
?write:	jp write	; write physical block(s)\r
\r
?lists:	jp listst	; return list device status\r
?sctrn:	jp sectrn	; translate logical to physical sector\r
\r
?conos:	jp conost	; return console output status\r
?auxis:	jp auxist	; return aux input status\r
?auxos:	jp auxost	; return aux output status\r
?dvtbl:	jp devtbl	; return address of device def table\r
?devin:	jp cinit	; change baud rate of device\r
\r
?drtbl:	jp getdrv	; return address of disk drive table\r
?mltio:	jp multio	; set multiple record count for disk I/O\r
?flush:	jp flush	; flush BIOS maintained disk caching\r
\r
?mov:	jp move 	; block move memory to memory\r
?tim:	jp time 	; Signal Time and Date operation\r
?bnksl:	jp bnksel	; select bank for code execution and default DMA\r
?stbnk:	jp setbnk	; select different bank for disk I/O DMA operations.\r
?xmov:	jp xmove	; set source and destination banks for one operation\r
\r
	jp 0		; reserved for future expansion\r
	jp 0		; reserved for future expansion\r
	jp 0		; reserved for future expansion\r
\r
;----------------------------------------------------------------------\r
\r
hwini_tab:\r
	db	(hwini0_e-$)/2	;count\r
	db	rcr,CREFSH	;configure DRAM refresh\r
	db	dcntl,CWAITIO	;wait states\r
	db	ccr,M_NCD	;No Clock Divide\r
	db	cmr,PHI_X2	;X2 Clock Multiplier\r
	db	omcr,~M_IOC	;Operation Mode Control Register\r
				;MMU\r
	db	cbr,SYS$CBR	;Common Base Register\r
	db	cbar,USR$CBAR	;Common Base Area Register\r
				;ASCI0\r
	db	asext1,0	;disable BRG\r
	db	stat1,00000000b	;disable RX, TX interrupt, disable CTS1\r
	db	cntlb1,10000000b;PS:10 DR:16 Rate:1  --> BR = Phi/160\r
	db	cntla1,01100101b;RE TE RTS:0 8N2\r
hwini0_e:\r
	db	0		;stop mark\r
	db	0,0,0,0,0,0,0,0	;\r
\r
msg_boot:\r
	db cr,lf,'CPMLDR error: Unable to locate CP/M partition',cr,lf,0\r
\r
;-------------------------------------------------------------------------------\r
\r
    ; CP/M 3 Disk definition macros\r
\r
	maclib cpm3slr.lib	; dpb mcaro\r
\r
    ; The dph macro from the lib depends on GENCPM\r
\r
dphldr macro ?trans,?dpb,?csize,?asize,?dirbcb,?dtabcb\r
    local ?csv,?alv\r
	dw ?trans		; translate table address\r
	db 0,0,0,0,0,0,0,0,0	; BDOS Scratch area\r
	db 0			; media flag\r
	dw ?dpb			; disk parameter block\r
    if nul ?csize\r
	dw 0			; permanently mounted, no checksum vector\r
    else\r
     if ?csize = 0\r
	dw 0\r
     else\r
	dw ?csv			; checksum vector\r
     endif\r
    endif\r
    if nul ?asize\r
	dw 0			; no alloc vector\r
    else\r
     if ?asize = 0\r
	dw 0\r
     else\r
	dw ?alv			; allocation vector\r
     endif\r
    endif\r
	dw ?dirbcb\r
	dw ?dtabcb\r
	dw 0ffffh		; no hash\r
	db 0			; hash bank\r
    if not nul ?csize\r
     if ?csize <> 0\r
?csv	ds	?csize		; checksum vector\r
     endif\r
    endif\r
    if not nul ?asize\r
     if ?asize <> 0\r
?alv	ds	?asize		; allocation vector\r
     endif\r
    endif\r
    endm\r
\r
;-------------------------------------------------------------------------------\r
\r
	; dphldr translate$table,	- disk parameter header\r
	;	 disk$parameter$block,\r
	;	 checksum$size,			(optional)\r
	;	 alloc$size			(optional)\r
	;	 dir$bcb\r
	;	 data$bcb\r
dph0:\r
	dphldr 0,dpbsimhd512,0,0,bcb,bcb\r
\r
bcb:\r
	db	0ffh\r
	rept 9\r
	 db	0\r
	endm\r
	dw	buffer\r
\r
	; dpb	physical$sector$size,	- disk parameter block\r
	;	physical$sectors$per$track,\r
	;	number$tracks,\r
	;	block$size,\r
	;	number$dir$entries,\r
	;	track$offset,\r
	;	checksum$vec$size		(optional)\r
\r
dpbsimhd512:\r
	dpb 512,8,2048,4096,1024,6,8000h\r
\r
;-------------------------------------------------------------------------------\r
\r
wboot:                  ; jump vector locations not used\r
const:\r
conin:\r
list:\r
auxout:\r
auxin:\r
write:\r
listst:\r
conost:\r
auxist:\r
auxost:\r
devtbl:\r
cinit:\r
getdrv:\r
multio:\r
flush:\r
time:\r
bnksel:\r
setbnk:\r
xmove:\r
	ret\r
\r
;-------------------------------------------------------------------------------\r
; output bytes to ports\r
;\r
;     hl: tables of port,value pairs:\r
;         db n, port1,val1, port2,val2,... portn,valn\r
;         ...\r
;         db 0 ; Terminate table\r
\r
ioini1l:\r
	push	bc\r
	jr	io1_nxt\r
io1_lp:\r
	ld	c,(hl)		;port address\r
	inc	hl\r
	otim\r
	jr	nz,io1_lp\r
io1_nxt:\r
	ld	b,(hl)		;count\r
	inc	hl\r
	inc	b\r
	djnz	io1_lp\r
\r
	pop	bc\r
	ret\r
\r
;-------------------------------------------------------------------------------\r
; print message @<HL> up to a null\r
\r
?pmsg:\r
	ld a,(hl)\r
	or a\r
	ret z\r
	ld c,a\r
	push hl\r
	call ?cono\r
	pop hl\r
	inc hl\r
	jr ?pmsg\r
\r
;-------------------------------------------------------------------------------\r
\r
boot:\r
	; Init CPU, MMU, ASCI0\r
\r
	ld	hl,hwini_tab\r
	call	ioini1l\r
\r
	; Init disk partition\r
\r
	call	read_parttbl\r
	or	a\r
	jr	nz,boot_err\r
\r
	; check_signature\r
\r
	ld	hl,buffer+512-1\r
	ld	a,0aah\r
	cp	(hl)			; Test, if it has a valid MBR\r
	jr	nz,boot_err\r
	dec	hl\r
	cpl				; a=055h\r
	cp	(hl)			;\r
	jr	nz,boot_err\r
\r
	; Find CP/M paartition\r
	; Look for first CP/M partition and save partition offset\r
\r
	ld	hl,buffer+512-2-64+PART_TYPE	; Point to  partition type of first first partition table entry\r
	ld	de,16\r
	ld	b,4			; Max # of partition table entries\r
ploop:\r
	ld	a,PARTID_CPM\r
	sub	(HL)			; Test for CP/M Partition\r
	jr	nz,pnext\r
	ld	bc,4\r
	add	hl,bc			; Point to partition start (lba)\r
	ld	de,ptab_start\r
	ldir\r
	ret				;a=0\r
\r
pnext:\r
	add	hl,de\r
	djnz	ploop\r
\r
boot_err:\r
	ld	hl,msg_boot\r
	call	?pmsg\r
halt_loop:\r
	halt\r
	jr	halt_loop\r
\r
;-------------------------------------------------------------------------------\r
\r
conout:\r
	in0	a,(stat1)\r
	and	M_TDRE\r
	jr	z,conout\r
	out0	(tdr1),c\r
	ld	a,c\r
	ret\r
\r
;-------------------------------------------------------------------------------\r
\r
move:\r
	ex de,hl                ; we are passed source in DE and dest in HL\r
	ldir                    ; use Z80 block move instruction\r
	ex de,hl                ; need next addresses in same regs\r
	ret\r
\r
;-------------------------------------------------------------------------------\r
; Select Disk Drive.\r
; Return address of disk parameter header in <HL>\r
\r
seldsk:\r
	ld hl,dph0\r
	ret\r
\r
; Home selected drive.  Treated as SETTRK(0).\r
\r
home:\r
	ld	bc,0		; same as set track zero\r
\r
; Set Track. Saves track address from <BC> in @trk.\r
\r
settrk:\r
	ld	(@trk),bc\r
	ret\r
\r
; Set Sector.  Saves sector number from <BC> in @sect.\r
\r
setsec:\r
	ld	(@sect),bc\r
	ret\r
\r
; Set Disk Memory Address.  Saves DMA address from <BC> in @dma.\r
\r
setdma:\r
	ld	(@dma),bc\r
	ret\r
\r
; Translate sector address. Not needed. Return physical=logical.\r
\r
sectrn:\r
	ld	l,c\r
	ld	h,b\r
	ret\r
\r
;-----------------------------------------------------------------\r
\r
chk_to:\r
	xor	a	;\r
to_l:\r
	dec	a\r
	jr	nz,to_l	;\r
	dec	hl	; 4\r
	ld	a,h	; 4\r
	or	l	; 4\r
	ret	nz	; 10/5\r
	ccf		; 3\r
	ret		; 9\r
\r
;-------------------------------------------------------------------------------\r
; Wait for ready signal with time out\r
;     return:\r
;	 a = 0 if ok\r
;	 a = ff if timeout\r
\r
wait_rdy_to:\r
	push	hl\r
	ld	hl,TIMEOUT\r
wrdy_l:\r
	in	a,(IdeCmd)\r
	xor	01000000b\r
	and	11000000b	; clears carry\r
	jr	z,wrdy_e\r
	call	chk_to\r
	jr	nc,wrdy_l\r
wrdy_e:\r
	pop	hl\r
	sbc	a,a\r
	ret\r
\r
\r
;-------------------------------------------------------------------------------\r
\r
do_ide_cmd:\r
	out	(IdeCmd),a	;\r
	call	wait_rdy_to\r
	ret	c\r
	in	a,(IdeCmd)\r
	and	10001001b	;\r
	ret\r
\r
\r
;-------------------------------------------------------------------------------\r
; Read partition table\r
\r
read_parttbl:\r
	ld	hl,ptab_start\r
	ld	b,8\r
rp_l:\r
	ld	(hl),0\r
	inc	hl\r
	djnz	rp_l\r
\r
	ld	hl,buffer\r
	ld	(@dma),hl\r
\r
;	fall thru\r
\r
;-------------------------------------------------------------------------------\r
; Read a sector\r
\r
; compute logical block number (lba) --> cf-controller\r
\r
	; TODO: sectors per track from dpb\r
	; lba = track * 8 + sector\r
\r
read:\r
	ld	iy,ptab_start\r
	xor	a\r
	ld	hl,(@trk)\r
	add	hl,hl\r
	adc	a,a		; *2\r
	add	hl,hl\r
	adc	a,a		; *4\r
	add	hl,hl\r
	adc	a,a		; *8\r
	ld	de,(@sect)\r
	add	hl,de\r
	adc	a,0\r
	ld	e,a\r
	call	wait_rdy_to\r
	ld	a,(iy+0)	; add partition start\r
	add	a,l\r
	out	(IdeSNum),a\r
	ld	a,(iy+1)\r
	adc	a,h\r
	out	(IdeCLo),a\r
	ld	a,(iy+2)\r
	adc	a,e\r
	out	(IdeCHi),a\r
	ld	a,(iy+3)\r
	adc	a,0\r
	and	00FH\r
	or	0E0H\r
	out	(IdeSDH),a\r
	ld	hl,(@dma)\r
\r
	ld	a,1		; number of sectors to read\r
	out	(IdeSCnt),a	; set sector count\r
\r
	ld	a,CmdRd\r
	out	(IdeCmd),a	; command: read sector data\r
	ld	bc,IdeDat	; I/O address\r
wdrq:\r
	in	a,(IdeCmd)	; wait for DRQ to become active\r
	bit	3,a\r
	jr	z,wdrq\r
	inir			; read 512 data bytes (2 x 256)\r
	inir\r
wnb:				; wait while busy\r
	in	a,(IdeCmd)	;\r
	rlca\r
	jr	c,wnb\r
	rrca			; restore status\r
	and	10001001b	; Busy, DRQ, or Error?\r
	ret	z		; return 0, if everything is ok\r
	ld	a,1\r
	ret\r
\r
;-------------------------------------------------------------------------------\r
\r
ptab_start:\r
	dw	0,0\r
@trk:	dw	0\r
@sect:	dw	0\r
@dma:	dw	0\r
\r
buffer:\r
	end\r
Commit	Line	Data
88c783bb L	1	title 'LDRBIOS for CP/M 3.0'\r
	2	\r
	3	; Port Address Equates\r
	4	\r
	5	include config.inc\r
	6	include z180reg.inc\r
	7	\r
	8	\r
	9	; IDE Task File Register Definitions\r
	10	\r
	11	IDEDat equ IDEBASE+0 ; Data Register\r
	12	IDEErr equ IDEBASE+1 ; Error Register\r
	13	IDEFeat equ IDEBASE+1 ; Feature Register\r
	14	IDESCnt equ IDEBASE+2 ; Sector Count\r
	15	IDESNum equ IDEBASE+3 ; Sector Number\r
	16	IDECLo equ IDEBASE+4 ; Cylinder Low\r
	17	IDECHi equ IDEBASE+5 ; Cylinder High\r
	18	IDESDH equ IDEBASE+6 ; Drive and Head\r
	19	IDECmd equ IDEBASE+7 ; Command / Status\r
	20	\r
	21	; IDE Hard disk commands:\r
	22	\r
	23	CmdHome equ 10h ; Recalibrate\r
	24	CmdRd equ 20h ; Read Sector\r
	25	CmdWr equ 30h ; Write Sector\r
	26	CmdInit equ 91h ; Initialize Drive Params\r
	27	CmdId equ 0ECh ; Read ID\r
	28	CmdSF equ 0EFh ; Set Feature\r
	29	\r
	30	; Partition Table Structures\r
	31	\r
	32	PART_TYPE equ 4\r
	33	PART_START equ 8\r
	34	PART_SIZE equ 12\r
	35	\r
	36	; Partition table id\r
	37	; (see http://www.win.tue.nl/~aeb/partitions/partition_types-1.html)\r
	38	\r
	39	PARTID1_FAT16 equ 00EH\r
	40	PARTID2_FAT16 equ 006H\r
	41	PARTID_CPM equ 052H\r
	42	\r
	43	\r
	44	TIMEOUT equ 1000\r
	45	\r
	46	cr equ 13\r
	47	lf equ 10\r
	48	\r
	49	\r
	50	.z80\r
	51	cseg\r
	52	\r
	53	; BIOS Jump vector.\r
	54	\r
	55	?boot: jp boot ; initial entry on cold start\r
	56	?wboot: jp wboot ; reentry on program exit, warm start\r
	57	\r
	58	?const: jp const ; return console input status\r
	59	?conin: jp conin ; return console input character\r
	60	?cono: jp conout ; send console output character\r
	61	?list: jp list ; send list output character\r
	62	?auxo: jp auxout ; send auxilliary output character\r
	63	?auxi: jp auxin ; return auxilliary input character\r
	64	\r
65	?home: jp home ; set disks to logical home\r
66	?sldsk: jp seldsk ; select disk drive, return disk parameter info\r
67	?sttrk: jp settrk ; set disk track\r
68	?stsec: jp setsec ; set disk sector\r
69	?stdma: jp setdma ; set disk I/O memory address\r
70	?read: jp read ; read physical block(s)\r
71	?write: jp write ; write physical block(s)\r
72	\r
73	?lists: jp listst ; return list device status\r
74	?sctrn: jp sectrn ; translate logical to physical sector\r
75	\r
76	?conos: jp conost ; return console output status\r
77	?auxis: jp auxist ; return aux input status\r
78	?auxos: jp auxost ; return aux output status\r
79	?dvtbl: jp devtbl ; return address of device def table\r
80	?devin: jp cinit ; change baud rate of device\r
81	\r
82	?drtbl: jp getdrv ; return address of disk drive table\r
83	?mltio: jp multio ; set multiple record count for disk I/O\r
84	?flush: jp flush ; flush BIOS maintained disk caching\r
85	\r
86	?mov: jp move ; block move memory to memory\r
87	?tim: jp time ; Signal Time and Date operation\r
88	?bnksl: jp bnksel ; select bank for code execution and default DMA\r
89	?stbnk: jp setbnk ; select different bank for disk I/O DMA operations.\r
90	?xmov: jp xmove ; set source and destination banks for one operation\r
91	\r
92	jp 0 ; reserved for future expansion\r
93	jp 0 ; reserved for future expansion\r
94	jp 0 ; reserved for future expansion\r
95	\r
96	;----------------------------------------------------------------------\r
97	\r
98	hwini_tab:\r
99	db (hwini0_e-$)/2 ;count\r
100	db rcr,CREFSH ;configure DRAM refresh\r
101	db dcntl,CWAITIO ;wait states\r
102	db ccr,M_NCD ;No Clock Divide\r
103	db cmr,PHI_X2 ;X2 Clock Multiplier\r
104	db omcr,~M_IOC ;Operation Mode Control Register\r
105	;MMU\r
106	db cbr,SYS$CBR ;Common Base Register\r
107	db cbar,USR$CBAR ;Common Base Area Register\r
108	;ASCI0\r
109	db asext1,0 ;disable BRG\r
110	db stat1,00000000b ;disable RX, TX interrupt, disable CTS1\r
111	db cntlb1,10000000b;PS:10 DR:16 Rate:1 --> BR = Phi/160\r
112	db cntla1,01100101b;RE TE RTS:0 8N2\r
113	hwini0_e:\r
114	db 0 ;stop mark\r
115	db 0,0,0,0,0,0,0,0 ;\r
116	\r
117	msg_boot:\r
118	db cr,lf,'CPMLDR error: Unable to locate CP/M partition',cr,lf,0\r
119	\r
120	;-------------------------------------------------------------------------------\r
121	\r
122	; CP/M 3 Disk definition macros\r
123	\r
124	maclib cpm3slr.lib ; dpb mcaro\r
125	\r
126	; The dph macro from the lib depends on GENCPM\r
127	\r
128	dphldr macro ?trans,?dpb,?csize,?asize,?dirbcb,?dtabcb\r
129	local ?csv,?alv\r
130	dw ?trans ; translate table address\r
131	db 0,0,0,0,0,0,0,0,0 ; BDOS Scratch area\r
132	db 0 ; media flag\r
133	dw ?dpb ; disk parameter block\r
134	if nul ?csize\r
135	dw 0 ; permanently mounted, no checksum vector\r
136	else\r
137	if ?csize = 0\r
138	dw 0\r
139	else\r
140	dw ?csv ; checksum vector\r
141	endif\r
142	endif\r
143	if nul ?asize\r
144	dw 0 ; no alloc vector\r
145	else\r
146	if ?asize = 0\r
147	dw 0\r
148	else\r
149	dw ?alv ; allocation vector\r
150	endif\r
151	endif\r
152	dw ?dirbcb\r
153	dw ?dtabcb\r
154	dw 0ffffh ; no hash\r
155	db 0 ; hash bank\r
156	if not nul ?csize\r
157	if ?csize <> 0\r
158	?csv ds ?csize ; checksum vector\r
159	endif\r
160	endif\r
161	if not nul ?asize\r
162	if ?asize <> 0\r
163	?alv ds ?asize ; allocation vector\r
164	endif\r
165	endif\r
166	endm\r
167	\r
168	;-------------------------------------------------------------------------------\r
169	\r
170	; dphldr translate$table, - disk parameter header\r
171	; disk$parameter$block,\r
172	; checksum$size, (optional)\r
173	; alloc$size (optional)\r
174	; dir$bcb\r
175	; data$bcb\r
176	dph0:\r
177	dphldr 0,dpbsimhd512,0,0,bcb,bcb\r
178	\r
179	bcb:\r
180	db 0ffh\r
181	rept 9\r
182	db 0\r
183	endm\r
184	dw buffer\r
185	\r
186	; dpb physical$sector$size, - disk parameter block\r
187	; physical$sectors$per$track,\r
188	; number$tracks,\r
189	; block$size,\r
190	; number$dir$entries,\r
191	; track$offset,\r
192	; checksum$vec$size (optional)\r
193	\r
194	dpbsimhd512:\r
195	dpb 512,8,2048,4096,1024,6,8000h\r
196	\r
197	;-------------------------------------------------------------------------------\r
198	\r
199	wboot: ; jump vector locations not used\r
200	const:\r
201	conin:\r
202	list:\r
203	auxout:\r
204	auxin:\r
205	write:\r
206	listst:\r
207	conost:\r
208	auxist:\r
209	auxost:\r
210	devtbl:\r
211	cinit:\r
212	getdrv:\r
213	multio:\r
214	flush:\r
215	time:\r
216	bnksel:\r
217	setbnk:\r
218	xmove:\r
219	ret\r
220	\r
221	;-------------------------------------------------------------------------------\r
222	; output bytes to ports\r
223	;\r
224	; hl: tables of port,value pairs:\r
225	; db n, port1,val1, port2,val2,... portn,valn\r
226	; ...\r
227	; db 0 ; Terminate table\r
228	\r
229	ioini1l:\r
230	push bc\r
231	jr io1_nxt\r
232	io1_lp:\r
233	ld c,(hl) ;port address\r
234	inc hl\r
235	otim\r
236	jr nz,io1_lp\r
237	io1_nxt:\r
238	ld b,(hl) ;count\r
239	inc hl\r
240	inc b\r
241	djnz io1_lp\r
242	\r
243	pop bc\r
244	ret\r
245	\r
246	;-------------------------------------------------------------------------------\r
247	; print message @<HL> up to a null\r
248	\r
249	?pmsg:\r
250	ld a,(hl)\r
251	or a\r
252	ret z\r
253	ld c,a\r
254	push hl\r
255	call ?cono\r
256	pop hl\r
257	inc hl\r
258	jr ?pmsg\r
259	\r
260	;-------------------------------------------------------------------------------\r
261	\r
262	boot:\r
263	; Init CPU, MMU, ASCI0\r
264	\r
265	ld hl,hwini_tab\r
266	call ioini1l\r
267	\r
268	; Init disk partition\r
269	\r
270	call read_parttbl\r
271	or a\r
272	jr nz,boot_err\r
273	\r
274	; check_signature\r
275	\r
276	ld hl,buffer+512-1\r
277	ld a,0aah\r
278	cp (hl) ; Test, if it has a valid MBR\r
279	jr nz,boot_err\r
280	dec hl\r
281	cpl ; a=055h\r
282	cp (hl) ;\r
283	jr nz,boot_err\r
284	\r
285	; Find CP/M paartition\r
286	; Look for first CP/M partition and save partition offset\r
287	\r
288	ld hl,buffer+512-2-64+PART_TYPE ; Point to partition type of first first partition table entry\r
289	ld de,16\r
290	ld b,4 ; Max # of partition table entries\r
291	ploop:\r
292	ld a,PARTID_CPM\r
293	sub (HL) ; Test for CP/M Partition\r
294	jr nz,pnext\r
295	ld bc,4\r
296	add hl,bc ; Point to partition start (lba)\r
297	ld de,ptab_start\r
298	ldir\r
299	ret ;a=0\r
300	\r
301	pnext:\r
302	add hl,de\r
303	djnz ploop\r
304	\r
305	boot_err:\r
306	ld hl,msg_boot\r
307	call ?pmsg\r
308	halt_loop:\r
309	halt\r
310	jr halt_loop\r
311	\r
312	;-------------------------------------------------------------------------------\r
313	\r
314	conout:\r
315	in0 a,(stat1)\r
316	and M_TDRE\r
317	jr z,conout\r
318	out0 (tdr1),c\r
319	ld a,c\r
320	ret\r
321	\r
322	;-------------------------------------------------------------------------------\r
323	\r
324	move:\r
325	ex de,hl ; we are passed source in DE and dest in HL\r
326	ldir ; use Z80 block move instruction\r
327	ex de,hl ; need next addresses in same regs\r
328	ret\r
329	\r
330	;-------------------------------------------------------------------------------\r
331	; Select Disk Drive.\r
332	; Return address of disk parameter header in <HL>\r
333	\r
334	seldsk:\r
335	ld hl,dph0\r
336	ret\r
337	\r
338	; Home selected drive. Treated as SETTRK(0).\r
339	\r
340	home:\r
341	ld bc,0 ; same as set track zero\r
342	\r
343	; Set Track. Saves track address from <BC> in @trk.\r
344	\r
345	settrk:\r
346	ld (@trk),bc\r
347	ret\r
348	\r
349	; Set Sector. Saves sector number from <BC> in @sect.\r
350	\r
351	setsec:\r
352	ld (@sect),bc\r
353	ret\r
354	\r
355	; Set Disk Memory Address. Saves DMA address from <BC> in @dma.\r
356	\r
357	setdma:\r
358	ld (@dma),bc\r
359	ret\r
360	\r
361	; Translate sector address. Not needed. Return physical=logical.\r
362	\r
363	sectrn:\r
364	ld l,c\r
365	ld h,b\r
366	ret\r
367	\r
368	;-----------------------------------------------------------------\r
369	\r
370	chk_to:\r
371	xor a ;\r
372	to_l:\r
373	dec a\r
374	jr nz,to_l ;\r
375	dec hl ; 4\r
376	ld a,h ; 4\r
377	or l ; 4\r
378	ret nz ; 10/5\r
379	ccf ; 3\r
380	ret ; 9\r
381	\r
382	;-------------------------------------------------------------------------------\r
383	; Wait for ready signal with time out\r
384	; return:\r
385	; a = 0 if ok\r
386	; a = ff if timeout\r
387	\r
388	wait_rdy_to:\r
389	push hl\r
390	ld hl,TIMEOUT\r
391	wrdy_l:\r
392	in a,(IdeCmd)\r
393	xor 01000000b\r
394	and 11000000b ; clears carry\r
395	jr z,wrdy_e\r
396	call chk_to\r
397	jr nc,wrdy_l\r
398	wrdy_e:\r
399	pop hl\r
400	sbc a,a\r
401	ret\r
402	\r
403	\r
404	;-------------------------------------------------------------------------------\r
405	\r
406	do_ide_cmd:\r
407	out (IdeCmd),a ;\r
408	call wait_rdy_to\r
409	ret c\r
410	in a,(IdeCmd)\r
411	and 10001001b ;\r
412	ret\r
413	\r
414	\r
415	;-------------------------------------------------------------------------------\r
416	; Read partition table\r
417	\r
418	read_parttbl:\r
419	ld hl,ptab_start\r
420	ld b,8\r
421	rp_l:\r
422	ld (hl),0\r
423	inc hl\r
424	djnz rp_l\r
425	\r
426	ld hl,buffer\r
427	ld (@dma),hl\r
428	\r
429	; fall thru\r
430	\r
431	;-------------------------------------------------------------------------------\r
432	; Read a sector\r
433	\r
434	; compute logical block number (lba) --> cf-controller\r
435	\r
436	; TODO: sectors per track from dpb\r
437	; lba = track * 8 + sector\r
438	\r
439	read:\r
440	ld iy,ptab_start\r
441	xor a\r
442	ld hl,(@trk)\r
443	add hl,hl\r
444	adc a,a ; *2\r
445	add hl,hl\r
446	adc a,a ; *4\r
447	add hl,hl\r
448	adc a,a ; *8\r
449	ld de,(@sect)\r
450	add hl,de\r
451	adc a,0\r
452	ld e,a\r
453	call wait_rdy_to\r
454	ld a,(iy+0) ; add partition start\r
455	add a,l\r
456	out (IdeSNum),a\r
457	ld a,(iy+1)\r
458	adc a,h\r
459	out (IdeCLo),a\r
460	ld a,(iy+2)\r
461	adc a,e\r
462	out (IdeCHi),a\r
463	ld a,(iy+3)\r
464	adc a,0\r
465	and 00FH\r
466	or 0E0H\r
467	out (IdeSDH),a\r
468	ld hl,(@dma)\r
469	\r
470	ld a,1 ; number of sectors to read\r
471	out (IdeSCnt),a ; set sector count\r
472	\r
473	ld a,CmdRd\r
474	out (IdeCmd),a ; command: read sector data\r
475	ld bc,IdeDat ; I/O address\r
476	wdrq:\r
477	in a,(IdeCmd) ; wait for DRQ to become active\r
478	bit 3,a\r
479	jr z,wdrq\r
480	inir ; read 512 data bytes (2 x 256)\r
481	inir\r
482	wnb: ; wait while busy\r
483	in a,(IdeCmd) ;\r
484	rlca\r
485	jr c,wnb\r
486	rrca ; restore status\r
487	and 10001001b ; Busy, DRQ, or Error?\r
488	ret z ; return 0, if everything is ok\r
489	ld a,1\r
490	ret\r
491	\r
492	;-------------------------------------------------------------------------------\r
493	\r
494	ptab_start:\r
495	dw 0,0\r
496	@trk: dw 0\r
497	@sect: dw 0\r
498	@dma: dw 0\r
499	\r
500	buffer:\r
501	end\r