.Z80
;***************************************************************
;File:  IDEGEN.MAC
;Purp:  Utility to write OS image to hard disk on Davidge DSB
;	4/6 machines with RehDesign GIDE interface
;Auth:  John D. Baker
;
; Revision History:
;
; 26 January 1996  (JDB)
;	Completed additions to read system image from reserved
;	tracks of IDE hard disk.
;
; 24 January 1996  (JDB)
;	Completed functions to read in a system image from file
;	and select which "disk" is to have image written to it.
;
; 19 January 1996  (JDB)
;	Created.

; Definition of used I/O addresses:

GIDE	equ	20h		; base address of GIDE board

IdeDOR	equ	GIDE+6		; Digital Output Register
IdeDat	equ	GIDE+8		; Data Register
IdeErr	equ	GIDE+9		; Error Register
IdeWrPc	equ	IdeErr		; Write Precomp REgister
IdeSCnt	equ	GIDE+0Ah	; Sector Count
IdeSNum	equ	GIDE+0Bh	; Sector Number
IdeCLo	equ	GIDE+0Ch	; Cylinder Low
IdeCHi	equ	GIDE+0Dh	; Cylinder High
IdeSDH	equ	GIDE+0Eh	; Drive and Head
IdeCmd	equ	GIDE+0Fh	; Command
IdeStat	equ	IdeCmd		; Status

; Commands for IDE hard disk drives:

CmdRd	equ	20h		; Read Sector
CmdWr	equ	30h		; Write Sector

; CP/M equates:

bdos	equ	5		;call here...
fcb0	equ	5ch		;first file control block
fcb1	equ	fcb0+10h	;second file control block
currec	equ	fcb0+20h	;current record
r0	equ	currec+1	;random 0
r1	equ	r0+1		;random 1
r2	equ	r1+1		;random 2
tbuff	equ	80h		;default dma/command tail buffer


;CP/M functions:

boot	equ	0	;total system reset (warm boot)
conin	equ	1	;console input
conout	equ	2	;console output
prntstr	equ	9	;CP/M print string
constat	equ	11	;console status
openf	equ	15	;open file
closef	equ	16	;close file
srchf	equ	17	;search for first
srchn	equ	18	;search for next
rdseq	equ	20	;read sequential
setdma	equ	26	;set dma buffer


; host disk params:

hstsiz	equ	512	;bytes per host sector
offset	equ	2	;number of reserved tracks

stktop	equ	0780h	;this is as large as we can be
hstbuf	equ	stktop	;if we want to allow a 512-byte boot sector


	aseg

	org	0100h

	ld	sp,stktop	;can't get bigger than this
;
	ld	hl,hstbuf	;start host buffer here
	ld	(adrhst),hl	;set it up
	ld	hl,0000
	ld	(hsttrk),hl	;cylinder 0
	ld	a,1
	ld	(hstsec),a	;sector 1
	xor	a		;0 in A
cnthds:
	ld	(hstdsk),a	;start at head 0
	call	ReadHst		;read a sector
	jr	nz,cnterr	;jrif an error
	ld	a,(hstdsk)	;get head
	inc	a		;bump to next
	jr	cnthds		;and go to next
;
cnterr:			;actually, we don't care about error type
	ld	a,(hstdsk)	;get disk number
	dec	a		;normalize to 0
	cp	0ah		;bigger than 9?
	jr	c,cnter1	;skip if <=9
	add	a,7		;bump to letters
cnter1:
	add	a,'0'		;make ASCII
	ld	(srcmxh),a	;store in source message
	ld	(dstmxh),a	;and in destination message
;
;
	ld	de,signon	;point at message
	ld	c,prntstr	;print it
	call	bdos
;
	ld	a,(tbuff)	;check for command tail
	or	a		;set flags
	jr	z,plain		;jump if no system file specified
;
	ld	de,fcb0		;point at first fcb
	ld	c,openf		;open the file
	call	bdos		;do it
	inc	a		;check return code
	jr	nz,openok	;jump if file found
;
	ld	de,nofilmsg	;point at message
	ld	c,prntstr
	call	bdos		;print
	ld	hl,tbuff	;point at buffer
	ld	a,(hl)		;get byte count
	inc	hl		;bump past space
	add	a,l		;point to end
	inc	hl		;to first char
	ld	e,l
	ld	d,h		;pointer in DE
	ld	l,a		;point at end
	ld	(hl),'$'	;mark end
	ld	c,prntstr
	call	bdos		;print file name
	jr	plain		; and jump to standard
;
openok:
	ld	a,0dh		;start at record 13
	ld	(currec),a	;put it there
	ld	de,hstbuf	;start reading here
readlp:
	ld	hl,80h		;sector size
	add	hl,de		;make next transfer
	push	hl		;save on stack
	ld	c,setdma
	call	bdos		;and tell bdos about it
	ld	de,fcb0		;get FCB again
	ld	c,rdseq		;read a sector
	call	bdos		;do it!
	pop	de		;get next dma address back
	or	a		;set flags
	jr	z,readlp	;jump if more sectors
;
plain:
	ld	de,srcprmt
	ld	c,prntstr
	call	bdos		;print source disk prompt
;
	call	getkey		;get keypress
	jr	z,havsys	;jump if OS image already in memory
	call	asc2bin		;convert to binary
	jr	c,plain		;jump if bad selection
	ld	b,a		;save in B
	ld	a,(srcmxh)	;get max head number
	call	asc2bin		;make binary
	cp	b		;check range
	jr	c,plain		;jump if head out of range
;
	ld	a,b		;head in range, put in A
;
	call	ReadSys		;read the OS from system tracks
				;and fall through to write operation
;
havsys:
	ld	de,dstprmt
	ld	c,prntstr
	call	bdos		;print destination disk prompt
;
	call	getkey
	jp	z,exit		;jump if carriage return
	call	asc2bin		;convert to binary
	jr	c,havsys	;jump if bad selection
	ld	b,a		;save in B
	ld	a,(dstmxh)	;get max head number
	call	asc2bin		;make binary
	cp	b		;check range
	jr	c,havsys	;jump if head out of range
;
	ld	a,b		;get selected head back
	call	WrtSys		;write the OS
	jr	havsys		;and go again.

;
ReadSys:
	call	RdWrInit	;set up data areas
RdLoop:
	call	ReadHst		;read a sector
	call	nz,RdWrErr	;handle error
	call	bumpsec		;call if no error
	jr	nz,RdLoop	;jump if more sectors
	ret			;and go back

;
WrtSys:
	call	RdWrInit	;set up data areas
wrloop:
	call	WriteHst	;write a sector
	call	nz,RdWrErr	;handle error
	call	bumpsec		;call if no error
	jr	nz,wrloop	;jump if more sectors
	ret			;return if finished


;***************************************************************
;Function:  bumpsec
;Purpose:   increment host sector number, decrement sector count
;Entry:     data areas set up
;Exit:      host sector number incremented, sector count decremented
;Uses:	    HL

bumpsec:
	ld	(adrhst),hl	;save new transfer address
	ex	de,hl		;save in DE in case of error
	ld	hl,hstsec	;point at host sector
	inc	(hl)		;bump to next host sector
	inc	hl		;bump to sector count
	dec	(hl)		;--sctrcnt
	ret			;and go back


;***************************************************************
;Function:  RdWrErr
;Purpose:   Handle errors on read or write
;Entry:     Error reading or writing IDE sector
;Exit:      if was a NOT FOUND error, host sector number reset,
;	    host track incremented
;	    otherwise, error message displayed and operation
;	    aborted
;Uses:	    All

RdWrErr:
	call	chknf		;check if was sector ID not found	
	jr	z,nxpct		;jrif not end of track
;
	ld	hl,hstsec	;point at hstsec
	ld	(hl),0ffh	;-1 in host sector (sort of)
	inc	hl		;bump to sector count
	inc	(hl)		;back up the sector count
	ld	hl,(hsttrk)	;get current track
	inc	hl		;bump to next
	ld	(hsttrk),hl	;and put it back
	ld	c,l
	ld	b,h		;current track in BC
	ld	hl,(maxtrk)	;get last track to write
	or	a		;clear carry
	sbc	hl,bc		;subtract
	jr	c,sysfull	;jump out if system tracks full
	ex	de,hl		;else get old transfer address back
	ret			;and go back


;***************************************************************
;Function:  sysfull
;Purpose:   print message if OS image longer than system tracks
;Entry:     jump from RdWrErr if next track is past system tracks
;Exit:      top of stack discarded, error message printed, control
;	    returned to instruction following the call to ReadSys
;	    or WrtSys.
;Uses:	    All

sysfull:
	pop	de		;throw away previous return address
	ld	de,fullmsg	;point at message
	ld	c,prntstr
	call	bdos
	ld	hl,sctrcnt	;get count of remaining sectors
	ld	h,0		;0 in H
	ld	b,9
ttpolp:
	add	hl,hl		;*2^B
	djnz	ttpolp		;loop to make byte count
	call	prword		;say how many bytes remain
	ret			;and go back


;***************************************************************
;Function:  nxpct
;Purpose:   print message if Read/Write error was other than IDNF
;Entry:     jump from RdWrErr if error was other than ID NOT FOUND
;Exit:      top of stack discarded, error message printed, control
;	    returned to instruction following the call to ReadSys
;	    or WrtSys.
;Uses:	    All

nxpct:
	pop	de		;throw away old return address
	ld	de,nxpctmsg	;point at message
	ld	c,prntstr	;function in C
	push	af		;save error register
	call	bdos		;do it
	pop	af		;get error register back
	call	prbyte		;print it
	ret			;and go back

;
exit:
	ld	c,boot		;get out!
	jp	bdos		;like right now!


;***************************************************************

RdWrInit:
	ld	(hstdsk),a	;set up drive (really head number)
;
	ld	hl,frsttrk
	ld	de,hsttrk
	ld	bc,3
	ldir			;initialize track and sector
;
	ld	hl,(syslen)	;get # of bytes to read/write
	ld	de,hstsiz	;get host sector size
;
	xor	a		;0 in A and clear carry
	cpl			;-1
divlp:
	inc	a		;bump up quotient
	sbc	hl,de		;subtract
	jr	nc,divlp	;until carry
;
	add	hl,de		;restore HL to positive
;
	ld	(sctrcnt),a	;save sector count
	ld	a,h		;get remainder
	or	l		;check if non 0
	jr	z,hvcnt		;jrif no fractional sector
	ld	hl,sctrcnt	;else point at sector count
	inc	(hl)		;and bump up by one.
hvcnt:
	ld	hl,(nrsrvd)	;get number of reserved tracks
	ld	h,0		;0 in H
	ex	de,hl		; count in DE
	ld	hl,(frsttrk)	;get starting track
	add	hl,de		;add in reserved track count
	dec	hl		;normalize to maximum track number
	ld	(maxtrk),hl	;save it here.
;
	ld	hl,(sysbuf)	;get start of system
	ld	(adrhst),hl	;put it here
	ex	de,hl		;and save in DE in case of error
	ret			;end of initiliazation

	
;***************************************************************
;Function:  WriteHst
;Purpose:   Do physical write to IDE drive
;Entry:     hstdsk, hsttrk, hstdsk set up
;Exit:      sector in hstbuf written to disk
;Used:      all

Writehst:
	call	tfsetup		;set up Task File
	ld	a,CmdWr		;get a write command
	out	(IdeCmd),a	;send it to Task File
	call	WaitDrq		;wait for data
	otir
	otir			;write 512 bytes
	jr	chkerr		;check for/report errors


;***************************************************************
;Function:  ReadHst
;Purpose:   Do physical read of IDE drive
;Entry:     hstdsk, hsttrk, hstdsk set up
;Exit:      sector read into hstbuf
;Used:      all

Readhst:
	call	tfsetup		;set up Task File
	ld	a,CmdRd		;get a read command
	out	(IdeCmd),a	;send to task file
	call	WaitDrq		;wait for data
	inir
	inir			;read 512 bytes
chkerr:	
	in	a,(IdeStat)	;get status
	and	1		;check error bit
	ret			;return error/no error


;***************************************************************
;Function:  TFsetup
;Purpose:   send host parms to IDE Task File registers
;Entry:     hstdsk, hsttrk, hstsec set up
;Exit:      Task file registers set up.  HL points to hstbuf,
;	    BC has count, data port address

tfsetup:
	in	a,(IdeStat)	;get status
	rla			;BSY bit to Carry
	jr	c,tfsetup	;loop until not BUSY
;
	ld	a,1		;1-sector transfer
	out	(IdeSCnt),a	;tell IDE drive
	ld	a,(hstsec)	;get host sector number
	inc	a		;bump up to 1
	out	(IdeSNum),a	;send to Task File
	ld	hl,(hsttrk)	;get host track
	ld	a,l		;get low order byte
	out	(IdeCLo),a	;send to Task File
	ld	a,h		;get high-order byte
	out	(IdeCHi),a	;send to task file
	ld	a,(hstdsk)	;get host disk number
	or	0a0h		;make into SDH byte
	out	(IdeSDH),a	;send to drive!
;
	ld	hl,(ADRHST)	;HL points to host buffer
	ld	bc,IdeDat	;BC has count, port
	ret			;and go back
	

;***************************************************************
;Function:  WaitDrq
;Purpose:   Wait until data available or ready for data
;Entry:     None
;Exit:      None
;Uses:      AF

WaitDrq:
	in	a,(IdeCmd)
	bit	3,a
	jr	z,WaitDrq
	ret


;***************************************************************
;Function:  getkey
;Purpose:   Wait for, echo and return keypress
;Entry:     none
;Exit:      character in A, Z set if was carriage return.
;Uses:      All

getkey:
	ld	c,constat
	call	bdos
	or	a		;set flags
	jr	z,getkey	;wait until key pressed
	ld	c,conin
	call	bdos		;fetch
	cp	0dh		;carriage return?
	ret			;and go back


;***************************************************************
;Function:  asc2bin
;Purpose:   convert ASCII hex numeric character to binary value
;Entry:     A = ASCII char
;Exit:      Carry set if not valid hex digit, Carry clear and
;	    A = binary value if valid hex digit.
;Uses:      AF

asc2bin:
	sub	30h		;normalize
	ret	c		;return if less than '0'
	cp	0ah		;bigger than '9'?
	jr	c,asc2b1	;jrif <= 9
	sub	7		;bump down to A-F
	cp	10h		;is bigger than F?
asc2b1:
	ccf			;make Carry reflect error condition
	ret			;and go back


;***************************************************************
;Function:  chknf
;Purpose:   detect ID Not Found error
;Entry:     Status register error bit set
;Exit:      Z clear if ID not found, Z set if other error
;Uses:      AF

chknf:
	in	a,(IdeErr)	;error, find out which
	bit	4,a		;did we run off the end of the track?
	ret			;and go back


;***************************************************************
;Routine:  PRWORD
;Purpose:  Print 16-bit value to console
;Entry:    HL = word
;Exit:     16-bit value displayed as 4 hex digits on console
;Uses:     ALL

prword:
	ld	a,h		;get high byte
	call	prbyte		;print it
	ld	a,l		;get low byte and fall through to
				;prbyte to print it


;***************************************************************
;Routine:  PRBYTE
;Purpose:  Print 8-bit value to console
;Entry:    A = byte
;Exit:     8-bit value displayed as 2 hex digits on console
;Uses:     ALL

prbyte:
	push	af		;save byte for later
	rrca
	rrca			;move upper nybble
	rrca			;to lower
	rrca
	call	prnyb		;print it
	pop	af		;get byte back and fall through
				;to prnyb to print lower nybble


;***************************************************************
;Routine:  PRNYB
;Purpose:  Print 4-bit value to console
;Entry:    A(0:3) = nybble of interest
;Exit:     4-bit value displayed as 1 hex digit on console
;Uses:     ALL

prnyb:
	and	0fh		;mask lower nybble
	cp	0ah		;bigger than 9?
	jr	c,prnyb1	;no, jump around
	add	a,7		;else bump to letters
prnyb1:
	add	a,30h		;make into hex digit
				;and fall through to pchar

;***************************************************************
;Routine:  pchar
;Purpose:  print character in A on the console
;Entry:    A has ASCII character
;Exit:     character in A printed to console
;Uses:     BC, DE, AF
;

pchar:
	push	hl
	ld	e,a
	ld	c,conout
	call	bdos
	pop	hl
	ret


;***************************************************************
;Fixed data area
;

; Patch the following two words with the starting address and
; length (in bytes) of the buffer holding the OS image.  Values
; below are for the DRI standard MOVCPM.

sysbuf:
	defw	0980h		;MOVCPM leaves OS image here
syslen:
	defw	1600h		;bios-ccp is this many bytes

; Patch the following word with the starting host track.  Patch
; the next byte with the starting 0-relative host sector of the
; starting track.  Patch the next byte with the number of system
; tracks.  Values below are for GIDE BIOS extension for Davidge
; DSB 4/6.

frsttrk:
	defw	0		;start on track (cylinder) 0
frstsec:
	defb	1		;skip boot sector on track 0
nrsrvd:
	defb	offset		;2 reserved tracks.


;***************************************************************
; Messages....
;

signon:
	defb	0dh,0ah,'IDEGEN v0.9 -- John D. Baker, '
	defb	'26 January 1996$'

fullmsg:
	defb	0dh,0ah,0ah,'System tracks full!  '
	defb	'Bytes unwritten:  0x$'

nxpctmsg:
	defb	0dh,0ah,0ah,'Unexpected error from IDE drive!  '
	defb	0dh,0ah,'Error register:  0x$'

nofilmsg:
	defb	0dh,0ah,0ah,'No file:  $'

srcprmt:
	defb	0dh,0ah,0ah,'Source head [0-'
srcmxh:
	defb	'F] or <CR> to skip:  $'

dstprmt:
	defb	0dh,0ah,0ah,'Destination head [0-'
dstmxh:
	defb	'F] or <CR> to abort:  $'
	

;***************************************************************
;Ram Variables and uninitialized data
;

hstdsk:
	defs	1		;host disk number
hsttrk:
	defs	2		;host track number
hstsec:
	defs	1		;host sector number
sctrcnt:
	defs	1		;count of sectors to write
maxtrk:
	defs	2		;max reserved track number
adrhst:
	defs	2		;address of host transfer buffer
;
	defs	24		;reserve at least this much for stack

;must end by 0780h to allow a 512-byte boot sector...

	if	$ gt 0780h
	  .printx "	***  IDEGEN TOO LARGE!!!  ***	"
	endif

	end