loop opt. (z80 code)

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

	title 'Boot loader module for CP/M 3.0'\r
\r
\r
\r
	public	hwinit,?init,?ldccp,?rlccp\r
\r
	public	f_cpu\r
\r
	extrn	?boot,?conin\r
	extrn	pr.inln,pr.crlf,pr.dec,pr.decl\r
	extrn	ioini1l,msginit,mmuinit,intinit,cpu_frq\r
	extrn	prt0ini,gs_rtc\r
	extrn	@civec,@covec,@aivec,@aovec,@lovec\r
	extrn	@cbnk,?bnksl\r
\r
	include config.inc\r
	include	z180reg.inc\r
\r
\r
ccpsize	equ	0c80h\r
\r
	; CP/M BDOS Function Interfaces\r
\r
resetdsk	equ	13\r
open		equ	15\r
read		equ	20\r
setdma		equ	26\r
setmulti	equ	44\r
bdos		equ	5\r
\r
\r
	 if	banked\r
tpa$bank equ	1\r
	 else\r
tpa$bank equ	0\r
	 endif\r
\r
\r
	dseg			; init done from banked memory\r
\r
hwinit:\r
	ld	a,(INIDONE)\r
	cp	INIDONEVAL\r
	jr	z,hwini_skip\r
	ld	hl,hwini_tab\r
	call	ioini1l\r
	ld	a,0c3h\r
	ld	hl,?boot\r
	ld	(0),a\r
	ld	(1),hl\r
hwini_skip:\r
	call	mmuinit		; setup mmu registers\r
	call	msginit\r
	call	cpu_frq\r
	ld	(f_cpu),hl\r
	ld	(f_cpu+2),de\r
	ret\r
\r
?init:\r
	ld	hl,1000000000000000b	; assign console to AVRCON:\r
	ld	(@civec),hl\r
	ld	(@covec),hl\r
	ld	hl,0000000000000000b	; assign printer to nothing:\r
	ld	(@lovec),hl\r
	ld	hl,0100000000000000b	; assign AUX to ASCI0:\r
	ld	(@aivec),hl\r
	ld	(@aovec),hl\r
\r
\r
	call	intinit			; setup interrupts and vectors\r
	call	prt0ini			; init timer\r
	ei\r
	ld	c,2\r
	call	gs_rtc			; get time and date\r
\r
	xor	a\r
	ld	(@cbnk),a		; right now in bank 0\r
\r
	call	pr.inln			; print signon message\r
	db	13,10,13,10,'CP/M Version 3.0, Z180-Stamp BIOS',13,10,0\r
\r
	call	pr.inln\r
	db	'Estimated CPU clock [Hz]: ',0\r
\r
	ld	hl,(f_cpu)\r
	ld	de,(f_cpu+2)\r
	call	pr.decl\r
	call	pr.crlf\r
	ret\r
\r
\r
	cseg			; boot loading must be done from resident memory\r
\r
; 	This version of the boot loader loads the CCP from a file\r
; 	called CCP.COM on the system drive (A:).\r
\r
\r
?ldccp:\r
				; First time, load the A:CCP.COM file into TPA\r
	ld	c,resetdsk\r
	call	bdos\r
	xor	a\r
	ld	(ccp$fcb+15),a	; zero extent\r
	ld	hl,0\r
	ld	(fcb$nr),hl	; start at beginning of file\r
	ld	de,ccp$fcb\r
	ld	c,open		; open file containing CCP\r
	call	bdos\r
	inc	a\r
	jp	z,no$ccp	; error if no file...\r
	ld	de,0100h\r
	ld	c,setdma		; start of TPA\r
	call	bdos\r
	ld	de,128\r
	ld	c,setmulti	; allow up to 16k bytes\r
	call	bdos\r
	ld	de,ccp$fcb\r
	ld	c,read		; load the thing\r
	call	bdos		; read records\r
				; now,\r
				;   copy CCP to bank 0 for reloading\r
	ld	hl,0100h\r
	ld	bc,ccpsize	; clone 3K, just in case\r
	ld	a,(@cbnk)\r
	push	af		; save current bank\r
ld$1:\r
	ld	a,tpa$bank\r
	call	?bnksl		; select TPA\r
	ld	a,(hl)\r
	push	af		; get a byte\r
	ld	a,2\r
	call	?bnksl		; select extra bank\r
	pop	af\r
	ld	(hl),a		; save the byte\r
	cpi			; bump pointer, drop count\r
	jp	pe,ld$1\r
	pop	af\r
	call	?bnksl		; restore original bank\r
	ret\r
\r
no$ccp:				; here if we couldn't find the file\r
	call	pr.inln		; report this...\r
	db	13,10,'BIOS Err on A: No CCP.COM file',0\r
\r
	call	?conin		; get a response\r
	jp	?ldccp		; and try again\r
\r
\r
?rlccp:\r
	ld	hl,0100h\r
	ld	bc,ccpsize	; clone 3K\r
rl$1:\r
	ld	a,2\r
	call	?bnksl		; select extra bank\r
	ld	a,(hl)		; get a byte\r
	ex	af,af'\r
	ld	a,tpa$bank\r
	call	?bnksl		; select TPA\r
	ex	af,af'\r
	ld	(hl),a		; save the byte\r
	cpi			; bump pointer, drop count\r
	jp	pe,rl$1\r
	ret\r
\r
\r
ccp$fcb:db	1,'CCP     ','COM',0,0,0,0\r
	ds	16\r
fcb$nr:	db	0,0,0\r
\r
\r
	dseg\r
hwini_tab:\r
	db	(hwini0_e-$)/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
;TODO:	db	omr,	;Operation Mode Control Register\r
hwini0_e:\r
	db	0		;stop mark\r
\r
	cseg\r
f_cpu	dw	0,0		;detected CPU clock frequency [Hz]\r
\r
	end\r