data.8

tiny bios--了解BIOS非常好的资料

	;
	; BIOS configuration data
	;
	; (C)1997-2001 Pascal Dornier / PC Engines; All rights reserved.
	; This file is licensed pursuant to the COMMON PUBLIC LICENSE 0.5.
	;
	; This data is modified to store system configuration, such as
	; PCI data, hard disk parameters, etc.
	;
	; pd 991020 add hd_top
	;
	even
	db	"_DAT"	;header for checksum utility
	dw	d_sum-d_beg	;pointer to checksum
	
d_beg:			;start of data	
	;
	; Hard disk parameters
	;
hd_prm0:	db	dpt_len dup 0
hd_prm1:	db	dpt_len dup 0
hd_top:	db	82h	;top HDD + 1
	;
	; PCI data
	;
	
	; this is a procedure to avoid problems in protected mode access...
	
getlbus:	db	0b0h	;MOV AL
d_lastbus: db	0	;last PCI bus
	ret

#if def	CDBOOT
	even
d_cdlba:	dw	0,0	;base LBA for last session
d_cdbase:	dw	0	;CD-ROM port base
d_cddrv:	db	0b0h	;slave drive
d_cdsec:	db	15	;sectors per track
d_cdflag:	db	0	;1 = enable CD emulation

#endif
	;
	; Data checksum
	;
d_sum:	db	0	;checksum, end of data block
			;(filled in by utility)
	;
	; calculate data checksum
	;
d_dosum:	
#if ! def	M6117
	wbinvd		;write back cache
#endif
	mov	al,0
	mov	si,offset d_beg
	mov	cx,d_sum-d_beg
d_dosum1:	add 	al,[cs:si]	;calculate checksum
	inc	si
	loop	d_dosum1
	neg	al
	mov 	[cs:si],al
#if ! def	M6117
	wbinvd
#endif
	ret