2 # Copyright (c) 1999 Global Technology Associates, Inc.
5 # Redistribution and use in source and binary forms, with or without
6 # modification, are permitted provided that the following conditions
8 # 1. Redistributions of source code must retain the above copyright
9 # notice, this list of conditions and the following disclaimer.
10 # 2. Redistributions in binary form must reproduce the above copyright
11 # notice, this list of conditions and the following disclaimer in the
12 # documentation and/or other materials provided with the distribution.
14 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS``AS IS'' AND
15 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 # PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
18 # BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
19 # OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
20 # OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
21 # BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22 # WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
23 # OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
24 # EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 # From: btx.s 1.10 1999/02/25 16:27:41 rnordier
27 # $FreeBSD: src/sys/boot/pc98/kgzldr/crt.s,v 1.4 2002/09/24 02:17:13 nyan Exp $
28 # $DragonFly: src/sys/boot/pc98/kgzldr/Attic/crt.s,v 1.3 2003/11/10 06:08:39 dillon Exp $
31 # Screen defaults and assumptions.
34 .set SCR_MAT,0xe1 # Mode/attribute
36 .set SCR_MAT,0x7 # Mode/attribute
38 .set SCR_COL,0x50 # Columns per row
39 .set SCR_ROW,0x19 # Rows per screen
41 # BIOS Data Area locations.
44 .set BDA_POS,0x53e # Cursor position
46 .set BDA_SCR,0x449 # Video mode
47 .set BDA_POS,0x450 # Cursor position
52 # void crt_putchr(int c)
54 crt_putchr: movb 0x4(%esp,1),%al # Get character
56 xorl %ecx,%ecx # Zero for loops
57 movb $SCR_MAT,%ah # Mode/attribute
58 movl $BDA_POS,%ebx # BDA pointer
59 movw (%ebx),%dx # Cursor position
63 movl $0xb8000,%edi # Regen buffer (color)
64 cmpb %ah,BDA_SCR-BDA_POS(%ebx) # Mono mode?
66 xorw %di,%di # Regen buffer (mono)
68 crt_putchr.1: cmpb $0xa,%al # New line?
72 movb %al,(%edi,%ecx,1) # Write char
74 movb %ah,(%edi,%ecx,1) # Write attr
77 crt_putchr.2: movw %dx,%ax
83 crt_putchr.3: cmpw $SCR_ROW*SCR_COL*2,%dx
85 xchgl %eax,%ecx # Save char
86 movb $SCR_COL,%al # Columns per row
87 mulb %dh # * row position
88 addb %dl,%al # + column
89 adcb $0x0,%ah # position
91 xchgl %eax,%ecx # Swap char, offset
92 movw %ax,(%edi,%ecx,1) # Write attr:char
93 incl %edx # Bump cursor
94 cmpb $SCR_COL,%dl # Beyond row?
96 crt_putchr.2: xorb %dl,%dl # Zero column
98 crt_putchr.3: cmpb $SCR_ROW,%dh # Beyond screen?
101 leal 2*SCR_COL(%edi),%esi # New top line
102 movw $(SCR_ROW-1)*SCR_COL/2,%cx # Words to move
105 movb $' ',%al # Space
109 movb $SCR_COL,%cl # Columns to clear
113 movw $(SCR_ROW-1)*SCR_COL*2,%dx
115 movb $SCR_ROW-1,%dh # Bottom line
117 crt_putchr.4: movw %dx,(%ebx) # Update position