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freebsd/sys/boot/pc98/kgzldr/crt.s
Yoshihiro Takahashi 8df8626ebd Added kgzldr for pc98.
crt.s is based on btx.s.
2002-01-18 09:00:38 +00:00

119 lines
3.5 KiB
ArmAsm

#
# Copyright (c) 1999 Global Technology Associates, Inc.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
# OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
# OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
# BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
# OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
# EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# From: btx.s 1.10 1999/02/25 16:27:41 rnordier
# $FreeBSD$
#
# Screen defaults and assumptions.
.`ifdef' PC98
.set SCR_MAT,0xe1 # Mode/attribute
.else
.set SCR_MAT,0x7 # Mode/attribute
.endif
.set SCR_COL,0x50 # Columns per row
.set SCR_ROW,0x19 # Rows per screen
# BIOS Data Area locations.
.`ifdef' PC98
.set BDA_POS,0x53e # Cursor position
.else
.set BDA_SCR,0x449 # Video mode
.set BDA_POS,0x450 # Cursor position
.endif
.globl _(crt_putchr)
# void crt_putchr(int c)
_(crt_putchr): movb 0x4(%esp,1),%al # Get character
pusha # Save
xorl %ecx,%ecx # Zero for loops
movb $SCR_MAT,%ah # Mode/attribute
movl $BDA_POS,%ebx # BDA pointer
movw (%ebx),%dx # Cursor position
.`ifdef' PC98
movl $0xa0000,%edi
.else
movl $0xb8000,%edi # Regen buffer (color)
cmpb %ah,BDA_SCR-BDA_POS(%ebx) # Mono mode?
jne crt_putchr.1 # No
xorw %di,%di # Regen buffer (mono)
.endif
crt_putchr.1: cmpb $0xa,%al # New line?
je crt_putchr.2 # Yes
.`ifdef' PC98
movw %dx,%cx
movb %al,(%edi,%ecx,1) # Write char
addl $0x2000,%ecx
movb %ah,(%edi,%ecx,1) # Write attr
addw $0x02,%dx
jmp putchr.3
putchr.2: movw %dx,%ax
movb $SCR_COL*2,%dl
div %dl
incb %al
mul %dl
movw %ax,%dx
putchr.3: cmpw $SCR_ROW*SCR_COL*2,%dx
.else
xchgl %eax,%ecx # Save char
movb $SCR_COL,%al # Columns per row
mulb %dh # * row position
addb %dl,%al # + column
adcb $0x0,%ah # position
shll %eax # * 2
xchgl %eax,%ecx # Swap char, offset
movw %ax,(%edi,%ecx,1) # Write attr:char
incl %edx # Bump cursor
cmpb $SCR_COL,%dl # Beyond row?
jb crt_putchr.3 # No
crt_putchr.2: xorb %dl,%dl # Zero column
incb %dh # Bump row
crt_putchr.3: cmpb $SCR_ROW,%dh # Beyond screen?
.endif
jb crt_putchr.4 # No
leal 2*SCR_COL(%edi),%esi # New top line
movw $(SCR_ROW-1)*SCR_COL/2,%cx # Words to move
rep # Scroll
movsl # screen
movb $' ',%al # Space
.`ifdef' PC98
xorb %ah,%ah
.endif
movb $SCR_COL,%cl # Columns to clear
rep # Clear
stosw # line
.`ifdef' PC98
movw $(SCR_ROW-1)*SCR_COL*2,%dx
.else
movb $SCR_ROW-1,%dh # Bottom line
.endif
crt_putchr.4: movw %dx,(%ebx) # Update position
popa # Restore
ret # To caller