diff options
Diffstat (limited to 'stand/i386/kgzldr/crt.S')
| -rw-r--r-- | stand/i386/kgzldr/crt.S | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/stand/i386/kgzldr/crt.S b/stand/i386/kgzldr/crt.S new file mode 100644 index 000000000000..cfb479fd2d84 --- /dev/null +++ b/stand/i386/kgzldr/crt.S @@ -0,0 +1,83 @@ +# +# 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. + + .set SCR_MAT,0x7 # Mode/attribute + .set SCR_COL,0x50 # Columns per row + .set SCR_ROW,0x19 # Rows per screen + +# BIOS Data Area locations. + + .set BDA_SCR,0x449 # Video mode + .set BDA_POS,0x450 # Cursor position + + .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 + 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) +crt_putchr.1: cmpb $0xa,%al # New line? + je crt_putchr.2 # Yes + 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? + 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 + movb $SCR_COL,%cl # Columns to clear + rep # Clear + stosw # line + movb $SCR_ROW-1,%dh # Bottom line +crt_putchr.4: movw %dx,(%ebx) # Update position + popa # Restore + ret # To caller |