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/*
* Mach Operating System
* Copyright (c) 1992, 1991 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*
* from: Mach, Revision 2.2 92/04/04 11:34:26 rpd
* $Id: serial.S,v 1.1 1996/11/22 11:11:32 graichen Exp $
*/
/*
Copyright 1988, 1989, 1990, 1991, 1992
by Intel Corporation, Santa Clara, California.
All Rights Reserved
Permission to use, copy, modify, and distribute this software and
its documentation for any purpose and without fee is hereby
granted, provided that the above copyright notice appears in all
copies and that both the copyright notice and this permission notice
appear in supporting documentation, and that the name of Intel
not be used in advertising or publicity pertaining to distribution
of the software without specific, written prior permission.
INTEL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
IN NO EVENT SHALL INTEL BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* Serial bootblock interface routines
* Copyright (c) 1994, J"org Wunsch
*
* Adaption to OpenBSD - Thomas Graichen
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* THE AUTHOR ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. THE AUTHOR DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*/
#ifdef SERIAL
.file "serial.s"
#include <machine/asm.h>
#include "../../../dev/isa/comreg.h"
#define COMBRD(x) (1843200 / (16*(x)))
.text
/*
* The serial port interface routines implement a simple polled i/o
* interface to a standard serial port. Due to the space restrictions
* for the boot blocks, no BIOS support is used (since BIOS requires
* expensive real/protected mode switches), instead the rudimentary
* BIOS support is duplicated here.
*
* The base address for the i/o port is passed from the Makefile in
* the COMCONSOLE preprocessor macro. Console parameters are currently
* hard-coded to CONSPEED (9600) Bd, 8 bit. This can be changed in the
* init_serial() function.
*/
/*
* void putc(ch) char ch;
* send ch to serial port
*
*/
ENTRY(putc)
push %ebp
mov %esp, %ebp
push %edx
mov $COMCONSOLE + 5, %edx # line status reg
1: inb %dx, %al
test $0x20, %al
jz 1b # TX buffer not empty
movb 0x8(%ebp), %al
sub $5, %edx # TX output reg
outb %al, %dx # send this one
pop %edx
pop %ebp
ret
/*
* int getc(void)
* read a character from serial port
*/
ENTRY(getc)
push %ebp
mov %esp, %ebp
push %edx
mov $COMCONSOLE + 5, %edx # line status reg
1:
inb %dx, %al
testb $0x01, %al
jz 1b # no RX char available
xor %eax, %eax
sub $5, %edx # RX buffer reg
inb %dx, %al # fetch (first) character
and $0x7F, %eax # remove any parity bits we get
cmp $0x7F, %eax # make DEL...
jne 2f
mov $0x08, %eax # look like BS
2:
pop %edx
pop %ebp
ret
/*
* int ischar(void)
* if there is a character pending, return true; otherwise return 0
*/
ENTRY(ischar)
push %ebp
mov %esp, %ebp
push %edx
xorl %eax, %eax
mov $COMCONSOLE + 5, %edx # line status reg
inb %dx, %al
andb $0x01, %al # RX char available?
pop %edx
pop %ebp
ret
/*
* void init_serial(void)
* initialize the serial console port to 9600 Bd, 8 bpc
*/
ENTRY(init_serial)
push %ebp
mov %esp, %ebp
push %edx
mov $COMCONSOLE + 3, %edx # line control reg
movb $0x80, %al
outb %al, %dx # enable DLAB
sub $3, %edx # divisor latch, low byte
mov $COMBRD(CONSPEED), %ax # 9600 Bd by default
outb %al, %dx
inc %edx # divisor latch, high byte
movb %ah, %al
outb %al, %dx
add $2, %edx # line control reg
movb $0x13, %al
outb %al, %dx # 8 bit, no parity, 1 stop bit
inc %edx # modem control reg
mov $3, %al
outb %al, %dx # enable DTR/RTS
/* now finally, flush the input buffer */
inc %edx # line status reg
1:
inb %dx, %al
testb $0x01, %al
jz 2f # no more characters buffered
sub $5, %edx # rx buffer reg
inb %dx, %al # throw away
add $5, %edx
jmp 1b
2:
pop %edx
pop %ebp
ret
#endif /* #ifdef SERIAL */
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