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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
* $FreeBSD$
*/
/*
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
*
* 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.
*/
.file "serial.S"
#include <isa/sioreg.h>
#include "asm.h"
.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 and speed for the i/o port are passed from the
* Makefile in the COMCONSOLE and CONSPEED preprocessor macros. The
* line control parameters are currently hard-coded to 8 bits, no
* parity, 1 stop bit (8N1). This can be changed in init_serial().
*/
/*
* void serial_putc(int ch);
* Write character `ch' to port COMCONSOLE.
*/
ENTRY(serial_putc)
movl $10000, %ecx # timeout
movl $COMCONSOLE + 5, %edx # line status reg
1:
decl %ecx
je 2f
inb %dx, %al
testb $0x20, %al
je 1b # TX buffer not empty
movb 4(%esp), %al
subl $5, %edx # TX output reg
outb %al, %dx # send this one
2:
ret
/*
* int serial_getc(void);
* Read a character from port COMCONSOLE.
*/
ENTRY(serial_getc)
mov $COMCONSOLE + 5, %edx # line status reg
1:
inb %dx, %al
testb $0x01, %al
je 1b # no rx char available
xorl %eax, %eax
subl $5, %edx # rx buffer reg
inb %dx, %al # fetch (first) character
andb $0x7F, %al # remove any parity bits we get
cmpb $0x7F, %al # make DEL...
jne 2f
movb $0x08, %al # look like BS
2:
ret
/*
* int serial_ischar(void);
* If there is a character in the input buffer of port COMCONSOLE,
* return nonzero; otherwise return 0.
*/
ENTRY(serial_ischar)
xorl %eax, %eax
movl $COMCONSOLE + 5, %edx # line status reg
inb %dx, %al
andb $0x01, %al # rx char available?
ret
/*
* void init_serial(void);
* Initialize port COMCONSOLE to speed CONSPEED, line settings 8N1.
*/
ENTRY(init_serial)
movl $COMCONSOLE + 3, %edx # line control reg
movb $0x80, %al
outb %al, %dx # enable DLAB
subl $3, %edx # divisor latch, low byte
movb $COMBRD(CONSPEED) & 0xff, %al
outb %al, %dx
incl %edx # divisor latch, high byte
movb $COMBRD(CONSPEED) >> 8, %al
outb %al, %dx
incl %edx # fifo control register (if any)
xorl %eax,%eax
outb %al, %dx # disable fifo to reduce worst-case busy-wait
incl %edx # line control reg
movb $0x03, %al
outb %al, %dx # 8N1
incl %edx # modem control reg
outb %al, %dx # enable DTR/RTS
/* Flush the input buffer. */
incl %edx # line status reg
1:
subl $5, %edx # rx buffer reg
inb %dx, %al # throw away (unconditionally the first time)
addl $5, %edx # line status reg
inb %dx, %al
testb $0x01, %al
jne 1b # more
ret
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