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