46 lines
947 B
C
46 lines
947 B
C
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/*
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* Copyright (c) 2018 Intel Corporation
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include "x86_64-hw.h"
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/* Super-primitive 8250 serial output-only driver, 115200 8n1 */
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#define _PORT 0x3f8
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static inline void _serout(int c)
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{
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while (!(ioport_in8(_PORT + 5) & 0x20)) {
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}
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ioport_out8(_PORT, c);
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}
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static inline void serial_putc(int c)
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{
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if (c == '\n') {
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_serout('\r');
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}
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_serout(c);
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}
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static inline void serial_puts(const char *s)
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{
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while (*s) {
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serial_putc(*s++);
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}
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}
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static inline void serial_init(void)
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{
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/* In fact Qemu already has most of this set up and works by
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* default
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*/
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ioport_out8(_PORT+1, 0); /* IER = 0 */
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ioport_out8(_PORT+3, 0x80); /* LCR = 8n1 + DLAB select */
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ioport_out8(_PORT, 1); /* Divisor Latch low byte */
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ioport_out8(_PORT+1, 0); /* Divisor Latch high byte */
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ioport_out8(_PORT+3, 0x03); /* LCR = 8n1 + DLAB off */
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ioport_out8(_PORT+4, 0x03); /* MCR = DTR & RTS asserted */
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}
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