72 lines
1.8 KiB
C
72 lines
1.8 KiB
C
/*
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* Copyright 2011 Steffen Vogel, Chair for Operating Systems,
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* RWTH Aachen University
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* This file is part of MetalSVM.
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*/
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#include <asm/uart.h>
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#include <asm/io.h>
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/**
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* @author Steffen Vogel <steffen.vogel@rwth-aachen.de>
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*/
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static inline int is_transmit_empty()
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{
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return inportb(UART_PORT + 5) & 0x20;
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}
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static inline int received()
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{
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return inportb(UART_PORT + 5) & 1;
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}
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void uart_init()
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{
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outportb(UART_PORT + 1, 0x00); // Disable all interrupts
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outportb(UART_PORT + 3, 0x80); // Enable DLAB (set baud rate divisor)
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outportb(UART_PORT + 0, 0x0C); // Set divisor to 12 (lo byte) 9600 baud
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outportb(UART_PORT + 1, 0x00); // (hi byte)
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outportb(UART_PORT + 3, 0x03); // 8 bits, no parity, one stop bit (8N1)
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outportb(UART_PORT + 2, 0xC7); // Enable FIFO, clear them, with 14-byte threshold
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outportb(UART_PORT + 4, 0x0B); // IRQs enabled, RTS/DSR set
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}
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char uart_getchar()
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{
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while (!received());
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return inportb(UART_PORT);
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}
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void uart_putchar(char chr)
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{
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while (!is_transmit_empty());
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outportb(UART_PORT, chr);
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}
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void uart_puts(const char* str)
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{
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while (*str) uart_putchar(*(str++));
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}
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int uart_gets(char* str, size_t len)
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{
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size_t ret = 0;
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while (ret < len)
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str[ret] = uart_getchar();
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return ret;
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}
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