78 lines
1.5 KiB
C
78 lines
1.5 KiB
C
/**
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* Serial Port Driver
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* vim:tabstop=4
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* vim:noexpandtab
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*/
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#include <system.h>
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#define SERIAL_PORT_A 0x3F8
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#define SERIAL_PORT_B 0x2F8
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#define SERIAL_PORT_C 0x3E8
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#define SERIAL_PORT_D 0x2E8
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void
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serial_handler(
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struct regs *r
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) {
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char serial = serial_recv();
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/*
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* Fix the serial input assuming it is ascii
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*/
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switch (serial) {
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case 127:
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serial = 0x08;
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break;
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case 13:
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serial = '\n';
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break;
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default:
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break;
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}
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if (keyboard_buffer_handler) {
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keyboard_buffer_handler(serial);
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}
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}
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void
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serial_install() {
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/* We will initialize the first serial port */
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outportb(SERIAL_PORT_A + 1, 0x00);
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outportb(SERIAL_PORT_A + 3, 0x80); /* Enable divisor mode */
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outportb(SERIAL_PORT_A + 0, 0x03); /* Div Low: 03 Set the port to 38400 bps */
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outportb(SERIAL_PORT_A + 1, 0x00); /* Div High: 00 */
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outportb(SERIAL_PORT_A + 3, 0x03);
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outportb(SERIAL_PORT_A + 2, 0xC7);
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outportb(SERIAL_PORT_A + 4, 0x0B);
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irq_install_handler(4, serial_handler); /* Install the serial input handler */
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outportb(SERIAL_PORT_A + 1, 0x01); /* Enable interrupts on receive */
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}
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int
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serial_rcvd() {
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return inportb(SERIAL_PORT_A + 5) & 1;
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}
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char
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serial_recv() {
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while (serial_rcvd() == 0);
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return inportb(SERIAL_PORT_A);
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}
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int
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serial_transmit_empty() {
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return inportb(SERIAL_PORT_A + 5) & 0x20;
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}
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void
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serial_send(char out) {
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while (serial_transmit_empty() == 0);
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outportb(SERIAL_PORT_A, out);
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}
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void
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serial_string(char * out) {
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for (int i = 0; i < strlen(out); ++i) {
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serial_send(out[i]);
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}
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}
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