60 lines
1.2 KiB
C
60 lines
1.2 KiB
C
#if defined (BIOS)
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#include <stdint.h>
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#include <stddef.h>
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#include <stdbool.h>
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#include <drivers/serial.h>
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#include <sys/cpu.h>
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#include <lib/misc.h>
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#include <lib/config.h>
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static bool serial_initialised = false;
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static uint32_t serial_baudrate;
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static void serial_initialise(void) {
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if (serial_initialised || config_ready == false) {
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return;
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}
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char *baudrate_s = config_get_value(NULL, 0, "SERIAL_BAUDRATE");
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if (baudrate_s == NULL) {
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serial_baudrate = 9600;
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} else {
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serial_baudrate = strtoui(baudrate_s, NULL, 10);
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}
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// Init com1
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outb(0x3f8 + 3, 0x00);
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outb(0x3f8 + 1, 0x00);
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outb(0x3f8 + 3, 0x80);
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uint16_t divisor = (uint16_t)(115200 / serial_baudrate);
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outb(0x3f8 + 0, divisor & 0xff);
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outb(0x3f8 + 1, (divisor >> 8) & 0xff);
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outb(0x3f8 + 1, 0x00);
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outb(0x3f8 + 3, 0x03);
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outb(0x3f8 + 2, 0xc7);
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outb(0x3f8 + 4, 0x0b);
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serial_initialised = true;
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}
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void serial_out(uint8_t b) {
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serial_initialise();
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while ((inb(0x3f8 + 5) & 0x20) == 0);
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outb(0x3f8, b);
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}
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int serial_in(void) {
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serial_initialise();
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if ((inb(0x3f8 + 5) & 0x01) == 0) {
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return -1;
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}
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return inb(0x3f8);
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}
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#endif
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