Files
RockOS/kernel/drivers/serial/serial.c
2026-07-14 17:40:30 -05:00

38 lines
1017 B
C

#include <drivers/serial/serial.h>
#include <common.h>
#define COM1 0x3F8
int is_transmit_empty() {
return inb(COM1 + 5) & 0x20;
}
void write_serial(char a) {
while (is_transmit_empty() == 0);
outb(COM1, a);
}
void print_serial(const char* str) {
for (int i = 0; str[i] != '\0'; i++) {
write_serial(str[i]);
}
}
void print_serial_hex(uint32_t val) {
char hex_chars[] = "0123456789ABCDEF";
print_serial("0x");
for (int i = 28; i >= 0; i -= 4) {
write_serial(hex_chars[(val >> i) & 0x0F]);
}
}
void init_serial() {
outb(COM1 + 1, 0x00); // Disable all interrupts
outb(COM1 + 3, 0x80); // Enable DLAB (set baud rate divisor)
outb(COM1 + 0, 0x01); // Set divisor to 1 (lo byte) -> 115200 baud
outb(COM1 + 1, 0x00); // (hi byte)
outb(COM1 + 3, 0x03); // 8 bits, no parity, one stop bit
outb(COM1 + 2, 0xC7); // Enable FIFO, clear them, with 14-byte threshold
outb(COM1 + 4, 0x0B); // IRQs enabled, RTS/DSR set
}