#include <sys/stddef.h>
#include <early/uart.h>
#include <sys/log.h>

#define COM1_PORT 0x3F8

void serial_init(void) {
    outb(COM1_PORT + 1, 0x00);    // Disable interrupts
    outb(COM1_PORT + 3, 0x80);    // Enable DLAB (set baud rate divisor)
    outb(COM1_PORT + 0, 0x01);    // Set divisor to 1 (lo byte) -> 115200 baud
    outb(COM1_PORT + 1, 0x00);    //                  (hi byte)
    outb(COM1_PORT + 3, 0x03);    // 8 bits, no parity, one stop bit
    outb(COM1_PORT + 2, 0xC7);    // Enable FIFO, clear them, with 14-byte threshold
    outb(COM1_PORT + 4, 0x0B);    // IRQs enabled, RTS/DSR set
}

static int serial_tx_ready(void) {
    return inb(COM1_PORT + 5) & 0x20;
}

void serial_putchar(char c) {
    while (serial_tx_ready() == 0);
    outb(COM1_PORT, c);
}

void kernel_main(void) {
    serial_init();
    register_console_callback(serial_putchar);
    printk("wkern version %s (Compiler %s, Linker %s) on %s\n", VERSION, COMPILER_NAME, LINKER_NAME, ARCH_NAME);
}