1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
|
#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);
}
|
