Folder restructuration

src/io/serial/serial.c

@@ -0,0 +1,62 @@
+#include <kernel.h>
+#include "serial.h"
+
+void outb(int port, unsigned char data)
+{
+    __asm__ __volatile__("outb %%al, %%dx" :: "a" (data),"d" (port));
+}
+
+unsigned char inb(int port)
+{
+    unsigned char data = 0;
+    __asm__ __volatile__("inb %%dx, %%al" : "=a" (data) : "d" (port));
+    return data;
+}
+
+// COM1
+#define PORT 0x3F8
+
+int serial_init()
+{
+    outb(PORT + 1, 0x00);      // Disable all interrupts
+    outb(PORT + 3, 0x80);    // Enable DLAB (set baud rate divisor)
+    outb(PORT + 0, 0x03);    // Set divisor to 3 (lo byte) 38400 baud
+    outb(PORT + 1, 0x00);    //                  (hi byte)
+    outb(PORT + 3, 0x03);    // 8 bits, no parity, one stop bit
+    outb(PORT + 2, 0xC7);    // Enable FIFO, clear them, with 14-byte threshold
+    outb(PORT + 4, 0x0B);    // IRQs enabled, RTS/DSR set
+    outb(PORT + 4, 0x1E);    // Set in loopback mode, test the serial chip
+    outb(PORT + 0, 0xAE);    // Test serial chip (send byte 0xAE and check if serial returns same byte)
+
+    if (inb(PORT) != 0xAE)
+    {
+        return -EIO;
+    }
+
+    // Set normal operation mode
+    outb(PORT + 4, 0x0F);
+
+    serial_kputs("\n\nkernel: serial: Serial initialization OK!\n");
+    return 0;
+}
+
+static int is_transmit_empty()
+{
+    return inb(PORT + 5) & 0x20;
+}
+
+void write_serial(char c)
+{
+    while (!is_transmit_empty()); // wait for free spot
+    outb(PORT, c);
+}
+
+void serial_kputs(const char* str)
+{
+    unsigned int i=0;
+    while (str[i])
+    {
+        write_serial(str[i]);
+        i++;
+    }
+}