Sending data (debug printing) to serial port

src/kernel/boot/debug.c

@@ -1,11 +1,10 @@
 #include <stddef.h>
 #include <stdarg.h>
 #include <stdint.h>
+#include <serial.h>
 
 // TODO: Temporary declarations
 void vga_write(char c);
-void serial_write(int port, char c);
-#define PORT_COM1 0
 
 
 void num2str(char *buf, uint64_t num, uint64_t base)

src/kernel/boot/debug.tt

@@ -20,11 +20,11 @@ void vga_write(char c)
   static int i = 0;
   vga_recv[i++] = c;
 }
-void serial_write(int port, char c)
+void serial_write(uint16_t port, uint8_t c)
 {
   (void)port;
   static int i = 0;
-  serial_recv[i++] = c;
+  serial_recv[i++] = (char)c;
 }
 
 TEST(putch_sends_character_to_vga)

src/kernel/boot/kmain.c

@@ -1,4 +1,6 @@
 #include <memory.h>
+#include <serial.h>
+#include <debug.h>
 
 void clear_screen()
 {
@@ -17,10 +19,20 @@ void print_string(char *str)
   }
 }
 
+void vga_write(char c)
+{
+// TODO: DUMMY
+  (void)c;
+}
+
 void kmain()
 {
   clear_screen();
   print_string("Hello from c, world!");
+
+  serial_init(PORT_COM1);
+  debug_printf("Hello from debug printing function!\n");
+  debug_printf("A number:%d\n", 12345);
   for(;;);
 }