feat: cleanup init code, small other refactors

kernel/drivers/serial.c

@@ -2,9 +2,10 @@
 // Created by rick on 28-01-21.
 //
 
-#include <myke/drivers/serial.h>
 #include <sys/types.h>
 #include <myke/drivers/ports.h>
+#include <myke/libk/kprint.h>
+#include <myke/util/init.h>
 
 #define SERIAL_INTERRUPT_DATA_AVAILABLE     (1 << 0)
 #define SERIAL_INTERRUPT_TRANSMITTER_EMPTY  (1 << 1)
@@ -51,7 +52,7 @@
 #define MODEM_CONTROL_LOOPBACK_MODE             (1 << 4)
 #define MODEM_CONTROL_AUTOFLOW_CONTROL_ENABLED  (1 << 5)
 
-int serial_init() {
+int serial_init_hw() {
     port_byte_out(PORT_SERIAL_0 + PORT_SERIAL_INTERRUPT, 0);    // Disable all interrupts
     port_byte_out(PORT_SERIAL_0 + PORT_SERIAL_LINE_CONTROL,
                   LINE_CONTROL_DIVISOR);    // Enable DLAB (set baud rate divisor)
@@ -114,4 +115,17 @@ void serial_kprint(const char *msg) {
         write_serial(c);
         i++;
     }
-}
+}
+
+void serial_init() {
+    if (serial_init_hw() != 0) {
+        return;
+    }
+    kprint_register(serial_kprint);
+}
+
+INIT_FUNCTION(100) = {
+        .name = "serial",
+        .stage = INIT_STAGE_EARLY_BOOT_0,
+        .init = serial_init,
+};