From 2db9847f4138d159c4f6e99740fe889806a7f722 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pavel=20Kala=C5=A1=20=28Floxen=29?=
 <pavelkalas2048@seznam.cz>
Date: Sun, 12 Jul 2026 12:15:17 +0200
Subject: [PATCH] =?UTF-8?q?Napojen=20printk=20na=20COM1,=20v=C3=BDstup=20s?=
 =?UTF-8?q?e=20te=C4=8F=20zrcadl=C3=AD=20na=20VGA=20i=20s=C3=A9riov=C3=BD?=
 =?UTF-8?q?=20port?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 kernel/printk.c | 39 ++++++++++++++++++++++++++-------------
 1 file changed, 26 insertions(+), 13 deletions(-)

diff --git a/kernel/printk.c b/kernel/printk.c
index 4c3d5a4..de7323a 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -15,6 +15,22 @@
 
 #include "display.h"
 #include "printk.h"
+#include "serial.h"
+
+static void printk_putc(char c) {
+    display_putc(c);
+    serial_write_char(c);
+}
+
+static void printk_puts(const char *s) {
+    if (!s) {
+        s = "(null)";
+    }
+
+    while (*s) {
+        printk_putc(*s++);
+    }
+}
 
 static void print_u64(unsigned long long value, unsigned int base) {
     char buf[32];
@@ -22,7 +38,7 @@ static void print_u64(unsigned long long value, unsigned int base) {
     int i = 0;
 
     if (value == 0) {
-        display_putc('0');
+        printk_putc('0');
         return;
     }
 
@@ -32,12 +48,12 @@ static void print_u64(unsigned long long value, unsigned int base) {
     }
 
     while (i > 0) {
-        display_putc(buf[--i]);
+        printk_putc(buf[--i]);
     }
 }
 
 void aster_print(const char *text) {
-    display_write(text);
+    printk_puts(text);
 }
 
 void printk(const char *fmt, ...) {
@@ -47,32 +63,29 @@ void printk(const char *fmt, ...) {
 
     while (*fmt) {
         if (*fmt != '%') {
-            display_putc(*fmt++);
+            printk_putc(*fmt++);
             continue;
         }
 
         ++fmt;
         switch (*fmt) {
             case '%':
-                display_putc('%');
+                printk_putc('%');
                 break;
             case 'c': {
                 int c = va_arg(args, int);
-                display_putc((char)c);
+                printk_putc((char)c);
                 break;
             }
             case 's': {
                 const char *s = va_arg(args, const char *);
-                if (!s) {
-                    s = "(null)";
-                }
-                display_write(s);
+                printk_puts(s);
                 break;
             }
             case 'd': {
                 long v = va_arg(args, int);
                 if (v < 0) {
-                    display_putc('-');
+                    printk_putc('-');
                     print_u64((unsigned long long)(-v), 10);
                 } else {
                     print_u64((unsigned long long)v, 10);
@@ -91,12 +104,12 @@ void printk(const char *fmt, ...) {
             }
             case 'p': {
                 unsigned long long v = (unsigned long long)va_arg(args, void *);
-                display_write("0x");
+                printk_puts("0x");
                 print_u64(v, 16);
                 break;
             }
             default:
-                display_putc('?');
+                printk_putc('?');
                 break;
         }
         ++fmt;