Napojen printk na COM1, výstup se teď zrcadlí na VGA i sériový port

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) {
+                printk_puts(s);
-                    s = "(null)";
-                }
-                display_write(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;