feat: Added nanoprintf, kprintf and GDT

kernel/src/util/kprintf.c

@@ -0,0 +1,28 @@
+#include <dev/serial.h>
+#include <util/kprintf.h>
+
+#define NANOPRINTF_USE_FIELD_WIDTH_FORMAT_SPECIFIERS 1
+#define NANOPRINTF_USE_PRECISION_FORMAT_SPECIFIERS 1
+#define NANOPRINTF_USE_LARGE_FORMAT_SPECIFIERS 1
+#define NANOPRINTF_USE_SMALL_FORMAT_SPECIFIERS 1
+#define NANOPRINTF_USE_FLOAT_FORMAT_SPECIFIERS 0
+#define NANOPRINTF_USE_BINARY_FORMAT_SPECIFIERS 1
+#define NANOPRINTF_USE_WRITEBACK_FORMAT_SPECIFIERS 0
+#define NANOPRINTF_IMPLEMENTATION
+#include <nanoprintf.h>
+
+int kprintf(const char *fmt, ...)
+{
+    va_list args;
+    va_start(args, fmt);
+    char buffer[1024];
+    int length = npf_vsnprintf(buffer, sizeof(buffer), fmt, args);
+
+    if (length >= 0 && length < (int)sizeof(buffer))
+    {
+        serial_write(COM1, (uint8_t *)buffer, length);
+    }
+
+    va_end(args);
+    return length;
+}

kernel/src/util/kprintf.h

@@ -0,0 +1,7 @@
+#ifndef KPRINTF_H
+#define KPRINTF_H
+
+/* Minimal kprintf using nanoprintf, see external/nanoprintf.h */
+int kprintf(const char *fmt, ...);
+
+#endif // KPRINTF_H

kernel/src/util/log.h

@@ -0,0 +1,8 @@
+#ifndef LOG_H
+#define LOG_H
+
+#include <util/kprintf.h>
+
+#define early(fmt, ...) kprintf("early: " fmt "\n", ##__VA_ARGS__)
+
+#endif // LOG_H