Project restructure (no new code added)

Moved all header files into include/ and removed their C counterparts -> code inside .h files
Also added a kernel.ld linker file
since we don't have many code files in src/ now, i removed src/kernel/
only real code change is that i moved memcopy() and memset() into string.h from system.h

include/system.h

@@ -0,0 +1,41 @@
+#ifndef SYSTEM_H
+#define SYSTEM_H
+
+#include "stdint.h"
+
+// Port functions
+uint8_t inb(uint16_t port) {
+    uint8_t result;
+    asm volatile("inb %1, %0" : "=a"(result) : "Nd"(port));
+    return result;
+}
+
+void outb(uint16_t port, uint8_t data) {
+    asm volatile("outb %0, %1" :: "a"(data), "Nd"(port));
+}
+
+uint16_t inw(uint16_t port) {
+    uint16_t result;
+    asm volatile("inw %1, %0" : "=a"(result) : "Nd"(port));
+    return result;
+}
+
+void outw(uint16_t port, uint16_t data) {
+    asm volatile("outw %0, %1" :: "a"(data), "Nd"(port));
+}
+
+
+// Assembly stuff
+void cli() {
+    asm volatile("cli");
+}
+
+void sti() {
+    asm volatile("sti");
+}
+
+void hlt() {
+    asm volatile("hlt");
+}
+
+#endif