added part 4

Part4/10_scheduler/kernel/kernel.c

@@ -0,0 +1,41 @@
+#include "kernel.h"
+
+void _start() {
+    free_mem_addr = 0x20000;
+    global_id = 0;
+    memory_limit = 0x40000;
+    isr_install();
+    irq_install();
+
+    kprint("Type something, it will go through the kernel\n"
+        "Type END to halt the CPU\n> ");
+}
+
+void user_input(char *input) {
+    if (strcmp(input, "END") == 0) {
+        kprint("Stopping the CPU. Bye!\n");
+        asm volatile("hlt");
+    } else if (strcmp(input, "ADD") == 0) {
+	u32 *n0; n0 = (u32 *) 16; n0++;
+	node *n1; n1 = NULL;
+	kmalloc( 20, 0, (u32 *) &n1);
+        n1->id = global_id++;
+	n1->base = global_id*100;
+	n1->size = global_id*10;
+	n1->next = NULL;
+	n1->previous = NULL;
+	kprint("ADDED: ");
+	char c[16];
+	hex_to_ascii( (u32 ) n1, c);
+	kprint( c);
+	kprint( "  id:  ");
+	hex_to_ascii( n1->id, c);
+	kprint( c);
+    } else if (strcmp(input, "ZOO") == 0) { 
+	kprint("ZOO.\n");
+    }
+
+    kprint("You said: ");
+    kprint(input);
+    kprint("\n> ");
+}

Part4/10_scheduler/kernel/kernel.h

@@ -0,0 +1,12 @@
+#ifndef KERNEL_H
+#define KERNEL_H
+
+void user_input(char *input);
+
+#include "../cpu/isr.h"
+#include "../drivers/screen.h"
+#include "../libc/string.h"
+#include "../libc/mem.h"
+#include "../libc/globals.h"
+
+#endif