1 files changed, 94 insertions, 10 deletions

diff --git a/src/user/init.cc b/src/user/init.cc
index 3c42adf..85252be 100644
--- a/src/user/init.cc
+++ b/src/user/init.cc
@@ -1,34 +1,118 @@
 #include "user/user.h"
 
-int main();
+int strlen(const char *s)
+{
+    int n = 0;
+    while (s[n])
+        n++;
+    return n;
+}
 
-extern "C" void _start()
+void print(const char *s)
 {
-    exit(main());
+    write(1, s, strlen(s));
+}
+
+void print_int(int val)
+{
+    char buf[16];
+    int i = 0;
+    if (val == 0)
+    {
+        print("0");
+        return;
+    }
+    if (val < 0)
+    {
+        print("-");
+        val = -val;
+    }
+    while (val > 0)
+    {
+        buf[i++] = (val % 10) + '0';
+        val /= 10;
+    }
+    while (i > 0)
+    {
+        char c = buf[--i];
+        write(1, &c, 1);
+    }
+}
+
+void pass() { print(" -> [PASS]\n"); }
+void fail()
+{
+    print(" -> [FAIL]\n");
+    exit(1);
 }
 
 int main()
 {
+    print("\n=== Lume OS Full Validation ===\n");
+
+    print("[TEST 1] Write\n");
+    print("  System call write is working.");
+    pass();
+
+    print("[TEST 2] GetPID\n");
+    int parent_pid = getpid();
+    print("  Parent PID: ");
+    print_int(parent_pid);
+    if (parent_pid > 0)
+        pass();
+    else
+        fail();
+
+    print("[TEST 3] Fork, Wait & COW\n");
+    int val = 100;
     int pid = fork();
 
     if (pid < 0)
     {
-        write(1, "Fork failed\n", 12);
-        exit(1);
+        print("  Fork Failed\n");
+        fail();
     }
 
     if (pid == 0)
     {
-        write(1, "Hello from Child!\n", 18);
+        print("  [Child] PID: ");
+        print_int(getpid());
+        print("\n");
+
+        if (val != 100)
+        {
+            print("  [Child] Data corruption!\n");
+            exit(1);
+        }
+
+        val = 200;
+        print("  [Child] Modified val to 200. Exiting.\n");
         exit(0);
     }
     else
     {
-        write(1, "Parent waiting...\n", 18);
-        wait(0);
-        write(1, "Parent: Child exited.\n", 22);
+        print("  [Parent] Waiting for child...\n");
+        int child_pid = wait(0);
+
+        print("  [Parent] Child ");
+        print_int(child_pid);
+        print(" exited.\n");
+
+        print("  [Parent] Check val (Expect 100): ");
+        print_int(val);
+
+        if (val == 100)
+            pass();
+        else
+        {
+            print("  [Parent] Memory Isolation Failed! Val=");
+            print_int(val);
+            fail();
+        }
     }
 
-    while (1);
+    print("\n=== All Tests Passed ===\n");
+    while (1)
+        ;
     return 0;
 }
\ No newline at end of file