syscalls: hopefully implement chdir syscall

src/tasking/syscalls.c

@@ -406,6 +406,35 @@ int sys_execve(TrapFrame *tf) {
 
 int sys_chdir(TrapFrame *tf)
 {
+    l9660_dir new_cwd;
+    l9660_file placeholder_file;
+
+    int status = follow_path((char*)tf->ebx, &placeholder_file, &new_cwd);
+
+    if(status == L9660_OK)
+    {
+        *(current->cwd) = new_cwd;
+    }
+
+    switch(status)
+    {
+        case L9660_EIO:
+            return -5;//-EIO
+            break;
+        case L9660_EBADFS:
+            return -5;//EIO as well
+            break;
+        case L9660_ENOENT:
+            return -2;
+            break;
+        case L9660_ENOTDIR:
+            return -20;//ENOTDIR
+            break;
+        default:
+            return -5;//EIO
+            break;
+    }
+
     //strcat(current->cwd->fat->path, "/");
     //strcat(current->cwd->fat->path, (char*)tf->ebx);
 
@@ -503,7 +532,7 @@ uint32_t sys_brk(TrapFrame *tf)
         debug_log("mapping page %X to %X\n", phys_addr, virt_addr);
         memset(virt_addr, 0, 0x1000);
         current->brk = (void*)tf->ebx;
-        debug_log("new brk is %X\n", (uint32_t)current->brk);
+        //debug_log("new brk is %X\n", (uint32_t)current->brk);
     }
     return (uint32_t)current->brk;
 }