Rename printk() to printf().

[pintos-anon] / src / threads / loader.S

diff --git a/src/threads/loader.S b/src/threads/loader.S
index 8e5eeb722e1051c7b94df7f3b7ff1ce8f8b51268..9e2f37716a8da3ff48489e707b6e88ce47a21ee0 100644 (file)
--- a/src/threads/loader.S
+++ b/src/threads/loader.S
@@ -1,5 +1,45 @@
-#include "mmu.h"
-#include "loader.h"
+/* This file is derived from source code used in MIT's 6.828
+   course.  The original copyright notice is reproduced in full
+   below. */
+
+/*
+ * Copyright (C) 1997 Massachusetts Institute of Technology 
+ *
+ * This software is being provided by the copyright holders under the
+ * following license. By obtaining, using and/or copying this software,
+ * you agree that you have read, understood, and will comply with the
+ * following terms and conditions:
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose and without fee or royalty is
+ * hereby granted, provided that the full text of this NOTICE appears on
+ * ALL copies of the software and documentation or portions thereof,
+ * including modifications, that you make.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS," AND COPYRIGHT HOLDERS MAKE NO
+ * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED. BY WAY OF EXAMPLE,
+ * BUT NOT LIMITATION, COPYRIGHT HOLDERS MAKE NO REPRESENTATIONS OR
+ * WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR
+ * THAT THE USE OF THE SOFTWARE OR DOCUMENTATION WILL NOT INFRINGE ANY
+ * THIRD PARTY PATENTS, COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS. COPYRIGHT
+ * HOLDERS WILL BEAR NO LIABILITY FOR ANY USE OF THIS SOFTWARE OR
+ * DOCUMENTATION.
+ *
+ * The name and trademarks of copyright holders may NOT be used in
+ * advertising or publicity pertaining to the software without specific,
+ * written prior permission. Title to copyright in this software and any
+ * associated documentation will at all times remain with copyright
+ * holders. See the file AUTHORS which should have accompanied this software
+ * for a list of all copyright holders.
+ *
+ * This file may be derived from previously copyrighted software. This
+ * copyright applies only to those changes made by the copyright
+ * holders listed in the AUTHORS file. The rest of this file is covered by
+ * the copyright notices, if any, listed below.
+ */
+
+#include "threads/loader.h"
+#include "threads/mmu.h"
        
 ##############################################################################
 # Kernel loader.
@@ -12,6 +52,12 @@
 # first byte of the kernel, where start.S is linked.
 ##############################################################################
        
+/* Flags in control register 0 */
+#define CR0_PE 0x00000001      /* Protection Enable. */
+#define CR0_EM 0x00000004      /* (Floating-point) Emulation. */
+#define CR0_PG 0x80000000      /* Paging. */
+#define CR0_WP 0x00010000      /* Write-Protect enable in kernel mode. */
+
 .globl start                           # Entry point   
 start: .code16                         # This runs in real mode
        cli                             # Disable interrupts
@@ -159,9 +205,9 @@ read_sector:
        addl $0x1000, %eax
        loop 1b
 
-       # Turn on paging.
+       # Turn on paging and kernel write-protect.
        movl %cr0, %eax
-       orl $CR0_PG, %eax
+       orl $CR0_PG | CR0_WP, %eax
        movl %eax, %cr0
        jmp 1f
 1:
@@ -175,9 +221,10 @@ read_sector:
        
 ##### Jump to kernel entry point.
 
-       movl $LOADER_PHYS_BASE + LOADER_BASE, %esp
+       movl $LOADER_PHYS_BASE + 0x20000, %esp
        movl $LOADER_PHYS_BASE + LOADER_KERN_BASE, %eax
-       jmp *%eax
+       call *%eax
+       jmp panic
 
 ##### GDT