Set CR0_WP in CR0.

diff --git a/src/threads/loader.S b/src/threads/loader.S
index 535c442c4f1f39a0d59cf43aa51c0e3cc8beee33..41289d1281f82ac3ccd6a62a2199f9ecbbaa2d8c 100644 (file)
--- a/src/threads/loader.S
+++ b/src/threads/loader.S
@@ -17,6 +17,7 @@
 #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
@@ -165,9 +166,9 @@ 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: