Index: kernel/arch/amd64/src/boot/multiboot.S
===================================================================
--- kernel/arch/amd64/src/boot/multiboot.S	(revision 3b0f1b9a04083e5b48162443937d5e8d8303e4d0)
+++ kernel/arch/amd64/src/boot/multiboot.S	(revision 4928165de7cf0ac048c2faf57cbe0209de03919c)
@@ -168,5 +168,5 @@
 	
 	movl %cr4, %eax
-	btsl $5, %eax
+	orl $CR4_PAE, %eax
 	movl %eax, %cr4
 	
@@ -176,12 +176,12 @@
 	
 	/* Enable long mode */
-	movl $EFER_MSR_NUM, %ecx
+	movl $AMD_MSR_EFER, %ecx
 	rdmsr                     /* read EFER */
-	btsl $AMD_LME_FLAG, %eax  /* set LME = 1 */
+	orl $AMD_LME, %eax        /* set LME = 1 */
 	wrmsr
 	
 	/* Enable paging to activate long mode (set CR0.PG = 1) */
 	movl %cr0, %eax
-	btsl $31, %eax
+	orl $CR0_PG, %eax
 	movl %eax, %cr0
 	
Index: kernel/arch/amd64/src/boot/multiboot2.S
===================================================================
--- kernel/arch/amd64/src/boot/multiboot2.S	(revision 3b0f1b9a04083e5b48162443937d5e8d8303e4d0)
+++ kernel/arch/amd64/src/boot/multiboot2.S	(revision 4928165de7cf0ac048c2faf57cbe0209de03919c)
@@ -209,5 +209,5 @@
 	
 	movl %cr4, %eax
-	btsl $5, %eax
+	orl $CR4_PAE, %eax
 	movl %eax, %cr4
 	
@@ -217,12 +217,12 @@
 	
 	/* Enable long mode */
-	movl $EFER_MSR_NUM, %ecx
+	movl $AMD_MSR_EFER, %ecx
 	rdmsr                     /* read EFER */
-	btsl $AMD_LME_FLAG, %eax  /* set LME = 1 */
+	orl $AMD_LME, %eax        /* set LME = 1 */
 	wrmsr
 	
 	/* Enable paging to activate long mode (set CR0.PG = 1) */
 	movl %cr0, %eax
-	btsl $31, %eax
+	orl $CR0_PG, %eax
 	movl %eax, %cr0