From b44ae30b529cdd0374c8590e34d4d398adaf8b03 Mon Sep 17 00:00:00 2001
From: Maxim Baryshnikov <barysmax@fel.cvut.cz>
Date: Thu, 12 May 2016 01:52:18 +0200
Subject: [PATCH] l4: bootstrap: Add some commented code for experiments with
 paging.

---
 .../server/src/ARCH-x86/crt0.S                | 29 ++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/l4/pkg/bootstrap_custom/server/src/ARCH-x86/crt0.S b/l4/pkg/bootstrap_custom/server/src/ARCH-x86/crt0.S
index 37725ee67..91140542f 100644
--- a/l4/pkg/bootstrap_custom/server/src/ARCH-x86/crt0.S
+++ b/l4/pkg/bootstrap_custom/server/src/ARCH-x86/crt0.S
@@ -10,7 +10,15 @@
 #include <l4/sys/compiler.h>
 #ifdef JAILHOUSE
 #include "inmate.h" 
+
 #define X86_CR0_PE		0x00000001
+#define X86_CR0_WP		0x00010000
+#define X86_CR0_PG		0x80000000
+
+#define X86_CR4_PSE		0x00000010
+
+#define MSR_MTRR_DEF_TYPE	0x000002ff
+#define MTRR_ENABLE		0x00000800
 
 .code16
     .section ".jh.boot", "ax"
@@ -32,6 +40,7 @@ start16:
 
 .code32
 
+.global loader_gdt
 loader_gdt:
 	.quad	0
 	.quad	0x00cf9b000000ffff
@@ -54,7 +63,23 @@ loader_pdpt:
 
 	.globl	_start
 _start:
-#ifdef REALMODE_LOADING
+#ifdef REALMODE_LOADING	
+	/*
+	mov %cr4,%eax
+	or $X86_CR4_PSE,%eax
+	mov %eax,%cr4
+
+	mov $loader_pdpt + FSEGMENT_BASE,%eax
+	mov %eax,%cr3
+
+	mov $(X86_CR0_PG | X86_CR0_WP | X86_CR0_PE),%eax
+	mov %eax,%cr0
+	
+	movl $MSR_MTRR_DEF_TYPE,%ecx
+	rdmsr
+	or $MTRR_ENABLE,%eax
+	wrmsr
+	*/
 	cld
 	cli
 	mov	$(3 * 8), %eax
@@ -239,3 +264,5 @@ _stack_seg:
 	.space	8192
 	.globl	_stack
 _stack:
+
+
-- 
2.39.2