Add comments to make it clear why these two lines are written like that:

movl    $REAL_XIP_ROM_BASE, %eax
  orl     $MTRR_TYPE_WRBACK, %eax

Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de>
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>



git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5908 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

src/cpu/amd/car/cache_as_ram.inc

@@ -269,6 +269,11 @@ clear_fixed_var_mtrr_out:
 	 */
 	movl	$MTRRphysBase_MSR(1), %ecx
 	xorl	%edx, %edx
+	/*
+	 * IMPORTANT: The two lines below can _not_ be written like this:
+	 *   movl $(REAL_XIP_ROM_BASE | MTRR_TYPE_WRBACK), %eax
+	 * http://www.coreboot.org/pipermail/coreboot/2010-October/060855.html
+	 */
 	movl	$REAL_XIP_ROM_BASE, %eax
 	orl	$MTRR_TYPE_WRBACK, %eax
 	wrmsr

src/cpu/intel/car/cache_as_ram.inc

@@ -221,6 +221,11 @@ clear_fixed_var_mtrr_out:
 	 */
 	movl	$MTRRphysBase_MSR(1), %ecx
 	xorl	%edx, %edx
+	/*
+	 * IMPORTANT: The two lines below can _not_ be written like this:
+	 *   movl $(REAL_XIP_ROM_BASE | MTRR_TYPE_WRBACK), %eax
+	 * http://www.coreboot.org/pipermail/coreboot/2010-October/060855.html
+	 */
 	movl	$REAL_XIP_ROM_BASE, %eax
 	orl	$MTRR_TYPE_WRBACK, %eax
 	wrmsr

src/cpu/intel/model_106cx/cache_as_ram.inc

@@ -97,6 +97,11 @@ clear_mtrrs:
 #else
 #define REAL_XIP_ROM_BASE CONFIG_XIP_ROM_BASE
 #endif
+	/*
+	 * IMPORTANT: The two lines below can _not_ be written like this:
+	 *   movl $(REAL_XIP_ROM_BASE | MTRR_TYPE_WRBACK), %eax
+	 * http://www.coreboot.org/pipermail/coreboot/2010-October/060855.html
+	 */
 	movl	$REAL_XIP_ROM_BASE, %eax
 	orl	$MTRR_TYPE_WRBACK, %eax
 	wrmsr

src/cpu/intel/model_6ex/cache_as_ram.inc

@@ -97,6 +97,11 @@ clear_mtrrs:
 #else
 #define REAL_XIP_ROM_BASE CONFIG_XIP_ROM_BASE
 #endif
+	/*
+	 * IMPORTANT: The two lines below can _not_ be written like this:
+	 *   movl $(REAL_XIP_ROM_BASE | MTRR_TYPE_WRBACK), %eax
+	 * http://www.coreboot.org/pipermail/coreboot/2010-October/060855.html
+	 */
 	movl	$REAL_XIP_ROM_BASE, %eax
 	orl	$MTRR_TYPE_WRBACK, %eax
 	wrmsr

src/cpu/intel/model_6fx/cache_as_ram.inc

@@ -104,6 +104,11 @@ clear_mtrrs:
 #else
 #define REAL_XIP_ROM_BASE CONFIG_XIP_ROM_BASE
 #endif
+	/*
+	 * IMPORTANT: The two lines below can _not_ be written like this:
+	 *   movl $(REAL_XIP_ROM_BASE | MTRR_TYPE_WRBACK), %eax
+	 * http://www.coreboot.org/pipermail/coreboot/2010-October/060855.html
+	 */
 	movl	$REAL_XIP_ROM_BASE, %eax
 	orl	$MTRR_TYPE_WRBACK, %eax
 	wrmsr

src/cpu/via/car/cache_as_ram.inc

@@ -97,6 +97,11 @@ clear_fixed_var_mtrr_out:
 	 */
 	movl	$MTRRphysBase_MSR(1), %ecx
 	xorl	%edx, %edx
+	/*
+	 * IMPORTANT: The two lines below can _not_ be written like this:
+	 *   movl $(REAL_XIP_ROM_BASE | MTRR_TYPE_WRBACK), %eax
+	 * http://www.coreboot.org/pipermail/coreboot/2010-October/060855.html
+	 */
 	movl	$REAL_XIP_ROM_BASE, %eax
 	orl	$MTRR_TYPE_WRBACK, %eax
 	wrmsr