Patrick Rudolph has uploaded this change for review.

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src/arch/x86/exit_car: Add proper x86_64 code

Don't truncate upper bits in assemlby code and thus allow loading
of postcar stage above 4GiB. Tested on qemu.

Change-Id: I42d1086f1220e44076ccf613244fc3c6d804805b
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
---
M src/arch/x86/exit_car.S
1 file changed, 24 insertions(+), 3 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/73/59873/1

diff --git a/src/arch/x86/exit_car.S b/src/arch/x86/exit_car.S
index 9b89ffb..5d1ffdc 100644
--- a/src/arch/x86/exit_car.S
+++ b/src/arch/x86/exit_car.S
@@ -111,13 +111,20 @@
 
 #if CONFIG(SOC_SETS_MSRS)
 
+#if ENV_X86_64
+	mov	%rsp, %rbp
+
+	/* Need to align stack to 16 bytes at the call instruction. Therefore
+	   account for the 1 push. */
+	movq	$0xfffffffffffffff0, %rax
+	and	%rax, %rsp
+	mov	%rbp, %rdi
+#else
 	mov	%esp, %ebp
 	/* Need to align stack to 16 bytes at the call instruction. Therefore
 	   account for the 1 push. */
 	andl	$0xfffffff0, %esp
-#if ENV_X86_64
-	mov	%rbp, %rdi
-#else
+
 	sub	$12, %esp
 	push	%ebp
 #endif
@@ -125,10 +132,18 @@
 	call	soc_set_mtrrs
 	/* Ignore fixing up %esp since we're setting it a new value. */
 
+#if ENV_X86_64
+	/* rax: new top_of_stack with setup_stack_and_mtrrs data removed */
+	mov	%rax, %rsp
+	/* Align stack to 16 bytes at call instruction. */
+	movq	$0xfffffffffffffff0, %rax
+	and	%rax, %rsp
+#else
 	/* eax: new top_of_stack with setup_stack_and_mtrrs data removed */
 	movl	%eax, %esp
 	/* Align stack to 16 bytes at call instruction. */
 	andl	$0xfffffff0, %esp
+#endif
 	call	soc_enable_mtrrs
 #else /* CONFIG_SOC_SETS_MSRS */
 	/* Clear variable MTRRs. */
@@ -174,8 +189,14 @@
 	wrmsr
 #endif /* CONFIG_SOC_SETS_MSRS */
 
+#if ENV_X86_64
+	/* Align stack to 16 bytes at call instruction. */
+	movq	$0xfffffffffffffff0, %rax
+	and	%rax, %rsp
+#else
 	/* Align stack to 16 bytes at call instruction. */
 	andl	$0xfffffff0, %esp
+#endif
 	/* Call into main for postcar. */
 	call main
 	/* Should never return. */

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