From 57fa1b8279d78b3083b086708d857422ed99beca Mon Sep 17 00:00:00 2001
From: Eric Biederman <ebiederm@xmission.com>
Date: Tue, 1 Jul 2003 06:51:27 +0000
Subject: - Code to enable and disable use of the sse and mmx registers

git-svn-id: svn://svn.coreboot.org/coreboot/trunk@930 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
---
 src/cpu/k8/disable_mmx_sse.inc | 27 +++++++++++++++++++++++++++
 src/cpu/k8/enable_mmx_sse.inc  | 14 ++++++++++++++
 2 files changed, 41 insertions(+)
 create mode 100644 src/cpu/k8/disable_mmx_sse.inc
 create mode 100644 src/cpu/k8/enable_mmx_sse.inc

(limited to 'src/cpu/k8')

diff --git a/src/cpu/k8/disable_mmx_sse.inc b/src/cpu/k8/disable_mmx_sse.inc
new file mode 100644
index 0000000000..5ce9dfdc1f
--- /dev/null
+++ b/src/cpu/k8/disable_mmx_sse.inc
@@ -0,0 +1,27 @@
+	/* Clear out an mmx state */
+	emms
+
+	/*
+	 * Put the processor back into a reset state
+	 * with respect to the xmm registers.
+	 */
+	
+	pxor %xmm0, %xmm0
+	pxor %xmm1, %xmm1
+	pxor %xmm2, %xmm2
+	pxor %xmm3, %xmm3
+	pxor %xmm4, %xmm4
+	pxor %xmm5, %xmm5
+	pxor %xmm6, %xmm6
+	pxor %xmm7, %xmm7
+
+	/* Disable floating point emulation */
+	movl	%cr0, %eax
+	andl	$~(1<<2), %eax
+	movl	%eax, %cr0
+
+	/* Disable sse instructions */
+	movl	%cr4, %eax
+	andl	$~(3<<9), %eax
+	movl	%eax, %cr4
+
diff --git a/src/cpu/k8/enable_mmx_sse.inc b/src/cpu/k8/enable_mmx_sse.inc
new file mode 100644
index 0000000000..5551525d68
--- /dev/null
+++ b/src/cpu/k8/enable_mmx_sse.inc
@@ -0,0 +1,14 @@
+	/*
+	 * Enabling mmx registers is a noop
+	 * Enable the use of the xmm registers
+	 */
+
+	/* Disable floating point emulation */
+	movl	%cr0, %eax
+	andl	$~(1<<2), %eax
+	movl	%eax, %cr0
+
+	/* Enable sse instructions */
+	movl	%cr4, %eax
+	orl	$(1<<9), %eax
+	movl	%eax, %cr4
-- 
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