- 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

diff --git a/src/cpu/k8/disable_mmx_sse.inc b/src/cpu/k8/disable_mmx_sse.inc
new file mode 100644 (file)
index 0000000..5ce9dfd
--- /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 (file)
index 0000000..5551525
--- /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