New patch to review for coreboot: 33bf5fa baytrail: allow downstream use of SSE instructions

[Aaron Durbin]

Aaron Durbin ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/4881

-gerrit

commit 33bf5faf7a285392c8e6e03bbf60c87deb56111c
Author: Aaron Durbin 
Date:   Thu Oct 10 12:47:47 2013 -0500

baytrail: allow downstream use of SSE instructions

If a payload is compiled to use SSE instructions it will
    fault with an undefined opcode because SSE instructions weren't
    enabled. Therefore enable SSE instructions at runtime.

BUG=chrome-os-partner:22991
    BRANCH=None
    TEST=Built and booted with SSE enabled payload. No exceptions seen.

Change-Id: I919c1ad319c6ce8befec5b4b1fd8c6343d51ccc1
    Signed-off-by: Aaron Durbin 
    Reviewed-on: https://chromium-review.googlesource.com/172642
    Reviewed-by: Stefan Reinauer 
---
 src/soc/intel/baytrail/ramstage.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/soc/intel/baytrail/ramstage.c b/src/soc/intel/baytrail/ramstage.c
index 10c030f..229e367 100644
--- a/src/soc/intel/baytrail/ramstage.c
+++ b/src/soc/intel/baytrail/ramstage.c
@@ -20,6 +20,7 @@
 #include <arch/cpu.h>
 #include <console/console.h>
 #include <cpu/intel/microcode.h>
+#include <cpu/x86/cr.h>
 #include <cpu/x86/msr.h>
 #include <device/device.h>
 #include <device/pci_def.h>
@@ -109,6 +110,9 @@ void baytrail_init_pre_device(void)

fill_in_pattrs();

+	/* Allow for SSE instructions to be executed. */
+	write_cr4(read_cr4() | CR4_OSFXSR | CR4_OSXMMEXCPT);
+
    /* Get GPIO initial states from mainboard */
    config = mainboard_get_gpios();
    setup_soc_gpios(config);