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Diffstat (limited to 'src/soc/intel/apollolake/cpu.c')
-rw-r--r--src/soc/intel/apollolake/cpu.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/src/soc/intel/apollolake/cpu.c b/src/soc/intel/apollolake/cpu.c
index 949736821e..8b8f963e4c 100644
--- a/src/soc/intel/apollolake/cpu.c
+++ b/src/soc/intel/apollolake/cpu.c
@@ -53,6 +53,13 @@ static const struct reg_script core_msr_script[] = {
REG_SCRIPT_END
};
+static void enable_untrusted_mode(void)
+{
+ msr_t msr = rdmsr(MSR_POWER_MISC);
+ msr.lo |= ENABLE_IA_UNTRUSTED;
+ wrmsr(MSR_POWER_MISC, msr);
+}
+
static void soc_core_init(device_t cpu)
{
/* Set core MSRs */
@@ -63,6 +70,8 @@ static void soc_core_init(device_t cpu)
* implemented in microcode.
*/
enable_pm_timer_emulation();
+ /* Drop privilege level */
+ enable_untrusted_mode();
}
static struct device_operations cpu_dev_ops = {