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soc/intel/apollolake: Drop privilege level to IA_UNTRUSTED

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As per guidelines CPU security level should be dropped before OS start,
so that certain MSRs are locked out. Drop privilege levels on all logical
CPUs.

BUG=chrome-os-partner:60454
TEST=iotools rdmsr x 0x120, make sure bit 6 is set, rdmsr x 0x121 results
in io error.

Change-Id: I67540f6da16f58b822db9160d00b7a5e235188db
Signed-off-by: Andrey Petrov <andrey.petrov@intel.com>
Reviewed-on: https://review.coreboot.org/17665
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
This commit is contained in:
Andrey Petrov
2016-11-30 17:58:38 -08:00
committed by Aaron Durbin
parent 3b637531c9
commit 89e39b5c55
3 changed files with 12 additions and 1 deletions
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9
src/soc/intel/apollolake/cpu.c
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@ -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 = {